Bootstrap drive circuit, motor control device, compressor and vehicle

Abstract

A bootstrap drive circuit, a motor control device, a compressor, and a vehicle are provided. The bootstrap drive circuit (100) includes a bootstrap unit (110), a negative voltage unit (120), a drive unit (130), and a voltage stabilization unit (140), in which the bootstrap unit (110) is for providing a bootstrap voltage to the voltage stabilization unit (140), the voltage stabilization unit (140) is for performing a stabilization process on the bootstrap voltage to output a stable drive voltage to the drive unit (130), and the drive unit (130) drives a corresponding switching transistor (Q1) to conduct according to the stable drive voltage when receiving a conduction control signal, and controls the negative voltage unit (120) to generate a stable cutoff negative voltage according to the stable drive voltage when receiving a cutoff control signal, thereby driving the switching transistor (Q1) to cut off.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This disclosure claims priority to a Chinese patent application having application number 202210378498.X, entitled "Bootstrap driving circuit, motor control device, compressor and vehicle," filed on April 12, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to the technical field of drive control, and more particularly to bootstrap drive circuits, motor controls, compressors, and vehicles. [Background technology]

[0003] Third-generation semiconductors, such as those made of silicon carbide (SiC), offer high switching frequencies, high voltage and heat / cold resistance, and are smaller in volume than silicon (Si) devices for the same performance, making them suitable for a wide range of applications in fields such as electric vehicles. To reliably shut off power devices, power devices made of SiC generally require a negative voltage. However, with related technologies, there is a risk that shutting off a power device at a negative voltage may exceed the negative voltage fluctuation range allowed by the power device. Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure aims to solve, at least to some extent, at least one technical problem in the related art, and therefore, a first object of the present disclosure is to provide a bootstrap driving circuit, in which a voltage stabilization unit performs voltage stabilization processing on the bootstrap voltage, thereby reducing the fluctuation of the driving voltage and improving the reliability of the bootstrap driving circuit.

[0005] A second object of the present disclosure is to provide an electric motor control device.

[0006] A third object of the present disclosure is to provide a compressor.

[0007] A fourth object of the present disclosure is to provide a vehicle. [Means for solving the problem]

[0008] To achieve the above object, an embodiment of a first aspect of the present disclosure provides a bootstrap driving circuit including a bootstrap unit, a negative voltage unit, a driving unit, and a voltage stabilization unit, wherein the bootstrap unit is for providing a bootstrap voltage to the voltage stabilization unit, the voltage stabilization unit is for stabilizing the bootstrap voltage and outputting a stable driving voltage to the driving unit, and the driving unit is for, when receiving a conduction control signal, driving a corresponding switching transistor to conduct in accordance with the stable driving voltage, and when receiving a cut-off control signal, controlling the negative voltage unit to generate a stable cut-off negative voltage in accordance with the stable driving voltage, thereby driving the switching transistor to cut off.

[0009] In a bootstrap drive circuit according to an embodiment of the present disclosure, the bootstrap unit provides a bootstrap voltage to the voltage stabilization unit, which stabilizes the bootstrap voltage and outputs a stabilized drive voltage to the drive unit. When the drive unit receives a conduction control signal, it drives the corresponding switching transistor to conduct according to the stabilized drive voltage. When the drive unit receives a cutoff control signal, it controls the negative voltage unit to generate a stabilized cutoff negative voltage according to the stabilized drive voltage, and the drive unit drives the switching transistor to cut off according to the stabilized cutoff negative voltage. In this way, the voltage stabilization unit stabilizes the bootstrap voltage, reducing drive voltage fluctuations and improving the reliability of the bootstrap drive circuit.

[0010] According to an embodiment of the present disclosure, the input terminal of the voltage stabilizing unit is connected to the output terminal of the bootstrap unit, the reference ground terminal of the voltage stabilizing unit is connected to the negative terminal of the bootstrap unit and the negative power supply pin of the driving unit respectively, the output terminal of the voltage stabilizing unit is connected to the positive power supply pin of the driving unit, the output pin of the driving unit is connected to the positive terminal of the negative voltage unit, and the negative terminal of the negative voltage unit is connected to the control terminal of the switching transistor.

[0011] According to one embodiment of the present disclosure, the voltage stabilizing unit includes a linear voltage stabilizing power supply or a switching power supply.

[0012] According to one embodiment of the present disclosure, the switching transistor is an upper arm switching transistor of an inverter circuit.

[0013] According to one embodiment of the present disclosure, the power supply further includes a charge control unit, which controls the negative voltage unit to charge when the switching transistor is conductive, and performs secondary stabilization processing on the cut-off negative voltage generated by the negative voltage unit.

[0014] According to one embodiment of the present disclosure, the charging control unit includes: a controllable switch module connected between the negative terminal of the negative voltage unit and the negative terminal of the bootstrap unit; and a logic control module that controls the controllable switch module to be conductive so that the negative voltage unit is charged by the driving voltage.

[0015] According to one embodiment of the present disclosure, the logic control module is further used to obtain the voltage across the negative voltage unit, and at the rising edge of the driving voltage output from the driving unit, if it determines that the negative voltage unit is undervoltage based on the voltage across the negative voltage unit, it controls the controllable switch module to be conductive.

[0016] According to an embodiment of the present disclosure, the logic control module is further used for controlling the controllable switch module to be conductive at the rising edge of the driving voltage output from the driving unit.

[0017] According to an embodiment of the present disclosure, the controllable switch module includes a MOS transistor and a current-limiting resistor, wherein the current-limiting resistor is connected between the drain of the MOS transistor and the negative terminal of the negative voltage unit, or the current-limiting resistor is connected between the source of the MOS transistor and the negative terminal of the bootstrap unit.

[0018] According to an embodiment of the present disclosure, when the MOS transistor has a body diode, the controllable switch module further includes a first diode, an anode of the first diode connected to the source of the MOS transistor, and a cathode of the first diode connected to the negative terminal of the bootstrap unit.

[0019] According to an embodiment of the present disclosure, the bootstrap unit includes a power supply, a bootstrap diode, a bootstrap resistor, and a bootstrap capacitor, wherein the negative terminal of the power supply is grounded, the anode of the bootstrap diode is connected to the positive terminal of the power supply, one terminal of the bootstrap resistor is connected to the cathode of the bootstrap diode, the positive terminal of the bootstrap capacitor is connected to the other terminal of the bootstrap resistor, and the bootstrap unit has a first node, the negative terminal of the bootstrap capacitor is connected to the reference ground terminal of the voltage stabilizing unit, and the first node functions as an output terminal of the bootstrap unit.

