阅读说明：本技术 电动汽车用轮毂永磁电机控制系统及其能量转化控制策略 (Wheel hub permanent magnet motor control system for electric automobile and energy conversion control strategy thereof ) 是由 李伟力 汤昊岳 李金阳 于 2021-08-16 设计创作，主要内容包括：本发明提供了一种电动汽车用轮毂永磁电机控制系统及其能量转化控制策略,轮毂永磁电机的外定子和内定子的三相绕组出线端分别与两个变流器相连,两个变流器均为三相电压桥式逆变电路,两个变流器通过直流供电系统供电。控制系统根据路况实时的切换电机的运行状态,实现能量的自适应转化。当电动汽车处于爬坡阶段时,双定子共同工作于电动状态,为电动汽车提供较大的输出扭矩；当电动汽车处于下坡或刹车阶段时,内定子切换成发电状态,将电能回馈到电池中,提高电池的续航能力；当电动汽车处于平坦路况时,外定子处于电动状态,内定子不参与能量转换。本发明可以有效的提升轮毂电机的功率密度、增强能量利用率,解决电动汽车行驶里程受限的问题。(The invention provides a hub permanent magnet motor control system for an electric automobile and an energy conversion control strategy thereof. The control system switches the running state of the motor in real time according to road conditions to realize the self-adaptive conversion of energy. When the electric automobile is in a climbing stage, the double stators work together in an electric state to provide a larger output torque for the electric automobile; when the electric automobile is in a downhill or braking stage, the inner stator is switched into a power generation state, electric energy is fed back to the battery, and the cruising ability of the battery is improved; when the electric automobile is in a flat road condition, the outer stator is in an electric state, and the inner stator does not participate in energy conversion. The invention can effectively improve the power density of the hub motor, enhance the energy utilization rate and solve the problem of limited driving mileage of the electric automobile.)

1. A control system of a hub permanent magnet motor for an electric automobile is characterized by comprising the hub permanent magnet motor, two converters and a direct current power supply system;

the three-phase winding wire outlet ends of the outer stator and the inner stator of the hub permanent magnet motor are respectively connected with two converters, the two converters are three-phase voltage bridge type inverter circuits, and the two converters supply power through a direct current power supply system.

2. The in-wheel permanent magnet motor control system for the electric automobile according to claim 1, wherein the direct current power supply system is composed of a storage battery, a super capacitor and a DC-DC conversion controller.

3. The in-wheel permanent magnet motor control system for the electric vehicle as claimed in claim 2, wherein the in-wheel permanent magnet motor is a single rotor-double stator in-wheel permanent magnet motor.

4. The hub permanent magnet motor for the electric vehicle as claimed in claim 2, wherein the hub permanent magnet motor is a dual-rotor and dual-stator hub permanent magnet motor, and a magnetic and electric isolating material is added between the outer rotor and the inner rotor, so that the magnetic circuits of the outer rotor and the inner rotor are independent from each other and have no magnetic coupling relationship.

5. A control method applied to the control system of the hub permanent magnet motor for the electric vehicle of claim 3, wherein when the hub permanent magnet motor is a single-rotor double-stator hub permanent magnet motor, the method comprises the following steps:

when the road condition that the horsepower of the electric automobile needs to be increased for running is needed, the converters connected with the outer stator winding and the inner stator winding of the hub motor work in an inversion mode, and the outer stator and the inner stator are in an electric state;

when the electric automobile is in a downhill road condition or a brake braking mode, the first converter connected with the outer stator winding of the hub motor still works in an inversion mode, the second converter connected with the inner stator winding of the hub motor works in a rectification mode, redundant alternating current can be converted into direct current energy through the second converter, and the direct current energy is fed back to the storage battery through the DC-DC converter and the super capacitor;

when the electric automobile is on an urban level road or an expressway, the first converter connected with the outer stator winding of the hub motor works in an inversion mode, the outer stator is in an electric state, and accordingly power is provided for wheels.

