Method and device for determining working point of range extender

文档序号：804812 发布日期：2021-03-26 浏览：37次中文

阅读说明：本技术 增程器工作点的确定方法和装置 (Method and device for determining working point of range extender ) 是由安术于 2020-11-24 设计创作，主要内容包括：本申请提供一种增程器工作点的确定方法和装置,前述方法包括：获取所述增程器的当前工况状态；根据所述当前工况状态确定与当前工况状态匹配的功率跟随曲线；根据需求功率和所述当前功率跟随曲线确定所述增程器的工作点。采用这样的方法,能够根据增程器的实际运行工况状态,确定在此运行工况状态下的较优的控制策略,继而尽可能地保证按照需求功率输出,并保证增程器使用的经济性和舒适性等问题。(The application provides a method and a device for determining a working point of a range extender, wherein the method comprises the following steps: acquiring the current working condition state of the range extender; determining a power following curve matched with the current working condition state according to the current working condition state; and determining the working point of the range extender according to the required power and the current power following curve. By adopting the method, a better control strategy in the operating condition state can be determined according to the actual operating condition state of the range extender, so that the output according to the required power is ensured as much as possible, and the problems of economy, comfort and the like of the use of the range extender are solved.)

1. A method of determining an operating point of a range extender, comprising:

acquiring the current working condition state of the range extender;

determining a power following curve matched with the current working condition state of the range extender according to the current working condition state;

and determining the working point of the range extender according to the required power and the power following curve.

2. The method of determining the range extender operating point of claim 1, wherein the current operating condition state comprises an air intake state of the range extender;

acquiring the current working condition state of the range extender, wherein the current working condition state comprises the following steps:

acquiring an atmospheric pressure signal at the position of the range extender; and/or acquiring the altitude of the position of the range extender;

determining an intake state of the range extender based on the barometric pressure signal and/or the altitude;

determining a power following curve matched with the current working condition state of the range extender according to the current working condition state, wherein the power following curve comprises the following steps: and determining the power following curve according to the air inlet state of the range extender.

3. The method of determining the range extender operating point of claim 1, wherein the current operating condition state comprises a temperature of the range extender;

acquiring the current working condition state of the range extender, wherein the current working condition state comprises the following steps: acquiring the temperature of the range extender;

determining a power following curve matched with the current working condition according to the current working condition state, wherein the power following curve comprises the following steps: and determining the power following curve according to the temperature of the range extender.

4. The method of determining the range extender operating point of claim 1, wherein the current operating condition state comprises a state of a ventilation mechanism in the range extender;

acquiring the current working condition state of the range extender, wherein the current working condition state comprises the following steps: acquiring a ventilation mechanism state signal of the range extender, and determining the ventilation mechanism state of the range extender based on the ventilation mechanism state signal;

determining a power following curve matched with the current working condition state according to the current working condition state, wherein the power following curve comprises the following steps: and determining the power following curve according to the state of the ventilation mechanism.

5. The method for determining the working point of the range extender according to any one of claims 1 to 4, wherein determining the power following curve of the state matched with the current working condition of the range extender according to the current working condition state comprises the following steps:

determining a current universal characteristic curve corresponding to the current working condition state;

and taking the optimal power following curve under the current universal characteristic curve as a power following curve matched with the current working condition.

6. The method for determining the working point of the range extender according to any one of claims 1 to 4, wherein determining the power following curve matched with the current working condition state of the range extender according to the current working condition state comprises the following steps:

determining a power attenuation coefficient matched with the current working condition state according to the current working condition state;

and determining a power following curve matched with the current working condition state based on the power attenuation coefficient and the power following curve under the standard working condition.

7. The method of determining the range extender operating point of any of claims 1-4, further comprising:

acquiring a resonance frequency interval of the range extender and/or a carrier provided with the range extender;

determining a power following curve matched with the current working condition state of the range extender according to the current working condition state, wherein the power following curve comprises the following steps: and determining a power following curve matched with the current working condition state according to the current working condition state under the premise of considering the resonance frequency interval.

8. The method for determining the operating point of the range extender according to any one of claims 1 to 4, wherein after determining the operating point of the range extender according to the required power and the power following curve, the method further comprises:

controlling the range extender to operate at the working point, and then acquiring the actual output power of the generator driven by the range extender;

and adjusting the working point of the range extender according to a power following curve matched with the current working condition state until the actual output power is matched with the required power.

9. An apparatus for determining an operating point of a range extender, comprising:

the working condition acquisition unit is used for acquiring the current working condition state of the range extender;

the power following curve determining unit is used for determining a power following curve matched with the current working condition state of the range extender according to the current working condition state;

and the working point determining unit is used for determining the working point of the range extender according to the required power and the power following curve.

10. The apparatus for determining the range extender operating point of claim 9, wherein the power-following curve determining unit comprises:

the universal curve determining subunit is used for determining a current universal characteristic curve corresponding to the current working condition state;

and the current power following curve determining subunit is used for taking the formulated optimal power following curve under the current universal characteristic curve as a power following curve matched with the current working condition state.

11. The apparatus for determining the range extender operating point of claim 9, wherein the power-following curve determining unit comprises:

the power attenuation coefficient determining unit is used for determining a power attenuation coefficient matched with the current working condition according to the current working condition state;

and the current power following curve determining subunit is used for determining a power following curve matched with the current working condition based on the power attenuation coefficient and the power following curve under the standard working condition.