[0020] According to one embodiment of the present disclosure, the negative voltage unit includes a negative voltage capacitor and a first voltage stabilizing diode, the positive terminal of the negative voltage capacitor is connected to the output pin of the driving unit, the negative terminal of the negative voltage capacitor functions as the negative terminal of the negative voltage unit, the anode of the first voltage stabilizing diode is connected to the negative terminal of the negative voltage capacitor, and the cathode of the first voltage stabilizing diode is connected to the positive terminal of the negative voltage capacitor.

[0021] To achieve the above object, an embodiment of a second aspect of the present disclosure provides a motor control device, including an inverter circuit and the above-mentioned bootstrap drive circuit, where the bootstrap drive circuit is used to drive a switching transistor in the inverter circuit to turn on or off.

[0022] In the motor control device according to the embodiment of the present disclosure, the voltage stabilization unit performs voltage stabilization processing on the bootstrap voltage using the above-described bootstrap drive circuit, thereby reducing fluctuations in the drive voltage and improving the reliability of the motor control device.

[0023] According to an embodiment of the present disclosure, the inverter circuit is a three-phase bridge inverter circuit, a single-phase full-bridge inverter circuit, or a single-phase half-bridge inverter circuit.

[0024] To achieve the above-mentioned object, an embodiment of a third aspect of the present disclosure provides a compressor including an electric motor and the above-mentioned electric motor control device used to drive the operation of the electric motor.

[0025] In the compressor according to the embodiment of the present disclosure, the voltage stabilization unit performs voltage stabilization processing on the bootstrap voltage using the motor control device described above, thereby reducing fluctuations in the drive voltage and improving the reliability of the motor control device, thereby improving the reliability of the compressor.

[0026] To achieve the above object, an embodiment of a fourth aspect of the present disclosure provides a vehicle including the compressor described above.

[0027] In a vehicle according to an embodiment of the present disclosure, the compressor has a voltage stabilization unit that performs voltage stabilization processing on the bootstrap voltage, thereby reducing fluctuations in the drive voltage and improving the reliability of the compressor, thereby improving the reliability of the vehicle.

[0028] Additional aspects and advantages of the disclosure will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the disclosure. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 2 is a circuit topology diagram of a related bootstrap driver circuit. [Figure 2] FIG. 1 is a structural schematic diagram of a bootstrap driving circuit according to an embodiment of the present disclosure. [Figure 3] FIG. 10 is a structural schematic diagram of a bootstrap driving circuit according to another embodiment of the present disclosure. [Figure 4] FIG. 10 is a structural schematic diagram of a bootstrap driving circuit according to yet another embodiment of the present disclosure. [Figure 5] FIG. 2 is a circuit topology diagram of a bootstrap driver circuit according to an embodiment of the present disclosure. [Figure 6]FIG. 2 is a block diagram of the principle of a logic control module according to an embodiment of the present disclosure. [Figure 7] FIG. 4 is a waveform diagram of a bootstrap driving circuit according to a first embodiment of the present disclosure. [Figure 8] FIG. 10 is a waveform diagram of a bootstrap driving circuit according to a second embodiment of the present disclosure. [Figure 9] FIG. 10 is a waveform diagram of a bootstrap driving circuit according to a third embodiment of the present disclosure. [Figure 10] FIG. 10 is a waveform diagram of a bootstrap driving circuit according to a fourth embodiment of the present disclosure. [Figure 11] FIG. 1 is a block diagram of an electric motor control device according to an embodiment of the present disclosure. [Figure 12] FIG. 1 is a block diagram of a compressor according to an embodiment of the present disclosure. [Figure 13] FIG. 1 is a block diagram of a vehicle according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, the embodiments of the present invention will be described in detail. Examples of the described embodiments are shown in the drawings, and the same or similar numbers throughout the drawings indicate the same or similar elements or elements with the same or similar functions. The examples described below with reference to the drawings are illustrative and are used only to interpret the present disclosure, and cannot be understood as limiting the present disclosure.

[0031] Figure 1 shows the circuit topology of a related bootstrap driver. As shown in Figure 1, the negative voltage module consists of a parallel-connected capacitor Cz and a voltage-stabilizing diode Dz. When the switching transistor needs to be turned on, the voltage at the OUT pin of the driver chip is VDD-V1 (VDD is the power supply voltage, V1 is the conduction voltage of diode D1). This voltage is applied to the gate of the switching transistor via the voltage-stabilizing diode Dz. The gate drive voltage of the switching transistor becomes VDD-V1-Vz (Vz is the stabilizing voltage of the voltage-stabilizing diode Dz), causing the switching transistor to be turned on. When the switching transistor needs to be turned off, the voltage at the OUT pin of the driver chip drops to 0. When the switching transistor is turned on, the potential at the left end of capacitor Cz is higher than the potential at the right end, and the voltage across capacitor Cz is Vz. This voltage across capacitor Cz cannot change drastically. Therefore, when the switching transistor is turned off, the potential across capacitor Cz remains high on the left side and low on the right side, and the potential difference across both ends remains Vz. Therefore, when the OUT pin of the driver chip drops to 0, the potential at the left end of capacitor Cz becomes 0, and the potential at the right end of capacitor Cz is maintained at -Vz. At this time, the gate drive voltage of the switching transistor becomes -Vz, and the switching transistor is cut off by the negative voltage.

[0032] The stability of the voltage across capacitor Cz, i.e., the negative voltage, is related not only to the voltage stabilization diode Dz but also to the duty cycle of the drive signal, and changes in the duty cycle can cause instability in the negative voltage. In particular, if the bootstrap voltage of the upper arm, i.e., the voltage across the bootstrap capacitor CBOOT, also fluctuates, the stability of the negative voltage will deteriorate further, which will lead to instability in the gate drive voltage of the switching transistor and a decrease in overall circuit performance. Therefore, fluctuations in the bootstrap voltage must be strictly controlled.

[0033] In contrast, in an embodiment of the present disclosure, a bootstrap drive circuit is provided in which a voltage stabilization unit performs voltage stabilization processing on the bootstrap voltage, thereby reducing fluctuations in the drive voltage and improving the reliability of the bootstrap drive circuit.

[0034] 2 is a structural schematic diagram of a bootstrap driving circuit according to an embodiment of the present disclosure. As shown in FIG. 2, the bootstrap driving circuit 100 may include a bootstrap unit 110, a negative voltage unit 120, a driving unit 130, and a voltage stabilizing unit 140.