6. A control method applied to the control system of the hub permanent magnet motor for the electric vehicle of claim 4, wherein when the hub permanent magnet motor is a dual-rotor and dual-stator hub permanent magnet motor, the method comprises the following steps:

when the road condition that the electric automobile needs to increase horsepower for operation is met, the first converter and the second converter work in an inversion mode, and direct current electric energy is converted into alternating current electric energy to supply power for an outer stator winding and an inner stator winding of the hub permanent magnet motor;

when the electric automobile is in a downhill road condition or a brake braking mode, the first converter is in an inversion mode, the outer stator is still in an electric state so as to maintain less electric energy required by the electric automobile, the inner stator works in a power generation state, the second converter is in a rectification mode and converts redundant alternating current electric energy into direct current electric energy, and then the direct current electric energy is fed back to the storage battery through the DC-DC converter and the super capacitor;

when the electric automobile is on an urban level road or an expressway, the first converter is in an inversion mode, the outer stator is still in an electric state, so that electric energy required by the electric automobile is maintained, the storage battery does not provide electric energy for the second converter any more, and the second converter and the inner stator winding do not work.

Technical Field

The invention relates to the technical field of hub motors and control thereof, in particular to a hub permanent magnet motor control system for an electric automobile and an energy conversion control strategy thereof.

Background

With the increasing requirements on energy conservation and environmental protection, the usage amount of new energy electric vehicles is increased year by year, the number of electric vehicles in China is increased to 2000 thousands in 2035 years, and the sales amount accounts for 50% of the total sales amount of the vehicles. For the wheel hub permanent magnet motor with a single rotor-single stator structure commonly applied to the existing electric automobile, when the wheel hub permanent magnet motor is in a road condition that the electric automobile needs to increase horsepower to operate, such as an ascending slope, silt and a concave ground, the motor works in an overload state, and negative problems of insufficient power of the whole automobile, heating of the motor and the like can occur. When the wheel hub permanent magnet motor is in a downhill or braking state, the recovery efficiency of the electric energy of the wheel hub permanent magnet motor in the single-rotor and single-stator structure is relatively low, and energy waste is caused.

Therefore, a method for enhancing energy utilization rate and effectively improving endurance capacity of the storage battery is needed.

Disclosure of Invention

The invention provides a wheel hub permanent magnet motor control system for an electric automobile and an energy conversion control strategy thereof, and aims to solve the problems in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme.

A control system of a hub permanent magnet motor for an electric automobile comprises the hub permanent magnet motor, two converters and a direct current power supply system;

the three-phase winding wire outlet ends of the outer stator and the inner stator of the hub permanent magnet motor are respectively connected with two converters, the two converters are three-phase voltage bridge type inverter circuits, and the two converters supply power through a direct current power supply system.

Preferably, the direct current power supply system is composed of a storage battery, a super capacitor and a DC-DC conversion controller.

Preferably, the hub permanent magnet motor is a single-rotor double-stator hub permanent magnet motor.

Preferably, the hub permanent magnet motor is a double-rotor double-stator hub permanent magnet motor, and a magnetic and electric isolating material is added between the outer rotor and the inner rotor, so that the magnetic circuits of the outer rotor and the inner rotor are independent from each other and have no magnetic coupling relationship.

Another aspect of the present invention also provides a control method applied to the control system of the hub permanent magnet motor for an electric vehicle according to claim 3, where the hub permanent magnet motor is a single-rotor double-stator hub permanent magnet motor, including the following steps:

when the road condition that the horsepower of the electric automobile needs to be increased for running is needed, the converters connected with the outer stator winding and the inner stator winding of the hub motor work in an inversion mode, and the outer stator and the inner stator are in an electric state;

when the electric automobile is in a downhill road condition or a brake braking mode, the first converter connected with the outer stator winding of the hub motor still works in an inversion mode, the second converter connected with the inner stator winding of the hub motor works in a rectification mode, redundant alternating current can be converted into direct current energy through the second converter, and the direct current energy is fed back to the storage battery through the DC-DC converter and the super capacitor;

when the electric automobile is on an urban level road or an expressway, the first converter connected with the outer stator winding of the hub motor works in an inversion mode, the outer stator is in an electric state, and accordingly power is provided for wheels.

