Active discharge circuit, discharge method, controller, discharge system, and vehicle

Abstract

The present application relates to an active discharge circuit, a discharge method, a controller, a discharge system, and a vehicle. The active discharge circuit comprises a first transmission bus, a second transmission bus, a first capacitor, a motor control circuit, a motor, and a second capacitor. The motor control circuit controls, on the basis of a motor control signal having an injection frequency, the motor to discharge the first capacitor and / or the second capacitor, so that no additional discharge components are required, and control of the entire discharge process is simplified, thereby improving the efficiency and safety of an active discharge operation.

Description

Active bleed circuit, bleed method, controller, bleed system and vehicle

[0001] The present application claims priority to the Chinese patent application No. 2024110975656, filed on August 9, 2024, entitled "Active bleed circuit, bleed method, controller, bleed system and vehicle", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of electric vehicles, in particular to an active bleed circuit, a bleed method, a controller, a bleed system and a vehicle. BACKGROUND

[0003] With the rapid development of new energy vehicles and the update iteration of their product technologies, especially the large-scale use of silicon carbide (SiC) motor controllers, the voltage platform of the power battery of the whole vehicle is getting higher and higher, thereby bringing greater challenges to the high-voltage safety of the whole vehicle. High-voltage safety is the most concerned indicator, and high-voltage safety involves high-voltage insulation, high-voltage active bleed, high-voltage passive bleed, high-voltage leakage, etc., among which the active bleed function requires that the first capacitor be discharged to below 60V within a specified time after the power of the whole vehicle is turned off.

[0004] On the existing motor controller, the bleed is mainly through a resistor. The resistor bleed requires an external switching tube and a high-power resistor for bleed. On the one hand, the hardware design needs to increase the high-power resistor and the switching tube, which brings pressure on the cost of the controller components. On the other hand, the structure or the circuit board needs to provide a radiator for the bleed resistor, which increases the development and sample making cost of the PCB or the structure. The overall function implementation cost is too high, and the structure and the hardware design are relatively complex. SUMMARY

[0005] The present application provides an active bleed circuit, a vehicle and a bleed method.

[0006] In order to achieve the above-mentioned purpose, according to the first aspect of the present application, an active bleed circuit is provided, which comprises a first transmission bus, a second transmission bus, a first capacitor, a motor control circuit, a motor and a second capacitor. The first transmission bus is used to connect the first pole of a battery pack, and the second transmission bus is used to connect the second pole of the battery pack. The first capacitor is connected to the first transmission bus and the second transmission bus. The motor control circuit is connected to the first transmission bus and the second transmission bus. The motor is connected to the motor control circuit. The first end of the second capacitor is electrically connected to the first transmission bus and / or the motor, and the second end of the second capacitor is connected to the second transmission bus. The motor control circuit controls the motor to bleed the first capacitor and / or the second capacitor according to the motor control signal of the injection frequency.

[0007] According to a second aspect of the present application, a bleeding method is provided, comprising: obtaining a frequency signal; outputting a motor control signal according to the frequency signal, so that the motor generates electromagnetic vibration to consume energy of the first capacitor and / or the second capacitor.

[0008] According to a third aspect of the present application, a controller is provided, comprising a processor and a memory connected to the processor, the memory being configured to store a computer program, and the processor being configured to execute the computer program to implement the bleeding method.

[0009] According to a fourth aspect of the present application, a bleeding system is provided, comprising the active bleeding circuit and the controller, the controller being configured to output the motor control signal to the motor control circuit, so that the motor generates electromagnetic vibration to consume energy of the first capacitor and / or the second capacitor.

[0010] According to a fifth aspect of the present application, a vehicle is provided, comprising the active bleeding circuit, or the controller, or the bleeding system.

[0011] In the active bleeding circuit of the embodiments of the present application, the motor control circuit controls the motor to bleed the first capacitor and / or the second capacitor according to the motor control signal of the injected frequency, without the need to add additional bleeding devices, and the whole process of bleeding is simplified, and the efficiency and safety of the active bleeding operation are improved.

[0012] Other features and advantages of the present application will be described in detail in the following detailed description of the embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0014] FIG. 1 shows a block diagram of the active bleeding circuit of the embodiments of the present application;

[0015] FIG. 2 shows a schematic diagram of the active bleeding circuit of the embodiments of the present application provided with a motor;

[0016] FIG. 3 shows a schematic diagram of the first case of the single-motor active bleeding of the embodiments of the present application;

[0017] FIG. 4 shows a schematic diagram of the second case of the single-motor active bleeding of the embodiments of the present application;

[0018] FIG. 5 shows a schematic diagram of the third case of the single-motor active bleeding of the embodiments of the present application;

[0019] Fig. 6 shows a schematic diagram of two motors in the active bleeding circuit according to an embodiment of the present application;

[0020] Fig. 7 shows a schematic diagram of two motor active bleeding according to an embodiment of the present application;

[0021] Fig. 8 shows a schematic diagram of three motors in the active bleeding circuit according to an embodiment of the present application;

[0022] Fig. 9 shows a schematic diagram of three motor active bleeding according to an embodiment of the present application;

[0023] Fig. 10 shows a flow chart of the bleeding method according to an embodiment of the present application;

[0024] Fig. 11 shows a schematic diagram of high-order dq coordinate voltage solution of multi-phase winding.

[0025] Legend: 100-active bleeding circuit, 101-battery pack, 102-first switch module, 103-first capacitor, 104-motor control circuit, 105-motor, 106-second switch module, 107-second capacitor, 108-charging and discharging interface, L1-first transmission bus, L2-second transmission bus, K0-precharge switch, K1-first switch, K2-second switch, K3-third switch, K4-fourth switch, K5-fifth switch, R-precharge resistor, VT1-first power switch, VT2-second power switch, VT3-third power switch, VT4-fourth power switch, VT5-fifth power switch, VT6-sixth power switch, VT7-seventh power switch, VT10-eighth power switch. Specific embodiments

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0027] The application mainly provides an active bleeding circuit 100, which is applied to an electric vehicle. The active bleeding circuit 100 comprises a first transmission bus, a second transmission bus, a first capacitor, a motor control circuit, a motor and a second capacitor, the first transmission bus is used for connecting a first pole of a battery pack, and the second transmission bus is used for connecting a second pole of the battery pack; the first capacitor is connected to the first transmission bus and the second transmission bus; the motor control circuit is connected to the first transmission bus and the second transmission bus; the motor is connected to the motor control circuit; a first end of the second capacitor is electrically connected to the first transmission bus and / or the motor, and a second end of the second capacitor is connected to the second transmission bus; wherein the motor is controlled to bleed the first capacitor and / or the second capacitor according to a motor control signal of an injection frequency through the motor control circuit. In the active bleeding circuit 100 of the application, the motor is controlled to bleed the first capacitor and / or the second capacitor according to the motor control signal of the injection frequency through the motor control circuit, without the need of adding additional devices, and the whole process of bleeding can be simplified, and the efficiency and safety of the active bleeding action are improved.