[0035] Here, the bootstrap unit 110 is for providing a bootstrap voltage to the voltage stabilization unit 140, the voltage stabilization unit 140 is for stabilizing the bootstrap voltage and outputting a stable driving voltage to the driving unit 130, and when the driving unit 130 receives a conduction control signal, it drives the corresponding switching transistor Q1 to conduct according to the stable driving voltage, while when the driving unit 130 receives a cutoff control signal, it controls the negative voltage unit 120 to generate a stable cutoff negative voltage according to the stable driving voltage, and drives the switching transistor Q1 to cut off.

[0036] The voltage stabilizing unit 140 may include a power supply with low voltage loss (i.e., voltage stabilization function), such as a linear voltage stabilizing power supply or a switching power supply. The switching transistor Q1 may be a transistor that needs to be cut off at a negative voltage, such as a MOS transistor or an IGBT transistor, and is not specifically limited thereto. When the circuit is used in an inverter circuit, the switching transistor Q1 may be the upper arm switching transistor of the inverter circuit.

[0037] 2, the input terminal VIN of the voltage stabilizing unit 140 is connected to the output terminal of the bootstrap unit 110, the reference ground terminal COM of the voltage stabilizing unit 140 is connected to the negative terminal of the bootstrap unit 110 and the negative power supply pin VSS of the driving unit 130, and the output terminal VOUT of the voltage stabilizing unit 140 is connected to the positive power supply pin VDD of the driving unit 130. Thus, the bootstrap voltage output from the bootstrap unit 110 is processed by the voltage stabilizing unit 140 to provide a stable driving voltage for the driving unit 130. The output terminal OUT of the driving unit 130 is connected to the positive terminal of the negative voltage unit 120, and the negative terminal of the negative voltage unit 120 is connected to the control terminal of the switching transistor Q1.

[0038] When the switching transistor Q1 needs to be controlled to be conductive according to control needs, the output pin OUT of the driver unit 130 is connected to the power supply pin VDD, and the bootstrap voltage output from the bootstrap unit 110 is stabilized by the voltage stabilization unit 140, and the stabilized driving voltage is supplied to the driver unit 130. At this time, the voltage of the output pin OUT of the driver unit 130 becomes equal to the driving voltage (denoted as Vcc) provided by the voltage stabilization unit 140, and this voltage is provided to the gate of the switching transistor Q1 via the negative voltage unit 120. The gate driving voltage of the switching transistor Q1 is the difference between the voltage of the output pin OUT of the driver unit 130 and the voltage across the negative voltage unit 120 (i.e., Vcc-Vcn, where Vcn is the voltage across the negative voltage unit 120), and the switching transistor Q1 is conductive.

[0039] When control is required to cut off the switching transistor Q1, the output pin OUT of the driving unit 130 is connected to the ground pin VSS, and the voltage of the output pin OUT of the driving unit 130 is the same as the voltage of the ground pin VSS, both of which are 0. Meanwhile, based on the characteristic that the voltage across the negative voltage unit 120 does not change suddenly, the negative voltage unit 120 provides a cut-off negative voltage (i.e., -Vcn) to the gate of the switching transistor Q1. Because the driving voltage of the driving unit 130 is stabilized by the voltage stabilization unit 140 and does not fluctuate, the gate of the switching transistor Q1 receives a stable cut-off negative voltage (i.e., stable -Vcn), thereby ensuring stable cut-off of the switching transistor Q1.

[0040] The bootstrap drive circuit according to the above embodiment reduces fluctuations in the drive voltage by performing voltage stabilization processing on the bootstrap voltage using the voltage stabilization unit, thereby improving the reliability of the bootstrap drive circuit.

[0041] In some embodiments of the present disclosure, as shown in FIG. 3 , the above-mentioned bootstrap driving circuit 100 further includes a charge control unit 150, which controls the negative voltage unit 120 to charge when the switching transistor Q1 is conducting, and performs secondary stabilization of the cut-off negative voltage generated by the negative voltage unit 120.

[0042] The negative voltage unit 120 is also used to stabilize the positive voltage for conducting the switching transistor Q1 during charging.

[0043] That is, the bootstrap driver circuit 100 includes not only the voltage stabilization unit 140 but also the charge control unit 150. The voltage stabilization unit 140 stabilizes the bootstrap voltage to ensure the stability of the bootstrap voltage, thereby ensuring the stability of the voltage supplied to the negative voltage unit 120, and effectively solves the problem of instability in the driving voltage and negative cut-off voltage of the switching transistor caused by the instability of the bootstrap voltage. Meanwhile, the charge control unit 150 provides a charging path for the negative voltage unit 120, stabilizes the voltage across the negative voltage unit 120, and effectively solves the impact of changing the duty cycle of the driving signal on the negative cut-off voltage, thereby improving the stability of the driving voltage and negative cut-off voltage in two aspects and improving the reliability of the bootstrap driver circuit.

[0044] For example, when the switching transistor Q1 needs to be controlled to be conductive according to control needs, the output pin OUT of the driving unit 130 is connected to the power supply pin VDD, and the bootstrap voltage output from the bootstrap unit 110 is stabilized by the voltage stabilization unit 140 and then supplied to the driving unit 130. At this time, the voltage of the output pin OUT of the driving unit 130 becomes the same as the driving voltage (denoted as Vcc) provided by the voltage stabilization unit 140, and this voltage is provided to the gate of the switching transistor Q1 via the negative voltage unit 120. The gate driving voltage of the switching transistor Q1 becomes the difference between the voltage of the output pin OUT of the driving unit 130 and the voltage across the negative voltage unit 120 (i.e., Vcc - Vcn, where Vcn is the voltage across the negative voltage unit 120), and the switching transistor Q1 is conductive. While the switching transistor Q1 is conductive, the charge control unit 150 controls the negative voltage unit 120 to charge, thereby stabilizing the voltage across the negative voltage unit 120. When this voltage is stable, the gate drive voltage of the corresponding switching transistor Q1 is also stable, that is, the positive voltage for turning on the switching transistor Q1 is stable, and the switching transistor Q1 is in a stable conducting state.

[0045] When the switching transistor Q1 needs to be controlled to be turned off according to the control requirements, the output pin OUT of the driver unit 130 is connected to the ground pin VSS. At this time, the voltage of the output pin OUT of the driver unit 130 is the same as the voltage of the ground pin VSS, both of which are 0. Meanwhile, based on the characteristic that the voltage across the negative voltage unit 120 does not change suddenly, the negative voltage unit 120 provides a cut-off negative voltage (i.e., -Vcn) to the gate of the switching transistor Q1. When the switching transistor Q1 is conducting, not only does it stabilize the bootstrap voltage, but it also compensates for the voltage across the negative voltage unit 120 to keep it stable. Therefore, the gate of the switching transistor Q1 receives a stable cut-off negative voltage (i.e., a stable -Vcn), thereby ensuring stable cut-off of the switching transistor Q1.

