CN117944516A

CN117944516A - Power switching method and device of power battery, readable storage medium and vehicle

Info

Publication number: CN117944516A
Application number: CN202410217043.9A
Authority: CN
Inventors: 杨钫; 刘建康; 王燕; 霍云龙; 牛超凡; 刘力源; 车显达
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2024-02-27
Filing date: 2024-02-27
Publication date: 2024-04-30

Abstract

The invention discloses a power switching method and device of a power battery, a readable storage medium and a vehicle. Wherein the method comprises the following steps: controlling a power battery of the vehicle to discharge according to a first discharge power in response to the vehicle being in a driving state, wherein the first discharge power is used for indicating the maximum discharge power of the power battery; acquiring the required discharge power of the vehicle in the process that the power battery discharges according to the first discharge power; responding to the fact that the required discharge power is larger than the second discharge power, and obtaining the duration time that the required discharge power is larger than the second discharge power, wherein the second discharge power is used for indicating the minimum discharge power of the power battery; determining a target discharge power of the power battery based on the duration and the operating state of the power battery; the discharge power of the power battery is switched from the first discharge power to the target discharge power. The invention solves the technical problem that the discharge power of the power battery can not be accurately adjusted.

Description

Power switching method and device of power battery, readable storage medium and vehicle

Technical Field

The present invention relates to the field of power battery technologies, and in particular, to a power switching method and apparatus for a power battery, a readable storage medium, and a vehicle.

Background

At present, with the continuous progress of battery technology, the endurance mileage and performance of a power battery of a vehicle are remarkably improved, and the performance and efficiency of the vehicle can be improved by adjusting the discharge power of the power battery. Therefore, accurate adjustment of the discharge power of the power battery of the vehicle is helpful to help the vehicle achieve better performance and endurance mileage, promote user experience, and promote development of new energy automobiles.

In the related art, the charge and discharge power of the power battery of the vehicle is adjusted through a single power chart, and the power chart may not match the current use condition of the power battery as the discharge time increases, in this case, if the charge and discharge power of the power battery is continuously adjusted through the single power chart, the problem that the battery discharge power is too high and frequently triggers an under-voltage fault may occur, so that the battery performance is damaged due to over-discharge, or the discharge power of the battery is too low, the use effect of the vehicle is affected, and the technical problem that the discharge power of the power battery cannot be accurately adjusted exists.

Aiming at the technical problem that the discharge power of the power battery cannot be accurately regulated, no effective solution is proposed at present.

Disclosure of Invention

The embodiment of the invention provides a power switching method and device of a power battery, a readable storage medium and a vehicle, which are used for at least solving the technical problem that the discharge power of the power battery cannot be accurately adjusted.

According to an aspect of an embodiment of the present invention, there is provided a power switching method of a power battery. The method may include: controlling a power battery of the vehicle to discharge according to a first discharge power in response to the vehicle being in a driving state, wherein the first discharge power is used for indicating the maximum discharge power of the power battery; acquiring required discharge power of the vehicle in the process that the power battery is discharged according to the first discharge power, wherein the required discharge power is used for indicating the discharge power of the power battery required by the vehicle in a running state; responding to the fact that the required discharge power is larger than the second discharge power, and obtaining the duration time that the required discharge power is larger than the second discharge power, wherein the second discharge power is used for indicating the minimum discharge power of the power battery; determining a target discharge power of the power battery based on the duration and the operating state of the power battery; the discharge power of the power battery is switched from the first discharge power to the target discharge power.

Optionally, determining the target discharge power of the power battery based on the duration and the operating state of the power battery includes: determining a target discharge power map corresponding to the power battery based on the duration and the working state of the power battery, wherein the target discharge power map is at least used for indicating a mapping relation between the discharge power of the power battery and the state of charge of the power battery and a mapping relation between the discharge power of the power battery and the battery temperature of the power battery; the target discharge power is determined in a target discharge power map based on a state of charge of the power battery and a battery temperature of the power battery.

Optionally, the working states of the power battery at least include a discharging state and a charging state, and determining the target discharging power map corresponding to the power battery based on the duration and the working states of the power battery includes: in response to the power battery being in a discharge state, wherein the duration is not longer than the first duration, determining a target discharge power map corresponding to the power battery as a first discharge power map; responding to the fact that the power battery is in a discharging state, wherein the duration time is longer than the first duration time and shorter than the second duration time, and determining a target discharging power map corresponding to the power battery as a second discharging power map; and in response to the power battery being in a discharge state and the duration being longer than the second duration, determining that the target discharge power of the power battery is the third discharge power map.

Optionally, when the state of charge of the power battery and the battery temperature are unchanged, a first discharge duration of the power battery for discharging according to the discharge power in the first discharge power map is smaller than a second discharge duration of the power battery for discharging according to the discharge power in the second discharge power map, and the second discharge duration is smaller than a third discharge duration of the power battery for discharging according to the discharge power in the third discharge power map.

Optionally, in response to the power cell discharging according to the discharge power in the third discharge power map, or in response to the power cell discharging according to the discharge power in the second discharge power map, the method further comprises: determining a target discharge power map of the power battery as a first discharge power map in response to the required discharge power of the vehicle being less than the second discharge power and the duration of the required discharge power of the vehicle being less than the second discharge power exceeding a duration threshold, or in response to the power battery being in a charged state; and controlling the power battery to discharge based on the first discharging power map.

Optionally, determining the target discharge power map corresponding to the power battery based on the duration and the working state of the power battery includes: in response to the working state of the power battery being a charging state, and the duration being not greater than the first duration, determining a target discharge power map corresponding to the power battery as a first discharge power map; and responding to the working state of the power battery to be a charging state, wherein the duration time is longer than the first time and shorter than the second time, and determining the target discharging power map corresponding to the power battery as a first discharging power map.

