阅读说明：本技术 一种车载动力电池大功率直流电能计量方法及系统 (Vehicle-mounted power battery high-power direct-current electric energy metering method and system ) 是由 张世帅 柳宇航 楚中建 杨磊 王明才 臧其威 谷岭 汪会财 刘型志 胡可 黄会 于 2020-06-19 设计创作，主要内容包括：本发明实施例公开了一种车载动力电池大功率直流电能计量方法及系统,包括对动力电池自放电预实验,建立自放电电量W与电动汽车环境参数之间的多元关系模型；将动力电池的负荷按照功能关联分为若干个相互并联的耦合模块,利用电能计量单元实时计算每个所述耦合模块的直线电流；实时监控动力电池单次充电后的初始总电量C,并且计算动力电池在使用过程中的每个所述耦合模块的耗能总量；根据所述多元关系模型得到的自放电电量W,以及所有耦合模块的消耗电总量Q,计算动力电池单次充电后的电能剩余量q；本方案可实时确定动力电池的实时动态变化的自放电电量,计算动力电池在单次充电后的自放电总量,提高统计动力电池的电池剩余容量的准确性。(The embodiment of the invention discloses a method and a system for metering high-power direct-current electric energy of a vehicle-mounted power battery, which comprises the steps of carrying out a self-discharge pre-experiment on the power battery, and establishing a multivariate relation model between self-discharge electric quantity W and environmental parameters of an electric vehicle; dividing the load of a power battery into a plurality of coupling modules which are connected in parallel according to functional association, and calculating the linear current of each coupling module in real time by using an electric energy metering unit; monitoring initial total electric quantity C of the power battery after single charging in real time, and calculating the total energy consumption of each coupling module in the using process of the power battery; calculating the residual quantity Q of the electric energy of the power battery after single charging according to the self-discharge electric quantity W obtained by the multivariate relation model and the total quantity Q of the consumed electricity of all the coupling modules; the scheme can determine the self-discharge electric quantity of the power battery which dynamically changes in real time, calculate the total self-discharge quantity of the power battery after single charging, and improve the accuracy of counting the battery residual capacity of the power battery.)

1. A method for metering high-power direct-current electric energy of a vehicle-mounted power battery is characterized by comprising the following steps:

step 100, performing a self-discharge pre-experiment on the power battery, and establishing a multivariate relation model between self-discharge electric quantity W and environmental parameters of the electric vehicle;

200, dividing the load of the power battery into a plurality of coupling modules which are connected in parallel according to functional association, and calculating the linear current of each coupling module in real time by using an electric energy metering unit;

step 300, monitoring the initial total electric quantity C of the power battery after single charging in real time, and calculating the total energy consumption of each coupling module in the using process of the power battery;

and step 400, calculating the residual electric energy Q after the power battery is charged once according to the self-discharge electric quantity W obtained by the multivariate relation model and the total electric quantity Q consumed by all the coupling modules.

2. The method for measuring the high-power direct-current electric energy of the vehicle-mounted power battery according to claim 1, wherein in step 100, the environmental parameters of the electric vehicle mainly include a battery temperature, a battery dead time and a battery usage duration, the self-discharge electric quantity W is in a negative correlation with the battery temperature, and the self-discharge electric quantity W is in a positive correlation with the battery dead time and the battery usage duration.

3. The method for measuring the high-power direct-current electric energy of the vehicle-mounted power battery according to claim 2, wherein after the multivariate relation model between the self-discharge electric quantity W and the environmental parameters of the electric vehicle is established in step 100, the temperature of the battery is monitored in real time by using a temperature sensor, and the total service life of the battery and the load no-load life of the battery after single charging are respectively calculated by using two timers.

The multivariate relation model is used for starting to finish the next charging after the charging of the power battery of the electric automobile is finished, a timer used for counting the total service life of the power battery is always monitored, the power battery returns to zero once every time the power battery is replaced, the timer used for counting the load no-load time of the power battery after single charging is set to zero once and is used for timing again, and the functional relation among the battery temperature, the battery no-load time and the battery service life and the power battery self-discharge amount is determined through a self-discharge pre-experiment of the power battery.

4. The method for measuring the electric quantity of the power battery on board the electric automobile as claimed in claim 3, wherein in step 200, the load of the power battery is divided into a plurality of coupling modules which are connected in parallel, the load related to the function is divided into the same coupling module, and the electric energy metering unit comprises a current monitor for detecting the current of each coupling module and a voltage monitor for monitoring the actual voltage value of the power battery.

