CN116160872A

CN116160872A - Pre-charging method and device for high-voltage bus capacitor, storage medium and vehicle controller

Info

Publication number: CN116160872A
Application number: CN202111415919.3A
Authority: CN
Inventors: 毛涛月; 李想想; 李维诚; 石雷; 薛鹏辉
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2021-11-25
Filing date: 2021-11-25
Publication date: 2023-05-26

Abstract

The invention discloses a pre-charging method and device of a high-voltage bus capacitor, a storage medium and a vehicle controller, wherein the pre-charging method of the high-voltage bus capacitor comprises the following steps: when a precharge command is received, acquiring an initial voltage of a high-voltage bus capacitor; when the initial voltage of the high-voltage bus capacitor is smaller than the first target voltage, the DC-DC converter is controlled by adopting different pre-charging modes according to the initial voltage of the high-voltage bus capacitor, so that the starting battery charges the high-voltage bus capacitor through the DC-DC converter. Therefore, the pre-charging method of the high-voltage bus capacitor in the electric automobile can safely and efficiently pre-charge the high-voltage bus capacitor, saves pre-charging cost and maintenance cost, has higher controllability, and can also prolong the service life of a circuit.

Description

Pre-charging method and device for high-voltage bus capacitor, storage medium and vehicle controller

Technical Field

The invention relates to the technical field of vehicle control, in particular to a pre-charging method of a high-voltage bus capacitor in an electric automobile, a computer readable storage medium, a vehicle controller and a pre-charging device of the high-voltage bus capacitor in the electric automobile.

Background

With the increasing severity of environmental pollution and the reduction of fossil energy reserves, people pay more attention to the pollution problem of automobiles, and the development of battery technology brings new possibility to the automobile industry, so that electric automobiles are rapidly developed, and more components are being occupied in the automobile industry.

The electric automobile generally uses a power battery between 200V and 800V as the energy of the whole automobile, and the motor controller is often larger in DC high-voltage bus capacitance due to the electrical characteristics of the motor controller, when the whole automobile is electrified, if the main contactor is directly closed, the high voltage of the battery pack is used for charging the large capacitor to generate extremely large current, and the main contactor and the bus capacitance are easily damaged. Therefore, in order to prevent this, it is necessary to precharge the bus capacitor in advance, and close the main contactor after the voltage of the bus capacitor reaches a voltage value similar to the voltage of the battery pack.

In the related art, as shown in fig. 1, the pre-charging process of the bus capacitor C1 (C1 represents the sum of all the capacitors on the bus capacitor) is generally implemented by an additional pre-charging resistor R2 and a pre-charging contactor S2, that is, the pre-charging contactor S2 is closed to pre-charge the bus capacitor C1 for a period of time, and then the main contactor S1 is closed to short-circuit the pre-charging resistor R2, and the battery pack is used to directly charge the bus capacitor C1.

The pre-filling mode is simpler, but has certain disadvantages at the same time, such as: 1. the pre-charging resistor and the pre-charging contactor have higher cost; 2. each time of pre-charging, the pre-charging resistor consumes a part of electric energy, and the pre-charging energy loss is increased; 3. the pre-charging contactor belongs to a physical contact switch, the controllability is poor, the switching times are limited, and the maintenance cost of a circuit is increased; 4. if a short circuit fault occurs in the high-voltage load, the problem of burning out the precharge resistor is usually caused, and the circuit is damaged.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, an object of the present invention is to provide a method for pre-charging a high-voltage bus capacitor in an electric vehicle, which can safely and efficiently pre-charge the high-voltage bus capacitor, and simultaneously save pre-charging cost and maintenance cost, has high controllability, and can also improve the service life of a circuit.

A second object of the present invention is to propose a computer readable storage medium.

A third object of the present invention is to propose a vehicle controller.

The fourth object of the present invention is to provide a pre-charging device for a high-voltage bus capacitor in an electric vehicle.

To achieve the above object, an embodiment of a first aspect of the present invention provides a method for pre-charging a high-voltage bus capacitor in an electric vehicle, wherein the electric vehicle includes a DC-DC converter and a starting battery, a high-voltage end of the DC-DC converter is connected to the high-voltage bus capacitor through a high-voltage bus, and a low-voltage end of the DC-DC converter is connected to the starting battery, the pre-charging method includes: when a precharge command is received, acquiring the initial voltage of the high-voltage bus capacitor; and when the initial voltage of the high-voltage bus capacitor is smaller than the first target voltage, the DC-DC converter is controlled by adopting different pre-charging modes according to the initial voltage of the high-voltage bus capacitor, so that the starting battery charges the high-voltage bus capacitor through the DC-DC converter.