12. The apparatus for determining the range extender operating point of claim 9, further comprising:

the resonant frequency determining unit is used for acquiring a resonant frequency interval of a carrier provided with the range extender;

and the power following curve determining unit determines a power following curve matched with the current working condition state according to the current working condition state under the premise of considering the resonance frequency interval.

13. The apparatus for determining the range extender operating point of claim 9, further comprising:

the actual power determining unit is used for controlling the range extender to operate at the working point and then acquiring the actual output power of the generator driven by the range extender;

and the working point fine adjustment unit is used for adjusting the working point of the range extender according to a power following curve matched with the current working condition state until the actual output power is matched with the required power.

14. A range extender system is characterized by comprising a controller, a range extender and a sensor;

the sensor is used for detecting a sensor signal of the working state of the range extender and sending the sensor signal to the controller;

the controller is configured to determine an operating point of the range extender according to a determination method for performing the operating point of the range extender according to any one of claims 1 to 8, and control the range extender to operate at the operating point.

15. A range extended electric vehicle comprising a generator and the range extender system of claim 14; the output shaft of the range extender is connected with the input shaft of the generator so as to drive the generator to rotate and generate electricity.

Technical Field

The application relates to the technical field of range-extending electric automobiles, in particular to a method and a device for determining a working point of a range extender.

Background

The range-extended electric automobile adopts the range extender to drive the generator to rotate and output electric energy to the motor and/or the battery, so that the decoupling of the range extender and a vehicle driving mechanism is realized, and a complex transmission mechanism is saved, so that a reasonable torque-rotating speed working point can be selected according to the actual working characteristics of the range extender, the reduction of oil consumption is realized, and the NVH (Noise, Vibration, Harshness) of the vehicle is considered.

At present, many range-extended electric automobiles adopt a power following technology, and the working point of a range extender is determined according to required power. In order to adapt to the power following technology and enable the range extender to output required power, the current method of the working point of the range-extending electric automobile is to make an optimal power following curve under a conventional application condition on the basis of the universal characteristic curve of the range extender; when the range extender works, the working point of the range extender is determined on the optimal power following curve according to the required power, and the rotating speed of the range extender is selected and determined according to the working point.

The aforementioned optimum power following curve is an optimum power following curve under normal application conditions. However, the vehicle may be in various possible operating conditions in actual use, such as a low-pressure operating condition that may enter a plateau, a high-temperature operating condition of a range extender, and a mechanical failure operating condition. Under the working condition environment, a working point is determined according to the required power and the optimal power following curve, and when the range extender works at the working point, the range extender cannot output the required power and the generated energy is insufficient.

Disclosure of Invention

In order to solve the technical problem or at least partially solve the technical problem, the application provides a method and a device for determining an operating point of a range extender.

In one aspect, the present application provides a method for determining a working point of a range extender, including:

acquiring the current working condition state of the range extender;

determining a power following curve matched with the current working condition state of the range extender according to the current working condition state;

and determining the working point of the range extender according to the required power and the power following curve.

Optionally, the current operating condition state comprises an air inlet state of the range extender;

acquiring the current working condition state of the range extender, wherein the current working condition state comprises the following steps:

acquiring an atmospheric pressure signal at the position of the range extender; and/or acquiring the altitude of the position of the range extender;

determining an intake state of the range extender based on the barometric pressure signal and/or the altitude;

Optionally, the current operating condition state comprises a temperature of the range extender;

acquiring the current working condition state of the range extender, wherein the current working condition state comprises the following steps: acquiring the temperature of the range extender;

Optionally, the current operating condition state comprises a state of a ventilation mechanism in the range extender;

Optionally, determining a power following curve of a state matched with the current operating condition of the range extender according to the current operating condition state includes:

determining a current universal characteristic curve corresponding to the current working condition state;

and taking the optimal power following curve under the current universal characteristic curve as a power following curve matched with the current working condition.

Optionally, determining a power following curve matched with the current operating condition state of the range extender according to the current operating condition state includes:

determining a power attenuation coefficient matched with the current working condition state according to the current working condition state;

and determining a power following curve matched with the current working condition state based on the power attenuation coefficient and the power following curve under the standard working condition.

Optionally, the method further comprises: acquiring a resonance frequency interval of the range extender and/or a carrier provided with the range extender;

determining a power following curve matched with the current working condition state of the range extender according to the current working condition state, wherein the power following curve comprises the following steps: and determining a power following curve matched with the current working condition state according to the current working condition state under the premise of considering the resonance frequency interval.

Optionally, after determining the operating point of the range extender according to the required power and the power following curve, the method further includes:

controlling the range extender to operate at the working point, and then acquiring the actual output power of the generator driven by the range extender;

In another aspect, the present application provides a device for determining a working point of a range extender, including:

the working condition acquisition unit is used for acquiring the current working condition state of the range extender;

and the working point determining unit is used for determining the working point of the range extender according to the required power and the power following curve.

Optionally, the power following curve determining unit includes:

the universal curve determining subunit is used for determining a current universal characteristic curve corresponding to the current working condition state;

Optionally, the power following curve determining unit includes:

the power attenuation coefficient determining unit is used for determining a power attenuation coefficient matched with the current working condition according to the current working condition state;

Optionally, the method further comprises:

the resonant frequency determining unit is used for acquiring a resonant frequency interval of a carrier provided with the range extender;

Optionally, the method further comprises:

the actual power determining unit is used for controlling the range extender to operate at the working point and then acquiring the actual output power of the generator driven by the range extender;

In yet another aspect, the present application provides a range extender system comprising a controller, a range extender, and a sensor;

the sensor is used for detecting a sensor signal of the working state of the range extender and sending the sensor signal to the controller;

the controller is used for determining the working point of the range extender according to the determination method for executing the working point of the range extender, and controlling the range extender to operate at the working point.