[0046] In the above-described embodiment, the stabilization of the bootstrap voltage by the voltage stabilization unit and the compensation of the negative cut-off voltage generated by the negative voltage unit by the charge control unit greatly improve the stability of the driving voltage and the negative cut-off voltage of the switching transistor, allowing the switching transistor to stably conduct and cut off, and improving the reliability of the circuit.

[0047] In some embodiments of the present disclosure, as shown in FIG. 4 , the charging control unit 150 may include a controllable switch module 151 connected between the negative terminal of the negative voltage unit 120 and the negative terminal of the bootstrap unit 110, and a logic control module 152 that controls the controllable switch module 151 to be conductive and allow the driving voltage to charge the negative voltage unit 120.

[0048] Optionally, the controllable switch module 151 includes a MOS transistor or the like, and controls the conduction of the MOS transistor or the like to provide a charging path for the negative voltage unit 120, thereby realizing charging of the negative voltage unit 120 and compensating for the blocking negative voltage.

[0049] 4, when the switching transistor Q1 needs to be controlled to be conductive, the output pin OUT of the driver unit 130 is connected to the power supply pin VDD, and the bootstrap voltage output from the bootstrap unit 110 is stabilized by the voltage stabilization unit 140 and then supplied to the driver unit 130. The voltage of the output pin OUT of the driver unit 130 is the same as the voltage of the power supply pin VDD, forming a driving voltage, which is supplied to the switching transistor Q1 via the negative voltage unit 120 to turn on the switching transistor Q1. During this process, the logic control module 152 may control the controllable switch module 151, such as a MOS transistor, to be conductive for a short period of time at an appropriate time. At this time, the bootstrap unit 110 forms a charging path together with the voltage stabilizing unit 140, the power supply pin VDD and output pin OUT of the driver unit 130, the negative voltage unit 120, and the controllable switch module 151, and charges the negative voltage unit 120 with the driving voltage provided by the bootstrap unit 110, ensuring that the voltage across the negative voltage unit 120 is stable, thereby ensuring stable conduction of the switching transistor Q1. When the switching transistor Q1 needs to be turned off, the logic control module 152 controls the controllable switch module 151, such as a MOS transistor, to the off state, and at the same time, the output pin OUT of the driver unit 130 is connected to the ground pin VSS. Based on the characteristics that the voltage across the negative voltage unit 120 does not change drastically, the negative voltage unit 120 provides a stable negative voltage for turning off the switching transistor Q1, thereby ensuring stable turning off of the switching transistor Q1.

[0050] In this embodiment, a controllable switch module 151 such as a MOS transistor is provided, and the charge to the negative voltage unit 120 can be controlled by controlling the conduction and cutoff of the controllable switch module 151, so that the negative voltage unit 120 can provide a stable cutoff negative voltage, and at the same time, the driving voltage of the switching transistor Q1 can be stabilized. The circuit structure is simple, easy to implement, low cost, and small in volume.

[0051] In some embodiments of the present disclosure, the logic control module 152 is further used to control the controllable switch module 151 to conduct at a fixed frequency or a random frequency.

[0052] It should be noted that the fixed frequency here is unrelated to the switching frequency of the driving signal and may be specifically set according to actual circumstances. When the controllable switch module 151 is controlled to be conductive at a fixed frequency, no external trigger is required. The logic control module 152 controls the controllable switch module 151 to be conductive once at regular time intervals, and after a short period of time, controls the controllable switch module 151 to be cut off, and this process is repeated to charge the negative voltage unit 120.

[0053] Because this fixed frequency is independent of the driving signal, it is possible that the controllable switch module 151 is on but the switching transistor Q1 is not on. When the switching transistor Q1 is not on, the power supply pin VDD and the output pin OUT of the driving unit 130 are disconnected, and the driving power supply does not charge the negative voltage unit 120. On the other hand, when the switching transistor Q1 is on, the power supply pin VDD and the output pin OUT of the driving unit 130 are connected, and the driving power supply charges the negative voltage unit 120.

[0054] This method is easy to implement because it does not require an external trigger, i.e., a feedback signal. However, whether the controllable switch module 151 conducts or discharges the negative voltage unit 120 is randomly determined. Therefore, if the duty ratio of the driving signal is low, the negative voltage unit 120 may not be effectively charged for a long period of time. On the other hand, if the driving power supply charges the negative voltage unit 120, the gate driving voltage of the switching transistor Q1 is lowered, which may result in distortion of the output current of circuits such as the inverter circuit corresponding to the switching transistor Q1. Furthermore, because the frequency is fixed, harmonic frequencies generated in the output current tend to be concentrated at one or several points, which is detrimental to electromagnetic compatibility (EMC) design. Therefore, this method is suitable for circuits such as inverter circuits with relatively low performance requirements and no need for a low duty ratio, ensuring stable conduction and shutdown of the switching transistor Q1 and circuit performance.

[0055] The random frequency is random jitter, meaning that the controllable switch module 151 turns on and off at an indefinite time. This solves the problem of harmonic frequencies generated in the output current concentrating at one or several points when using a fixed frequency, and is useful for electromagnetic compatibility design. This method is also applicable when the performance requirements for circuits such as inverter circuits are relatively low and a low duty cycle is not required, ensuring stable turn-on and turn-off of the switching transistor Q1 and circuit performance in such cases.

[0056] In some other embodiments of the present disclosure, the logic control module 152 is further used to obtain the voltage across the negative voltage unit 120, and control the controllable switch module 151 to be conductive when it determines that the negative voltage unit 120 is undervoltage based on the voltage across the negative voltage unit 120.

[0057] For example, the logic control module 152 samples the voltage across the negative voltage unit 120, and when the voltage across the negative voltage unit 120 is below a certain threshold (which can be set according to actual circumstances), the logic control module 152 controls the controllable switch module 151 to conduct for a short period of time so that the driving power source can charge the negative voltage unit 120.

[0058] In this method, the switching frequency of the controllable switch module 151 can be minimized, i.e., the controllable switch module 151 is turned on only when the negative voltage unit 120 is undervoltage. Simulation results show that the controllable switch module 151 is turned on only once every hundreds or even thousands of switching periods (measured in milliseconds) of the switching transistor Q1 to charge the negative voltage unit 120 and ensure the required voltage. However, even in this method, if the gate drive voltage of the switching transistor Q1 is reduced when the controllable switch module 151 is turned on, there is a risk of harmonic frequencies being generated in the output current. The higher the frequency of the output current (when the circuit is used to drive an electric motor, the frequency of the output current is calculated by multiplying the motor's rotational speed by the number of pole pairs in the motor), the greater the impact of harmonic frequencies generated by the conduction of the controllable switch module 151. Therefore, this method is suitable for circuits such as inverter circuits where high performance requirements are not required, and in such cases it ensures stable conduction and cutoff of the switching transistor Q1 and circuit performance.