In the pre-charging method for the high-voltage bus capacitor in the electric automobile, when the pre-charging instruction is received, the first target voltage can be determined, the initial voltage of the current high-voltage bus capacitor is obtained, if the initial voltage of the high-voltage bus capacitor is smaller than the first target voltage, the corresponding pre-charging mode can be adopted to charge the high-voltage bus capacitor according to the specific value of the initial voltage of the high-voltage bus capacitor, and particularly, the DC-DC converter is controlled to charge the high-voltage bus capacitor by utilizing the starting battery. Therefore, the pre-charging method of the high-voltage bus capacitor in the electric automobile can safely and efficiently pre-charge the high-voltage bus capacitor, meanwhile, the pre-charging cost and the maintenance cost are saved, the controllability is high, and the service life of a circuit can be prolonged.

In some embodiments of the present invention, the DC-DC converter is controlled in different pre-charge modes according to an initial voltage of the high voltage bus capacitor, including: when the initial voltage of the high-voltage bus capacitor is smaller than a first preset voltage, controlling the DC-DC converter in a constant-current charging mode, wherein the first preset voltage is smaller than the first target voltage; and when the initial voltage of the high-voltage bus capacitor is larger than or equal to a first preset voltage, a constant-power charging mode is adopted to control the DC-DC converter.

In some embodiments of the present invention, in controlling the DC-DC converter in a constant current charging mode, the pre-charging method further includes: when the real-time voltage of the high-voltage bus capacitor is larger than a second preset voltage, determining that constant-current pre-charging is completed on the high-voltage bus capacitor, wherein the second preset voltage is larger than or equal to the first preset voltage, and the second preset voltage is smaller than the first target voltage; and when the real-time voltage of the high-voltage bus capacitor is smaller than or equal to a second preset voltage and the duration time is longer than a first preset time, determining that the constant-current pre-charging of the high-voltage bus capacitor is overtime.

In some embodiments of the present invention, when constant current pre-charging is completed for the high voltage bus capacitor, the pre-charging method further includes: and when the real-time voltage of the high-voltage bus capacitor is smaller than the first target voltage, the DC-DC converter is controlled by adopting a constant-power charging mode.

In some embodiments of the invention, during control of the DC-DC converter in a constant power charging mode, the pre-charging method further comprises: when the real-time voltage of the high-voltage bus capacitor is larger than or equal to the first target voltage, determining that constant power pre-charging is completed on the high-voltage bus capacitor; and when the real-time voltage of the high-voltage bus capacitor is smaller than the first target voltage and the duration time is longer than a second preset time, determining that the constant-power pre-charging of the high-voltage bus capacitor is overtime.

In some embodiments of the present invention, in the process of controlling the DC-DC converter in the constant current charging mode, the output voltage of the DC-DC converter is further limited to be less than or equal to a third preset voltage, where the third preset voltage is greater than the second preset voltage.

In some embodiments of the invention, during control of the DC-DC converter in a constant power charging mode, the output voltage of the DC-DC converter is also limited to be less than the second target voltage, wherein the second target voltage is greater than the first target voltage.

In some embodiments of the present invention, when the voltage of the high-voltage bus capacitor is equal to or greater than the first target voltage, the pre-charging method further includes: when the voltage of the high-voltage bus capacitor is smaller than or equal to a second target voltage, determining that the high-voltage bus capacitor is completely precharged, wherein the second target voltage is larger than the first target voltage; and when the voltage of the high-voltage bus capacitor is larger than a second target voltage, determining that the voltage of the high-voltage bus capacitor is abnormal.

To achieve the above objective, a second aspect of the present invention provides a computer readable storage medium, on which a pre-charging program of a high voltage bus capacitor in an electric vehicle is stored, where the pre-charging program of the high voltage bus capacitor in the electric vehicle is executed by a processor to implement the pre-charging method of the high voltage bus capacitor in the electric vehicle according to the above embodiment.

The computer readable storage medium of the embodiment of the invention can safely and efficiently precharge the high-voltage bus capacitor by executing the precharge program of the high-voltage bus capacitor in the electric vehicle corresponding to the precharge method of the high-voltage bus capacitor in the embodiment, saves the precharge cost and the maintenance cost, has higher controllability and can also improve the service life of a circuit.

In order to achieve the above object, an embodiment of a third aspect of the present invention provides a vehicle controller, which includes a memory, a processor, and a pre-charging program for a high-voltage bus capacitor in an electric vehicle stored in the memory and capable of running on the processor, wherein the pre-charging method for the high-voltage bus capacitor in the electric vehicle is implemented when the processor executes the pre-charging program for the high-voltage bus capacitor in the electric vehicle.

The vehicle controller provided by the embodiment of the invention comprises the memory and the processor, wherein the processor executes the pre-charging program of the high-voltage bus capacitor in the electric vehicle stored on the memory, so that the high-voltage bus capacitor can be safely and efficiently pre-charged, the pre-charging cost and the maintenance cost are saved, the controllability is higher, and the service life of the circuit can be prolonged.