In yet another aspect, the present application provides a range extended electric vehicle comprising a generator and a range extender system as described above; the output shaft of the range extender is connected with the input shaft of the generator so as to drive the generator to rotate and generate electricity.

According to the method and the device for determining the working point of the range extender, when the range extender is in a certain operation working condition state, the corresponding power following curve can be found out according to the operation working condition state and serves as the power following curve matched with the current working condition state, and then the working point of the range extender is determined according to the power following curve and the required power. By adopting the method, a better control strategy in the operating condition state can be determined according to the actual operating condition state of the range extender, so that the output according to the required power is ensured as much as possible, and the problems of economy, comfort and the like of the use of the range extender are solved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a graph of the universal characteristic of a range extender;

fig. 2 is a flowchart of a method for determining an operating point of a range extender according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a device for determining a working point of a range extender provided in an embodiment of the present application;

fig. 4 is a schematic structural diagram of an electronic device provided in an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a range extender system provided in an embodiment of the present application;

wherein: 11-a working condition obtaining unit, 12-a power following curve determining unit and 13-a working point determining unit; 21-processor, 22-memory, 23-communication interface, 24-bus system; 31-controller, 32-range extender and 33-sensor.

Detailed Description

In order that the above-mentioned objects, features and advantages of the present application may be more clearly understood, the solution of the present application will be further described below. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, but the present application may be practiced in other ways than those described herein; it is to be understood that the embodiments described in this specification are only some embodiments of the present application and not all embodiments.

The application provides a method and a device for determining a working point of a range extender, so that the working point for meeting power follow-up output can be determined under various possible operating condition states of the range extender, and the range extender is ensured to operate in a better oil consumption state and/or the whole vehicle is in a better NVH state.

In order to more clearly understand the meanings of various technical terms in the embodiments of the present application, before describing the method and the device for determining the operating point of the range extender provided in the embodiments of the present application, first, the change characteristics and reasons of the output power of the range extender are analyzed, and the meaning of the power following curve of the range extender is explained based on the universal operating characteristic curve of the range extender.

The output power of the range extender is directly related to the output torque and the rotating speed when the range extender operates, and can be determined according to the ratio of P to (T multiplied by N) ÷ 9550 (wherein P is power, T is torque and N is rotating speed); to output a particular power, a corresponding speed and torque output needs to be selected.

According to the heat engine principle, the range extender converts chemical energy into mechanical energy in a mode of enabling gas in the cylinder to be subjected to thermal expansion and do work outwards by burning fuel, and outputs power through a crankshaft connected with the cylinder; in order to ensure a large torque output, it is necessary to ensure that a sufficient detonation pressure is generated in the power stroke of the range extender, and the fuel-air mixture is combusted in the power stroke as much as possible to avoid the fuel-air mixture from detonating before the ignition point (i.e. the detonation phenomenon occurs).

In addition, the rotating speed characteristic of the range extender can also change the air intake characteristic of the range extender, and then the torque output of the range extender is influenced; in general, in the case of an external environment determination, the output torque of the range extender increases gradually and reaches a maximum in a certain speed range during the increase of the speed of the range extender, and then decreases instead as the speed of the range extender continues to increase.

Factors that affect the magnitude of the pressure of the deflagration gas in the power stroke include: the air inflow in the suction stroke of the range extender, the oxygen content in the air inlet and the sealing performance of the cylinder in the power stroke. In practical application, the amount of the air inflow and the oxygen content in the air inflow are directly related to the atmospheric pressure of the environment where the range extender is located; the sealing performance of the cylinder is directly related to the working state characteristic of the range extender air exchange mechanism; the ventilation mechanism of the range extender comprises a mechanism which is composed of a timing chain (or a timing belt), a timing camshaft, an inlet valve, an outlet valve, a pressure spring and the like and can adjust the inlet and outlet states of a cylinder according to the rotation state of a crankshaft.

Under the condition that the anti-knock characteristic of the fuel is determined, factors influencing the knocking of the fuel-air mixture before an ignition point comprise the temperature of the cylinder wall of the range extender and the compression ratio of the range extender; after the range extender is structurally shaped, the compression ratio is also determined generally, so that in practical application, the factor influencing the detonation of the fuel-air mixture at the ignition point, namely the temperature of the cylinder wall of the range extender, is the temperature of the cylinder wall of the range extender.

From the above analysis, therefore, when the range extender is rotating at a constant speed, the factors influencing the torque output of the range extender include: the atmospheric pressure of the environment where the range extender is located, the working state of a ventilation mechanism in the range extender and the temperature state of the range extender.

Fig. 1 is a universal characteristic diagram of a range extender, and how to construct a power following curve of the range extender is described below with reference to the universal characteristic diagram.

As shown in fig. 1, the horizontal axis of the universal characteristic curve of the range extender is the rotating speed, and the vertical axis is the output torque; curves marked with similar contour lines such as 230, 240, 245, 250 … … in the figure are range extender fuel consumption characteristic curves, which represent the fuel consumption characteristics of the range extender under the condition of specific rotating speed and torque output, and the smaller the value is, the smaller the corresponding fuel consumption is marked; the smooth curve (hyperbolic curve) from the top left to the bottom right in the figure is the equipower output curve of the range extender, and the equipower output curve farther from the coordinate axis indicates the larger output power.