[0028] FIG. 1 shows a block diagram of the active bleeding circuit 100 of the application. As shown in FIG. 1, the active bleeding circuit 100 comprises a first transmission bus L1, a second transmission bus L2, a first capacitor 103 (C1a), a motor control circuit 104, a motor 105 and a second capacitor 107 (C2a) charge-discharge interface 108. The first transmission bus L1 is used for connecting a first pole of a battery pack 101, and the second transmission bus L2 is used for connecting a second pole of the battery pack 101. A first switch module 102 is connected to the battery pack 101, a first capacitor 103 (C1a) is connected to the first switch module 102, a motor control circuit 104 is connected to the first capacitor 103 (C1a), a motor 105 is connected to the motor control circuit 104, a second switch module 106 is connected to the motor control circuit 104, a second capacitor 107 (C2a) is connected to the second switch module 106, and a charge-discharge interface 108 is connected to the second capacitor 107 (C2a).

[0029] The first pole of the battery pack 101 is connected to the first transmission bus L1, and the second pole of the battery pack 101 is connected to the second transmission bus L2. The bus can be a high-voltage bus. In FIG. 1, the first switch module 102, the first capacitor 103 (C1a), the motor control circuit 104, the second switch module 106, the second capacitor 107 (C2a) and the charge-discharge interface 108 can be mounted between the high-voltage first transmission bus L1 and the high-voltage second transmission bus L2, and the battery pack 101, the first switch module 102, the first capacitor 103 (C1a), the motor control circuit 104, the second switch module 106, the second capacitor 107 (C2a) and the charge-discharge interface 108 are arranged in parallel.

[0030] The motor control circuit 104 controls the motor 105 to discharge the first capacitor 103 (C1a) and / or the second capacitor 107 (C2a) according to the motor control signal of the injected frequency.

[0031] FIG. 2 shows a schematic diagram of a motor provided in the active discharge circuit 100 according to an embodiment of the present application.

[0032] In an embodiment, the first switch module includes a pre-charge switch K0 and a pre-charge resistor R. The first end of the pre-charge switch K0 is connected to the first pole of the battery pack 101 (E1), the second end of the pre-charge switch K0 is connected to the first end of the pre-charge resistor R, and the second end of the pre-charge resistor R is connected to the first transmission bus.

[0033] When the first capacitor C1a needs to be pre-charged, the pre-charge switch K0 is closed, thereby completing the pre-charging of the first capacitor C1a. After the pre-charging is completed, the pre-charge switch K0 is opened.

[0034] The first switch module 102 further includes a first switch K1 and a second switch K2. The first end of the first switch K1 is connected to the second pole of the battery pack, and the second end of the first switch K1 is connected to the second end of the first capacitor C1a. The first end of the second switch K2 is connected to the first pole of the battery pack, and the second end of the second switch K2 is connected to the first end of the first capacitor C1a.

[0035] The first end of the first capacitor C1a is connected to the first transmission bus, and the second end of the first capacitor C1a is connected to the second transmission bus.

[0036] The motor control circuit includes a plurality of bridge arms, for example, m bridge arms, where m is a natural number. The two ends of the plurality of bridge arms are connected in parallel to the first transmission bus and the second transmission bus, and the midpoint of each bridge arm is connected to the motor. The first end of each bridge arm in the plurality of bridge arms is connected to the first transmission bus, and the second end of each bridge arm in the plurality of bridge arms is connected to the second transmission bus.

[0037] The motor control circuit is configured to control the duty cycle of the upper bridge arm and / or the lower bridge arm of at least one bridge arm according to the pulse width modulation signal to control the active discharge process.

[0038] The bridge arm includes two power switches, the two power switches of the bridge arm are connected in series, and a midpoint of each bridge arm is located between the two power switches of the bridge arm. The power switch can be a device such as a bipolar transistor (BJT), a metal-oxide-semiconductor field-effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), and the like, and the application is not limited thereto. Optionally, the power switch is a three-terminal device.

[0039] The motor includes a stator winding, and the stator winding includes m phase coils.

[0040] In some possible implementations, the motor is a neutral line lead-out. A first end of each phase coil is connected to a midpoint of a bridge arm, and a second end of each phase coil is connected to a neutral line N1, and the neutral line N1 is connected to the second switch module 106. Wherein, N1 can be regarded as a neutral point.

[0041] In another possible implementation, the motor is a phase line lead-out. The m phase coils include a first coil and at least one second coil, and the first coil is used to be electrically connected to a first end of the second capacitor, so that the first coil is connected in series with the at least one second coil.

[0042] In an embodiment, the motor is an electrically excited synchronous motor (EESM). The electrically excited synchronous motor generates a rotor magnetic field by using an excitation winding, and a stator generates a rotating magnetic field by using alternating current. When the rotating magnetic field and the rotor magnetic field interact, the motor generates a torque to drive the vehicle to travel.

[0043] Taking m=3 as an example, the motor control circuit is a three-phase motor control circuit. At this time, the motor control circuit includes three bridge arms, and each bridge arm in the three bridge arms is connected in parallel to the first transmission bus and the second transmission bus, and a midpoint of each bridge arm is connected to the motor. Specifically, the motor control circuit includes a first bridge arm, a second bridge arm, and a third bridge arm.

[0044] The first bridge arm comprises a first power switch VT1 and a second power switch VT2, a first end of the first power switch VT1 is connected to the processor, a second end of the first power switch VT1 is connected to a midpoint of the first bridge arm, a third end of the first power switch VT1 is a first end of the first bridge arm, and the third end of the first power switch VT1 is connected to the first transmission bus. A first end of the second power switch VT2 is connected to the processor, a second end of the second power switch VT2 is a second end of the first bridge arm, the second end of the second power switch VT2 is connected to the second transmission bus, and a third end of the second power switch VT2 is connected to the midpoint of the first bridge arm.

[0045] The second bridge arm comprises a third power switch VT3 and a fourth power switch VT4, a first end of the third power switch VT3 is connected to the processor, a second end of the third power switch VT3 is connected to a midpoint of the second bridge arm, and a third end of the third power switch VT3 is connected to the first transmission bus. A first end of the fourth power switch VT4 is connected to the processor, a second end of the fourth power switch VT4 is connected to the second transmission bus, and a third end of the fourth power switch VT4 is connected to the midpoint of the second bridge arm.

[0046] The third bridge arm comprises a fifth power switch VT5 and a sixth power switch VT6, a first end of the fifth power switch VT5 is connected to the processor, a second end of the fifth power switch VT5 is connected to a midpoint of the third bridge arm, and a third end of the fifth power switch VT5 is connected to the first transmission bus. A first end of the sixth power switch VT6 is connected to the processor, a second end of the sixth power switch VT6 is connected to the second transmission bus, and a third end of the sixth power switch VT6 is connected to the midpoint of the third bridge arm.

[0047] In an embodiment, there is a parasitic diode on each power switch of the bridge arm. Taking FIG. 2 as an example, a first pole of a parasitic diode VD1 of the first power switch VT1 is connected to the second end of the first power switch VT1, a first pole of a parasitic diode VD3 of the third power switch VT3 is connected to the second end of the third power switch VT3, a first pole of a parasitic diode VD5 of the fifth power switch VT5 is connected to the second end of the fifth power switch VT5, and the second poles of the parasitic diodes of the first power switch VT1, the third power switch VT3 and the fifth power switch VT5 are all connected to the first transmission bus. A second pole of a parasitic diode VD2 of the second power switch VT2 is connected to the third end of the second power switch VT2, a second pole of a parasitic diode VD4 of the fourth power switch VT4 is connected to the third end of the fourth power switch VT4, a second pole of a parasitic diode VD6 of the sixth power switch VT6 is connected to the third end of the sixth power switch VT6, and the first poles of the parasitic diodes of the second power switch VT2, the fourth power switch VT4 and the sixth power switch VT6 are all connected to the second transmission bus.