To achieve the above object, a fourth aspect of the present invention provides a pre-charging device for a high-voltage bus capacitor in an electric vehicle, the electric vehicle including a DC-DC converter and a starting battery, a high-voltage end of the DC-DC converter being connected to the high-voltage bus capacitor through a high-voltage bus, a low-voltage end of the DC-DC converter being connected to the starting battery, the pre-charging device comprising: the receiving module is used for receiving the pre-charging instruction; the determining module is used for acquiring the initial voltage of the high-voltage bus capacitor when the receiving module receives the pre-charging instruction; and the pre-charging control module is used for controlling the DC-DC converter in different pre-charging modes according to the initial voltage of the high-voltage bus capacitor when the initial voltage of the high-voltage bus capacitor is smaller than the first target voltage, so that the starting battery charges the high-voltage bus capacitor through the DC-DC converter.

The pre-charging device comprises a receiving module, a determining module and a pre-charging control module, wherein after the receiving module receives a pre-charging instruction, a first target voltage can be determined through the determining module, the initial voltage of the current high-voltage bus capacitor is obtained, and then the pre-charging control module can charge the high-voltage bus capacitor in different pre-charging modes according to specific values of the initial voltage of the high-voltage bus capacitor when the initial voltage of the high-voltage bus capacitor is smaller than the first target voltage, and particularly, the DC-DC converter is controlled to charge the high-voltage bus capacitor by using a starting battery. The pre-charging device for the high-voltage bus capacitor in the electric automobile can safely and efficiently pre-charge the high-voltage bus capacitor, saves pre-charging cost and maintenance cost, has higher controllability, and can further improve the service life of a circuit.

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

Drawings

FIG. 1 is a schematic diagram of a pre-charge circuit for a bus capacitor according to the related art;

FIG. 2 is a block diagram of a high voltage bus capacitor pre-charge system for an electric vehicle according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a precharge circuit of an electric vehicle high voltage bus capacitor according to one embodiment of the invention;

FIG. 4 is a flow chart of a method for pre-charging a high voltage bus capacitor in an electric vehicle according to one embodiment of the invention;

FIG. 5 is a flow chart of a method for pre-charging a high voltage bus capacitor in an electric vehicle according to one embodiment of the invention;

FIG. 6 is a flow chart of a method for constant current pre-charging of a high voltage bus capacitor in an electric vehicle according to one embodiment of the invention;

FIG. 7 is a flow chart of a constant power pre-charge method for a high voltage bus capacitor in an electric vehicle according to one embodiment of the invention;

FIG. 8 is a flow chart of a method for pre-charging a high voltage bus capacitor in an electric vehicle according to one embodiment of the invention;

fig. 9 is a block diagram of a vehicle controller according to an embodiment of the present invention;

fig. 10 is a block diagram illustrating a structure of a pre-charging device for a high-voltage bus capacitor in an electric vehicle according to an embodiment of the present invention.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

The following describes a method and a device for pre-charging a high-voltage bus capacitor, a storage medium and a vehicle controller according to an embodiment of the present invention with reference to the accompanying drawings.

Fig. 2 is a block diagram of a high voltage bus capacitor pre-charge system for an electric vehicle according to an embodiment of the present invention.

As shown in fig. 2, the pre-charging system includes a high-voltage battery pack 1, a DC bus 2, a DC-DC converter 3, and a starting battery 4, wherein the DC-DC converter 3 is connected to the DC bus 2 and the starting battery 4, respectively, a bus capacitor is disposed in the DC bus 2, the DC-DC converter 3 converts the voltage in the starting battery 4 into high-voltage power, and pre-charges the bus capacitor in the DC bus 2. The high-voltage battery pack 1 is connected with the direct-current bus 2, and after the pre-charging of the bus capacitor is completed, the bus can be directly powered by the high-voltage battery pack 1.

Specifically, referring to fig. 3, fig. 3 is a schematic diagram of a pre-charging circuit of a high-voltage bus capacitor of an electric vehicle according to an embodiment of the present invention, and as can be seen from fig. 2 and 3, the high-voltage battery pack 1 includes a battery module 11 and a main contactor S1, and the direct-current bus 2 includes a high-voltage bus capacitor C1, and a high-voltage circuit connecting the main contactor S1 and the DC-DC converter 3. In the high-voltage battery pack 1, one end of a main contactor S1 is connected with the positive electrode of a battery module 11, the other end of the main contactor S1 is connected with the positive electrode bus in a direct-current bus 2, the negative electrode of the battery module 11 is connected with the negative electrode bus in the direct-current bus 2, the direct-current bus 2 is also connected with two ends of a bus capacitor C1, the high-voltage end of a DC-DC converter 3 is connected with the high-voltage bus capacitor C1 through a high-voltage bus line, and the low-voltage end of the DC-DC converter 3 is connected with a starting battery 4.

Fig. 4 is a flowchart of a method of pre-charging a high voltage bus capacitor in an electric vehicle according to one embodiment of the present invention.

As shown in fig. 4, the invention provides a pre-charging method of a high-voltage bus capacitor in an electric automobile, which comprises the following steps:

s10, when a precharge command is received, the initial voltage of the high-voltage bus capacitor is obtained.