According to another aspect of the embodiment of the invention, a power switching device of a power battery is also provided. The apparatus may include: a control unit for controlling the power battery of the vehicle to discharge according to a first discharge power in response to the vehicle being in a running state, wherein the first discharge power is used for indicating the maximum discharge power of the power battery; the first acquisition unit is used for acquiring the required discharge power of the vehicle in the process that the power battery is discharged according to the first discharge power, wherein the required discharge power is used for indicating the discharge power of the power battery required by the vehicle in a running state; the second acquisition unit is used for responding to the fact that the required discharge power is larger than the second discharge power, and acquiring the duration time that the required discharge power is larger than the second discharge power, wherein the second discharge power is used for indicating the minimum discharge power of the power battery; a determining unit for determining a target discharge power of the power battery based on the duration and the operating state of the power battery; and the switching unit is used for switching the discharge power of the power battery from the first discharge power to the target discharge power.

According to another aspect of the embodiment of the present invention, there is also provided a computer-readable storage medium including a stored program, where the program when executed by a processor controls a device in which the storage medium is located to perform the power switching method of the power battery in the embodiment of the present invention.

According to another aspect of an embodiment of the present invention, there is also provided a processor. The processor is used for running a program, wherein the program executes the power switching method of the power battery in the embodiment of the invention when running.

According to another aspect of an embodiment of the present invention, there is also provided a vehicle. The vehicle is used for executing the power switching method of the power battery of the embodiment of the invention.

In the embodiment of the invention, in response to the vehicle being in a running state, the power battery of the vehicle is controlled to discharge according to the first discharge power, wherein the first discharge power is used for indicating the maximum discharge power of the power battery; acquiring required discharge power of the vehicle in the process that the power battery is discharged according to the first discharge power, wherein the required discharge power is used for indicating the discharge power of the power battery required by the vehicle in a running state; responding to the fact that the required discharge power is larger than the second discharge power, and obtaining the duration time that the required discharge power is larger than the second discharge power, wherein the second discharge power is used for indicating the minimum discharge power of the power battery; determining a target discharge power of the power battery based on the duration and the operating state of the power battery; the discharge power of the power battery is switched from the first discharge power to the target discharge power. That is, in the embodiment of the invention, when the vehicle is in a driving state, the vehicle is firstly discharged according to the maximum discharge power of the power battery, the maximum available discharge demand is provided for the vehicle, and when the actual demand discharge power of the vehicle is greater than the minimum discharge power, the target discharge power of the power battery is determined according to the actual demand discharge power of the power battery and the working state of the battery, and the discharge power of the power battery is switched to the target discharge power, so that the purpose of flexibly adjusting the discharge power of the power battery according to the actual demand discharge power of the vehicle is achieved, the purpose of accurately adjusting the discharge power of the power battery is further achieved, and the technical problem that the discharge power of the power battery cannot be accurately adjusted is solved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute a limitation on the application. In the drawings:

fig. 1 is a flowchart of a power switching method of a power battery according to an embodiment of the present invention;

FIG. 2 is a flow chart of a method for power train capability calculation and switching control of a pure electric vehicle according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a peak drive torque in accordance with an embodiment of the present invention;

FIG. 4 is a schematic diagram of a peak recovery torque in accordance with an embodiment of the present invention;

FIG. 5 is a flow chart of a method of power cell discharge power map switching according to an embodiment of the present invention;

FIG. 6 is a flow chart of a method of power battery charge map switching according to an embodiment of the present invention;

Fig. 7 is a schematic view of a power switching device of a power battery according to an embodiment of the present invention.

Detailed Description

In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, functional unit, or apparatus that comprises a list of steps or units is not necessarily limited to those steps or units that are expressly listed or inherent to such process, method, functional unit, or apparatus.

Example 1

According to an embodiment of the present invention, there is provided an embodiment of a power switching method of a power battery, it being noted that the steps shown in the flowchart of the drawings may be performed in a computer system such as a set of computer executable instructions, and that although a logical order is shown in the flowchart, in some cases the steps shown or described may be performed in an order different from that herein.

Fig. 1 is a flowchart of a power switching method of a power battery according to an embodiment of the present invention, and as shown in fig. 1, the method may include the steps of:

step S101, in response to the vehicle being in a running state, controlling the power battery of the vehicle to discharge at the first discharge power.

In the solution provided in the above step S101 of the present invention, the first discharge power is used to indicate the maximum discharge power of the power battery.

In this embodiment, when the vehicle is in a driving state, the power battery of the vehicle is controlled to discharge at the first discharge power, i.e., the vehicle is controlled to discharge at the maximum discharge power, to provide the vehicle with the maximum available discharge demand.

For example, a plurality of charge-discharge power map (map) tables are designed by bench test in advance, and three are illustrated here as an example. For example, the three discharge power maps are named as a 10s discharge power map, a 30s discharge power map, and a 60s discharge power map, respectively, the 10s discharge power map may also be referred to as a first discharge power map, dischar _map1, 10s map, the 30s discharge power map may also be referred to as a second discharge power map, dischar _map2, 30s map, and the 60s discharge power map may also be referred to as a third discharge power map, dischar _map3, and 60s map. The larger the discharge power of the power battery is and the shorter the discharge duration is, therefore, the discharge power in dischar _map1 is larger than dischar _map2 and larger than dischar _map3, based on which the maximum discharge power in dischar _map1 can be determined, in which case the first discharge power can be obtained from dischar _map1 according to the current state of charge and battery temperature of the power battery. Wherein the discharging power map is at least used for indicating the mapping relation between the discharging power of the power battery and the charge state of the power battery, and the mapping relation between the discharging power of the power battery and the battery temperature of the power battery, which are only exemplary.

Alternatively, the power Battery of the vehicle is controlled to be discharged at the first discharge power by a Battery Management System (BMS) MANAGEMENT SYSTEM.

Step S102, obtaining the required discharge power of the vehicle in the process of discharging the power battery according to the first discharge power.

In the technical solution provided in the above step S102 of the present invention, the required discharge power is used to indicate the discharge power of the power battery required by the vehicle in the running state, and the required discharge power may also be referred to as the required discharge power of the whole vehicle, the required battery power of the whole vehicle, and the like.