The method comprises the steps of constructing a power following curve of the range extender, namely determining a point with lower oil consumption at a corresponding power output point in all possible rotating speed-torque outputs determined in the graph 1, considering the stability of rotating speed change of the range extender, the adjusting characteristic of a ventilation mechanism and the NVH performance of a vehicle where the range extender is located, and connecting the power points to determine a power selection curve. As shown in fig. 1, the broken line of the point a, and the broken lines of the points B and C are the corresponding two power following curves.

In order to determine the operating point of the range extender using the power following technique, an optimal power following curve is established for the range extender in the prior art, such as the broken line where the point a in fig. 1 is located. After the required power is determined, the optimal power following curve of the range extender is searched according to the required power, and the corresponding working point is determined. For example, the corresponding operating point at a certain required power is point a.

However, the aforementioned optimum power following curve is a curve of the range extender under a better operating condition, and does not represent various operating characteristics that may deteriorate the operating condition. When the range extender works in a severe operating condition state, the working point determined according to the required power is the point A, but the torque output characteristic of the range extender is deteriorated at the moment, and the actual working point is the point B. And determining that the output power of the range extender at the actual working point B is less than the required power according to the ratio of P to (T multiplied by N) ÷ 9550. In this case, it is not possible to determine how to adjust the operating point of the range extender, so that the output power of the range extender is smaller than the required power, and the vehicle in which the range extender is located may have power shortage and other problems.

The method for determining the working point of the range extender provided by the embodiment of the application is a method for determining the working point of the range extender, which is provided aiming at the problems, so that the range extender can achieve the required power under the condition that the running working condition state is deteriorated, and the range extender is ensured to be in a better oil consumption state.

Fig. 2 is a flowchart of a method for determining an operating point of a range extender according to an embodiment of the present disclosure. As shown in fig. 2, the method for determining the heard range extender operating point according to the embodiment of the present application includes steps S101 to S103.

S101: and acquiring the current working condition state of the range extender.

In the embodiment of the application, the current working condition state of the range extender is the operating working condition state of the range extender at the current moment; in practical application, the range extender is provided with a sensor for acquiring an environmental characteristic signal or a sensor of a self state, and the current working condition state of the range extender can be determined according to the sensor signal.

In specific application, the current working condition state of the range extender is obtained by the following steps.

1. First case

In the first case, the current operating state of the range extender is the intake state of the range extender, and the step of determining the intake state of the range extender comprises steps S1011-S1012.

S1011: and acquiring an atmospheric pressure signal at the position of the range extender.

In one application of the embodiment of the application, an atmospheric pressure sensor for collecting an ambient pressure signal is configured in the range extender; the barometric pressure sensor may be used to measure a barometric pressure signal at the location of the range extender.

S1012: an intake state of the range extender is determined based on the barometric pressure signal.

According to practical application experience, the atmospheric pressure signal directly influences the amount of gas entering a range extender cylinder, and when the range extender is in a certain specific rotating speed state, the gas inlet state of the range extender is directly related to the atmospheric pressure regardless of whether the range extender is a natural suction range extender or a booster-type range extender, so that the atmospheric pressure directly influences the detonation gas pressure formed in the range extender cylinder; in addition, according to the relationship between the atmospheric pressure and the air content, the smaller the atmospheric pressure is, the smaller the oxygen content of the air is, and the pressure of the detonation gas formed in the range extender cylinder is also influenced. Thus, the barometric pressure signal may be used as a basis for determining the intake state of the range extender, thereby determining the intake state of the range extender (of course, the determined intake state of the range extender may be an operating state that is directly related to the barometric pressure signal, but cannot be quantitatively described).

2. Second case

In another application of the embodiment of the present application, the sensor configured to the range extender is a position sensor; the current working state of the range extender is still the air inlet state of the range extender, and correspondingly acquiring the current working condition state of the range extender comprises steps S1013-S1014.

S1013: and acquiring a position signal of the range extender, and determining the altitude of the position of the range extender based on the position signal.

In the embodiment of the application, the position sensor may be an inertial sensor or a satellite navigation sensor. After the position signal of the range extender is obtained, the position of the range extender in the absolute coordinate system can be determined based on the position signal, and the altitude signal of the range extender can be determined by combining map information.

S1014: the air intake state of the range extender is determined based on the poster height.

According to practical experience, the atmospheric pressure and the oxygen content are different at different altitudes, the altitude has positive correlation with the atmospheric pressure and the atmospheric oxygen content, and the atmospheric pressure and the atmospheric oxygen content are directly related with the air inlet state of the range extender; and the air inlet state of the range extender is directly related to the atmospheric pressure and the atmospheric oxygen content. Thus, the atmospheric pressure state can be directly characterized by the altitude, and the intake state of the range extender can be directly determined according to the altitude.

3. Third case

In another application of the embodiment of the application, the sensor of the range extender configuration is a temperature sensor installed in the cooling mechanism for measuring the working state of the cooling mechanism. Correspondingly, the current working condition state of the range extender is determined as the temperature of the range extender. Acquiring the temperature of the range extender includes acquiring a temperature of coolant in the cooling mechanism, and determining the temperature of the range extender based on the temperature of the coolant.

As mentioned above, in order to operate the range extender in a better operating state, the range extender needs to be located in a reasonable temperature range to avoid the knocking problem. For this purpose, the range extender is provided with a cooling mechanism which brings the range extender into a reasonable temperature range by cooling the coolant flowing through the range extender cylinder.