Specifically, in this embodiment, the DC-DC converter 3 may be used to receive a precharge command, where the precharge command may be triggered by a vehicle power-on command, that is, when the vehicle powers on, the precharge command may be triggered, and when the DC-DC converter 3 receives the precharge command, the first target voltage may be determined, and the initial voltage of the current high-voltage bus capacitor may be obtained at the same time. It is understood that the first target voltage in this embodiment may be equal to the voltage of the battery module 11 or may be close to the voltage of the battery module 11. In addition, in this embodiment, after receiving the precharge command, the voltage of the current bus capacitor C1 may be obtained to determine whether the bus capacitor C1 needs to be precharged, and if so, which precharge mode needs to be adopted to precharge the same.

And S20, when the initial voltage of the high-voltage bus capacitor is smaller than the first target voltage, controlling the DC-DC converter in different pre-charging modes according to the initial voltage of the high-voltage bus capacitor so that the starting battery charges the high-voltage bus capacitor through the DC-DC converter.

Specifically, after the initial voltage of the current high-voltage bus capacitor is obtained, the initial voltage value of the high-voltage bus capacitor can be judged, when the initial voltage of the high-voltage bus capacitor is smaller than the first target voltage, the high-voltage bus capacitor needs to be pre-charged, if the battery pack is directly used for charging at the moment, the bus capacitor is likely to be damaged, and a circuit is destroyed, so that the voltage of the high-voltage bus capacitor needs to be increased by pre-charging, then the main contactor S1 is closed, and the battery pack 1 is used for supplying power to the bus.

It should be noted that, the first target voltage in this embodiment may be determined according to the current voltage of the battery module 11 in the battery pack 1, where the high-voltage bus capacitor may be tested by experiments to determine how much the difference between the charging voltage and the high-voltage bus capacitor voltage is in the charging process, so that the high-voltage bus capacitor may not be damaged. For example, if the difference between the charging voltage and the high-voltage bus capacitor voltage is 10 v, the high-voltage bus capacitor will not be damaged, and if the current voltage of the battery module 11 is 180 v, the first target voltage may be 170 v, that is, when it is determined that the high-voltage bus capacitor voltage is less than 170 v, the corresponding pre-charging mode may be adopted to control the DC-DC converter to charge the high-voltage bus capacitor by using the starter battery.

It will be appreciated that the DC-DC converter may adjust the output voltage v as required, so that it is ensured that the voltage provided by the starter battery 4, after being processed by the DC-DC converter, will not charge the high voltage bus capacitor more than the voltage of the high voltage bus capacitor. Alternatively, the starter battery typically employs a lead acid battery or a lithium iron phosphate battery.

In one embodiment of the present invention, as shown in fig. 5, the DC-DC converter is controlled in different pre-charge modes according to the initial voltage of the high-voltage bus capacitor, including:

s501, when the initial voltage of the high-voltage bus capacitor is smaller than a first preset voltage, a constant-current charging mode is adopted to control the DC-DC converter, wherein the first preset voltage is smaller than a first target voltage.

Specifically, if the initial voltage of the high-voltage bus capacitor is smaller than the first preset voltage, a constant-current charging mode is adopted to charge the high-voltage bus capacitor, the maximum current of the pre-charging is controlled, and the safety of the bus capacitor and the charging circuit during the pre-charging is ensured. For example, the first preset voltage may be 100 volts, and the first preset voltage is less than the first target voltage.

S502, when the initial voltage of the high-voltage bus capacitor is larger than or equal to a first preset voltage, a constant-power charging mode is adopted to control the DC-DC converter.

Specifically, if the initial voltage of the high-voltage bus capacitor is larger than or equal to the first preset voltage, the high-voltage bus capacitor is charged in a constant-power charging mode, the maximum power of the pre-charging is controlled, the pre-charging program can be rapidly completed, and the bus capacitor can be safely and rapidly pre-charged.

In this embodiment, both the constant current charging mode and the constant power charging mode are performed by converting the voltage supplied from the starter battery by the DC-DC converter.

In an embodiment of the present invention, as shown in fig. 6, in the process of controlling the DC-DC converter in the constant current charging mode, the pre-charging method further includes: when the real-time voltage of the high-voltage bus capacitor is larger than a second preset voltage, determining that constant-current pre-charging of the high-voltage bus capacitor is completed, wherein the second preset voltage is larger than or equal to a first preset voltage, and the second preset voltage is smaller than a first target voltage; and when the real-time voltage of the high-voltage bus capacitor is smaller than or equal to the second preset voltage and the duration time is longer than the first preset time, determining that the constant-current pre-charging of the high-voltage bus capacitor is overtime.