In this embodiment, after the power battery of the vehicle is controlled to discharge at the first discharge power in step S101, the required discharge power of the vehicle is obtained during the process of discharging the power battery at the first discharge power, and then the discharge power of the power battery is adjusted according to the required discharge power of the vehicle.

For example, in the process that the power battery discharges according to the first discharge power, parameters such as acceleration, running speed, road condition and the like of the vehicle can be monitored in real time, so as to determine the current power demand of the vehicle, thereby determining the discharge power provided by the power battery actually required by the vehicle, that is, the required discharge power of the vehicle.

Step S103, in response to the required discharge power being greater than the second discharge power, a duration of time that the required discharge power is greater than the second discharge power is obtained.

In the solution provided in the above step S103 of the present invention, the second discharge power is used to indicate the minimum discharge power of the power battery. For example, as can be seen from the foregoing description, the discharge power corresponding to the 60s discharge power map is the minimum discharge power, and based on this, the second discharge power may be the discharge power corresponding to the 60s discharge power map, which is merely an exemplary example and is not limited to the specific content of the second discharge power.

In this embodiment, after the required discharge power of the vehicle is obtained according to step S102, the required discharge power of the vehicle is compared with the second discharge power, and when the required discharge power of the vehicle is greater than the second discharge power, the duration for which the required discharge power is greater than the second discharge power is further obtained.

For example, after the required discharge power of the vehicle is obtained, further determining whether the required discharge power of the vehicle is the second discharge power, and if so, triggering a timing function of the vehicle to record a duration of time that the required discharge power of the vehicle is greater than the second discharge power, where the duration of time may be represented by T1.

Step S104, determining the target discharge power of the power battery based on the duration and the operating state of the power battery.

In the technical solution provided in the above step S104 of the present invention, the working state of the power battery may be at least a discharging state and a charging state.

In this embodiment, after the duration for which the required discharge power is greater than the second discharge power is obtained according to step S103, the target discharge power map of the power battery is determined according to the duration, and the operating state of the power battery. The target discharging power map is at least used for indicating a mapping relation between the discharging power of the power battery and the state of charge of the power battery and a mapping relation between the discharging power of the power battery and the battery temperature of the power battery. The target discharge power pattern may be at least one of a first discharge power pattern (dischar _map1), a second discharge power pattern (dischar _map2), and a third discharge power pattern (dischar _map3).

Alternatively, the operating state of the power battery may be determined based on the actual required discharge power of the vehicle. For example, when the required discharge power of the whole vehicle is a negative value, the kinetic energy of the vehicle is converted into electric energy and fed back to the battery in the deceleration or braking process, and the power battery is in an energy recovery state at this time, so that the working state of the power battery can be determined to be a charging state; when the power of the battery required by the whole vehicle is positive, the vehicle is required to release electric energy from the power battery to provide power for driving the vehicle to run, and the working state of the power battery can be determined to be a discharging state.

Optionally, when the power battery is in a discharging state and the duration of the actual required discharging power of the whole vehicle is not longer than the first duration, determining the target discharging power map corresponding to the power battery as the first discharging power map; when the duration time of the actual required discharge power of the whole vehicle is longer than the first duration time and shorter than the second duration time, determining a target discharge power map corresponding to the power battery as a second discharge power map; and when the duration time of the actual required discharge power of the whole vehicle is longer than the second discharge power is longer than the second duration time, determining the target discharge power map corresponding to the power battery as a third discharge power map.

For example, assuming that the first duration is 10s, the second duration is 30s, and the third duration is 60s, when the duration of the actual required discharge power of the whole vehicle is greater than the second discharge power by 5s, because the duration of 5s <10s, that is, the actual required discharge power of the whole vehicle is greater than the second discharge power, is not greater than the first duration, in this case, it may be determined that the target discharge power map corresponding to the power battery is the first discharge power map, that is, the power battery is controlled to discharge according to the discharge power in the first discharge power map, so as to provide the maximum available discharge requirement for the vehicle.

Optionally, after determining the target discharge power map, determining the target discharge power in the target discharge power map according to the state of charge of the power battery and the battery temperature of the power battery based on the mapping relationship between the target discharge power map and the state of charge of the power battery and the mapping relationship between the discharge power of the power battery and the battery temperature of the power battery.

For example, assuming that the state of charge of the power battery in the target discharge power map is 15%, the corresponding discharge power is 20W when the battery temperature is-30 ℃, in this case, if the current state of charge of the power battery is 15%, the battery temperature of the power battery is-30 ℃, the target discharge power determined in the target discharge power map is 20W.

Optionally, when the working state of the power battery is a charging state, a duration time that the actual required discharge power of the whole vehicle is greater than the second discharge power is obtained, and when the duration time is greater than the first time and less than the second time, the target discharge power map corresponding to the power battery is determined to be the first discharge power map.

Optionally, when the working state of the power battery is a charging state, the duration of the actual required discharge power of the whole vehicle is greater than the second discharge power, and when the duration is not greater than the first duration, the target discharge power spectrum corresponding to the power battery is determined to be the first discharge power spectrum.

In this embodiment, during the running of the vehicle, when the power battery is in a charged state, that is, when the power battery is in an energy recovery state, the target discharge power map corresponding to the power battery may also be determined according to the duration that the discharge power actually required by the whole vehicle is greater than the second discharge power, so that the target discharge power is determined from the target discharge power map according to the charged state of the power battery and the battery temperature.

Step S105, switching the discharge power of the power battery from the first discharge power to the target discharge power.

In the technical solution provided in the above step S105 of the present invention, after determining the target discharge power of the power battery according to step S104, the discharge power of the power battery is switched from the first discharge power to the target discharge power.

In this embodiment, after determining the target discharge power of the power battery, the discharge power of the power battery is switched from the first discharge power to the target discharge power. For example, the discharge power of the power battery is switched by the battery management system of the vehicle, which is merely an exemplary example, and a specific method of adjusting the discharge power of the power battery is not limited.