[0048] The stator winding of the electrically excited synchronous motor transmits three-phase current, which is A phase, B phase and C phase respectively. The A phase coil is connected to the midpoint A11 of the first bridge arm, the B phase coil is connected to the midpoint B11 of the second bridge arm, and the C phase coil is connected to the midpoint C11 of the third bridge arm. Among them, the electrically excited synchronous motor can be three-phase four-wire system. In FIG. 2, the winding A1, the winding A2, the winding A3 and the winding A4 can lead to the connection points of the A phase coil, the winding B1, the winding B2, the winding B3 and the winding B4 can lead to the connection points of the B phase coil, and the winding C1, the winding C2, the winding C3 and the winding C4 can lead to the connection points of the C phase coil, and then form n1, n2, n3 and n4 four junction points, and then be connected to the neutral line N1. The electrically excited synchronous motor can also be three-phase three-wire system.

[0049] In an embodiment, the motor further comprises a rotor coil, and the motor control circuit further comprises an excitation control module connected to the first transmission bus, the second transmission bus and the rotor coil, and the excitation control module is configured to control an excitation parameter of the rotor of the electrically excited synchronous motor. The excitation parameter can be a parameter such as excitation voltage, excitation current, etc.

[0050] The excitation control module comprises a seventh power switch VT7, an eighth power switch VT10, a first diode VD8 and a second diode VD9. The first end of the seventh power switch VT7 is connected to the processor, the second end of the seventh power switch VT7 is connected to the second pole of the first diode VD8, the third end of the seventh power switch VT7 is connected to the first transmission bus, and the first pole of the first diode VD8 is connected to the second transmission bus. The first end of the eighth power switch VT10 is connected to the processor, the second end of the eighth power switch VT10 is connected to the first pole of the second transmission bus, the third end of the eighth power switch VT10 is connected to the first pole of the second diode VD9, and the second pole of the second diode VD9 is connected to the third end of the seventh power switch VT7.

[0051] There is a parasitic diode on each of the seventh power switch VT7 and the eighth power switch VT10. The first pole of the parasitic diode VD7 of the seventh power switch VT7 is connected to the second end of the seventh power switch VT7, and the second pole of the parasitic diode VD7 of the seventh power switch VT7 is connected to the third end of the seventh power switch VT7. The first pole of the parasitic diode VD10 of the eighth power switch VT10 is connected to the second end of the eighth power switch VT10, and the second pole of the parasitic diode VD10 of the eighth power switch VT10 is connected to the third end of the eighth power switch VT10.

[0052] The first end of the rotor coil is connected to a midpoint between the seventh power switch VT7 and the first diode VD8, and the second end of the rotor coil is connected to a midpoint between the eighth power switch VT10 and the second diode VD9. The first end of the rotor coil can be a positive end, and the second end of the rotor coil can be a negative end. Alternatively, the first end of the rotor coil is connected to the second pole of the first diode VD8, and the second end of the rotor coil is connected to the first pole of the second diode VD9.

[0053] The second switch module 106 includes a third switch K3 and a fourth switch K4, the fourth switch K4 is a motor switch, the first end of the third switch K3 is connected to the second end of the second capacitor C2a, and the second end of the third switch K3 is connected to the charge-discharge interface; the first end of the fourth switch K4 is connected to the neutral point of the multi-phase coil or the first coil in the multi-phase coil, and the second end of the fourth switch K4 is connected to the first end of the second capacitor C2a.

[0054] The second switch module 106 further includes a fifth switch K5, the fifth switch K5 is a first pole switch, the first end of the fifth switch K5 is connected to the first transmission bus, and the second end of the fifth switch K5 is connected to the first end of the second capacitor C2a.

[0055] The first end of the second capacitor C2a is connected to the charge-discharge interface, and the second end of the second capacitor C2a is connected to the second transmission bus.

[0056] In one of the embodiments, each bridge arm includes an upper bridge arm and a lower bridge arm, wherein, in the active bleeding process, the upper bridge arm and the lower bridge arm of at least one bridge arm of the motor control circuit are alternately turned on, so that the bus voltage across the first capacitor and the interface voltage across the second capacitor are charged and discharged back and forth through the bridge arm and the motor winding, and the energy consumption of the bridge arm and the motor winding is discharged. The motor control circuit is configured to control the duty cycle of the upper bridge arm and / or the lower bridge arm of at least one bridge arm according to a pulse width modulation signal to control the active bleeding process.

[0057] In one of the embodiments, a plurality of motors are arranged in the active bleeding circuit, and the plurality of motors are configured to use the motors that can normally work and have a temperature within a safe range for bleeding.

[0058] In one of the embodiments, the plurality of motors include a first motor and a second motor, the second motor is connected to a second motor control circuit, the first motor is connected to a first motor control circuit, the first motor is a synchronous motor with electric excitation, the second motor is a first alternating current motor, and the priority of using the first motor for bleeding is higher than the priority of using the second motor for bleeding.

[0059] In one of the embodiments, the second motor is an asynchronous motor, the plurality of motors further comprises a third motor, the third motor is a synchronous motor, the third motor is connected to a third motor control circuit, and the priority of discharging by using the second motor is higher than the priority of discharging by using the third motor.

[0060] In this way, by reasonably setting the priority of the discharging device, the discharging function can be ensured to be normal to a greater extent, and the normal operation of the vehicle can be ensured.

[0061] FIG. 3 shows a schematic diagram of a first case of single motor active discharging according to an embodiment of the application.

[0062] As shown in FIG. 3, in the mode of boosting charging of the battery pack by the charging and discharging port, the bus voltage across the first capacitor C1a and the interface voltage across the second capacitor C2a are inconsistent, and it is necessary to pull the bus voltage across the first capacitor C1a and the interface voltage across the second capacitor C2a to be consistent before active discharging, so as to make the bus voltage across the first capacitor C1a and the interface voltage across the second capacitor C2a consistent.

[0063] In the mode of boosting charging of the battery pack by the charging and discharging port, the third switch K3 and the fourth switch K4 are in the attracted state. In order to make the bus voltage across the first capacitor C1a and the interface voltage across the second capacitor C2a consistent, the first switch K1, the second switch K2 and the third switch K3 are adjusted to be in the open state, and the fourth switch K4 is kept in the attracted state. The plurality of upper bridge arms of the motor control circuit are turned on, for example, in FIG. 3, the first power switch VT1, the third power switch VT3 and the fifth power switch VT5 of the motor control circuit are upper bridge arms and are in the conducting state, and then the three-phase coils of the motor are turned on. Since the first capacitor C1a stores charges, a current loop along the clockwise direction is formed between the first capacitor C1a, the upper bridge arms of the motor control circuit, the motor and the fourth switch K4 of the second switch module 106. Since the fourth switch K4 is kept in the attracted state, the current passes through the second capacitor C2a, so as to quickly make the bus voltage across the first capacitor C1a and the interface voltage across the second capacitor C2a consistent.