Preferably, when the hub permanent magnet motor is a double-rotor and double-stator hub permanent magnet motor, the method comprises the following steps:

when the road condition that the electric automobile needs to increase horsepower for operation is met, the first converter and the second converter work in an inversion mode, and direct current electric energy is converted into alternating current electric energy to supply power for an outer stator winding and an inner stator winding of the hub permanent magnet motor;

when the electric automobile is in a downhill road condition or a brake braking mode, the first converter is in an inversion mode, the outer stator is still in an electric state so as to maintain less electric energy required by the electric automobile, the inner stator works in a power generation state, the second converter is in a rectification mode and converts redundant alternating current electric energy into direct current electric energy, and then the direct current electric energy is fed back to the storage battery through the DC-DC converter and the super capacitor;

when the electric automobile is on an urban level road or an expressway, the first converter is in an inversion mode, the outer stator is still in an electric state, so that electric energy required by the electric automobile is maintained, the storage battery does not provide electric energy for the second converter any more, and the second converter and the inner stator winding do not work.

According to the technical scheme provided by the wheel hub permanent magnet motor control system for the electric automobile and the energy conversion control strategy thereof, the system can enable the electric automobile to change the working modes of the wheel hub motor and the converter according to different road condition information, and realize the energy self-adaptive bidirectional flow between the storage battery and the wheel hub motor, so that the power density of the wheel hub permanent magnet motor for the electric automobile can be improved, the horsepower and the overall operation performance of the wheel hub permanent magnet motor are improved, the utilization rate of energy is enhanced, the cruising ability of the storage battery is effectively improved, and the technical problem that the driving mileage of the electric automobile is limited is solved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of a control method of a hub permanent magnet motor control system for an electric vehicle;

fig. 2 is a schematic structural diagram of a single-rotor-double-stator hub permanent magnet motor;

fig. 3 is a schematic structural diagram of a hub permanent magnet motor which is a dual-rotor and dual-stator hub permanent magnet motor;

description of reference numerals:

1, an outer stator 2, an outer stator winding 3, a rotor permanent magnet 4, a rotating shaft 5, an inner stator winding 6, an outer stator 8, an outer stator winding 9, an outer rotor permanent magnet 10, a rotating shaft 11, an inner stator winding 12, an inner stator winding 13, an inner rotor permanent magnet 14, a magnetic isolation and electric isolation material.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

For the convenience of understanding of the embodiments of the present invention, the following description will be further explained by taking several specific embodiments as examples with reference to the drawings, and the embodiments of the present invention are not limited thereto.

Examples

The embodiment provides a wheel hub permanent magnet motor control system for electric automobile, including wheel hub permanent magnet motor, two converters and direct current power supply system, the three-phase winding leading-out terminal of wheel hub permanent magnet motor's outer stator and inner stator links to each other with two converters respectively, and two converters are three-phase voltage bridge type inverter circuit, and two converters pass through the direct current power supply system power supply. The direct-current power supply system in the embodiment is composed of a storage battery, a super capacitor and a DC-DC converter. The two converters are respectively a converter 1 and a converter 2, and the converter 1 and the converter 2 can work in an inversion or rectification mode according to road condition information of the electric automobile and perform energy self-adaptive bidirectional transmission with a direct current power supply system.