It should be noted that the above-described embodiments may be performed by a battery management system of a vehicle or a control unit of a vehicle.

In the steps S101 to S105, when the vehicle is in a driving state, the vehicle is firstly discharged according to the maximum discharge power of the power battery, the maximum available discharge requirement is provided for the vehicle, and when the actual required discharge power of the vehicle is greater than the minimum discharge power, the target discharge power of the power battery is determined according to the actual required discharge power of the power battery and the working state of the battery, and the discharge power of the power battery is switched to the target discharge power, so that the purpose of flexibly adjusting the discharge power of the power battery according to the actual required discharge power of the vehicle is achieved, and the purpose of accurately adjusting the discharge power of the power battery is achieved, and the technical problem that the discharge power of the power battery cannot be accurately adjusted is solved.

The above-described method of this embodiment is further described below.

As an alternative embodiment, step S104, determining the target discharge power of the power battery based on the duration and the operating state of the power battery, includes: determining a target discharge power map corresponding to the power battery based on the duration and the working state of the power battery, wherein the target discharge power map is at least used for indicating a mapping relation between the discharge power of the power battery and the state of charge of the power battery and a mapping relation between the discharge power of the power battery and the battery temperature of the power battery; the target discharge power is determined in a target discharge power map based on a state of charge of the power battery and a battery temperature of the power battery.

In this embodiment, as can be seen from the foregoing description, the duration is used to indicate the duration that the actually required discharge power of the vehicle is greater than the second discharge power, and the target discharge power map corresponding to the power battery may be determined according to the duration and the operating state of the power battery. The target discharge power spectrum may be at least a first discharge power spectrum (denoted as dischar _map1), a second discharge power spectrum (denoted as dischar _map2), or a third discharge power spectrum (denoted as dischar _map3).

Optionally, after determining the target discharge power map, the target discharge power of the power battery may be determined in the target discharge power map according to the state of charge of the power battery and the battery temperature of the power battery, because the target discharge power map is at least used to include a mapping relationship between the discharge power of the power battery and the state of charge of the power battery, and a mapping relationship between the discharge power of the power battery and the battery temperature of the power battery.

As an alternative embodiment, the operating states of the power battery include at least a discharging state and a charging state, and determining the target discharging power map corresponding to the power battery based on the duration and the operating state of the power battery includes: in response to the power battery being in a discharge state, wherein the duration is not longer than the first duration, determining a target discharge power map corresponding to the power battery as a first discharge power map; responding to the fact that the power battery is in a discharging state, wherein the duration time is longer than the first duration time and shorter than the second duration time, and determining a target discharging power map corresponding to the power battery as a second discharging power map; and in response to the power battery being in a discharge state and the duration being longer than the second duration, determining that the target discharge power of the power battery is the third discharge power map.

In the embodiment, when the power battery is in a discharging state, and the duration of the actual required discharging power of the whole vehicle is not longer than the first duration when the actual required discharging power of the whole vehicle is longer than the second discharging power, determining a target discharging power map corresponding to the power battery as a first discharging power map; when the duration time of the actual required discharge power of the whole vehicle is longer than the first duration time and shorter than the second duration time, determining a target discharge power map corresponding to the power battery as a second discharge power map; and when the duration time of the actual required discharge power of the whole vehicle is longer than the second discharge power is longer than the second duration time, determining the target discharge power map corresponding to the power battery as a third discharge power map.

For example, when the power battery is in a discharging state, assuming that the first duration is 10s, the second duration is 30s, and the third duration is 60s, the obtained actual required discharging power of the whole vehicle is longer than the second discharging power by 15s, and because 10s >15s <30s, that is, the duration that the actual required discharging power of the whole vehicle is longer than the second discharging power is longer than the first duration and is shorter than the second duration, the target discharging power map corresponding to the power battery can be determined to be the second discharging power map based on the first duration, the second duration, and the third duration.

As an alternative embodiment, when the state of charge of the power battery and the battery temperature are unchanged, the first discharge duration of the power battery discharging according to the discharge power in the first discharge power map is smaller than the second discharge duration of the power battery discharging according to the discharge power in the second discharge power map, and the second discharge duration is smaller than the third discharge duration of the power battery discharging according to the discharge power in the third discharge power map.

In this embodiment, as is known from the foregoing description, the greater the discharge power of the power battery is, the shorter the discharge duration is, and since the discharge power in dischar _map1 is greater than the discharge power in dischar _map2 and greater than the discharge power in dischar _map3, it can be determined that, when the state of charge of the power battery is unchanged from the battery temperature, the first discharge duration in which the power battery is discharged according to the discharge power in the first discharge power map is smaller than the second discharge duration in which the power battery is discharged according to the discharge power in the second discharge power map, and the second discharge duration is smaller than the third discharge duration in which the power battery is discharged according to the discharge power in the third discharge power map.

For example, when the state of charge of the power battery and the battery temperature are unchanged, the first discharge duration of the power battery discharging according to the discharge power in dischar _map1 may be 10s, the second discharge duration of the power battery discharging according to the discharge power in dischar _map2 may be 30s, and the third discharge duration of the power battery discharging according to the discharge power in dischar _map3 may be 60s.

As an alternative embodiment, the method further comprises, in response to the power cell discharging according to the discharge power in the third discharge power spectrum, or in response to the power cell discharging according to the discharge power in the second discharge power spectrum: determining a target discharge power map of the power battery as a first discharge power map in response to the required discharge power of the vehicle being less than the second discharge power and the duration of the required discharge power of the vehicle being less than the second discharge power exceeding a duration threshold, or in response to the power battery being in a charged state; and controlling the power battery to discharge based on the first discharging power map.

In this embodiment, when the required discharge power of the vehicle is smaller than the second discharge power and the duration of the required discharge power of the vehicle smaller than the second discharge power exceeds the duration threshold, the target discharge power map of the power battery is determined to be the first discharge power map. Wherein the time length threshold may be 60s, which is only an exemplary example and is not limited to a specific value of the time length threshold.