5. The method as claimed in claim 4, wherein the current monitor and the voltage monitor are connected with the control processing unit, the control processing unit correspondingly receives the current value of each coupling module and the actual voltage value of the power battery, the control processing unit establishes a power consumption metering model according to the power consumption of each coupling module, and the control processing unit superposes the real-time integration result of the current total amount of each power consumption metering model to obtain the total power consumption Q of the whole power battery load, the power consumption metering model establishes a two-dimensional coordinate system of the power consumption of each coupling module-the power consumption time, and the power consumption metering model calculates the power consumption of each coupling module in real time.

6. The method for measuring the electric quantity of the power battery on board the electric automobile according to claim 4, wherein the formula for calculating the total quantity Q of the consumed electricity of all the coupling modules according to the electricity consumption metering model is as follows:

wherein f (x1) is a real-time power function of the first coupling module in a time period from t1 to t2, f (x2) is a real-time power function of the second coupling module in a time period from t1 to t2, f (x3) is a real-time power function of the third coupling module in a time period from t1 to t2, and f (xn) is a real-time power function of the nth coupling module in a time period from t1 to t 2.

7. The method for measuring the high-power direct-current electric energy of the vehicle-mounted power battery according to claim 6, wherein the real-time electric energy function is a variation curve of consumed electric power, wherein f (xn) is In · U, In is a real-time current of an nth coupling module, U is an actual voltage value of the power battery, and n is greater than or equal to 1.

8. The method for measuring the high-power direct-current electric energy of the vehicle-mounted power battery according to claim 6, wherein in step 400, the calculation formula of the residual electric energy Q after the power battery is charged once is Q-C-W-Q, and the formula for calculating the endurance time T of the power battery at the current moment is:

T＝q/(I1’+I2’+I3’+……+In’)U；

wherein I1 'is the average current of the first coupling module in the time period t 1-t 2, I2' is the average current of the second coupling module in the time period t 1-t 2, I3 'is the average current of the third coupling module in the time period t 1-t 2, I4' is the average current of the fourth coupling module in the time period t 1-t 2, and U is the actual voltage value of the power battery in the time period t 1-t 2.

9. An on-board power battery high-power direct-current electric energy metering system according to the method of any one of claims 1 to 8, characterized by comprising:

the self-discharge amount calculation model (1) is used for calculating the self-discharge amount of the power battery in a no-load period after single charging;

the load division coupling module (2) is used for dividing the load of the power battery into a plurality of coupling modules which are connected in parallel according to the functional association;

the electric energy metering unit (3) is arranged in each coupling module and used for detecting the conduction current in each coupling module;

the charging monitoring module (4) is used for monitoring the charging current of the power battery charger and calculating the initial total electric energy of the power battery in the charging time period;

and the power consumption metering model (5) is used for calculating the power consumption real-time integral result of each coupling module.

10. The vehicle-mounted power battery high-power direct current electric energy metering system of claim 9, characterized in that: the power battery charging system is characterized by further comprising a control processing unit (6), wherein the control processing unit (6) is used for overall planning the initial electric quantity of the power battery and the consumed electric quantity of each coupling module and calculating the electric energy surplus of the power battery after being charged once in real time.

Technical Field

The embodiment of the invention relates to the technical field of battery electric energy calculation, in particular to a method and a system for measuring high-power direct-current electric energy of a vehicle-mounted power battery.

Background

With the increasing awareness of environmental protection, electric vehicles are becoming increasingly popular as vehicles. The electric vehicle (BEV) is a vehicle which uses a vehicle-mounted power supply as power and uses a motor to drive wheels to run and meets various requirements of road traffic and safety regulations. Because the influence on the environment is smaller than that of the traditional automobile, the prospect is widely seen.

At present, most of methods for calculating the high-power direct current electric energy of the vehicle-mounted power battery of the electric automobile are described in patent application No. 2016110782184, a current sampling module is directly utilized to sample the charging and discharging current of the power battery, a voltage sampling module is utilized to sample the charging and discharging voltage of the power battery, and the electric energy surplus of the battery is calculated through an electric energy conversion module; the processor module reads data of the input sampling current and voltage and converts the data into an electric quantity signal, and the electric quantity signal is displayed on an interface of the main control device in a curve image.