The wheel hub permanent magnet motor control system can realize the self-adaptive conversion of energy between the storage battery and the motor according to road conditions and the load condition of the electric automobile. Specifically, the hub permanent magnet motor is a single-rotor-double-stator hub permanent magnet motor or a double-rotor-double-stator hub permanent magnet motor, and a magnetic and electric isolating material is added between the outer rotor and the inner rotor of the double-rotor-double-stator hub permanent magnet motor, so that a magnetic circuit of the outer rotor and a magnetic circuit of the inner rotor are mutually independent and have no magnetic coupling relation.

Fig. 1 shows a control method schematic diagram of a hub permanent magnet motor control system for an electric vehicle, and fig. 2 shows a structural schematic diagram of a hub permanent magnet motor which is a single-rotor and double-stator hub permanent magnet motor, when the hub permanent magnet motor is a single-rotor and double-stator hub permanent magnet motor, the method comprises the following steps:

when the electric automobile needs to be operated under a condition of increasing horsepower, such as an uphill slope, silt, a concave ground and the like, the direct current electric energy of the storage battery is converted into direct current electric energy suitable for the converter 1 and the converter 2 through the super capacitor and the DC-DC converter controller, the converters 1 and 2 connected with the outer stator winding and the inner stator winding of the hub motor work in an inversion mode, namely the storage battery transmits energy to the converter and the double stators through the super capacitor and the DC-DC converter, and the direct current electric energy is converted into alternating current electric energy to supply power to the outer stator winding and the inner stator winding of the hub permanent magnet motor. The outer stator and the inner stator are both in an electric state, a magnetic field generated by the winding current of the outer stator and the winding current of the inner stator is mutually coupled with a magnetic field generated by the permanent magnet of the rotor to form a main magnetic circuit, and the hub motor only has one air gap magnetic field. The rotor is connected with the wheels through a speed change gear box to provide horsepower for the electric automobile. At the moment, the outer stator and the inner stator are both in an electric state, so that the output torque of the hub motor is increased, double torque is provided for wheels, and the power of the electric automobile is increased.

When the electric automobile is in a downhill road condition or a brake braking mode, the direct current electric energy of the storage battery still supplies power for the converter 1, and the converter 1 connected with the outer stator winding of the hub motor still works in an inversion mode, so that less electric energy required by the electric automobile is maintained. The inner stator works in a power generation state, the converter 2 connected with the inner stator winding of the hub motor works in a rectification mode, redundant alternating current energy is converted into direct current energy through the converter 2 and is fed back to the storage battery through the DC-DC converter and the super capacitor, so that the energy waste is reduced, at the moment, the outer stator is in an electric state, the inner stator is in a power generation state, and a magnetic field generated by the current of the outer stator winding and a magnetic field generated by the current of the inner stator winding still form a main magnetic circuit with a magnetic field generated by the permanent magnet of the rotor.

When the electric automobile is on an urban level road or an expressway, the direct current electric energy of the storage battery still supplies power for the converter 1, the converter 1 connected with the outer stator winding of the hub motor works in an inversion mode, the outer stator is in an electric state, power is provided for wheels, at the moment, the converter 2, the DC-DC converter, the super capacitor and the storage battery are disconnected, and the converter 2 and the inner stator do not participate in energy conversion. The magnetic field generated by the current of the outer stator winding and the magnetic field generated by the permanent magnet of the rotor form an air gap magnetic field, which is equivalent to the working mode of the hub motor in the traditional single-rotor-single-stator structural form.

Fig. 3 is a schematic structural diagram of a hub permanent magnet motor which is a dual-rotor and dual-stator hub permanent magnet motor, and when the hub permanent magnet motor is a dual-rotor and dual-stator hub permanent magnet motor, the method comprises the following steps:

when the electric automobile is in the road conditions such as uphill, silt and concave requiring the electric automobile to increase the horsepower, downhill road conditions or a brake braking mode, and the urban level road or the expressway, the working modes of the outer stator and the inner stator are the same as those of the converter 1 and the converter 2.