In practical application, the sensor in the cooling mechanism can adopt a cooling liquid temperature sensor, and the temperature state of the range extender is determined by using the cooling liquid temperature measured by the cooling liquid temperature sensor; of course, in practical application, a sensor for directly measuring the temperature of the range extender cylinder body can be used, and the temperature of the range extender cylinder body or the cylinder cover can be directly measured.

4. Fourth case

In yet another application of the embodiment of the present application, the working state of the range extender includes a ventilation mechanism state of the range extender. The sensor that increases the journey ware configuration is ventilation mechanism state sensor, and corresponding, confirms the current operating mode state that increases the journey ware, includes: and acquiring a ventilation mechanism state signal, and determining the ventilation mechanism state of the range extender based on the ventilation mechanism state signal.

For example, in one type of range extender, the breathing mechanism employed is that of variable timing valve technology, which includes a variable phase camshaft, a phase adjuster, and a camshaft position sensor. A camshaft position sensor may be used to determine the camshaft position, and thus the open state of the valve. When the ventilation mechanism breaks down, the movement characteristic of the variable-phase camshaft is limited, the opening state of the valve cannot be adjusted according to the rotating speed of the engine, namely the valve can break down, the ventilation mechanism of the range extender can be determined to break down according to the signal output by the camshaft position sensor, and the sealing performance of the cylinder cannot be guaranteed, so that the output torque of the range extender is reduced.

When in practical application, the current working condition state of the range extender can also be determined by using the combination of the 4 conditions. Of course, in other applications of the embodiment of the present application, other state information may also be used to represent the current operating condition state of the range extender, and the corresponding sensor is used to detect the corresponding signal, so as to determine the current operating condition state of the range extender.

After determining the current operating state of the range extender in step S101, steps S102 and S103 may be subsequently performed.

S102: and determining a power following curve matched with the current working condition state according to the current working condition state.

In the embodiment of the present application, particularly when step 102 is executed, the current power following curve matching the current operating condition of the range extender is determined according to the various possible current operating conditions (e.g., the intake air condition, the temperature condition, and the ventilation mechanism condition) determined in the foregoing S101.

In order to perform the step of determining the current power following curve according to the current operating condition state in step S102, the corresponding power following curves in various operating condition states need to be specified in advance. In the specific application of the embodiment of the application, the methods for establishing the power following curves corresponding to different operating condition states include the following methods.

First method

The method comprises the steps of adjusting the operation condition of the range extender to a specific operation condition, recording the oil consumption of the range extender under different rotating speeds and torque output (namely establishing a universal characteristic curve of the range extender), then determining the optimal state corresponding to each power on the basis of the universal characteristic curve corresponding to each operation condition state, screening according to each power optimal state to determine the optimal power following curve under the corresponding operation condition, and taking the optimal power following curve as the power following curve matched with the current operation condition of the range extender.

Taking the current working condition state as the air inlet state of the range extender as an example. Acquiring the power following curves in each air intake state comprises the following steps: the range extender is arranged at different altitudes (namely different atmospheric pressures), the oil consumption of the range extender in different rotating speeds and torque output states is recorded at the altitudes, a universal characteristic curve corresponding to the atmospheric pressure state is established, and then an optimal power following curve is determined. For example, the range extender may be transported to heights with altitudes of 0m, 500m, 1000m, 1500m … … 5000m and 5000m, and the like, and the aforementioned operations may be performed to obtain an optimal power following curve corresponding to atmospheric pressure.

Taking the current working condition state as the temperature of the range extender as an example. Obtaining power following curves at various temperature states includes: the range extender operates in different temperature states, the oil consumption of the range extender in different rotating speeds and torque output states in different temperature states is recorded, a universal characteristic curve in a corresponding temperature state is established, and then an optimal power following curve is determined. It should be noted that the aforementioned test temperature should be performed as far as possible within the range of possible temperatures at which the range extender can power.

Taking the current working condition state as the ventilation mechanism state of the range extender as an example. Obtaining power following curves at various temperature states includes: the range extender operates in different ventilation mechanism fault states and various optional possible states, the oil consumption of the range extender in different rotating speed and torque output states in different ventilation mechanism states is recorded, a universal characteristic curve corresponding to the ventilation mechanism states is established, and then an optimal power following curve is determined. Correspondingly, determining the current power following curve according to the current working condition state comprises: determining a current universal characteristic curve corresponding to the current working condition state; and taking the optimal power following curve in the current universal characteristic curve as the current power following curve.

In practical application, the corresponding relation among different operating condition states, corresponding universal characteristic curves and a power following curve under the universal characteristic curves can be directly established according to the steps, the corresponding relation among the different operating condition states and the power following curve is established, and the current power following curve is directly determined according to the current operating condition state in later-stage application.

In practical application, it is not economical to directly establish power following curves corresponding to all operating condition states. For this purpose, a characteristic curve or a power-following curve can be established for a plurality of typical operating states. For example, the fuel consumption and the torque state of the optimal power following curve at each rotating speed under the typical operating condition state can be adopted, and a spline curve fitting or polynomial fitting mode is adopted to determine the universal characteristic curve and/or the power following curve under the current operating condition state.

Second method

The second method is based on the fact that in a degraded operating condition state, the output torque of the range extender is correspondingly reduced relative to that in a standard operating condition state, and the reduced proportion and the degradation condition of the operating condition state are in a positive correlation relationship.

According to the basic logic, the range extender can work according to the control instruction of the optimal power following curve under different operation condition states, the actual power output state is determined, and the power attenuation coefficient of the range extender under each operation condition state is established.