That is to say, the loss of the battery self-discharge electric quantity is not considered in the prior art, so the accuracy of calculating and counting the remaining quantity of the battery is low, and meanwhile, the mode of directly performing current sampling and voltage sampling on the power battery to calculate the electric energy remaining quantity of the battery is complex and the statistical mode is tedious.

Disclosure of Invention

Therefore, the embodiment of the invention provides a vehicle-mounted power battery high-power direct current electric energy metering method and a vehicle-mounted power battery high-power direct current electric energy metering system, a multi-element relation model among battery temperature, total battery use time, load no-load time of a battery after single charging and self-discharge amount of a power battery is established, real-time dynamically-changed self-discharge electric quantity of the power battery can be determined in real time, the self-discharge total amount of the power battery after single charging is calculated, and accuracy of counting battery residual capacity of the power battery is improved, so that the problem that in the prior art, loss of the battery self-discharge electric quantity is not considered, and therefore accuracy of counting residual quantity of the battery is low is solved.

In order to achieve the above object, an embodiment of the present invention provides the following: a method for metering high-power direct-current electric energy of a vehicle-mounted power battery comprises the following steps:

a method for metering high-power direct-current electric energy of a vehicle-mounted power battery comprises the following steps:

step 100, performing a self-discharge pre-experiment on the power battery, and establishing a multivariate relation model between self-discharge electric quantity W and environmental parameters of the electric vehicle;

200, dividing the load of the power battery into a plurality of coupling modules which are connected in parallel according to functional association, and calculating the linear current of each coupling module in real time by using an electric energy metering unit;

step 300, monitoring the initial total electric quantity C of the power battery after single charging in real time, and calculating the total energy consumption of each coupling module in the using process of the power battery;

and step 400, calculating the residual electric energy Q after the power battery is charged once according to the self-discharge electric quantity W obtained by the multivariate relation model and the total electric quantity Q consumed by all the coupling modules.

As a preferred aspect of the present invention, in step 100, the environmental parameters of the electric vehicle mainly include a battery temperature, a battery dead time, and a battery usage duration, the self-discharge electric quantity W is in a negative correlation with the battery temperature, and the self-discharge electric quantity W is in a positive correlation with the battery dead time and the battery usage duration.

As a preferred aspect of the present invention, in step 200, the load of the power battery is divided into a plurality of coupling modules connected in parallel, the load related to the function is divided into the same coupling module, and the electric energy metering unit includes a current monitor for detecting the current of each coupling module, and a voltage monitor for monitoring the actual voltage value of the power battery.

As a preferred scheme of the present invention, after a multivariate relation model between the self-discharge electric quantity W and the environmental parameters of the electric vehicle is established in step 100, the temperature of the battery is monitored in real time by using a temperature sensor, and the total usage duration of the battery and the load no-load duration of the battery after a single charge are respectively calculated by using two timers.

The multivariate relation model is used for starting to finish the next charging after the charging of the power battery of the electric automobile is finished, a timer used for counting the total service life of the power battery is always monitored, the power battery returns to zero once every time the power battery is replaced, the timer used for counting the load no-load time of the power battery after single charging is set to zero once and is used for timing again, and the functional relation among the battery temperature, the battery no-load time and the battery service life and the power battery self-discharge amount is determined through a self-discharge pre-experiment of the power battery.

As a preferred aspect of the present invention, in step 200, the load of the power battery is divided into a plurality of coupling modules connected in parallel, the load related to the function is divided into the same coupling module, and the electric energy metering unit includes a current monitor for detecting the current of each coupling module, and a voltage monitor for monitoring the actual voltage value of the power battery.

As a preferable scheme of the present invention, the current monitor and the voltage monitor are commonly connected to the control processing unit, the control processing unit correspondingly receives a current value of each coupling module and an actual voltage value of the power battery, the control processing unit establishes a power consumption metering model according to an electric quantity consumption of each coupling module, the control processing unit superposes a real-time integration result of a total current quantity of each power consumption metering model to obtain a total consumed electricity quantity Q of the whole power battery load, the power consumption metering model establishes a two-dimensional coordinate system of consumed power-consumed time of each coupling module, and the power consumption metering model calculates the consumed electric quantity of each coupling module in real time.