Optionally, when the power battery is in a charged state, determining the target discharge power map of the power battery as the first discharge power map.

For example, when the required discharging power is negative, it means that the vehicle converts energy in the power battery into electric energy and feeds the electric energy back to the battery during the deceleration or braking process, and the power battery is in the energy recovery state at this time, it may be determined that the power battery is in the charging state, and then it may be determined that the target discharging power map of the power battery is the first discharging power map.

Optionally, after determining that the target discharge power spectrum of the power battery is the first discharge power spectrum, controlling the power battery to discharge according to the first discharge power spectrum.

As an alternative embodiment, determining a target discharge power map corresponding to the power battery based on the duration and the operating state of the power battery includes: in response to the working state of the power battery being a charging state, and the duration being not greater than the first duration, determining a target discharge power map corresponding to the power battery as a first discharge power map; and responding to the working state of the power battery to be a charging state, wherein the duration time is longer than the first time and shorter than the second time, and determining the target discharging power map corresponding to the power battery as a first discharging power map.

In this embodiment, when the operating state of the power battery is a charging state and the duration is not longer than the first duration, the target discharge power map corresponding to the power battery is determined to be the first discharge power map.

Optionally, when the working state of the power battery is a charging state and the duration time is longer than the first time and shorter than the second time, determining the target discharge power map corresponding to the power battery as the first discharge power map.

In this embodiment, when the vehicle is in a driving state, the vehicle is firstly discharged according to the maximum discharge power of the power battery, the maximum available discharge demand is provided for the vehicle, and when the actual demand discharge power of the vehicle is greater than the minimum discharge power, the target discharge power of the power battery is determined according to the actual demand discharge power of the power battery and the working state of the battery, and the discharge power of the power battery is switched to the target discharge power, so that the purpose of flexibly adjusting the discharge power of the power battery according to the actual demand discharge power of the vehicle is achieved, the purpose of accurately adjusting the discharge power of the power battery is further achieved, and the technical problem that the discharge power of the power battery cannot be accurately adjusted is solved.

Example 2

The technical solution of the embodiment of the present invention will be illustrated in the following with reference to a preferred embodiment.

In the related art, the charge and discharge power of the power battery of the vehicle is adjusted through a single power chart, and the power chart may not match the current use condition of the power battery as the discharge time increases, in this case, if the charge and discharge power of the power battery is continuously adjusted through the single power chart, the problem that the battery discharge power is too high and frequently triggers an under-voltage fault may occur, so that the battery performance is damaged due to over-discharge, or the discharge power of the battery is too low, the use effect of the vehicle is affected, and the technical problem that the discharge power of the power battery cannot be accurately adjusted exists. Aiming at the technical problem that the discharge power of the power battery cannot be accurately regulated, no effective solution is proposed at present.

However, the embodiment of the invention provides a power assembly capacity calculation and switching control method for a pure electric vehicle, wherein the discharging capacity and the charging capacity of a power battery are calculated through a BMS, and the discharging power of the battery is flexibly switched according to the discharging capacity and the charging capacity of the power battery, so that the purpose of accurately adjusting the discharging power of the battery is realized, and the technical problem that the discharging power of the power battery cannot be accurately adjusted is solved.

Embodiments of the present invention are further described below.

Fig. 2 is a flowchart of a method for calculating the capability of a power train of a pure electric vehicle and controlling the switching, as shown in fig. 2, according to an embodiment of the present invention, the method includes the following steps:

Step S201, the driving and braking recovery capability of the motor is calculated and transmitted to the vehicle control unit.

In this embodiment, the motor drive and brake recovery capability is calculated by the motor controller MCU and sent to the vehicle control unit (Vehicle Control Unit, abbreviated VCU).

Alternatively, the peak driving torque and the peak recovery torque of the motor at different voltages are obtained through an electric drive bench test along with the change curve of the motor rotation speed. Fig. 3 is a schematic diagram of a peak driving torque according to an embodiment of the present invention, and fig. 4 is a schematic diagram of a peak recovery torque according to an embodiment of the present invention, and as shown in fig. 3 and 4, the current peak driving torque (t_drive_ini) and peak recovery torque (t_brake_ini) of the motor can be determined according to a look-up table of a motor bus voltage.

Alternatively, the motor external characteristic coefficient may be determined based on the motor temperature and the inverter temperature, the coefficient related to the inverter temperature is η_inv, the coefficient related to the motor temperature is η_motorr, and the motor peak drive torque capability may be: t_drive_max=t_drive_ini η_inv η_monitor, and the motor peak recovery capability may be: t_brake_max=t_brake_ini ×η_inv ×η_monitor.

Optionally, η_inv is related to the inverter temperature, the specific numerical value needs to be determined according to the measured data, table 1 is an inverter temperature coefficient comparison table, and as shown in table 1, the corresponding inverter temperature coefficient can be obtained according to the current inverter temperature and the linear interpolation table lookup.

Table 1 inverter temperature coefficient lookup table

Inverter temperature

T1

T2

T3

……

Tx

Tn

η_inv

1

η_inv_3

……

η_inv_x

0

Optionally, the η_monitor is related to the temperature of the motor body, the specific numerical value needs to be determined according to the measured data, and table 2 is a table for comparing the temperature coefficients of the motor body, as shown in table 2, and the corresponding temperature coefficient of the motor body can be obtained according to the current temperature of the motor body and the linear interpolation table.

Table 2 comparison table of temperature coefficient of motor body

Temperature of motor body

T11

T22

T33

……

Txx

Tnn

η_motor

1

η_motor_3

……

η_motor_x

0

Step S202, the discharging capability and the charging capability of the battery are calculated and transmitted to the vehicle control unit.

In this embodiment, the discharging capability and the charging capability of the battery are calculated by the BMS and transmitted to the vehicle control unit.