Specifically, referring to fig. 6, when it is determined that the high-voltage bus capacitor needs to be charged, and the high-voltage bus capacitor needs to be charged in a constant-current charging mode, the DC-DC converter may be controlled to start the constant-current output of the high-voltage terminal. In the constant current charging process, the voltage of the high-voltage bus capacitor can be judged, specifically, the real-time voltage of the high-voltage bus capacitor can be compared with a second preset voltage, and when the real-time voltage of the high-voltage bus capacitor is larger than the second preset voltage, the current constant current pre-charging mode is indicated to be completed, wherein the second preset voltage is larger than or equal to the first preset voltage, and the second preset voltage is smaller than the first target voltage. If the real-time voltage of the high-voltage bus capacitor is less than or equal to the second preset voltage in the constant-current charging process, further judging whether the current constant-current pre-charging mode exceeds the first preset time, if so, indicating that the current constant-current pre-charging mode has pre-charged the high-voltage bus capacitor over time, exiting the pre-charging program, and optionally, sending out an overtime alarm signal to remind a user when the overtime exits the pre-charging program; if the first preset time is not exceeded, whether the real-time voltage of the high-voltage bus capacitor is larger than the second preset voltage is judged again.

Alternatively, the second preset voltage in this embodiment may be 110 volts, the first preset time may be 200 milliseconds, and the third preset voltage may be 120 volts.

In this embodiment, when constant current precharge is completed for the high voltage bus capacitor, the precharge method further includes: and when the real-time voltage of the high-voltage bus capacitor is smaller than the first target voltage, a constant-power charging mode is adopted to control the DC-DC converter.

Specifically, after the high-voltage bus capacitor finishes constant-current pre-charging, it can be further determined whether the real-time voltage of the high-voltage bus capacitor is still smaller than the first target voltage, and if so, the DC-DC converter is controlled in a constant-power charging mode, so that the DC-DC converter can perform constant-power charging on the high-voltage bus capacitor. For example, in the above example, after the constant current pre-charging is completed, the voltage of the high voltage bus capacitor may be 110 v, if the first target voltage is 180 v, when the battery pack is used to directly charge the high voltage bus capacitor, the high voltage bus capacitor is still easy to be damaged, so the DC-DC converter may be controlled to continuously charge the high voltage bus capacitor in a constant power charging mode, so as to continuously increase the voltage of the high voltage bus capacitor in a pre-charging mode.

In some embodiments, as shown in fig. 6, in the process of controlling the DC-DC converter in the constant current charging mode, the output voltage of the DC-DC converter is further limited to be less than or equal to a third preset voltage, where the third preset voltage is greater than the second preset voltage.

Specifically, in the process of constant-current pre-charging of the high-voltage bus capacitor by the DC-DC converter, the voltage output by the high-voltage output end of the DC-DC converter is controlled to be smaller than or equal to a third preset voltage, so that the output power of the DC-DC converter is not too high in a constant-current mode, and the DC-DC converter is damaged.

In some embodiments of the present invention, as shown in fig. 7, the process of controlling the DC-DC converter in the constant power charging mode includes: when the real-time voltage of the high-voltage bus capacitor is larger than or equal to a first target voltage, determining that constant power pre-charging is completed on the high-voltage bus capacitor; and when the real-time voltage of the high-voltage bus capacitor is smaller than the first target voltage and the duration time is longer than the second preset time, determining that the constant power of the high-voltage bus capacitor is precharged overtime.

Specifically, referring to fig. 7, when it is determined that the high-voltage bus capacitor needs to be charged, and the high-voltage bus capacitor needs to be charged in a constant-power charging mode, the DC-DC converter can be controlled to start the constant-power output at the high-voltage end. In the constant power charging process, the voltage of the high-voltage bus capacitor can be judged, specifically, the voltage of the high-voltage bus capacitor can be compared with the first target voltage, and when the voltage of the high-voltage bus capacitor is greater than or equal to the first target voltage, the current constant power pre-charging mode is indicated to be completed. If the voltage of the high-voltage bus capacitor is less than or equal to the first target voltage in the constant power charging process, further judging whether the current constant power pre-charging mode exceeds the second preset time, if so, indicating that the current constant power pre-charging mode pre-charges the high-voltage bus capacitor over time, and exiting the pre-charging program, or alternatively, sending out an overtime alarm signal to remind a user when exiting the pre-charging program over time; and if the second preset time is not exceeded, judging whether the voltage of the high-voltage bus capacitor is larger than the first target voltage or not.

Alternatively, the second preset time in the present embodiment may be 500 milliseconds.

In some embodiments, as shown in fig. 7, during control of the DC-DC converter in the constant power charging mode, the output voltage of the DC-DC converter is also limited to be less than or equal to a second target voltage, where the second target voltage is greater than the first target voltage.

Specifically, in the process of performing constant power pre-charging on the high-voltage bus capacitor by the DC-DC converter, the voltage output by the high-voltage output end of the DC-DC converter is controlled to be smaller than or equal to the second target voltage, so that the charging voltage of the high-voltage bus capacitor is ensured not to exceed the second target voltage to cause abnormal high-voltage bus voltage, and the voltage of the high-voltage bus capacitor is ensured not to exceed the upper voltage bearing limit of the high-voltage bus capacitor to cause damage to the high-voltage bus capacitor.

In one embodiment of the present invention, when the voltage of the high-voltage bus capacitor is equal to or greater than the first target voltage, the pre-charging method further includes: when the voltage of the high-voltage bus capacitor is smaller than or equal to a second target voltage, determining that the high-voltage bus capacitor is completely precharged, wherein the second target voltage is larger than the first target voltage; and when the voltage of the high-voltage bus capacitor is larger than the second target voltage, determining that the voltage of the high-voltage bus capacitor is abnormal.

