An absorption circuit, an inverter, an electric drive system, a vehicle, and a voltage compensation method.

Abstract

This invention discloses an absorption circuit, an inverter, an electric drive system, a vehicle, and a voltage compensation method. The absorption circuit includes three parallel-connected switching components. Each switching component's single-phase half-bridge circuit incorporates a voltage acquisition and conversion device and a compensation transformer. The voltage acquisition and conversion device acquires the induced voltage generated by parasitic inductance in the single-phase half-bridge circuit and reverses this induced voltage to output a converted voltage. The compensation transformer outputs a compensation voltage to the single-phase half-bridge circuit based on the converted voltage. By incorporating a voltage acquisition and conversion device and a compensation transformer in the single-phase half-bridge circuit of each switching component of the inverter, the induced voltage generated during switching can be reduced and eliminated, thereby reducing electrical stress and electromagnetic emissions during power device operation and improving the safety of power device operation and the system's output performance.

Description

Technical Field

[0001] This disclosure relates to the field of absorption circuit technology, and more specifically, to an absorption circuit, an inverter, an electric drive system, a vehicle, and a voltage compensation method. Background Technology

[0002] Driven by the global energy crisis and environmental pollution, vehicle electrification has gradually become a trend. The electric drive system, as a key powertrain component of electric vehicles, is responsible for the vehicle's power delivery and necessary energy recovery. The main circuit of the inverter is the component in the electric drive system that converts electrical energy; this circuit consists of power devices configured according to a specific circuit topology. These power devices are the critical core components of the electric drive system, and their operational safety directly affects the overall vehicle safety. Operating in high-speed switching mode, these power devices are affected by the parasitic parameters of the main circuit and the power devices themselves, resulting in induced voltages during the switching process. These induced voltages have a decisive impact on the device's operational safety, system electromagnetic emissions, and performance output. Therefore, reducing or eliminating induced voltages is of paramount importance.

[0003] Typically, an absorption circuit is added to the main circuit. The function of the absorption circuit is to ensure that the voltage oscillating on the MOSFET does not exceed the nominal withstand voltage of the device. Existing absorption circuits are mostly based on capacitors, resistors, and diodes to absorb the induced voltage generated during the turn-off process of the device. Some technical solutions add switching devices and transient voltage suppressors (TVS) to the aforementioned circuit to control the operation of the absorption circuit above a specific voltage to absorb the induced voltage. The absorption mechanism of these circuits for induced voltage is the energy conversion between inductance and capacitance, as well as the energy consumption of resistors. Therefore, they are quite sensitive to the operating frequency. That is, the circuit parameters are optimal at the set frequency. If the frequency changes, the absorption effect will decrease and become ineffective, rendering the absorption circuit useless. Summary of the Invention

[0004] In view of this, the present disclosure aims to provide an absorption circuit, an inverter, an electric drive system, a vehicle, and a voltage compensation method to at least solve the technical problem that existing absorption circuits can only operate at specific frequencies.

[0005] In a first aspect, embodiments of this disclosure provide an absorption circuit comprising three parallel half-bridge topologies. In each half-bridge topology, a voltage acquisition and conversion device and a compensation transformer are provided in a single-phase half-bridge circuit. The voltage acquisition and conversion device is used to acquire the induced voltage generated by the parasitic inductance in the single-phase half-bridge circuit and reverse-convert the induced voltage to output a converted voltage. The compensation transformer is used to output a compensation voltage to the single-phase half-bridge circuit based on the converted voltage.

[0006] In one exemplary embodiment, the compensation voltage is determined by the turns ratio of the primary to the secondary side of the compensation transformer.

[0007] In one exemplary embodiment, the compensation voltage is out of phase and has the same amplitude as the induced voltage.

[0008] In one exemplary embodiment, the half-bridge topology circuit includes an IGBT power switch or a MOS power switch.

[0009] Secondly, embodiments of this disclosure provide an inverter for an electric drive system, the inverter being used to convert direct current into alternating current, and comprising the absorption circuit described in any of the above technical solutions.

[0010] Thirdly, embodiments of this disclosure provide an electric drive system that includes the inverter described in the above technical solutions.

[0011] Fourthly, embodiments of this disclosure provide a vehicle that includes the electric drive system described in the above technical solutions.

[0012] Fifthly, embodiments of this disclosure provide a voltage compensation method, the method comprising: acquiring an induced voltage generated by parasitic inductance in a switching component; reversing the induced voltage to output a converted voltage; and outputting a compensation voltage to the single-phase half-bridge circuit based on the converted voltage.

[0013] In one exemplary embodiment, the compensation voltage is determined by the turns ratio of the primary to the secondary side of the compensation transformer.

[0014] In one exemplary embodiment, the compensation voltage is out of phase and has the same amplitude as the induced voltage.

[0015] This disclosure reduces and eliminates the induced voltage generated during switching by setting a voltage acquisition and conversion device and a compensation transformer in the single-phase half-bridge circuit of each switching component of the inverter. At the same time, the circuit is not affected by the switching frequency of the power device, and can achieve the elimination of induced voltage in the electric drive system at different switching frequencies of the power device, reduce the electrical stress and electromagnetic emission in the operation of the power device, and improve the safety of the power device and the output performance of the system.