The corresponding step S102 is: after the current working condition state is determined, determining a power attenuation coefficient according to the current working condition state; and then, determining a power following curve matched with the current power based on the power attenuation coefficient and the power following curve under the standard working condition.

In the specific application of the embodiment of the application, the power attenuation coefficient under the typical operation condition can be obtained by testing the corresponding output power according to the control instruction under the standard operation condition in a plurality of typical operation condition states; the power attenuation coefficient under other operating condition states can be obtained by spline curve fitting or polynomial fitting according to the power attenuation coefficient under the typical operating condition state.

In the specific application of the embodiment of the application, the power attenuation coefficient under several typical operation condition states can also be determined. After the current working condition state is determined, the nearest typical operation working condition state is searched according to the current working condition state, the power attenuation coefficient in the typical operation working condition state is used as the power attenuation coefficient corresponding to the current working condition state, and the power following curve corresponding to the power attenuation coefficient is used as the power following curve matched with the current operation working condition.

In practical application, when determining the power following curve of the current working condition of the range extender, in addition to considering the oil consumption of the range extender for outputting a specific torque, the NVH problem of the whole vehicle caused by the vibration of the range extender also needs to be considered.

The corresponding embodiment of the application also comprises: acquiring a resonance frequency interval of a vehicle provided with the range extender; correspondingly, determining the current power following curve according to the current working condition state comprises considering a resonance frequency interval, and determining the power following curve matched with the current working condition state according to the current working condition state; that is to say, when the power following curve is determined, the rotating speed of the range extender is required to rapidly cross the corresponding resonance frequency interval according to the resonance frequency interval of the vehicle when the required power changes, and then the problem of NVH (noise, vibration and harshness) deterioration of the whole vehicle is avoided.

S103: and determining the working point of the range extender according to the required power and the current power following curve.

After the power following curve matched with the current working condition of the range extender is determined and the corresponding demand power instruction is obtained, which working point in the current power following curve can output the corresponding demand power can be searched according to the demand power, so that the working point is determined as the working point of the range extender.

After the working point of the range extender is determined, the rotating speed instruction corresponding to the working point can be issued to the range extender, the range extender is controlled to adjust the working state according to the rotating speed instruction, and then the required power can be output. It should be noted that a corresponding smooth adjustment strategy should be set when the working state of the range extender is adjusted, so as to avoid the problem of overlarge vibration caused by the excessively fast change of the rotating speed of the range extender.

According to the foregoing description, the method for determining the working point of the range extender provided in the embodiment of the present application can find the corresponding power following curve as the power following curve matched with the current working condition according to the operating working condition state when the range extender is in a certain operating working condition state, and then determine the working point of the range extender according to the current power following curve and the required power. By adopting the method, a better control strategy in the operating condition state can be determined according to the actual operating condition state of the range extender, so that the output according to the required power is ensured as much as possible, and the oil consumption characteristic of the range extender and the vibration characteristic of the whole vehicle are ensured.

And determining the working point of the range extender according to the steps S101-S103, and after the range extender is adjusted to run to the working point, the range extender runs to the working point and outputs power according to the running characteristic of the range extender. In practical application, because the actual operating condition state and the current power following curve are not likely to be completely matched, the output power and the required power of the range extender during operation at the operating point have a certain difference, and in order to avoid the problem of insufficient power or waste of redundant power caused by the difference between the output power and the required power, steps S104 and S105 are further included after steps S101 to S103.

S104: and controlling the range extender to operate at the working point, and then obtaining the actual output power of the generator driven by the range extender.

In the embodiment of the present application, the actual power output by the range extender can be represented by the actual output power of the generator. In a specific application, the actual output power can be determined by measuring the output voltage and the output current of the generator and utilizing the output voltage and the output current.

S105: and adjusting the working point of the range extender according to the power following curve matched with the current working condition state until the actual output power is matched with the required power.

In step S105, the working point of the range extender is adjusted according to the actual output power and the required power and the current power following curve, and the steps S1051-S1053 are included.

S1051: judging whether the difference value between the actual output power and the required power is greater than a set threshold value or not; if yes, go to S1052; if not, go to S1053.

S1052: and adjusting the working point of the range extender according to the power following curve.

In specific application, if the actual output power is smaller than the required power and the difference between the actual output power and the required power is larger than a set threshold, the output power of the range extender cannot meet the required power at the moment, so that the output power of the range extender needs to be increased according to a power following curve; and if the actual output power is larger than the required power and the difference value of the two sums is larger than the set threshold, the output power of the tested range extender is overlarge, so that the output power of the range extender needs to be reduced according to a power following curve.

S1052: the working state of the range extender is kept stable.

If the difference between the output power and the required power of the range extender is smaller than the set threshold, the working point of the range extender is determined to be reasonable, and therefore the working state of the range extender can be kept stable.

In addition to the fine adjustment of the operating point of the range extender according to the foregoing steps S1051 to S1053, in other applications of the embodiment of the present application, it can be ensured that the actual output power of the range extender is always slightly greater than the required power, and the operating point of the corresponding fine adjustment range extender is adjusted.

In addition, in order to maintain the structural stability of the range extender and the vehicle on which the range extender is mounted and avoid the problem of resonance caused by the rotation of the range extender at a specific rotation speed, the application may further include: acquiring a resonance frequency interval of the range extender and a carrier provided with the range extender, and determining a power following curve matched with the current working condition according to the current working condition state on the premise of considering the resonance power interval. In practical applications, the vehicle may be a vehicle, a frame structure or a container.