Specifically, after the DC-DC converter receives the first target voltage, the voltage of the current high-voltage bus capacitor may be compared with the first target voltage, when the voltage of the high-voltage bus capacitor is greater than or equal to the first target voltage, whether the voltage of the high-voltage bus capacitor is greater than the second target voltage is further determined, if the voltage of the high-voltage bus capacitor is greater than the second target voltage, it is indicated that the voltage of the current high-voltage bus capacitor is abnormal, the DC-DC converter should be immediately turned off, and an alarm signal is sent to notify the user; if the voltage of the high voltage bus capacitor is not greater than the second target voltage, the DC-DC converter is also turned off, indicating that no pre-charging is necessary.

It should be noted that, in this embodiment, the second target voltage is greater than the first target voltage, where the first target voltage and the second target voltage may be determined according to the current voltage of the battery module. For example, the current voltage of the battery module is 180 v, the high-voltage bus capacitor is within the range of 180±10 v, the battery module can directly charge the high-voltage bus capacitor, and the first target voltage can be 170 v, and the second target voltage can be 190 v. Alternatively, the high voltage bus capacitance may be controlled to be within 180.+ -.5 volts, or within 180.+ -.20 volts, depending on the application.

Fig. 8 is a flowchart of a method for pre-charging a high voltage bus capacitor in an electric vehicle according to an embodiment of the present invention. As shown in fig. 8, first, after receiving a precharge command and a first target voltage, the DC-DC converter determines whether the voltage of the high-voltage bus capacitor is less than the first target voltage, if the voltage of the high-voltage bus capacitor is greater than or equal to the first target voltage, further determines whether the voltage of the high-voltage bus capacitor is greater than a second target voltage, if the voltage of the high-voltage bus capacitor is greater than the second target voltage, turns off the DC-DC converter, and sends out an alarm signal of abnormal voltage or too high voltage; if the voltage of the high-voltage bus capacitor is less than or equal to the second target voltage, the DC-DC converter is turned off, and a signal of the completion of the pre-charging is sent out. If the voltage of the high-voltage bus capacitor is smaller than the first target voltage, further judging whether the voltage of the high-voltage bus capacitor is smaller than a first preset voltage, and when the voltage of the high-voltage bus capacitor is smaller than the first preset voltage, controlling the DC-DC converter in a constant-current charging mode, and limiting the voltage output by the DC-DC converter to be smaller than or equal to a third preset voltage; when the voltage of the high-voltage bus capacitor is larger than or equal to a first preset voltage, a constant-power charging mode is adopted to control the DC-DC converter, and the voltage output by the DC-DC converter is limited to be smaller than or equal to a second target voltage. And in the execution process of the constant current output mode and the constant power output mode, the voltage of the high-voltage bus capacitor is also repeatedly judged whether to be smaller than the first target voltage.

In addition, the DC-DC converter in the present invention may be a bidirectional converter, so that in the process of completing normal running when the electric vehicle is powered on, the starting battery may be charged through the DC-DC converter, that is, the voltage on the battery pack may be converted into a low voltage of 12 v by the DC-DC converter, so as to be used for the use of the entire vehicle piezoelectric device and the charging of the starting battery.

In summary, the method for pre-charging the high-voltage bus capacitor in the electric automobile can safely and efficiently pre-charge the high-voltage bus capacitor, saves pre-charging cost and maintenance cost, has higher controllability, and can also improve the service life of a circuit.

Further, the invention provides a computer readable storage medium, on which a pre-charging program of a high-voltage bus capacitor in an electric vehicle is stored, and when the pre-charging program of the high-voltage bus capacitor in the electric vehicle is executed by a processor, the pre-charging method of the high-voltage bus capacitor in the electric vehicle is realized.

Fig. 9 is a block diagram of a vehicle controller according to an embodiment of the present invention.

Further, as shown in fig. 9, the present invention proposes a vehicle controller 100, where the vehicle controller 100 includes a memory 101, a processor 102, and a pre-charging program of a high-voltage bus capacitor in an electric vehicle stored in the memory 101 and capable of running on the processor 102, and when the processor 102 executes the pre-charging program of the high-voltage bus capacitor in the electric vehicle, the pre-charging method of the high-voltage bus capacitor in the electric vehicle according to the above embodiment is implemented.

Further, as shown in fig. 2 and 3, the electric vehicle includes a DC-DC converter 3 and a starter battery 4, a high voltage end of the DC-DC converter 3 is connected to a high voltage bus capacitor C1 through a high voltage bus 2, a low voltage end of the DC-DC converter 3 is connected to the starter battery 4, and a pre-charging device 200 includes a receiving module 201, a determining module 202, and a pre-charging control module 203.