[0064] It should be noted that since the three-phase coils of the motor are turned on together, the phase current of the motor is consistent, which will not cause torque fluctuation problem, and can shorten the balancing time of the bus voltage across the first capacitor C1a and the interface voltage across the second capacitor C2a, so that the whole voltage balancing process is very fast.

[0065] FIG. 4 shows a schematic diagram of a second case of single motor active discharging according to an embodiment of the application.

[0066] As shown in FIG. 4, after the bus voltage across the first capacitor C1a and the interface voltage across the second capacitor C2a are consistent, the fifth switch K5 can be adjusted from the open state to the attracted state, so that there is no voltage difference across the fifth switch K5, thereby avoiding the generation of impulse current.

[0067] After the fifth switch K5 is attracted, the plurality of upper bridge arms of the motor control circuit are open, and the plurality of lower bridge arms of the motor control circuit are turned on. For example, in FIG. 4, the second power switch VT2, the fourth power switch VT4 and the sixth power switch VT6 of the motor control circuit are lower bridge arms and are in the on state. At this time, a current loop along the clockwise direction is formed between the second capacitor C2a, the motor, the lower bridge arms of the motor control circuit, the first capacitor C1a, the first transmission bus and the fifth switch K5, and another current loop along the counterclockwise direction is formed between the second capacitor C2a, the motor, the lower bridge arms of the motor control circuit and the second transmission bus.

[0068] FIG. 5 shows a schematic diagram of a third case of the single-motor active bleeding of the embodiment of the application.

[0069] As shown in FIG. 5, the fourth switch K4 and the fifth switch K5 remain in the attracted state, the plurality of upper bridge arms of the motor control circuit are turned on, and the plurality of lower bridge arms of the motor control circuit are open. At this time, a current loop along the clockwise direction is formed between the fourth switch K4, the motor, the upper bridge arms of the motor control circuit and the fifth switch K5.

[0070] It should be noted that the first case of FIG. 3, the second case of FIG. 4 and the third case of FIG. 5 can be implemented in the order of first, second and third, and are performed in turn. According to the control mode of FIGS. 3-5, the upper bridge arms and the lower bridge arms of the motor control circuit are alternately turned on, and in the process of turn-by-turn control, the processor can send a pulse width modulation signal to the first end of each power switch to perform pulse width modulation. The duty cycle of the pulse width modulation signal can be adjusted from small to large according to the time sequence.

[0071] In an embodiment, two motors can be provided in the active bleeding circuit 100. The active bleeding circuit 100 includes a first motor 1051 and a second motor 1052. The second motor is connected to a second motor control circuit, and the first motor is connected to a first motor control circuit. The second motor can be a synchronous motor, an asynchronous motor, an electrically excited motor, etc., and the first motor can be a synchronous motor, an asynchronous motor, an electrically excited motor, etc.

[0072] FIG. 6 shows a schematic diagram of the active bleeding circuit 100 provided with two motors according to an embodiment of the application.

[0073] As shown in FIG. 6, the structure of the second motor control circuit is exactly the same as that of the motor control circuit of FIG. 2, and the second motor control circuit is connected to the first transmission bus and the second transmission bus. The second motor is connected to the midpoint of each bridge arm of the second motor control circuit.

[0074] Different from FIG. 2, in FIG. 6, there is a thirty-first capacitor C31 in addition to the first capacitor C1a, the first motor control circuit is connected to the second end and the first end of the thirty-first capacitor C31, the second end of the thirty-first capacitor C31 is connected to the second end of the first capacitor C1a through the inductor L, and the first end of the thirty-first capacitor C31 is connected to the first end of the first capacitor C1a. The first motor is connected to the midpoint of each bridge arm of the first motor control circuit.

[0075] The battery pack 101 (E1) and other battery packs E2 are connected in series, the seventh switch K7 is connected between the battery pack 101 (E1) and the other battery packs E2, and the seventh switch K7 is connected with the neutral line N3; the first motor 1051 is respectively connected with the neutral line N3 and the first motor control circuit, and the first motor control circuit includes three bridge arms, which are the fourth bridge arm, the fifth bridge arm and the sixth bridge arm.

[0076] The fourth bridge arm includes the ninth power switch VT31 and the tenth power switch VT32, the first end of the ninth power switch VT31 is connected to the processor, the second end of the ninth power switch VT31 is connected to the midpoint A13 of the fourth bridge arm, the third end of the ninth power switch VT31 is the first end of the fourth bridge arm, and the third end of the ninth power switch VT31 is connected to the first transmission bus. The first end of the tenth power switch VT32 is connected to the processor, the second end of the tenth power switch VT32 is the second end of the fourth bridge arm, the second end of the tenth power switch VT32 is connected to the second transmission bus, and the third end of the tenth power switch VT32 is connected to the midpoint A13 of the fourth bridge arm.

[0077] The fifth bridge arm includes the eleventh power switch VT33 and the twelfth power switch VT34, the first end of the eleventh power switch VT33 is connected to the processor, the second end of the eleventh power switch VT33 is connected to the midpoint B13 of the fifth bridge arm, and the third end of the eleventh power switch VT33 is connected to the first transmission bus. The first end of the twelfth power switch VT34 is connected to the processor, the second end of the twelfth power switch VT34 is connected to the second transmission bus, and the third end of the twelfth power switch VT34 is connected to the midpoint B13 of the fifth bridge arm.

[0078] The sixth bridge arm comprises a thirteenth power switch VT35 and a fourteenth power switch VT36. The first end of the thirteenth power switch VT35 is connected to the processor, the second end of the thirteenth power switch VT35 is connected to the midpoint C13 of the sixth bridge arm, and the third end of the thirteenth power switch VT35 is connected to the first transmission bus. The first end of the fourteenth power switch VT36 is connected to the processor, the second end of the fourteenth power switch VT36 is connected to the second transmission bus, and the third end of the fourteenth power switch VT36 is connected to the midpoint C13 of the sixth bridge arm.

[0079] A parasitic diode exists on each power switch of the bridge arm. The first end of the parasitic diode VD31 of the ninth power switch VT31 is connected to the second end of the ninth power switch VT31, the first end of the parasitic diode VD33 of the eleventh power switch VT33 is connected to the second end of the eleventh power switch VT33, and the first end of the parasitic diode VD35 of the thirteenth power switch VT35 is connected to the second end of the thirteenth power switch VT35. The second ends of the parasitic diodes of the ninth power switch VT31, the eleventh power switch VT33 and the thirteenth power switch VT35 are all connected to the first transmission bus. The second end of the parasitic diode VD32 of the tenth power switch VT32 is connected to the third end of the tenth power switch VT32, the second end of the parasitic diode VD34 of the twelfth power switch VT34 is connected to the third end of the twelfth power switch VT34, and the second end of the parasitic diode VD36 of the fourteenth power switch VT36 is connected to the third end of the fourteenth power switch VT36. The first ends of the parasitic diodes of the tenth power switch VT32, the twelfth power switch VT34 and the fourteenth power switch VT36 are all connected to the second transmission bus.

[0080] FIG. 7 shows a schematic diagram of active bleeding of two motors according to an embodiment of the present application.