[0059] In some embodiments of the present disclosure, the logic control module 152 is further used to obtain the voltage across the negative voltage unit 120, and at the rising edge of the driving voltage output from the driving unit 130, if it determines that the negative voltage unit 120 is undervoltage based on the voltage across the negative voltage unit 120, then control the controllable switch module 151 to be conductive.

[0060] For example, the logic control module 152 samples the voltage across the negative voltage unit 120, and when the voltage across the negative voltage unit 120 is below a certain threshold (which can be set according to actual circumstances), the logic control module 152 controls the controllable switch module 151 to conduct for a short period of time at the rising edge of the driving voltage output from the driving unit 130 (i.e., the voltage at the output pin OUT of the driving unit 130), so that the driving power source can charge the negative voltage unit 120.

[0061] In this method, when the negative voltage unit 120 is undervoltage and the controllable switch module 151 is controlled to conduct at the rising edge of the drive voltage, not only minimizes the switching frequency of the controllable switch module 151 but also reduces the distortion of the drive voltage. That is, adding a short delay to the drive voltage to slightly reduce the duty cycle reduces the distortion of the drive voltage. Furthermore, simulation analysis shows that the loss in the duty cycle of the drive voltage caused by the controllable switch module 151 conducting is only about 0.2% of the original duty cycle, and such a small duty cycle loss has a very small impact on the output of circuits such as inverter circuits. Therefore, this method is suitable for circuits with high performance requirements, such as inverter circuits, and ensures stable conduction and cut-off of the switching transistor Q1 and circuit performance in such cases.

[0062] In some further embodiments of the present disclosure, the logic control module 152 is further used to control the controllable switch module 151 to be conductive at the rising edge of the driving voltage output from the driving unit 130.

[0063] For example, during each switching period of the switching transistor Q1, the logic control module 152 controls the controllable switch module 151 to conduct for a short period of time at the rising edge of the driving voltage output from the driving unit 130 (i.e., the voltage at the output pin OUT of the driving unit 130), so that the driving power supply charges the negative voltage unit 120.

[0064] This method reduces distortion of the drive voltage by adding a short-term delay to the drive voltage and slightly reducing the duty cycle. Simulation analysis shows that the loss of the drive voltage's duty cycle due to the conduction of the controllable switch module 151 is only about 0.2% of the original duty cycle. This small loss of duty cycle has a very small impact on the output of circuits such as inverters. Since a fixed duty cycle is lost in each switching cycle, the lost duty cycle can be automatically compensated for by a closed-loop control circuit such as an inverter, or the duty cycle of each switching cycle can be actively slightly increased and used to charge the negative voltage unit 120, thereby solving the problem of fixed losses in each cycle. This method is suitable for circuits with high performance requirements, such as inverters, and ensures stable on / off of the switching transistor Q1 and circuit performance. At the same time, software algorithms can be applied to virtually eliminate the generation of unnecessary harmonic frequencies in the output current of circuits such as inverters.

[0065] In the above embodiment, controlling the controllable switch module 151 to conduct in different ways not only ensures stable conduction / cutoff of the switching transistor Q1 and circuit performance, but also can be applied to different situations and meet different actual needs.

[0066] In some embodiments of the present disclosure, as shown in FIG. 5 , the controllable switch module 151 includes a MOS transistor M1 and a current-limiting resistor R1, where the current-limiting resistor R1 is connected between the drain of the MOS transistor M1 and the negative terminal of the negative voltage unit 120, or the current-limiting resistor R1 is connected between the source of the MOS transistor M1 and the negative terminal of the bootstrap unit 110 to limit the charging current of the negative voltage unit 120, thereby controlling the charging speed of the negative voltage unit 120.

[0067] In addition, as shown in FIG. 5, when a current limiting resistor R1 is connected between the drain of the MOS transistor M1 and the negative terminal of the negative voltage unit 120, the current limiting resistor R1 can limit not only the charging current of the negative voltage unit 120 but also the driving current of the switching transistor Q1, and the driving resistance of the switching transistor Q1 is the resistance of the current limiting resistor R1 connected in series with a resistor R3.

[0068] 5, when the MOS transistor M1 has a body diode, the controllable switch module 151 further includes a first diode D1, the anode of which is connected to the source of the MOS transistor M1 and the cathode of which is connected to the negative terminal of the bootstrap unit 110, thereby preventing the negative voltage unit 120 from being discharged in the reverse direction through the body diode of the MOS transistor M1.

[0069] Alternatively, a first diode D1 may be installed between the drain of the MOS transistor M1 and the negative terminal of the negative voltage unit 120. If the MOS transistor M1 does not have a body diode, the negative voltage unit 120 cannot discharge in the reverse direction through the MOS transistor M1. Therefore, if the MOS transistor M1 does not have a body diode, the first diode D1 may not be installed to save costs.

[0070] In some embodiments of the present disclosure, as shown in FIG. 5 , the bootstrap unit 110 may include: a power supply VCC having a negative terminal grounded; a bootstrap diode D2 having an anode connected to the positive terminal of the power supply VCC; a bootstrap resistor R2 having one terminal connected to the cathode of the bootstrap diode D2; and a bootstrap capacitor CBS having a positive terminal connected to the other terminal of the bootstrap resistor R2 and having a first node, a negative terminal connected to the reference ground terminal COM of the voltage stabilization unit 140, and the first node serving as an output terminal of the bootstrap unit 110.

[0071] Furthermore, as shown in FIG. 5, the negative voltage unit 120 includes a negative voltage capacitor CN, the positive terminal of which is connected to the output pin OUT of the driving unit 130 and the negative terminal of which serves as the negative terminal of the negative voltage unit 120, and a first voltage stabilizing diode ZD1, the anode of which is connected to the negative terminal of the negative voltage capacitor CN and the cathode of which is connected to the positive terminal of the negative voltage capacitor CN.

[0072] For example, when the switching transistor Q1 needs to be turned on, the power supply pin VDD of the driver unit 130 is connected to the output pin OUT, and the bootstrap capacitor CBS provides a driving voltage to the negative voltage unit 120 via the voltage stabilizing unit 140, the power supply pin VDD of the driver unit 130, and the output pin OUT. The driving voltage Vcc is the output voltage of the voltage stabilizing unit 140. In the negative voltage unit 120, the voltage across the negative voltage capacitor CN is set to Vcn (note that, in order to stabilize the driving voltage and cut-off negative voltage of the switching transistor Q1 at the beginning of operation, the MOS transistor M1 may be turned on for a short period of time before the circuit is turned on to pre-charge the negative voltage capacitor CN and ensure that it is in a stable voltage state). As a result, the gate driving voltage of the switching transistor Q1 becomes Vcc-Vcn, which causes the switching transistor Q1 to be turned on.