As a preferred embodiment of the present invention, the formula for calculating the total amount Q of consumed electricity of all the coupling modules according to the electricity consumption metering model is as follows:

wherein f (x1) is a real-time power function of the first coupling module in a time period from t1 to t2, f (x2) is a real-time power function of the second coupling module in a time period from t1 to t2, f (x3) is a real-time power function of the third coupling module in a time period from t1 to t2, and f (xn) is a real-time power function of the nth coupling module in a time period from t1 to t 2.

As a preferred embodiment of the present invention, the real-time electric energy function is specifically a variation curve of power consumption, where f (xn) is In · U, In is a real-time current of the nth coupling module, U is an actual voltage value of the power battery, and n is greater than or equal to 1.

In step 400, a calculation formula of the remaining electric energy Q after the power battery is charged once is C-W-Q, and a calculation formula of the endurance time T of the power battery at the current time is:

T＝q/(I1’+I2’+I3’+……+In’)U；

wherein I1 'is the average current of the first coupling module in the time period t 1-t 2, I2' is the average current of the second coupling module in the time period t 1-t 2, I3 'is the average current of the third coupling module in the time period t 1-t 2, I4' is the average current of the fourth coupling module in the time period t 1-t 2, and U is the actual voltage value of the power battery in the time period t 1-t 2.

In addition, the invention also provides a vehicle-mounted power battery high-power direct current electric energy metering system, which is characterized by comprising the following components:

the self-discharge amount calculation model is used for calculating the self-discharge amount of the power battery in the no-load period after single charging;

the load division coupling module is used for dividing the load of the power battery into a plurality of coupling modules which are connected in parallel according to functional association;

the electric energy metering unit is arranged in each coupling module and used for detecting the conduction current in each coupling module;

the charging monitoring module is used for monitoring the charging current of the power battery charger and calculating the initial total electric energy of the power battery in the charging time period;

and the power consumption metering model is used for calculating the power consumption real-time integral result of each coupling module.

As a preferable scheme of the invention, the system further comprises a control processing unit, and the control processing unit is used for comprehensively planning the initial electric quantity of the power battery and the consumed electric quantity of each coupling module, and calculating the electric energy residual quantity of the power battery after single charging in real time.

The embodiment of the invention has the following advantages:

(1) the method establishes a multivariate relation model among the battery temperature, the total service life of the battery, the load no-load time of the battery after single charging and the self-discharge capacity of the power battery, can determine the self-discharge electric quantity of the power battery which dynamically changes in real time after three related parameters are obtained through a detector, calculates the self-discharge total quantity of the power battery after single charging, and improves the accuracy of counting the residual capacity of the power battery;

(2) according to the invention, the battery load is divided into a plurality of coupling modules according to functional integration, and the current of each coupling module is linearly changed, so that the integral relation of the power consumption of each coupling module calculated by the power consumption metering model is simple, the power consumption metering models of each coupling module are superposed to obtain the total power consumption of all the coupling modules, the calculation operation is simple, and the metering precision is high.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.

FIG. 1 is a schematic flow chart of a method for measuring electric energy according to an embodiment of the present invention;

fig. 2 is a block diagram of an electric energy metering system according to an embodiment of the present invention.

In the figure:

1-self-discharge capacity calculation model; 2-load division coupling module; 3-an electric energy metering unit; 4-a charge monitoring module; 5-a power consumption metering model; 6-control the processing unit.

Detailed Description

The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, the present invention provides a method for measuring high-power dc power of a vehicle-mounted power battery, the battery power consumption function modules of an electric vehicle are various, and the present embodiment divides the power battery load that meets the same function association relationship into a plurality of coupling modules, that is, the loads in each coupling module are connected in series, but two different coupling modules are connected in parallel.

Therefore, the residual electric quantity of the electric automobile can be calculated by superposing and counting the power consumption capacity of each coupling module and the self-discharge electric quantity of the battery of the electric automobile, and the endurance time of the electric automobile under the current residual electric quantity is calculated according to the average current of the plurality of functional modules.

The method specifically comprises the following steps:

step 100, performing a self-discharge pre-experiment on the power battery, and establishing a multivariate relation model between self-discharge electric quantity W and environmental parameters of the electric vehicle.

Batteries for electric vehicles fall into two broad categories including batteries and fuel cells. The storage battery is suitable for pure electric vehicles and comprises a lead-acid storage battery, a nickel-metal hydride battery, a sodium-sulfur battery, a secondary lithium battery, an air battery and a ternary lithium battery, wherein the fuel battery is specially used for fuel cell electric vehicles and comprises an Alkaline Fuel Cell (AFC), a Phosphoric Acid Fuel Cell (PAFC), a Molten Carbonate Fuel Cell (MCFC), a Solid Oxide Fuel Cell (SOFC), a Proton Exchange Membrane Fuel Cell (PEMFC) and a Direct Methanol Fuel Cell (DMFC).