[0081] As shown in FIG. 7, in the mode of charging the battery pack by the charging and discharging port. In order to make the bus voltage between the first capacitor C1a and the interface voltage between the second capacitor C2a consistent, the second switch K2, the first switch K1 and the third switch K3 are adjusted to be in the open state, and the fourth switch K4 is kept in the attracted state. The upper bridge arm of the second motor control circuit is turned on, and then the three-phase coil of the second motor is turned on. At this time, the first capacitor C1a, the upper bridge arm of the second motor control circuit, the second motor and the fourth switch K4 form a current loop flowing along the clockwise direction. In addition, the thirty-first capacitor C31, the inductor L and the first capacitor C1a also form a current loop flowing along the counterclockwise direction, so that the voltage on the first capacitor C1a and the thirty-first capacitor C31 is discharged.

[0082] In an embodiment, three motors can be provided in the active bleeding circuit 100, the active bleeding circuit 100 includes a first motor 1051, a second motor 1052 and a third motor 1053, the first motor is connected to the first motor control circuit, the second motor is connected to the second motor control circuit, and the third motor is connected to the third motor control circuit. The first motor can be a synchronous motor, an asynchronous motor, an electrically excited motor, etc., the second motor can be a synchronous motor, an asynchronous motor, an electrically excited motor, etc., and the third motor can be a synchronous motor, an asynchronous motor, an electrically excited motor, etc.

[0083] FIG. 8 shows a schematic diagram of an active bleeding circuit 100 provided with three motors according to an embodiment of the present application.

[0084] As shown in FIG. 8, the structures of the first motor control circuit, the second motor control circuit and the third motor control circuit are all the same as that of the motor control circuit in FIG. 2. The first motor control circuit is connected to the first end and the second end of the thirty-first capacitor C31, the second motor control circuit is connected to the first end and the second end of the first capacitor C1a, and the third motor control circuit is connected to the first end and the second end of the twenty-first capacitor C21. The first motor is connected to the midpoint of each bridge arm of the first motor control circuit, the second motor is connected to the midpoint of each bridge arm of the second motor control circuit, and the third motor is connected to the midpoint of each bridge arm of the third motor control circuit.

[0085] Different from FIG. 2, the first end of the thirty-first capacitor C31 is connected to the first end of the inductor L, the second end of the inductor L is connected to the first end of the first capacitor C1a, the second end of the thirty-first capacitor C31 is connected to the second end of the first capacitor C1a and the second end of the twenty-first capacitor C21, and the first end of the twenty-first capacitor C21 is connected to the first pole of the battery pack through the second switch K2.

[0086] The twenty-second capacitor C22 is provided in parallel with the charging and discharging interface 2; the second motor 1052 is connected to the neutral line N2 and the second motor control circuit, the second motor control circuit includes three bridge arms, i.e., the seventh bridge arm, the eighth bridge arm and the ninth bridge arm;

[0087] The seventh bridge arm comprises a fifteenth power switch VT21 and a sixteenth power switch VT22. The first end of the fifteenth power switch VT21 is connected to the processor, the second end of the fifteenth power switch VT21 is connected to the midpoint A12 of the seventh bridge arm, the third end of the fifteenth power switch VT21 is the first end of the seventh bridge arm, and the third end of the fifteenth power switch VT21 is connected to the first transmission bus. The first end of the sixteenth power switch VT22 is connected to the processor, the second end of the sixteenth power switch VT22 is the second end of the seventh bridge arm, the second end of the sixteenth power switch VT22 is connected to the second transmission bus, and the third end of the sixteenth power switch VT22 is connected to the midpoint A12 of the seventh bridge arm.

[0088] The eighth bridge arm comprises a seventeenth power switch VT23 and an eighteenth power switch VT24. The first end of the seventeenth power switch VT23 is connected to the processor, the second end of the seventeenth power switch VT23 is connected to the midpoint B12 of the eighth bridge arm, and the third end of the seventeenth power switch VT23 is connected to the first transmission bus. The first end of the eighteenth power switch VT24 is connected to the processor, the second end of the eighteenth power switch VT24 is connected to the second transmission bus, and the third end of the eighteenth power switch VT24 is connected to the midpoint B12 of the eighth bridge arm.

[0089] The ninth bridge arm comprises a nineteenth power switch VT25 and a twentieth power switch VT26. The first end of the nineteenth power switch VT25 is connected to the processor, the second end of the nineteenth power switch VT25 is connected to the midpoint C12 of the ninth bridge arm, and the third end of the nineteenth power switch VT25 is connected to the first transmission bus. The first end of the twentieth power switch VT26 is connected to the processor, the second end of the twentieth power switch VT26 is connected to the second transmission bus, and the third end of the twentieth power switch VT26 is connected to the midpoint C12 of the ninth bridge arm.

[0090] A parasitic diode exists on each power switch of the bridge arm. The first pole of the parasitic diode VD21 of the fifteenth power switch VT21 is connected to the second end of the fifteenth power switch VT21, the first pole of the parasitic diode VD23 of the seventeenth power switch VT23 is connected to the second end of the seventeenth power switch VT23, the first pole of the parasitic diode VD25 of the nineteenth power switch VT25 is connected to the second end of the nineteenth power switch VT25, and the second poles of the parasitic diodes of the fifteenth power switch VT21, the seventeenth power switch VT23 and the nineteenth power switch VT25 are all connected to the first transmission bus; the second pole of the parasitic diode VD22 of the sixteenth power switch VT22 is connected to the third end of the sixteenth power switch VT22, the second pole of the parasitic diode VD24 of the eighteenth power switch VT24 is connected to the third end of the eighteenth power switch VT24, the second pole of the parasitic diode VD26 of the twentieth power switch VT26 is connected to the third end of the twentieth power switch VT26, and the first poles of the parasitic diodes of the sixteenth power switch VT22, the eighteenth power switch VT24 and the twentieth power switch VT26 are all connected to the second transmission bus.

[0091] Fig. 9 shows a schematic diagram of three-motor active bleeding of the embodiment of the application.

[0092] As shown in Fig. 9, for the three-electric-drive system, in the boost charging mode, the direct-current charging and discharging interface 1 is charged, the third switch K3 and the fourth switch K4 are attracted, and after the charging is completed, the twenty-first capacitor C21, the first capacitor C1a and the thirty-first capacitor C31 are discharged.

[0093] In the active bleeding process, the third switch K3 needs to be turned off, the fourth switch K4 needs to be kept attracted, then the first switch K1 and the second switch K2 are turned off, the same phase or opposite phase is adjusted by controlling the different drive winding bridge arm switches, and the switching frequency of the bridge arm is increased, so that the three-phase current flows into or out of the charging port at the same time, and the bus and the charging port are simultaneously discharged.

[0094] In the active bleeding process, when the bus voltage surge is greater than the highest voltage of the battery pack or a certain safety value, the duty cycle of the pulse width modulation signal in the motor control circuit is adjusted to make the current flow to the charging port; when the charging port voltage surge is close to the bus voltage at the time or a certain safety value, the duty cycle is adjusted to make the charging current flow to the bus side, so that the bus and the second capacitor C2a voltage are rapidly discharged, and torque fluctuation or even gear abnormal sound and other micro-noise problems are avoided, and the fourth switch K4 is turned off after the discharge is completed.