In addition to the method for determining the working point of the range extender, the application also provides a device for determining the working point of the range extender. Fig. 3 is a schematic structural diagram of a device for determining a working point of a range extender provided in an embodiment of the present application. As shown in fig. 3, the device for determining the operating point of the range extender includes a condition acquisition unit 11, a power-following curve determination unit 12, and an operating point determination unit 13.

The working condition obtaining unit 11 is used for obtaining the current working condition state of the range extender. In the embodiment of the application, the current working condition state of the range extender is the operating working condition state of the range extender at the current moment; in practical application, the range extender is provided with a sensor for acquiring an environmental characteristic signal or a sensor of a self state, and the current working condition state of the range extender can be determined according to the sensor signal. In specific application, the current working condition state of the range extender is obtained by the following steps.

Under the first condition, the current working state of the range extender is the air inlet state of the range extender, and the air inlet state of the range extender is determined; the acquiring the intake state includes: and acquiring an atmospheric pressure signal at the position of the range extender, and determining the intake pressure state of the range extender based on the atmospheric pressure signal.

In one application of the embodiment of the application, an atmospheric pressure sensor which is configured in the range extender and used for acquiring an ambient air pressure signal is arranged in the range extender; the barometric pressure sensor may be used to measure a barometric pressure signal at the location of the range extender.

According to practical application experience, the atmospheric pressure signal directly influences the amount of gas entering a range extender cylinder, and when the range extender is in a certain specific rotating speed state, the gas inlet state of the range extender is directly related to the atmospheric pressure regardless of whether the range extender is a natural suction range extender or a booster-type range extender, so that the atmospheric pressure directly influences the detonation gas pressure formed in the range extender cylinder; in addition, according to the relationship between the atmospheric pressure and the air content, the smaller the atmospheric pressure is, the smaller the oxygen content of the air is, and the pressure of the detonation gas formed in the range extender cylinder is also influenced. Thus, the barometric pressure signal may be used as a reference for determining the current operating state of the range extender, thereby determining the intake state of the range extender (of course, the determined intake state of the range extender may be an operating state that is directly related to the barometric pressure signal, but cannot be quantitatively described).

The sensor configured on the range extender in the second condition is a position sensor; the current working state of the range extender is still the air intake state of the range extender, and the acquiring of the air intake state comprises the following steps: the method comprises the steps of obtaining a position signal of the range extender, determining the altitude of the position of the range extender based on the position signal, and determining the air inlet state of the range extender based on the poster height.

In the third case, the current operating state is the temperature of the range extender. Obtaining the temperature of the region of increased support includes: acquiring the temperature of cooling liquid, and determining the temperature state of the range extender based on the temperature of the cooling liquid; determining the current power following curve according to the current operating condition state includes: and determining a power following curve matched with the current working condition state according to the temperature of the range extender.

In practical application, the sensor in the cooling mechanism can adopt a cooling liquid temperature sensor, and the temperature state of the range extender is determined by using the cooling liquid temperature measured by the cooling liquid temperature sensor; of course, in practical application, the temperature of the range extender can be measured by using a sensor for directly measuring the temperature of the cylinder of the range extender.

In the fourth case, the working state of the range extender is the state of the ventilation mechanism of the range extender. Acquiring the state of the ventilation mechanism comprises the following steps: and acquiring a ventilation mechanism state signal of the range extender, and determining the ventilation mechanism state of the range extender based on the ventilation mechanism state signal.

In another application of the embodiment of the present application, the sensor configured to the range extender is a ventilation mechanism state sensor to obtain a ventilation mechanism state.

The power following curve determining unit 12 is configured to determine a power following curve matching the current operating condition state according to the current operating condition state.

The power following curve selected in the embodiment of the application is a power following curve which is adaptive to or relatively adaptive to the current working condition of the range extender. In order to determine the power following curve according to the current working condition state, the corresponding power following curves in various operating working condition states need to be specified in advance.

In this embodiment of the application, the power following curve determining unit 12 may determine the power following curve corresponding to the current working condition state in the following construction manner.

In the first case: the power following curve comprises a universal curve determining subunit and a current power following curve determining subunit. The universal curve determining subunit is used for determining a current universal characteristic curve corresponding to the current working condition state; and the current power following curve determining subunit is used for taking the formulated optimal power following curve under the current universal characteristic curve as the current power following curve.

In order to adapt to the first situation, a method for establishing a power following curve corresponding to each current working condition state is as follows.

In the second case: the power following curve determining unit 12 includes a power attenuation coefficient determining unit and a current power following curve determining subunit. The power attenuation coefficient determining unit is used for determining a power attenuation coefficient according to the current working condition state; and the current power following curve determining subunit is used for determining a power following curve matched with the current working condition based on the power attenuation coefficient and the power following curve under the standard working condition.

In order to adapt to the second situation, a second method for formulating power following curves corresponding to the current working condition states is as follows: the range extender works according to the control instruction of the optimal power following curve under different operating condition states, the actual power output state is determined, and the power attenuation coefficient of the power output of the range extender relative to the output power under the standard optimal operating state under each operating condition state is established. The second method is based on the fact that in a degraded operating condition state, the output torque of the range extender is correspondingly reduced relative to that in a standard operating condition state, and the reduced proportion and the degradation condition of the operating condition state are in a positive correlation relationship.