Wherein, the receiving module 201 is configured to receive a precharge instruction; the determining module 202 is configured to obtain an initial voltage of the high-voltage bus capacitor when the receiving module receives the precharge command; the pre-charge control module 203 is configured to control the DC-DC converter in different pre-charge modes according to the initial voltage of the high-voltage bus capacitor when the initial voltage of the high-voltage bus capacitor is less than the first target voltage, so that the starting battery charges the high-voltage bus capacitor through the DC-DC converter.

In some embodiments of the present invention, the priming control module 203 is further configured to: when the initial voltage of the high-voltage bus capacitor is smaller than a first preset voltage, a constant-current charging mode is adopted to control the DC-DC converter, wherein the first preset voltage is smaller than a first target voltage; when the initial voltage of the high-voltage bus capacitor is larger than or equal to a first preset voltage, a constant-power charging mode is adopted to control the DC-DC converter.

In some embodiments of the present invention, the priming control module 203 is further configured to: when the real-time voltage of the high-voltage bus capacitor is larger than a second preset voltage, determining that constant-current pre-charging of the high-voltage bus capacitor is completed, wherein the second preset voltage is larger than or equal to a first preset voltage, and the second preset voltage is smaller than a first target voltage; and when the real-time voltage of the high-voltage bus capacitor is smaller than or equal to the second preset voltage and the duration time is longer than the first preset time, determining that the constant-current pre-charging of the high-voltage bus capacitor is overtime.

In some embodiments of the present invention, when constant current pre-charging is completed for the high voltage bus capacitor, the pre-charging control module 203 is further configured to: and when the real-time voltage of the high-voltage bus capacitor is smaller than the first target voltage, a constant-power charging mode is adopted to control the DC-DC converter.

In some embodiments of the present invention, the priming control module 203 is further configured to: when the real-time voltage of the high-voltage bus capacitor is larger than or equal to a first target voltage, determining that constant power pre-charging is completed on the high-voltage bus capacitor; and when the real-time voltage of the high-voltage bus capacitor is smaller than the first target voltage and the duration time is longer than the second preset time, determining that the constant power of the high-voltage bus capacitor is precharged overtime.

In some embodiments of the present invention, during the control of the DC-DC converter in the constant current charging mode, the pre-charging control module 203 is further configured to: and limiting the output voltage of the DC-DC converter to be less than or equal to a third preset voltage, wherein the third preset voltage is greater than the second preset voltage.

In some embodiments of the present invention, during control of the DC-DC converter in a constant power charging mode, the pre-charge control module 203 is further configured to: the output voltage of the limiting DC-DC converter is less than a second target voltage, wherein the second target voltage is greater than the first target voltage.

In some embodiments of the present invention, when the voltage of the high-voltage bus capacitor is greater than or equal to the first target voltage, the precharge control module 203 is further configured to: when the voltage of the high-voltage bus capacitor is smaller than or equal to a second target voltage, determining that the high-voltage bus capacitor is completely precharged, wherein the second target voltage is larger than the first target voltage; and when the voltage of the high-voltage bus capacitor is larger than the second target voltage, determining that the voltage of the high-voltage bus capacitor is abnormal.

It should be noted that, for the specific implementation of the device for pre-charging the high-voltage bus capacitor in the electric vehicle according to the embodiment of the present invention, reference may be made to the specific implementation of the method for pre-charging the high-voltage bus capacitor in the electric vehicle in the above embodiment, which is not described herein again.

In summary, the pre-charging device for the high-voltage bus capacitor in the electric automobile can safely and efficiently pre-charge the high-voltage bus capacitor, saves pre-charging cost and maintenance cost, has higher controllability, and can also prolong the service life of a circuit.

It should be noted that the logic and/or steps represented in the flowcharts or otherwise described herein, for example, may be considered as a ordered listing of executable instructions for implementing logical functions, and may be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). In addition, the computer readable medium may even be paper or other suitable medium on which the program is printed, as the program may be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.

It is to be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the various steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, as used in embodiments of the present invention, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or as implying any particular number of features in the present embodiment. Thus, a feature of an embodiment of the invention that is defined by terms such as "first," "second," etc., may explicitly or implicitly indicate that at least one such feature is included in the embodiment. In the description of the present invention, the word "plurality" means at least two or more, for example, two, three, four, etc., unless explicitly defined otherwise in the embodiments.

In the present invention, unless explicitly stated or limited otherwise in the examples, the terms "mounted," "connected," and "fixed" as used in the examples should be interpreted broadly, e.g., the connection may be a fixed connection, may be a removable connection, or may be integral, and it may be understood that the connection may also be a mechanical connection, an electrical connection, etc.; of course, it may be directly connected, or indirectly connected through an intermediate medium, or may be in communication with each other, or in interaction with each other. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to specific embodiments.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims

1. The utility model provides a pre-charge method of high voltage bus capacitor in electric automobile, its characterized in that, electric automobile includes DC-DC converter and starting battery, the high voltage end of DC-DC converter passes through the high voltage bus and is connected with high voltage bus capacitor, the low voltage end of DC-DC converter with starting battery is connected, pre-charge method includes:

when a precharge command is received, acquiring the initial voltage of the high-voltage bus capacitor;

when the initial voltage of the high-voltage bus capacitor is smaller than a first target voltage, the DC-DC converter is controlled in different pre-charging modes according to the initial voltage of the high-voltage bus capacitor, so that the starting battery charges the high-voltage bus capacitor through the DC-DC converter.