[0095] When multiple charging ports are charging at the same time, for example, DC charging and discharging interface 1 and DC charging and discharging interface 2 are charging at the same time, after charging is completed, in the active discharge process, the third switch K3 and the eighth switch K8 need to be disconnected, the fourth switch K4 and the sixth switch K6 are kept attracted, and then at least one motor is selected to use the above scheme for active discharge.

[0096] In an embodiment, the multi-motor drive of the present application can have various forms. For example, the active discharge circuit 100 includes one electrically excited motor, or one electrically excited motor and one permanent magnet synchronous motor, or one electrically excited motor and one / two permanent magnet synchronous motors, or one electrically excited motor and one permanent magnet synchronous motor and one asynchronous motor, etc. For another example, the active discharge circuit 100 includes two permanent magnet synchronous motors and one asynchronous motor. For another example, the active discharge circuit 100 includes one, two, four permanent magnet synchronous motor systems, etc. It can be understood that the present application does not limit the specific combination of multi-motor drive.

[0097] In an embodiment, the processor can also receive the temperature and fault state of the motor winding, power module, etc., and select at least one motor control circuit for control according to the temperature and fault state. According to the temperature and fault state of the motor winding, power module, etc., at least one controller module without fault and with temperature within a safe range is selected for active discharge to achieve active discharge of the internal capacitor of the motor control circuit. Selecting a power module without fault and with temperature within a safe range for discharge can reduce the risk of causing secondary damage and aggravating damage, and is more secure.

[0098] In an embodiment, the power winding module without fault and with temperature within a safe range is preferentially selected for active discharge, the electrically excited motor drive winding module circuit is secondly selected for active discharge, the asynchronous motor winding module is thirdly selected for active discharge if the electrically excited drive system has a fault, and the permanent magnet synchronous motor winding module is lastly selected for active discharge. If all electric drive systems have a fault, the DC / DC system and the OBC system are selected for active discharge, and the electric drive system active discharge fault is reported. In this way, the active discharge function can be maximally ensured to be normal, and the safety of the whole vehicle can be ensured.

[0099] It is worth noting that the electrically excited motor has a special excitation bridge arm. Even if the motor zero position is not accurate, the excitation bridge arm is used for discharge without the need for zero position and dq axis current control, and will not cause problems such as torque fluctuation, motor gear teeth, abnormal sound, etc. caused by inaccurate zero position and dq axis current control fluctuation of the synchronous motor. The asynchronous motor is secondly selected. The asynchronous motor has single-sided excitation and no permanent magnet, and does not need zero position and d-axis current control fluctuation, and is not prone to cause problems such as motor gear teeth and abnormal sound. The permanent magnet synchronous motor is lastly selected. The permanent magnet synchronous motor has a rotor magnetic field, and inaccurate zero position or d-axis current control fluctuation is prone to cause problems such as motor gear teeth and abnormal sound.

[0100] FIG. 10 shows a flow chart of a bleeding method according to an embodiment of the present application. As shown in FIG. 10, the bleeding method is applied to the active bleeding circuit described above, and the bleeding method comprises the following steps:

[0101] Step S10: obtaining a frequency signal.

[0102] Step S20: outputting a motor control signal according to the frequency signal, so that the motor generates electromagnetic vibration to consume the energy of the first capacitor and / or the second capacitor.

[0103] In one embodiment, outputting the motor control signal according to the frequency signal comprises: performing amplitude mapping processing on the frequency signal to obtain a current and / or voltage in an amplitude dimension; obtaining a current and / or voltage control signal in an n-order synchronous rotating coordinate system based on the current and / or voltage in the amplitude dimension; and injecting the current and / or voltage control signal in the n-order synchronous rotating coordinate system into a harmonic of a vector control system of the motor, so as to output the motor control signal by using the vector control system, the vector control system being a rotor field-oriented vector control system established based on the motor.

[0104] The frequency signal may be, but is not limited to, an audio signal.

[0105] In one embodiment, obtaining the current and / or voltage control signal in the n-order synchronous rotating coordinate system based on the current and / or voltage in the amplitude dimension comprises: performing n-order synchronous coordinate transformation on motor phase currents respectively, so as to extract n-order synchronous coordinate feedback harmonic current values; obtaining a target harmonic current value based on the current in the amplitude dimension; and performing proportional integral adjustment on the feedback harmonic current value and the target harmonic current value, so as to obtain a voltage control signal in the n-order synchronous rotating coordinate system.

[0106] In one embodiment, the motor control signal is used to control a duty cycle of a switch of a motor control circuit.

[0107] The above steps are specifically described as follows:

[0108] The vector control system is a rotor field-oriented vector control system established based on the motor.

[0109] In one embodiment, the vector control is also referred to as field-oriented control (FOC), which is a technology for controlling an alternating current motor by using a frequency converter, and the output of the motor is controlled by adjusting the output frequency, the size and the angle of the output voltage of the frequency converter. There are various methods for establishing a vector control system, which are not limited in the present application. Optionally, the motor described above is a permanent magnet synchronous motor.

[0110] The extracted audio signal or the sinusoidal signal is subjected to amplitude mapping processing to obtain a corresponding current in the amplitude dimension.

[0111] In an embodiment, an audio signal is extracted. The audio signal can be extracted from a music file. The music file can be a song file in various music formats such as mp3, wma, wav, flac, ape, etc., or a sinusoidal signal sin(2πf ts) such as a high-frequency sinusoidal wave with a frequency f ranging from 300 Hz to 1000 Hz, a MIDI file, a song file transmitted by Bluetooth, a digital signal processed by a music chip, an analog signal processed by a chip, an analog signal amplified by a power amplifier, a PCM encoded file, an analog or digital signal input by a microphone, or a music file corresponding to the digital signal.

[0112] After the audio signal is extracted, the controller performs amplitude mapping processing on the audio signal. Specifically, first, the extracted audio signal is subjected to normalization processing (signal value range -1 to 1), and then multiplied by the maximum current amplitude that the current controller can use to respond to music to perform conversion processing, to obtain a current Is and / or a voltage value Us in the amplitude dimension corresponding to the controller. Is is distributed to the dq axes of the n-order dq-axis synchronous rotating coordinate system through an angle theta to obtain a signal target harmonic current value Isdn and Isqn that the motor drive system can control; and / or the voltage value Us is distributed to the n-order target voltage signal Usdn1 and Usqn1 on the dq axes of the n-order synchronous rotating coordinate system through the angle theta. theta = K x 2πF Ts + theta_init, K ∈ real number, F is the frequency of the injected signal, F can control the rotation frequency of the rotating magnetic field, the high-speed rotating magnetic field, and scanning the rotor magnetic field will not cause the rotor to rotate, Ts is time, theta_init is the initial angle of injection, ranging from 0 to 360 degrees, which can be expressed by the following formula: Isdn = Is x cos(theta) Formula (1) Isqn = Is x sin(theta) Formula (2) Usdn1 = Us x cos(theta) Formula (3) Usqn1 = Us x sin(theta) Formula (4)

[0113] The current Is is distributed to the dq axis of the n-order synchronous rotating coordinate system through the angle theta to obtain the given target harmonic current values Isdn and Isqn (such as the current Id5th, Iq5th, Id7th, and Iq7th), the motor phase current is subjected to n-order synchronous coordinate transformation, and the n-order synchronous coordinate feedback harmonic current value is extracted; the target harmonic current value and the feedback harmonic current value are subjected to PI regulator to obtain the n-order control voltage signals Usdn and Usqn on the n-order synchronous rotating coordinate system; and the n-order control voltage signals Usdn and Usqn are subjected to n-order synchronous coordinate inverse transformation to obtain the voltage control signal of the motor driving system.