In the specific application of the embodiment of the application, the power attenuation coefficient under the typical operation condition can be obtained by testing the corresponding output power according to the control instruction under the standard operation condition in a plurality of typical operation condition states; the power attenuation coefficients under other operating conditions can be obtained by a fitting method according to the power attenuation coefficients under typical operating conditions.

In specific application of the embodiment of the application, the device for determining the working point of the range extender further comprises a resonant frequency determining unit; the resonant frequency determining unit is used for acquiring a carrier resonant frequency interval of the city extender and/or the range extender. Correspondingly, the power curve determining unit determines a corresponding power following curve according to the current working condition state under the premise of considering the resonance frequency interval. That is to say, when the power following curve matched with the current working condition is determined, the rotating speed of the range extender is required to rapidly cross the corresponding resonance frequency interval according to the resonance frequency interval of the vehicle when the required power changes, and then the problem of NVH (noise, vibration and harshness) deterioration of the whole vehicle is avoided.

The operating point determining unit 13 is configured to determine an operating point of the range extender according to the required power and the power following curve. After the power following curve matched with the current working condition state of the range extender is determined and the corresponding demand power instruction is obtained, which working point in the current power following curve can output the corresponding demand power can be searched according to the demand power, so that the working point is determined as the working point of the range extender.

The device for determining the working point of the range extender provided by the embodiment of the application can find out the corresponding power following curve as the current working condition state matching power following curve according to the running working condition state when the range extender is in a certain running working condition state, and then determines the working point of the range extender according to the power following curve and the required power. By adopting the method, a better control strategy in the operating condition state can be determined according to the actual operating condition state of the range extender, so that the output according to the required power is ensured as much as possible, and the oil consumption characteristic of the range extender and the vibration characteristic of the whole vehicle are ensured.

Besides the determining device of the range extender working point, the determining device of the range extender working point can also comprise an actual power determining unit and a working point fine-tuning unit; the actual power determining unit is used for controlling the range extender to operate at a working point and then acquiring the actual output power of the generator driven by the range extender; and the working point fine adjustment unit is used for adjusting the working point of the range extender according to the power following curve matched with the current working condition state until the actual output power is matched with the required power.

In specific application, the strategy for specifically adjusting the working point of the range extender by the working point fine adjustment unit is as follows: judging whether the difference value between the actual output power and the required power is greater than a set threshold value or not; if so, adjusting the working point of the range extender according to the current power following curve; if not, the working state of the range extender is kept stable.

In addition to providing the foregoing method and apparatus for determining the operating point of a range extender, the present application also provides a controller for determining the operating point of a range extender. Fig. 4 is a schematic structural diagram of an electronic device provided in an embodiment of the present application. As shown in fig. 4, the controller includes at least one processor 21, at least one memory 22, and at least one communication interface 23.

The memory 22 in this embodiment may be either volatile memory or nonvolatile memory, or a combination of the two. In some embodiments, memory 22 stores the following elements: executable units or data structures, or a subset thereof, or an expanded set thereof: an operating system and an application program. The operating system includes various system programs, such as a framework layer, a core library layer, a driver layer, and the like, and is used for implementing various basic tasks and processing hardware-based tasks. And the application programs comprise application programs of various application tasks. The program for implementing the method for determining the working point of the range extender provided by the embodiment of the application can be contained in an application program; in addition, the corresponding power meter following curves and/or range extender universal curves under various working conditions are also stored in the memory 2.

In the embodiment of the present application, the processor 21 executes the steps of the method for determining the operating point of the range extender by calling a program or an instruction (specifically, a program or an instruction stored in an application program) stored in the memory 22.

In the embodiment of the present application, the processor 21 may be a general-purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The steps of the method for determining the working point of the range extender provided by the embodiment of the application can be directly embodied as the execution of a hardware decoding processor, or the execution of the hardware decoding processor and a software unit in the decoding processor is combined. The software elements may be located in ram, flash, rom, prom, or eprom, registers, among other storage media that are well known in the art. The storage medium is located in a memory 22, and the processor 21 reads the information in the memory 22 and performs the steps of the method in combination with its hardware.

The communication interface 23 is used for implementing information transmission between the controller and the external device, for example, to obtain signals generated by various sensors, and generate and issue corresponding control strategy instructions to the range extender.

The memory, processor components in the controller are coupled together by a bus system 24 or other communication system, with the bus system 24 being used to enable communications among the components.

The embodiment of the application also provides a range extender system. Fig. 5 is a schematic structural diagram of a range extender system provided in an embodiment of the present application. As shown in fig. 5, the range extender system includes a controller 31, a range extender 32, and a sensor 33.

The sensor 33 is used for detecting the current working condition state of the range extender 32, generating a sensor 33 signal representing the working state of the range extender 32 and sending the sensor 33 signal to the controller 31; the sensor 33 in practical application may be the various possible sensors mentioned above.

The controller 31 is configured to determine an operating point of the range extender according to the aforementioned determination method of the operating point of the range extender, and control the operating point of the range extender 32. The range extender 32 is adapted to operate at a selected operating point to drive a generator coupled thereto to generate electricity.

In addition, the embodiment of the application also provides an extended range electric vehicle, which comprises a generator and the extended range device system; in addition, the range extender electric vehicle may further include a power battery, an electric motor for driving the wheels to rotate, and the like, which will not be described in detail, for details, refer to the related art documents. Of course, the range extender and the method for determining the operating point of the range extender provided in the embodiments of the present application may also be applied to other devices, for example, to temporary power generation equipment.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

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Method and device for determining working point of range extender

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