[0073] When the switching transistor Q1 needs to be turned off, the ground pin VSS is connected to the output pin OUT of the driving unit 130. Since the voltage across the negative voltage capacitor CN cannot change suddenly, the voltage at the negative terminal of the negative voltage capacitor CN becomes −Vcn, which provides a negative voltage for turning off the switching transistor Q1, and as a result, the switching transistor Q1 is turned off by the negative voltage.

[0074] In the process of controlling the on / off of the switching transistor Q1, the logic control module 152 controls the MOS transistor M1 to be on based on one of the above five methods, charges the negative voltage capacitor CN using the driving power supply, and compensates for the voltage Vcn across the negative voltage capacitor CN to ensure it is in a stable state, thereby ensuring the stability of the driving voltage, i.e., the positive voltage for turning on the switching transistor Q1 when it is on, and the stability of the negative voltage for turning off the switching transistor Q1 when it is turned off, thereby ensuring the stable on / off of the switching transistor Q1.

[0075] In some embodiments of the present disclosure, the internal principle diagram of the logic control module 152 is shown in Figure 6. Hereinafter, with reference to Figures 5 and 6, the control by the logic control module 152 to turn on the MOS transistor M1 and charge the negative voltage capacitor CN will be described.

[0076] Illustratively, the logic control module 152 controls the MOS transistor M1 to be conductive at a fixed frequency.

[0077] Specifically, as shown in FIG. 6, when the logic control module 152 controls the MOS transistor M1 to conduct at a fixed frequency, a timer within the logic control module 152 outputs a high-level signal to a latch at regular intervals, or a system MCU (e.g., in the case of an inverter circuit, the system MCU of the inverter circuit) periodically inputs a high-level signal to the latch, which then outputs a high-level pulse signal to the MOS driver circuit to drive the MOS transistor M1 to conduct for a short period of time. When the switching transistor Q1 is in a conducting state, the conduction of the MOS transistor M1 charges the negative voltage capacitor CN. When the switching transistor Q1 is in a cutoff state, the conduction of the MOS transistor M1 has no effect. The waveform when the MOS transistor M1 is conducted at a fixed frequency is shown in FIG. 7. From the above analysis, it can be seen that this method is applicable when the performance requirements for circuits such as inverter circuits are low and a low duty cycle is not required.

[0078] Illustratively, the logic control module 152 controls the MOS transistor M1 to conduct at a random frequency.

[0079] 6, when the logic control module 152 controls the MOS transistor M1 to be conductive at a random frequency, the system MCU may randomly input a high-level signal to the latch at a random frequency, and the latch may output a high-level pulse signal to the MOS driver circuit to drive the MOS transistor M1 to be conductive for a short period of time. From the above analysis, it can be seen that this method is applicable when the performance requirements for circuits such as an inverter circuit are low and a low duty cycle is not required.

[0080] As a third example, the logic control module 152 acquires the voltage across the negative voltage capacitor CN, and controls the MOS transistor M1 to be conductive when it determines that the negative voltage capacitor CN is undervoltage based on the voltage across the negative voltage capacitor CN.

[0081] Specifically, referring back to FIG. 6 , the comparator in the logic control module 152 stores the minimum allowable voltage Vcn_min across the negative voltage capacitor CN. The comparator samples the voltage across the negative voltage capacitor CN. When the voltage across the negative voltage capacitor CN is less than Vcn_min, the comparator sends a high-level signal to the latch, which then outputs a high-level pulse signal to the MOS driver, driving the MOS transistor M1 to conduct for a short period of time. When the switching transistor Q1 is in a conducting state, the conduction of the MOS transistor M1 charges the negative voltage capacitor CN. When the switching transistor Q1 is in a cutoff state, the conduction of the MOS transistor M1 has no effect. Thus, the MOS transistor M1 conducts only when the negative voltage capacitor CN is undervoltage, minimizing the switching frequency of the MOS transistor M1. The waveforms when the MOS transistor M1 conducts when the negative voltage capacitor CN is undervoltage are shown in FIG. 8. From the above analysis, it can be seen that this method can be applied when the performance requirements for circuits such as an inverse transform circuit are not high.

[0082] As a fourth example, the logic control module 152 acquires the voltage across the negative voltage capacitor CN, and at the rising edge of the driving voltage output from the driving unit 130, if it determines that the negative voltage capacitor CN is undervoltage based on the voltage across the negative voltage capacitor CN, it controls the MOS transistor M1 to be conductive.

[0083] Specifically, referring back to FIG. 6 , the comparator in the logic control module 152 samples the voltage across the negative voltage capacitor CN and outputs a high-level signal when the voltage across the negative voltage capacitor CN is less than Vcn_min. At the same time, a flip-flop is connected to the output pin OUT of the driver unit 130 and outputs a high-level signal at the rising edge of the signal output from the output pin OUT of the driver unit 130. The signals output from the comparator and the flip-flop are then output to the latch via an AND gate. That is, only when both the comparator and the flip-flop output high-level signals, the AND gate outputs a high-level signal to the latch, driving the MOS transistor M1 to conduct. That is, when the voltage across the negative voltage capacitor CN is less than Vcn_min and at the rising edge of the signal output from the output pin OUT of the driver unit 130, the logic control module 152 controls the MOS transistor M1 to conduct, thereby charging the negative voltage capacitor CN. This reduces the distortion of the driving voltage of the switching transistor Q1. The corresponding waveforms are shown in Figure 9. From the above analysis, it can be seen that this method can be applied when there are high requirements on circuits such as an inverse transform circuit.

[0084] As a fifth example, the logic control module 152 controls the MOS transistor M1 to be conductive at the rising edge of the driving voltage output from the driving unit 130.

[0085] Specifically, referring back to FIG. 6, the flip-flop in the logic control module 152 is connected to the output pin OUT of the driver unit 130, and outputs a high-level signal to the latch at the rising edge of the signal output from the output pin OUT of the driver unit 130. The latch outputs a high-level pulse signal to turn on the MOS transistor M1, thereby charging the negative voltage capacitor CN. The corresponding waveform is shown in FIG. 10. From the above analysis, it can be seen that this method is applicable to circuits with high requirements, such as an inverter circuit.