[0114] The voltage value Us is distributed to the n-order target voltage signals Usdn1 and Usqn1 on the dq axis of the n-order synchronous rotating coordinate system through the angle theta; the n-order target voltage signals Usdn1 and Usqn1 can also be obtained through the n-order dq axis synchronous rotating coordinate system motor parameter equivalent model, for example, Isdn and Isqn are subjected to the n-order dq axis synchronous rotating coordinate system motor parameter equivalent model, the n-order dq axis synchronous rotating coordinate system is subjected to the current conversion module to obtain the n-order target voltage signals Usdn1 and Usqn1, and the n-order target voltage signals Usdn1 and Usqn1 can be expressed by the following formulas: Usdn1 = [Isdn × (Rs + s × Ldn) - we × Lqn × Isqn] × Kp / Us Formula (5) Usqn1 = [Isqn × (Rs + s × Lqn) + we × Ldn × Isdn + we × ψfn] × Kp / Us Formula (6)

[0115] Wherein, s is the variable of Laplace transform, and Kp is not equal to zero. The current conversion module can also be a pure proportional coefficient relationship or a proportional differential relationship, and the target voltage control signals Usdn1 and Usqn1 are obtained as shown in the following formulas: Usdn1 = Isdn × Kp Formula (7) Usqn1 = Isqn × Kp Formula (8)

[0116] Wherein, Kp is not equal to zero.

[0117] The audio signal is converted into the current vector Is (n order target current Isdn, Isqn) and the voltage vector Us (n order target voltage Usdn, Usqn) on the dq axis synchronous rotating coordinate system of n order, n is a real number. The direction can be positive or negative. For example, the order can be n = 1, 2, 3, 4, 5, 6, 7... in the positive direction, n = 0, -1, -2, -3, -4, -5, -6, -7... in the negative direction, etc. For example, the audio signal can be converted into the current vector Is7 (current Isd7, Isq7) on the dq axis of 7 order in the positive direction, or the voltage vector Us-5 (voltage Usd-5, Usq-5) on the dq axis of -5 order, etc. The current and / or voltage is injected into the dq axis synchronous rotating coordinate system of n order. Since the higher order rotating coordinate system increases the control complexity, the high harmonic current and / or voltage injection process will not cause the motor to vibrate and make noise at the same frequency.

[0118] The harmonic is injected into the vector control system based on the voltage control signal. The target harmonic current value and the feedback harmonic current value are subjected to PI regulator to obtain the n order control voltage signal Usdn and Usqn in the corresponding n order synchronous rotating coordinate system; and / or the n order target voltage Usdn1 and Usqn1 are superimposed, and subjected to n order synchronous coordinate inverse transformation to obtain the voltage control signal; the voltage control signal is injected into the original FOC closed loop control system; the duty cycle of the bridge arm control signal is adjusted to make the motor produce electromagnetic vibration to emit sound corresponding to the audio signal, consume the energy of the first capacitor and / or the second capacitor, and will not cause the motor to vibrate and make noise.

[0119] Wherein, the current Is, the voltage Us is less than the maximum current and the maximum voltage allowed by the system.

[0120] Fig. 11 shows a schematic diagram of high order dq coordinate voltage solution of multiphase winding.

[0121] As shown in FIG. 11, for example, the phase currents of the motor are first subjected to -5 dq and +7 dq order coordinate transformation, respectively, and then the feedback -5th and +7th harmonic currents are extracted through a low-pass filter; then, Is is distributed to the dq axes of the n-order dq synchronous rotating coordinate system through the angle theta to obtain given target harmonic current values (currents Id5th, Iq5th, Id7th, Iq7th), and the target harmonic current values are subjected to PI regulator to obtain control voltage signals Usdn and Usqn (voltages Ud5th, Uq5th, Ud7th, Uq7th) in the corresponding n-order synchronous rotating coordinate system. The target harmonic current values are as follows: Id5th = Is x cos(theta), Iq5th = Is x sin(theta); Id7th = Is x cos(theta), Iq7th = Is x sin(theta);

[0122] Then, the control voltage signals Usdn and Usqn in the n-order synchronous rotating coordinate system are subjected to coordinate inverse transformation and injected into motor vector control. The voltages Ud5th, Uq5th, Ud7th, Uq7th are subjected to inverse PARK transformation to obtain voltages (voltages Ua5th, Ub5th, Ua7th, Ub7th) in the stationary coordinate system, which are injected into the original FOC closed-loop control system.

[0123] For example, the n-order target voltages Usdn1 and Usqn1 are extracted as follows: Ud5th1 = Us x cos(theta), Uq5th1 = Us x sin(theta); Ud7th1 = Us x cos(theta), Uq7th1 = Us x sin(theta).

[0124] Then, the n-order target voltages Usdn1 and Usqn1 are subjected to coordinate inverse transformation and injected into motor vector control: the voltages Ud5th1, Uq5th1, Ud7th1, Uq7th1 are then subjected to n-order inverse PARK transformation to obtain voltages (voltages Ua5th, Ub5th, Ua7th, Ub7th) in the stationary coordinate system, which are injected into the original FOC closed-loop control system.

[0125] By controlling the amplitude and / or voltage of the harmonic currents in the multiple synchronous rotating coordinate systems to control the magnetic field consumption ability, the first capacitor and the second capacitor are actively discharged, and by controlling the frequency of the harmonic currents in the multiple synchronous rotating coordinate systems to control the rotation frequency of the rotating magnetic field, the effect of no torque of the motor is achieved, and no noise problems such as jitter and gear teeth are generated.

[0126] In addition, the high harmonic current and / or voltage injection of the application, the multiple harmonic target value changes according to the amplitude and frequency of music or the multiple harmonic target value changes according to the high frequency sine wave. This control mode will not cause motor gear teeth, abnormal sound and other problems even if the zero position is not accurate, because the high-speed rotating harmonic current scans the rotor magnetic field and does not cause the rotor to rotate, the frequency is too high, and the rotor cannot respond at all, the harmonic torque is small.

[0127] In summary, the new active discharge method and circuit topology based on the switching module provided in the application make the active discharge action more efficient and safe, solve the problem that the motor control circuit in the existing active discharge technology is limited by the working state of the external load, and can only discharge through an external discharge resistor or use an external motor. Moreover, the discharge strategy provided in the application can select at least one controller module without faults and with a temperature within a safe range for active discharge to realize a new type of active discharge of the internal capacitor of the motor control circuit according to the temperature and fault state of the motor winding and power module, and ensure the safety of the vehicle. Whether it is single-motor or multi-motor direct connection charging and electric drive boost charging, the entire process of discharge control is simple, and the current flow direction can be adjusted in time according to the bus voltage and charging port voltage, so that voltage impact will not occur when the bus and the charging port discharge together, the device is protected, and torque fluctuation, gear teeth and other micro-noise will not occur.

[0128] The application further provides a controller, which comprises a processor and a memory connected to the processor, the memory being used to store a computer program, and the processor being used to execute the computer program to realize the discharge method described above.