Alternatively, three charging and discharging power maps are designed through bench test, the discharging maps are named dischar _map1, dischar _map2 and dischar _map3 respectively, the charging maps are named char_map1, char_map2 and char_map3 respectively, wherein dischar _map1, dischar _map2 and dischar _map3 corresponding to the three discharging maps are 10s,30s and 60s respectively, and the time is preferably a schematic value, not a unique fixed value, according to battery characteristics, and the power value in dischar _map1 at the same SOC and the same temperature >

The power value in dischar _map2 > the power value in dischar _map3.

Alternatively, the three charging maps are corresponding to the three charging maps of char_map1, char_map2 and char_map3, and the corresponding time systems are respectively 10s,30s and 60s, and the time systems are preferably schematic values, which are not unique fixed values, and the power values in char_map1 > the power values in char_map2 at the same SOC and the same temperature according to the battery characteristics

The power value in char_map3.

Alternatively, the power value corresponding to the charge-discharge power map is related to the battery SOC and the battery temperature, the discharge map is shown in table 3, and the charge map is shown in table 4. The corresponding time system means that the battery can be continuously output at 86kW for 10s for a period of time sustainable at a certain power, for example, at-30 ℃ and 90% soc in table 3. For example, in Table 4, at-20 ℃,90% SOC, the battery can be guaranteed to continue charging at 6kW for 10s.

Table 3 Power battery discharge Power control Table (section)

Table 4 Power battery charging Power control Table (section)

For example, an appropriate charge/discharge power map table may be selected according to the state of charge of the battery, the battery temperature, and the current operating condition of the battery, and then the corresponding charge/discharge power may be selected from the charge/discharge power map table.

In step S203, the vehicle control unit calculates the power train capability based on the driving and braking recovery capability of the motor, and the discharging capability and charging capability of the battery.

In this embodiment, the vehicle control unit calculates the powertrain capacity based on the drive and brake recovery capacity of the motor, and the discharge capacity and the charge capacity of the battery.

Optionally, for the driving condition, calculating the power assembly capacity t_ powertrain of the battery according to the battery discharging power p_ dischar, the motor peak driving torque t_drive, the motor current rotation speed n_motorr and the motor current efficiency η_motorr, which are specifically shown in the following formula:

T_powertrain＝min(T_drive,P_dischar*η_motor*9549/n_motor)

Optionally, for the energy recovery working condition, the power assembly capability t_ powertrain1 of the battery is calculated according to the battery charging power p_char and the motor peak driving torque t_drive1, the current motor rotation speed n_motor1 and the current motor efficiency η_motor1, which can be shown in the following formula:

T_powertrain1＝min(T_drive1,P_dischar1*9549/n_motor1/η_motor)

In the embodiment, through designing a proper battery charge and discharge power map and simultaneously carrying out proper switching control, on one hand, the power performance and economy of the whole vehicle are ensured, and on the other hand, the phenomenon that the battery is overcharged and overdischarged to cause an alarm or influence the service life of the battery is avoided; the corresponding relation between the external characteristics of the electric drive and the voltage and temperature is obtained through bench test and other means, and reasonable electric drive capacity is sent, so that the service life of the electric drive is guaranteed on one hand, and the power performance requirement of the whole vehicle is guaranteed on the other hand.

Fig. 5 is a flowchart of a method for switching the discharging power map of a power battery according to an embodiment of the present invention, as shown in fig. 5, the method includes the steps of:

in step S501, the power battery is controlled to output according to the default power.

In this embodiment, the power cells are controlled to discharge at a default power output, i.e., the power cells are controlled to discharge at a default power, wherein the default power is the power in the 10s map, i.e., the corresponding discharge power in dischar _map1.

Step S502, whether the battery power actually required by the whole vehicle is larger than the power value corresponding to the 60S map.

In this embodiment, the battery power actually required by the whole vehicle is obtained, and whether the battery power actually required by the whole vehicle is greater than a power value corresponding to 60smap is determined. If the actual battery power of the whole vehicle is greater than the power value corresponding to 60smap, step S503 is executed, and if the actual battery power of the whole vehicle is not greater than the power value corresponding to 60smap, step S501 is executed.

Step S503, start timing T1.

In this embodiment, the timer is started and the time is represented by T1.

In step S504, whether the battery power has a negative value during the timer.

In this embodiment, it is determined whether the battery power is negative during the timer, if negative, step S510 is performed, and if negative, step S505 is performed.

In step S505, T1 is greater than 10S.

In this embodiment, it is judged whether T1 is greater than 10S, if T1 is greater than 10S, step S506 is performed, and if T1 is not greater than 10S, step S501 is performed.

Step S506, the timer is continued.

In this embodiment, the power cell discharge time is continuously recorded.

In step S507, whether the battery power has a negative value during the timer.

In this embodiment, it is determined whether the battery power is negative during the timer, if negative, step S510 is performed, and if negative, step S508 is performed.

Step S508, whether T1 is greater than 30S.

In this embodiment, it is judged whether T1 is greater than 30S, if T1 is greater than 30S, step S509 is performed, and if T1 is not greater than 30S, step S512 is performed.

Step S509, the discharge power output is set at 60S map.

In this embodiment, the power cells are controlled to discharge at the discharge power in the 60s map, that is, at the corresponding discharge power in dischar _map3.

Step S510, stop timing.

In this embodiment, recording of the power battery discharge time is stopped.

In step S511, whether the first condition or the second condition is satisfied.

In this embodiment, it is determined whether the power cell discharge power satisfies the condition one or the condition two. Wherein, condition one is: the power of the battery required by the whole vehicle is less than or equal to the corresponding value in a map of 60s and lasts for more than a certain time (preferably 60 s); the second condition is: the power of the battery required by the whole vehicle is negative, namely the battery is in a charging state.

Alternatively, if the power battery discharge power satisfies the first condition or the second condition, step S501 is performed, and if the power battery discharge power does not satisfy the first condition or the second condition, step S509 is performed.

Step S512, output according to the discharge power in 30 smap.

In this embodiment, the power cells are controlled to discharge at a discharge power in the 30s map, that is, at a corresponding discharge power in dischar _map2.