After the battery is stored for a certain time in a dry mode (without electrolyte) or in a wet mode (with electrolyte), the capacity of the battery is automatically reduced, and the phenomenon is called self-discharge. The term "storage property" refers to the magnitude of self-discharge after a battery is stored under a certain condition (e.g., temperature and humidity) for a certain period of time when the battery is open.

During the storage period of the battery, although no electric energy is discharged, a self-discharge phenomenon always exists in the battery. Even in dry storage, the electrolyte enters substances such as moisture, air, carbon dioxide and the like due to poor sealing, so that part of active substances of the anode and the cathode in a thermodynamically unstable state form a microcell corrosion mechanism, and oxidation-reduction reaction occurs automatically and is consumed uselessly.

As is known, batteries have a certain service life, the longer the service life is, the closer the service life is, the more obvious the self-discharge condition inside the battery is, and the self-discharge condition is related to the service temperature and the idle time, when the service temperature is outside the standard temperature (generally-10 ℃ -50 ℃), the more serious self-discharge condition of the battery exists, and the condition of the battery is also related to the idle time, so the embodiment constructs the relationship between the self-discharge amount of the power battery and the environmental parameters of the battery by performing a pre-test on the vehicle-mounted power battery of the electric vehicle.

The environmental parameters of the electric automobile mainly comprise battery temperature, battery dead time and battery service life, the power battery has no self-discharge condition when working under load, the self-discharge electric quantity W and the battery temperature are in a negative correlation relationship, and the self-discharge electric quantity W and the battery dead time and the battery service life are in a positive correlation relationship.

Step 100, after a multivariate relation model between self-discharge electric quantity W and environmental parameters of the electric automobile is established, a temperature sensor is used for monitoring the temperature of the battery in real time, and two timers are used for calculating the total service life of the battery and the load no-load time of the battery after single charging respectively.

The model for calculating the self-discharge electric quantity W in the embodiment is from the completion of charging of the power battery of the electric vehicle to the completion of the next charging, wherein the timer for counting the total service life of the battery is always monitored, and the timer for counting the total service life of the power battery is in a long-term working state every time the power battery is replaced and returns to zero. And the timer for counting the load no-load time length of the power battery after single charging is set to zero every time for re-timing, and corresponding three parameter counting methods are different according to different environmental parameters, such as battery temperature, battery no-load time and battery use time length.

Therefore, the self-discharge electric quantity W of the power battery, which dynamically changes in real time, can be determined in real time after the three data, namely the battery temperature, the total service life of the battery and the load no-load life of the battery after single charging, are substituted into the multivariate relational model.

Step 200, dividing the load of the power battery into a plurality of coupling modules which are connected in parallel according to functional association, and calculating the direct current of each coupling module in real time by using an electric energy metering unit.

In step 200, dividing the load of the power battery into a plurality of coupling modules which are connected in parallel with each other, dividing the load related to functions into the same coupling module, wherein the electric energy metering unit comprises a current monitor for detecting the current of each coupling module and a voltage monitor for monitoring the actual voltage value of the power battery.

Because a plurality of the coupling modules are connected in parallel, the shunt current of each coupling module is different, the power consumption electric quantity of each coupling module is different, and the total output current of the power battery is the total superposed current of all the coupling modules.

The current monitor and the voltage monitor are connected with the control processing unit together, the control processing unit correspondingly receives the current value of each coupling module and the actual voltage value of the power battery, the control processing unit establishes a power consumption metering model according to the electric quantity consumption of each coupling module, and the control processing unit superposes the real-time integral result of the total current quantity of each power consumption metering model to obtain the total consumed electricity quantity Q of the whole power battery load.

The power consumption metering model establishes a two-dimensional coordinate system of power consumption electric energy-power consumption time of each coupling module, the power consumption metering model calculates the power consumption of each coupling module in real time, and a formula for calculating the total power consumption Q of all the coupling modules according to the power consumption metering model is as follows:

wherein f (x1) is a real-time power function of the first coupling module in a time period from t1 to t2, f (x2) is a real-time power function of the second coupling module in a time period from t1 to t2, f (x3) is a real-time power function of the third coupling module in a time period from t1 to t2, and f (xn) is a real-time power function of the nth coupling module in a time period from t1 to t 2.