[0129] The application further provides a discharge system, which comprises the active discharge circuit and the controller described above, and the controller is used to output a motor control signal to the motor control circuit to make the motor generate electromagnetic vibration to consume the energy of the first capacitor and / or the second capacitor.

[0130] The application further provides a vehicle comprising the active discharge circuit. In the above embodiments, the description of each embodiment focuses on different aspects, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0131] The application embodiments, implementation manners and related technical features can be combined or replaced with each other without conflict.

[0132] The above merely describes some preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the description of each embodiment of the present application has its own emphasis, the part not described in detail in one embodiment can be referred to the relevant description of other embodiments. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the technical solution content of the present application still falls within the scope of the technical solution of the present application.

Claims

1. An active bleeder circuit, characterized by, The active discharge circuit (100) comprises: a first transmission bus (L1) and a second transmission bus (L2), the first transmission bus (L1) being used for connecting a first pole of a battery pack (101), and the second transmission bus (L2) being used for connecting a second pole of the battery pack (101); a first capacitor (103) connected to the first transmission bus (L1) and the second transmission bus (L2); a motor control circuit (104) connected to the first transmission bus (L1) and the second transmission bus (L2); a motor (105) connected to the motor control circuit (104); a second capacitor (107), a first end of the second capacitor (107) being electrically connected to the first transmission bus (L1) and / or the motor (105), and a second end of the second capacitor (107) being connected to the second transmission bus (L2); wherein the motor control circuit (104) controls the motor (105) to discharge the first capacitor (103) and / or the second capacitor (107) through a motor control signal according to an injection frequency.

2. The active bleeder circuit of claim 1, wherein, The active discharge circuit (100) comprises a first switch module (102) connected to the battery pack (101), the first switch module (102) comprising a first switch (K1) and a second switch (K2), the first switch (K1) being connected between the second pole of the battery pack (101) and the second end of the first capacitor (103), and the second switch (K2) being connected between the first pole of the battery pack (101) and the first end of the first capacitor (103).

3. The active bleeder circuit of claim 2, wherein, The first end of the second capacitor (107) is electrically connected to the first transmission bus (L1), and the motor (105) is electrically connected to the first end of the first capacitor (103) through a motor switch.

4. The active bleeder circuit of claim 3, wherein, The motor control circuit (104) comprises a plurality of bridge arms, two ends of each bridge arm being connected to the first transmission bus (L1) and the second transmission bus (L2), and a midpoint of each bridge arm being connected to the motor (105), wherein the motor (105) comprises a stator winding, the stator winding comprising a plurality of phase coils, and a first end of each phase coil being connected to the midpoint of one bridge arm.

5. The active bleeder circuit of claim 4, wherein, A second end of each phase coil in the plurality of phase coils is commonly connected to a neutral line, and the neutral line is used for electrical connection with the first end of the second capacitor (107). Alternatively, the plurality of phase coils comprises a first coil and at least one second coil, the first coil being used for electrical connection with the first end of the second capacitor (107) so that the first coil and the at least one second coil are connected in series.

6. The active bleeder circuit of claim 4, wherein, The motor (105) further comprises a rotor coil, and the motor control circuit (104) further comprises an excitation control module connected to the first transmission bus (L1), the second transmission bus (L2), and the rotor coil, the excitation control module being used for controlling an excitation parameter of a motor rotor.

7. The active bleeder circuit of claim 6, wherein, The active bleeding circuit (100) further comprises a third switch (K3), a first end of the third switch (K3) is connected to a second end of the second capacitor (107), and a second end of the third switch (K3) is connected to the charge-discharge interface (108).

8. The active bleeder circuit of claim 7, wherein, Each of the bridge arms comprises an upper bridge arm and a lower bridge arm, wherein during the active bleeding process, the upper bridge arm and the lower bridge arm of at least one bridge arm of the motor control circuit (104) are alternately turned on, so that the bus voltage across the first capacitor (103) and the interface voltage across the second capacitor (107) are charged and discharged back and forth through the bridge arm and the motor winding, and the energy consumption of the bridge arm and the motor winding is discharged.

9. The active bleeder circuit of claim 8, wherein, The motor control circuit (104) is used to control the duty cycle of the upper bridge arm and / or the lower bridge arm of at least one bridge arm according to the pulse width modulation signal to control the active bleeding process.

10. The active bleeder circuit of claim 9, wherein, A plurality of motors (105) are arranged in the active bleeding circuit (100), and the plurality of motors (105) are configured to use the motors (105) that can normally work and have a temperature within a safe range for bleeding.

11. The active bleeder circuit of claim 10, wherein, The plurality of motors (105) comprise a first motor and a second motor, the second motor is connected to a second motor control circuit, the first motor is connected to a first motor control circuit, the first motor is an electrically excited synchronous motor, and the second motor is a first alternating current motor, and the priority of bleeding using the first motor is higher than the priority of bleeding using the second motor.

12. The active bleeder circuit of claim 11, wherein, The second motor is an asynchronous motor, the plurality of motors (105) further comprise a third motor, the third motor is a synchronous motor, the third motor is connected to a third motor control circuit, and the priority of bleeding using the second motor is higher than the priority of bleeding using the third motor.

13. A method of bleeding, characterized by The bleeding method is applied to the active bleeding circuit according to any one of claims 1-12, and the bleeding method comprises: obtaining a frequency signal; outputting a motor control signal according to the frequency signal to make the motor generate electromagnetic vibration to consume the energy of the first capacitor and / or the second capacitor.

14. The method of claim 13, wherein, The outputting of the motor control signal according to the frequency signal comprises: performing amplitude mapping processing on the frequency signal to obtain corresponding current and / or voltage in the amplitude dimension; based on the current and / or voltage in the amplitude dimension, obtaining current and / or voltage control signals in an n-order synchronous rotating coordinate system; injecting the current and / or voltage control signals in the n-order synchronous rotating coordinate system into harmonics of a vector control system of the motor to output the motor control signal by using the vector control system, and the vector control system is a rotor field oriented vector control system established based on the motor.

15. The bleed-off method according to claim 14, characterized in that, The obtaining of the current and / or voltage control signals in the n-order synchronous rotating coordinate system based on the current and / or voltage in the amplitude dimension comprises: performing n-order synchronous coordinate transformation on motor phase currents respectively to extract n-order synchronous coordinate feedback harmonic current values; based on the current in the amplitude dimension, obtaining target harmonic current values; The feedback harmonic current value and the target harmonic current value are proportionally and integrally adjusted to obtain a voltage control signal in a synchronous rotating coordinate system of n order.

16. A bleed method according to any of claims 13 to 15, characterised in that, The motor control signal is used to control the duty cycle of the switch of the motor control circuit.

17. A controller characterized by comprising: The processor is connected with a memory, and the memory is used to store a computer program, and the processor is used to execute the computer program to realize the method in any one of claims 13-16.

18. A bleed system characterized by, The controller in claim 17 is used to output the motor control signal to the motor control circuit to make the motor generate electromagnetic vibration to consume the energy of the first capacitor and / or the second capacitor.

19. A vehicle characterized by comprising: The active bleeding circuit in any one of claims 1-12, or the controller in claim 17, or the bleeding system in claim 18.

Images