Step S513, whether the condition 1 or the condition 2 is satisfied.

In this embodiment, it is determined whether the power battery discharge power satisfies the condition 1 or the condition 2, if the power battery discharge power satisfies the condition 1 or the condition 2, step S501 is performed, and if the power battery discharge power does not satisfy the condition 1 or the condition 2, step S512 is performed.

Fig. 6 is a flowchart of a method for switching power map of a power battery according to an embodiment of the present invention, as shown in fig. 6, the method includes the following steps:

in step S601, the power battery is controlled to output according to the default power.

Step S602, whether the battery power actually required by the whole vehicle is larger than the power value corresponding to 60 smap.

In this embodiment, the battery power actually required by the whole vehicle is obtained, and whether the battery power actually required by the whole vehicle is greater than a power value corresponding to 60smap is determined. If the actual battery power of the whole vehicle is greater than the power value corresponding to 60smap, step S63 is executed, and if the actual battery power of the whole vehicle is not greater than the power value corresponding to 60smap, step S61 is executed.

Step S603, start timing T1.

In this embodiment, the timer is started and the time is represented by T1.

In step S604, whether the battery power has a negative value during the timer.

In this embodiment, it is judged whether or not the battery power is negative during the timer, if negative, step S56 is performed, and if negative, step S65 is performed.

Step S605, T1 is greater than 10S.

In this embodiment, it is judged whether T1 is greater than 10S, if T1 is greater than 10S, step S606 is performed, and if T1 is not greater than 10S, step S61 is performed.

Step S606, keep timing.

In this embodiment, the power cell discharge time is continuously recorded.

In step S607, whether the battery power has a negative value during the timer.

In this embodiment, it is determined whether the battery power is negative during the timer, if negative, step S610 is performed, and if negative, step S608 is performed.

Step S608, whether T1 is greater than 30S.

In this embodiment, it is judged whether T1 is greater than 30S, if T1 is greater than 30S, step S609 is performed, and if T1 is not greater than 30S, step S612 is performed.

Step S609, output according to the discharge power in the 60S map.

In step S610, the timer is stopped.

In this embodiment, recording of the power battery discharge time is stopped.

In step S611, whether the condition three or the condition four is satisfied.

In this embodiment, it is determined whether the power cell discharge power satisfies the condition three or the condition four. Wherein, the third condition is: the absolute value of the battery power required by the whole vehicle is less than or equal to 60s of the absolute value of the corresponding numerical value in the map and lasts for more than a certain time (preferably 60 s); the fourth condition is: the power of the battery required by the whole vehicle is positive, namely the battery is in a discharging state.

Alternatively, if the power battery discharge power satisfies the condition three or the condition four, step S601 is performed, and if the power battery discharge power does not satisfy the condition three or the condition four, step S609 is performed.

Step S612, outputting according to the discharge power in 30 smap.

Step S613, whether condition 3 or condition 4 is satisfied.

In this embodiment, it is determined whether the power battery discharge power satisfies the condition 3 or the condition 4, if the power battery discharge power satisfies the condition 3 or the condition 4, step S601 is performed, and if the power battery discharge power does not satisfy the condition 3 or the condition 4, step S612 is performed.

In the above-mentioned fig. 5 and 6, the discharging capacity and the charging capacity of the power battery are calculated through the BMS, and according to the discharging capacity and the charging capacity of the power battery, the discharging power of the battery is flexibly switched, so that the purpose of accurately adjusting the discharging power of the battery is achieved, and further, the technical problem that the discharging power of the power battery cannot be accurately adjusted is solved.

Example 3

According to the embodiment of the invention, a power switching device of the power battery is also provided. The power switching device of the power battery may be used to perform the power switching method of the power battery in embodiment 1.

Fig. 7 is a schematic view of a power switching device of a power battery according to an embodiment of the present invention. As shown in fig. 7, the power switching device 700 of the power battery may include: a control unit 701, a first acquisition unit 702, a second acquisition unit 703, a determination unit 704, and a switching unit 705.

And a control unit 701 for controlling the power battery of the vehicle to discharge according to a first discharge power in response to the vehicle being in a running state, wherein the first discharge power is used for indicating the maximum discharge power of the power battery.

The first obtaining unit 702 is configured to obtain a required discharge power of the vehicle during a process of discharging the power battery according to the first discharge power, where the required discharge power is used to indicate a discharge power of the power battery required by the vehicle in a driving state.

And a second obtaining unit 703, configured to obtain, in response to the required discharge power being greater than the second discharge power, a duration in which the required discharge power is greater than the second discharge power, where the second discharge power is used to indicate the minimum discharge power of the power battery.

A determining unit 704, configured to determine a target discharge power of the power battery based on the duration and the operating state of the power battery.

And a switching unit 705 for switching the discharge power of the power battery from the first discharge power to the target discharge power.

Alternatively, the determining unit 704 may include: the first determining module is used for determining a target discharging power map corresponding to the power battery based on the duration and the working state of the power battery, wherein the target discharging power map is at least used for indicating the mapping relation between the discharging power of the power battery and the state of charge of the power battery and the mapping relation between the discharging power of the power battery and the battery temperature of the power battery; and a second determination module for determining a target discharge power in a target discharge power map based on a state of charge of the power battery and a battery temperature of the power battery.

Optionally, the determining unit 704 may further include: the third determining module is used for determining that the target discharge power map corresponding to the power battery is a first discharge power map in response to the power battery being in a discharge state and the duration being not longer than the first duration; the fourth determining module is used for determining that the target discharge power spectrum corresponding to the power battery is a second discharge power spectrum in response to the power battery being in a discharge state and the duration time being longer than the first time and shorter than the second time; and a fifth determining module, configured to determine, in response to the power battery being in a discharge state and the duration being longer than the second duration, that the target discharge power of the power battery is the third discharge power map.