[0086] In summary, in the bootstrap driving circuit according to the embodiment of the present disclosure, the voltage stabilization unit performs stabilization processing on the bootstrap voltage, thereby ensuring the stability of the bootstrap voltage, thereby ensuring the stability of the driving voltage and the negative cut-off voltage, and improving the driving performance of the circuit. Based on this, the charge control unit charges the negative voltage unit to compensate for the negative cut-off voltage, thereby ensuring the stability of the negative cut-off voltage and the driving voltage, and further improving the driving performance of the circuit.

[0087] Corresponding to the above-mentioned embodiment, the present disclosure further proposes an electric motor control device.

[0088] FIG. 11 is a block diagram of an electric motor control device according to one embodiment of the present disclosure.

[0089] The motor control device 300 in the embodiment of the present disclosure may include an inverter circuit 200 and the above-described bootstrap driving circuit 100. The bootstrap driving circuit 100 is used to drive the switching transistors in the inverter circuit 200 to turn on or off, specifically, to turn on or off the upper arm switching transistors and the lower arm switching transistors of each leg in the inverter circuit 200.

[0090] In some embodiments of the present disclosure, the inverter circuit 200 may be, but is not limited to, a three-phase bridge inverter circuit, a single-phase full-bridge inverter circuit, or a single-phase half-bridge inverter circuit. When the bootstrap driver circuit 100 drives the inverter circuit 200, the bootstrap unit in the bootstrap driver circuit 100 provides a bootstrap voltage to the voltage stabilization unit, which stabilizes the bootstrap voltage to output a stable driving voltage to the driver unit. When the driver unit receives a conduction control signal, it drives the corresponding switching transistor to conduct according to the stable driving voltage. When the driver unit receives a cutoff control signal, it controls the negative voltage unit to generate a stable cutoff negative voltage according to the stable driving voltage to drive the switching transistor to cut off.

[0091] In the motor control device according to the embodiment of the present disclosure, the bootstrap drive circuit described above allows the voltage stabilization unit to perform stabilization processing on the bootstrap voltage, thereby ensuring stability of the bootstrap voltage, thereby ensuring stability of the drive voltage and the negative cut-off voltage, and improving the drive performance of the circuit. Based on this, the charge control unit charges the negative voltage unit to compensate for the negative cut-off voltage, thereby ensuring stability of the negative cut-off voltage and the drive voltage, further improving the drive performance of the circuit.

[0092] Corresponding to the above-mentioned embodiment, the present disclosure further proposes a compressor.

[0093] FIG. 12 is a block diagram of a compressor according to one embodiment of the present disclosure.

[0094] The compressor 400 according to the embodiment of the present disclosure includes the electric motor M and the above-mentioned electric motor control device 300, which is used to drive the operation of the electric motor M.

[0095] In some embodiments, the compressor 400 may be an electric compressor including a drive unit and a compression unit. The drive unit in the electric compressor drives the compression unit to perform compression work. For example, the drive unit may include an electric motor M including a rotor and a stator and the above-mentioned electric motor control device 300, and the electric motor control device 300 drives the operation of the electric motor M to drive the compression work of the compression unit. In some embodiments, the electric compressor may be a low-backpressure compressor, in which the drive unit may be located in a low-pressure chamber communicating with the intake port of the compressor, and the compression unit may be located in a high-pressure chamber communicating with the discharge port of the compressor. In some embodiments, the electric compressor may be a horizontal compressor, in which the drive unit and the compression unit may be arranged side by side.

[0096] When the motor control device 300 drives the motor M to operate and drive the compression work of the compression unit, the bootstrap unit in the bootstrap driving circuit provides a bootstrap voltage to the voltage stabilizing unit, which stabilizes the bootstrap voltage and outputs a stable driving voltage to the driving unit. When the driving unit receives a conduction control signal, it drives the corresponding switching transistor to conduct according to the stable driving voltage, while when the driving unit receives a cutoff control signal, it controls the negative voltage unit to generate a stable cutoff negative voltage according to the stable driving voltage, and drives the switching transistor to cut off.

[0097] In the compressor according to the embodiment of the present disclosure, the motor control device described above allows the voltage stabilization unit to stabilize the bootstrap voltage, thereby ensuring the stability of the bootstrap voltage, thereby ensuring the stability of the driving voltage and the negative cutoff voltage, and improving the driving performance of the circuit. Based on this, the charge control unit charges the negative voltage unit to compensate for the negative cutoff voltage, thereby ensuring the stability of the negative cutoff voltage and the driving voltage, further improving the driving performance of the circuit and the performance of the compressor.

[0098] Corresponding to the above-mentioned embodiment, the present disclosure further proposes a vehicle.

[0099] FIG. 13 is a block diagram of a vehicle according to one embodiment of the present disclosure.

[0100] A vehicle 500 according to an embodiment of the present disclosure includes the compressor 400 described above.

[0101] In an embodiment of the present disclosure, a vehicle 500 includes the compressor 400 described in any of the above embodiments. The vehicle 500 may be a new energy vehicle. In some embodiments, the new energy vehicle may be a pure electric vehicle using an electric motor as the main driving force. In other embodiments, the new energy vehicle may be a hybrid vehicle using both an internal combustion engine and an electric motor as the main driving force. Regarding the internal combustion engine and electric motor that provide driving force for the new energy vehicle mentioned in the above embodiments, the internal combustion engine may use gasoline, diesel, hydrogen, etc. as fuel, and the method of supplying power to the electric motor may include, but is not limited to, a power battery, a hydrogen fuel cell, etc. Note that this description is merely an example of the structure of a new energy vehicle and does not limit the scope of protection of the present disclosure.

[0102] In the vehicle according to the embodiment of the present disclosure, the above-mentioned compressor allows the voltage stabilization unit to stabilize the bootstrap voltage, thereby ensuring the stability of the bootstrap voltage, thereby ensuring the stability of the driving voltage and the negative cut-off voltage, and improving the driving performance of the circuit. Based on this, the charge control unit charges the negative voltage unit to compensate for the negative cut-off voltage, thereby ensuring the stability of the negative cut-off voltage and the driving voltage, further improving the driving performance of the circuit and the performance of the compressor, and thereby further improving the performance of the vehicle.

[0103] It should be noted that the logic and / or steps depicted in flowcharts or otherwise described herein may be considered, for example, as a sequential listing of executable instructions for implementing logical functions, tangibly embodied in a computer-readable medium for use by or in conjunction with an instruction-execution system, device, or apparatus (such as a computer-based system, a system including a processor, or other system that receives and executes instructions from an instruction-execution system, device, or apparatus). As used herein, a "computer-readable medium" refers to a device that can contain, store, communicate, propagate, or transmit a program for use with the instruction-execution system, device, or apparatus, alone or in conjunction with the instruction-execution system, device, or apparatus. More specific examples (a non-exhaustive list) of computer-readable media include an electrical connection having one or more wires (electronic devices), a portable computer disk cassette (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), fiber optic devices, a portable compact disc read-only memory (CD-ROM), and the like. Furthermore, the computer readable medium may be, for example, paper or other suitable medium on which the program may be printed, since the paper or other medium may be optically scanned and then edited, interpreted, or processed in any other suitable manner as required to obtain said program electronically and store it in a computer memory.