2. The method for pre-charging a high-voltage bus capacitor in an electric vehicle according to claim 1, wherein the DC-DC converter is controlled in different pre-charging modes according to an initial voltage of the high-voltage bus capacitor, comprising:

When the initial voltage of the high-voltage bus capacitor is smaller than a first preset voltage, controlling the DC-DC converter in a constant-current charging mode, wherein the first preset voltage is smaller than the first target voltage;

and when the initial voltage of the high-voltage bus capacitor is larger than or equal to a first preset voltage, a constant-power charging mode is adopted to control the DC-DC converter.

3. The method for pre-charging a high-voltage bus capacitor in an electric vehicle according to claim 2, wherein in the process of controlling the DC-DC converter in a constant-current charging mode, the pre-charging method further comprises:

when the real-time voltage of the high-voltage bus capacitor is larger than a second preset voltage, determining that constant-current pre-charging is completed on the high-voltage bus capacitor, wherein the second preset voltage is larger than or equal to the first preset voltage, and the second preset voltage is smaller than the first target voltage;

and when the real-time voltage of the high-voltage bus capacitor is smaller than or equal to a second preset voltage and the duration time is longer than a first preset time, determining that the constant-current pre-charging of the high-voltage bus capacitor is overtime.

4. The method for pre-charging a high-voltage bus capacitor in an electric vehicle according to claim 3, wherein when constant-current pre-charging is completed for the high-voltage bus capacitor, the pre-charging method further comprises:

And when the real-time voltage of the high-voltage bus capacitor is smaller than the first target voltage, the DC-DC converter is controlled by adopting a constant-power charging mode.

5. The method for pre-charging a high voltage bus capacitor in an electric vehicle according to claim 2, wherein in the process of controlling the DC-DC converter in a constant power charging mode, the pre-charging method further comprises:

when the real-time voltage of the high-voltage bus capacitor is larger than or equal to the first target voltage, determining that constant power pre-charging is completed on the high-voltage bus capacitor;

and when the real-time voltage of the high-voltage bus capacitor is smaller than the first target voltage and the duration time is longer than a second preset time, determining that the constant-power pre-charging of the high-voltage bus capacitor is overtime.

6. The method according to any one of claims 2 to 5, characterized in that in the process of controlling the DC-DC converter in a constant current charging mode, the output voltage of the DC-DC converter is further limited to be equal to or less than a third preset voltage, wherein the third preset voltage is greater than the second preset voltage.

7. The method according to any one of claims 2 to 5, characterized in that during control of the DC-DC converter in a constant power charging mode, the output voltage of the DC-DC converter is also limited to be smaller than the second target voltage, which is larger than the first target voltage.

8. The method for pre-charging a high-voltage bus capacitor in an electric vehicle according to any one of claims 1 to 5, characterized in that when the voltage of the high-voltage bus capacitor is equal to or higher than the first target voltage, the pre-charging method further comprises:

when the voltage of the high-voltage bus capacitor is smaller than or equal to a second target voltage, determining that the high-voltage bus capacitor is completely precharged, wherein the second target voltage is larger than the first target voltage;

and when the voltage of the high-voltage bus capacitor is larger than a second target voltage, determining that the voltage of the high-voltage bus capacitor is abnormal.

9. A computer readable storage medium, characterized in that a pre-charging program of a high-voltage bus capacitor in an electric vehicle is stored thereon, and when the pre-charging program of the high-voltage bus capacitor in the electric vehicle is executed by a processor, the pre-charging method of the high-voltage bus capacitor in the electric vehicle according to any one of claims 1 to 8 is implemented.

10. A vehicle controller, characterized by comprising a memory, a processor and a pre-charging program of a high-voltage bus capacitor in an electric vehicle stored on the memory and capable of running on the processor, wherein the pre-charging method of the high-voltage bus capacitor in the electric vehicle according to any one of claims 1-8 is realized when the processor executes the pre-charging program of the high-voltage bus capacitor in the electric vehicle.

11. The utility model provides a pre-charge device of high voltage bus capacitor in electric automobile, its characterized in that, electric automobile includes DC-DC converter and starting battery, the high voltage end of DC-DC converter pass through the high voltage bus with high voltage bus capacitor connects, the low voltage end of DC-DC converter with starting battery connects, pre-charge device includes:

the receiving module is used for receiving the pre-charging instruction;

the determining module is used for acquiring the initial voltage of the high-voltage bus capacitor when the receiving module receives the pre-charging instruction;

and the pre-charging control module is used for controlling the DC-DC converter in different pre-charging modes according to the initial voltage of the high-voltage bus capacitor when the initial voltage of the high-voltage bus capacitor is smaller than the first target voltage, so that the starting battery charges the high-voltage bus capacitor through the DC-DC converter.