Optionally, the determining unit 704 may further include: a sixth determining module, configured to determine, in response to the required discharge power of the vehicle being less than the second discharge power and the duration of the required discharge power of the vehicle being less than the second discharge power exceeding a duration threshold, or in response to the power battery being in a charged state, that the target discharge power profile of the power battery is the first discharge power profile; and the control module is used for controlling the power battery to discharge based on the first discharging power map.

Optionally, the determining unit 704 may further include: a seventh determining module, configured to determine, in response to the operating state of the power battery being a charging state and the duration being not greater than the first duration, that a target discharge power spectrum corresponding to the power battery is a first discharge power spectrum; and the eighth determining module is used for determining that the target discharge power map corresponding to the power battery is the first discharge power map in response to the working state of the power battery being a charging state and the duration time being longer than the first time and shorter than the second time.

Example 4

According to an embodiment of the present invention, there is also provided a computer-readable storage medium including a stored program, wherein the program executes the power switching method of the power battery in embodiment 1.

Example 5

According to an embodiment of the present invention, there is also provided a processor for running a program, wherein the program executes the power switching method of the power battery in embodiment 1.

The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.

In the foregoing embodiments of the present invention, the descriptions of the embodiments are emphasized, and for a portion of this disclosure that is not described in detail in this embodiment, reference is made to the related descriptions of other embodiments.

In the several embodiments provided in the present application, it should be understood that the disclosed technology may be implemented in other manners. The above-described embodiments of the apparatus are merely exemplary, and the division of units may be a logic function division, and there may be another division manner in actual implementation, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some interfaces, units or modules, or may be in electrical or other forms.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present invention may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone functional units, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software functional component stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the methods of the embodiments of the present invention. And the aforementioned storage medium includes: a usb disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a removable hard disk, a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims

1. A power switching method of a power battery, comprising:

controlling a power battery of a vehicle to discharge according to a first discharge power in response to the vehicle being in a running state, wherein the first discharge power is used for indicating the maximum discharge power of the power battery;

acquiring required discharge power of the vehicle in the process that the power battery discharges according to the first discharge power, wherein the required discharge power is used for indicating the discharge power of the power battery required by the vehicle in the running state;

responsive to the required discharge power being greater than a second discharge power, obtaining a duration of the required discharge power being greater than the second discharge power, wherein the second discharge power is used for indicating a minimum discharge power of the power battery;

Determining a target discharge power of the power battery based on the duration and the operating state of the power battery;

and switching the discharge power of the power battery from the first discharge power to the target discharge power.

2. The method of claim 1, wherein determining the target discharge power of the power cell based on the duration, and the operating state of the power cell, comprises:

Determining a target discharge power map corresponding to the power battery based on the duration and the working state of the power battery, wherein the target discharge power map is at least used for indicating a mapping relation between the discharge power of the power battery and the state of charge of the power battery and a mapping relation between the discharge power of the power battery and the battery temperature of the power battery;

The target discharge power is determined in the target discharge power map based on the state of charge of the power battery and the battery temperature of the power battery.

3. The method of claim 2, wherein the operating state of the power cell includes at least a discharge state and a charge state, and wherein determining the target discharge power profile for the power cell based on the duration and the operating state of the power cell includes:

Determining that the target discharge power map corresponding to the power battery is a first discharge power map in response to the power battery being in the discharge state and the duration being not greater than a first duration;

Responding to the power battery in the discharging state, wherein the duration time is longer than a first duration time and shorter than a second duration time, and determining the target discharging power map corresponding to the power battery as a second discharging power map;

and in response to the power battery being in the discharge state and the duration being greater than the second duration, determining that the target discharge power of the power battery is a third discharge power map.

4. The method of claim 3, wherein a first discharge duration of the power battery discharging according to the discharge power in the first discharge power map is less than a second discharge duration of the power battery discharging according to the discharge power in the second discharge power map, the second discharge duration being less than a third discharge duration of the power battery discharging according to the discharge power in the third discharge power map, when the state of charge of the power battery and the battery temperature are unchanged.

5. A method according to claim 3, wherein the method further comprises, in response to the power cell discharging at the discharge power in the third discharge power profile, or in response to the power cell discharging at the discharge power in the second discharge power profile:

Determining that the target discharge power map of the power battery is the first discharge power map in response to the required discharge power of the vehicle being less than the second discharge power and the required discharge power of the vehicle being less than the second discharge power for a duration exceeding a duration threshold, or in response to the power battery being in the state of charge;

And controlling the power battery to discharge based on the first discharge power map.

6. A method according to claim 3, wherein determining a target discharge power profile for the power cell based on a duration of time and an operating state of the power cell comprises:

Determining that the target discharge power map corresponding to the power battery is the first discharge power map in response to the working state of the power battery being the charging state and the duration being not longer than the first duration;

And responding to the working state of the power battery as the charging state, wherein the duration time is longer than the first duration time and shorter than the second duration time, and determining the target discharging power map corresponding to the power battery as the first discharging power map.

7. A power switching device of a power battery, comprising:

A control unit for controlling a power battery of a vehicle to discharge according to a first discharge power in response to the vehicle being in a running state, wherein the first discharge power is used for indicating a maximum discharge power of the power battery;

A first obtaining unit, configured to obtain a required discharge power of the vehicle during a process that the power battery discharges according to the first discharge power, where the required discharge power is used to indicate a discharge power of the power battery required by the vehicle in the driving state;

A second obtaining unit, configured to obtain a duration in which the required discharge power is greater than a second discharge power in response to the required discharge power being greater than the second discharge power, where the second discharge power is used to indicate a minimum discharge power of the power battery;

A determining unit configured to determine a target discharge power of the power battery based on the duration and an operation state of the power battery;

And the switching unit is used for switching the discharge power of the power battery from the first discharge power to the target discharge power.

8. A computer readable storage medium, characterized in that the computer readable storage medium comprises a stored program, wherein the program, when run by a processor, controls a device in which the storage medium is located to perform the method of any one of claims 1 to 6.

9. A processor for running a program, wherein the program when run performs the method of any one of claims 1 to 6.

10. A vehicle for performing the method of any one of claims 1 to 6.