The real-time electric energy function is specifically a change curve of power consumption, wherein f (xn) is In · U, In is the real-time current of the nth coupling module, U is the actual voltage value of the power battery, and n is greater than or equal to 1.

In the embodiment, the current sampling module is not directly used for sampling the charging and discharging current of the power battery, the voltage sampling module is not used for sampling the charging and discharging voltage of the power battery, the electric energy surplus of the battery is calculated through the electric energy conversion module, but the partial currents of the plurality of parallel coupling modules are detected at the load end, and the total output current of the power battery is calculated mainly because of the following two reasons:

1. in all the coupling modules into which the load of the power battery of the electric vehicle is divided, a coupling module with constant direct current exists, and the change curve of the conduction current of all the coupling modules is a linear curve, so that the operation of calculating the consumed electric quantity (in ampere hour or milliampere hour) by utilizing the current integration of each coupling module by using the power consumption metering model of the embodiment is simple, and the accuracy is high.

2. On the contrary, in all the coupling modules into which the load of the power battery of the electric vehicle is divided, no matter which coupling module changes the current during the driving process, the output current of the power battery collected by the current sampling module installed on the power battery changes instantly, so the current curve output by the current sampling module does not change in an uncertain way and is irregular and recyclable, at this time, the operation of calculating the consumed electric quantity (in ampere-hour or milliampere-hour) by using the current integral of each coupling module by using the power consumption metering model is complex, and the accuracy of calculating the consumed electric quantity is low.

Therefore, in summary, in the embodiment, the battery load is divided into the plurality of coupling modules according to the functional integration, the load having the functional association relationship is divided into the same coupling module, the plurality of coupling modules are connected in parallel, the voltages of the plurality of coupling modules are the same, and the power of each coupling module is a linear function, so that when the power consumption metering model calculates the power consumption of each coupling module, the integration relationship is simple, the calculation procedure of the power consumption metering model is simple, the power consumption metering models of each coupling module are overlapped to obtain the total power consumption of all the coupling modules, the calculation operation is simple, and the metering accuracy is high.

And 300, monitoring the initial total electric quantity C of the power battery after single charging in real time, and calculating the total energy consumption of each coupling module of the power battery in the use time period, wherein the data of the initial total electric quantity C of the power battery is equal to the product of the charging current and the charging time of a charger of the power battery.

And step 400, calculating the residual electric energy Q after the power battery is charged once according to the self-discharge electric quantity obtained by the multivariate relation model and the real-time total electric quantity Q consumed by the load of the power battery.

The calculation formula of the residual electric energy Q after the power battery is charged once is C-W-Q, and the formula for calculating the endurance time T of the power battery at the current moment is as follows:

T＝q/(I1’+I2’+I3’+……+In’)U；

wherein I1 'is the average current of the first coupling module in the time period t 1-t 2, I2' is the average current of the second coupling module in the time period t 1-t 2, I3 'is the average current of the third coupling module in the time period t 1-t 2, I4' is the average current of the fourth coupling module in the time period t 1-t 2, and U is the actual voltage value of the power battery in the time period t 1-t 2.

In addition, as shown in fig. 2, the invention also provides a method for calculating the high-power direct-current electric energy of the vehicle-mounted power battery of the electric vehicle, which comprises the following steps:

the self-discharge capacity calculation model 1 is used for calculating the self-discharge capacity of the power battery in the no-load period after single charging;

the load division coupling module 2 is used for dividing the load of the power battery into a plurality of coupling modules which are connected in parallel according to functional association;

the electric energy metering unit 3 is arranged in each coupling module and used for detecting the conduction current in each coupling module;

the charging monitoring module 4 is used for monitoring the charging current of the power battery charger and calculating the initial total electric energy of the power battery in the charging time period;

and the power consumption metering model 5 is used for calculating the power consumption real-time integral result of each coupling module.

And the control processing unit 6 is used for comprehensively planning the initial electric quantity and each electric quantity consumed by the coupling module of the power battery and calculating the electric energy residual quantity after the power battery is charged once in real time.

In addition, according to the average current and the residual capacity (electric quantity) of the battery, the method can predict the endurance time of the battery of the electric automobile in the current power consumption mode, and plays a role in early warning and timely charging the electric automobile, so that the emergency power shortage situation is avoided.

Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.