[0104] It will be understood that portions of the present disclosure can be implemented by hardware, software, firmware, or a combination thereof. In the above-described embodiments, some steps and methods may be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, when implemented in hardware, as in other embodiments, the implementation may be implemented by any technology known in the art, such as a discrete logic circuit having logic gate circuits that implement logic functions on data signals, an application-specific integrated circuit (ASIC) having an appropriate combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), or a combination thereof.

[0105] In the description herein, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean that the specific features, structures, materials, or characteristics described in the embodiment or example are included in one or more of the embodiment or examples of the present invention. The denotative expressions of the above terms in the description herein do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics may be combined in any suitable manner in any one or more of the embodiment or examples.

[0106] Additionally, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implying the number of technical features. Thus, a feature qualified as "first" or "second" may expressly or imply the inclusion of one or more of that feature. In the description of this disclosure, "plurality" means two or more, such as two, three, etc., unless otherwise specifically qualified.

[0107] In this disclosure, unless otherwise expressly specified or limited, the terms "attached," "coupled," and "connected" should be understood broadly. For example, they may be fixed, detachable, or integral connections, mechanical or electrical connections, direct connections, or indirect connections via an intermediate medium, or internal communication or interacting relationships between two elements. Those skilled in the art will be able to understand the specific meanings of these terms in this disclosure depending on the specific circumstances.

[0108] Although embodiments of the present disclosure have been shown and described, those skilled in the art will understand that the above-described embodiments are illustrative and cannot be understood as limitations on the present disclosure, and that changes, combinations, modifications, substitutions, and variations can be made to the above-described embodiments within the scope of the present disclosure.

Claims

1. The battery includes a bootstrap unit, a negative voltage unit, a driving unit, a voltage stabilization unit, and a charge control unit; the bootstrap unit is for providing a bootstrap voltage to the voltage stabilization unit; the voltage stabilization unit performs a stabilization process on the bootstrap voltage to output a stable drive voltage to the drive unit; the driving unit, when receiving a conduction control signal, drives the corresponding switching transistor to conduct in accordance with the stable driving voltage, and when receiving a cut-off control signal, controls the negative voltage unit to generate a stable cut-off negative voltage in accordance with the stable driving voltage, thereby driving the switching transistor to cut off; the charging control unit controls the negative voltage unit to charge when the switching transistor is conductive, and performs secondary stabilization processing on the cutoff negative voltage generated by the negative voltage unit; The charging control unit a controllable switch module connected between the negative terminal of the negative voltage unit and the negative terminal of the bootstrap unit; a logic control module for controlling the controllable switch module to be conductive, so that the negative voltage unit is charged by the driving voltage; Bootstrap drive circuit.

2. The input terminal of the voltage stabilizing unit is connected to the output terminal of the bootstrap unit; a reference ground terminal of the voltage stabilizing unit is connected to a negative terminal of the bootstrap unit and a power supply negative terminal of the driving unit, respectively; The output terminal of the voltage stabilizing unit is connected to the power supply positive pin of the driving unit; The output pin of the driving unit is connected to the positive end of the negative voltage unit; The negative end of the negative voltage unit is connected to the control end of the switching transistor; 2. The bootstrap driver circuit of claim 1.

3. The voltage stabilizing unit includes a linear voltage stabilizing power supply or a switching power supply; 2. The bootstrap driver circuit of claim 1.

4. the switching transistor is an upper arm switching transistor of an inverter circuit; 2. The bootstrap driver circuit of claim 1.

5. The logic control module is further used for obtaining a voltage across the negative voltage unit, and controlling the controllable switch module to be conductive when it determines that the negative voltage unit is undervoltage based on the voltage across the negative voltage unit at the rising edge of the driving voltage output from the driving unit.

2. The bootstrap driver circuit of claim 1.

6. The logic control module is further used for controlling the controllable switch module to be conductive at a rising edge of the driving voltage output from the driving unit.

2. The bootstrap driver circuit of claim 1.

7. the controllable switch module includes a MOS transistor and a current limiting resistor; The current limiting resistor is connected between the drain of the MOS transistor and the negative terminal of the negative voltage unit; or the current limiting resistor is connected between the source of the MOS transistor and the negative terminal of the bootstrap unit; 2. The bootstrap driver circuit of claim 1.

8. When the MOS transistor has a body diode, the controllable switch module further includes a first diode, the anode of the first diode is connected to the source of the MOS transistor, and the cathode of the first diode is connected to the negative terminal of the bootstrap unit.

8. A bootstrap driver circuit according to claim 7.

9. the bootstrap unit includes a power supply, a bootstrap diode, a bootstrap resistor, and a bootstrap capacitor; The negative terminal of the power supply is grounded, an anode of the bootstrap diode is connected to the positive terminal of the power supply; one end of the bootstrap resistor is connected to the cathode of the bootstrap diode; a positive terminal of the bootstrap capacitor connected to the other terminal of the bootstrap resistor and having a first node, a negative terminal of the bootstrap capacitor connected to a reference ground terminal of the voltage stabilization unit, and the first node serving as an output terminal of the bootstrap unit; 3. A bootstrap driver circuit according to claim 2.

10. the negative voltage unit includes a negative voltage capacitor and a first voltage stabilizing diode; The positive terminal of the negative voltage capacitor is connected to the output pin of the driving unit, and the negative terminal of the negative voltage capacitor serves as the negative terminal of the negative voltage unit; The anode of the first voltage stabilizing diode is connected to the negative terminal of the negative voltage capacitor, and the cathode of the first voltage stabilizing diode is connected to the positive terminal of the negative voltage capacitor.

10. A bootstrap driver circuit according to claim 9.

11. an inverse conversion circuit; The bootstrap driving circuit according to any one of claims 1 to 10, further comprising: a bootstrap driving circuit used to drive a switching transistor in the inverter circuit to turn on or off; Electric motor control equipment.

12. The inverter circuit is a three-phase bridge inverter circuit, a single-phase full-bridge inverter circuit, or a single-phase half-bridge inverter circuit.

12. The motor control device according to claim 11.

13. An electric motor, 12. The electric motor control device according to claim 11, wherein the electric motor control device is used to drive and operate the electric motor. Compressor.

14. The compressor according to claim 13 vehicle.

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