When the electric automobile is required to be in a road condition of increasing horsepower operation, the electric automobile goes up a slope, is filled with silt, is in a concave place and the like, direct current electric energy of the storage battery is converted into direct current electric energy suitable for the converter 1 and the converter 2 through the super capacitor and the DC-DC conversion controller, the converter 1 and the converter 2 work in an inversion mode, and the direct current electric energy is converted into alternating current electric energy to supply power for an outer stator winding and an inner stator winding of the hub permanent magnet motor. An outer stator magnetic field formed by the outer stator winding current and an outer rotor permanent magnet magnetic field are coupled to form an air gap magnetic field, and an inner stator magnetic field formed by the inner stator winding current and an inner rotor permanent magnet magnetic field are coupled to form an air gap magnetic field. Because the magnetic and electric isolating material is added between the outer rotor permanent magnet and the inner rotor permanent magnet, schematically, the magnetic and electric isolating material in the embodiment is a copper ring coated with insulating paint on the outer part, two air gap magnetic fields are independent from each other, and have no coupling relation, which is equivalent to that two hub motors with the traditional single rotor-single stator structure provide horsepower for wheels together, and the power of the electric automobile is enhanced.

When the electric automobile is in a downhill road condition or a brake braking mode, the direct current electric energy of the storage battery still supplies power for the converter 1, the converter 1 is in an inversion mode, and the outer stator is still in an electric state, so that less electric energy required by the electric automobile is maintained. An outer stator magnetic field formed by the outer stator winding current and an outer rotor permanent magnet magnetic field are coupled to form an air gap magnetic field, which is equivalent to a motor working in a light load mode. The inner stator works in a power generation state, the converter 2 is in a rectification mode, redundant alternating current energy is converted into direct current energy, and the direct current energy is fed back to the storage battery through the DC-DC converter and the super capacitor. An inner stator magnetic field formed by the inner stator winding current and an inner rotor permanent magnet magnetic field are coupled to form an air gap magnetic field, which is equivalent to a generator.

When the electric automobile is on an urban level road or an expressway, the direct current electric energy of the storage battery still supplies power for the converter 1, the converter 1 is in an inversion mode, the outer stator is still in an electric state so as to maintain the electric energy required by the electric automobile, the storage battery does not provide electric energy for the converter 2 any more, and the converter 2 and the inner stator winding do not work. The inner rotor and the inner stator do not participate in energy conversion, and are the same as the wheel hub permanent magnet motor with a single-rotor-double-stator structure, and at the moment, an outer stator magnetic field formed by the winding current of the outer stator and a rotor permanent magnet magnetic field are coupled to form an air gap magnetic field, which is equivalent to a traditional wheel hub motor with a single-rotor-single-stator structure.

In conclusion, the power density of the wheel hub permanent magnet motor and the running performance of the motor are improved, the energy recovery rate is enhanced, the cruising ability of the storage battery and the driving mileage of the electric automobile are effectively improved, electric energy is saved, and remarkable economic benefits can be brought.

It will be appreciated by those skilled in the art that the foregoing types of applications are merely exemplary, and that other types of applications, whether presently existing or later to be developed, that may be suitable for use with the embodiments of the present invention, are also intended to be encompassed within the scope of the present invention and are hereby incorporated by reference.

In practical applications, the signal processing device may be disposed at another position inside the electronic transformer. The embodiment of the present invention is not limited to the specific placement position of the signal processing device, and any placement manner of the signal processing device in the interior of the electronic transformer is within the protection scope of the embodiment of the present invention.

It will be appreciated by those skilled in the art that the various network elements shown in fig. 1 for simplicity only may be fewer in number than in an actual network, but such omissions are clearly not to be considered as a prerequisite for a clear and complete disclosure of the inventive embodiments.

From the above description of the embodiments, it is clear to those skilled in the art that the present invention can be implemented by software plus necessary general hardware platform. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which may be stored in a storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the embodiments or some parts of the embodiments.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.