[0016] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0018] Figure 1 This is a schematic diagram of the main circuit of the three-phase full-bridge electric drive inverter provided in this disclosure;

[0019] Figure 2 This is a schematic diagram of the single-phase half-bridge main circuit of the integrated absorption circuit provided in this disclosure;

[0020] Figure 3 This is a schematic diagram of the three-phase full-bridge main circuit of the integrated absorption circuit provided in this disclosure;

[0021] Figure 4 This is a schematic diagram illustrating the effect of the induced voltage spike of the absorption circuit provided in this disclosure;

[0022] Figure 5 This is a schematic diagram of the electric drive system provided in this disclosure;

[0023] Figure 6 This is a structural schematic diagram of the vehicle provided in this disclosure;

[0024] Figure 7 This is a flowchart of the voltage compensation method corresponding to the absorption circuit provided in this disclosure. Detailed Implementation

[0025] The specific embodiments of this disclosure will now be described in detail with reference to the accompanying drawings, but these are not intended to limit the scope of this disclosure.

[0026] It should be understood that various modifications can be made to the embodiments disclosed herein. Therefore, the above description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope and spirit of this disclosure will be apparent to those skilled in the art.

[0027] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present disclosure and, together with the general description of the disclosure given above and the detailed description of the embodiments given below, serve to explain the principles of the disclosure.

[0028] These and other features of this disclosure will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0029] It should also be understood that although this disclosure has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this disclosure, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0030] The above and other aspects, features and advantages of this disclosure will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0031] Specific embodiments of the present disclosure are described thereafter with reference to the accompanying drawings; however, it should be understood that the disclosed embodiments are merely examples of the present disclosure and can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that could obscure the present disclosure. Therefore, the specific structural and functional details disclosed herein are not intended to be limiting, but merely to serve as the basis and representative basis for the claims to teach those skilled in the art to use the present disclosure in a variety of substantially any suitable detailed structures.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0033] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in still another embodiment,” all of which may refer to one or more of the same or different embodiments according to this disclosure.

[0034] The present disclosure will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] Example 1

[0036] In view of the problems of poor absorption effect in the absorption circuit of the prior art, the first aspect of this disclosure provides an absorption circuit to enhance the absorption effect of induced voltage generated by power devices, and improve the safety of power device operation and the output performance of the system.

[0037] Specifically Figure 1This is a schematic diagram of the main circuit of a three-phase full-bridge electric drive inverter. As can be seen, the circuit consists of six IGBT power switches. The upper bridge arm consists of IGBT power switches Q1, Q3, and Q5; the lower bridge arm consists of IGBT power switches Q2, Q4, and Q6. The collectors of IGBT power switches Q1, Q3, and Q5 in the upper bridge arm are connected to the positive terminal of the power supply. The emitters of IGBT power switches Q2, Q4, and Q6 in the lower bridge arm are connected to the negative terminal of the power supply. These three single-phase half-bridge circuits are connected in parallel to form the three-phase full-bridge circuit of the inverter.

[0038] During operation, power devices are affected by the main circuit and parasitic parameters of the power devices, and parasitic inductance is generated during the switching process. The parasitic inductances that affect the working safety and performance in the three parallel circuits are represented by L1, L4 and L7, respectively. The parasitic inductances L1, L4 and L7 are connected in series with the collectors of IGBT power switches Q1, Q3 and Q5, respectively.

[0039] To reduce the impact of parasitic inductance on the circuit, the following explanation will use one phase of a three-phase full-bridge circuit as an example. Figure 2 Here is a schematic diagram of the single-phase half-bridge main circuit of the integrated snubber circuit provided in this disclosure, as shown below. Figure 2 As shown, the U-phase half-bridge main circuit of the integrated absorption circuit includes a single-phase half-bridge main circuit 1, a voltage acquisition and conversion device 2, and a compensation transformer 3. The single-phase half-bridge main circuit 1 includes a unipolar inverter circuit composed of IGBT power switches Q1 and Q2. The positive input terminal of the inverter circuit, i.e., the collector of IGBT power switch Q1, is connected to the positive terminal of the DC voltage, and the negative input terminal of the inverter circuit, i.e., the emitter of IGBT power switch Q2, is connected to the negative terminal of the DC voltage. The parasitic inductance of the loop is represented by L1. The parasitic inductance L1 and the secondary inductance L2 of the compensation transformer 3 are connected in series between the positive terminal of the DC voltage and the collector of IGBT power switch Q1. The voltage acquisition and conversion device 2 is connected to both ends of the parasitic inductor L1 and is used to acquire the induced voltage generated by the parasitic inductor L1 in the single-phase half-bridge circuit, and to reverse the induced voltage to output a converted voltage; the compensation transformer 3 outputs a compensation voltage to the single-phase half-bridge circuit based on the converted voltage to reduce or eliminate the influence of the induced voltage generated by the parasitic inductor on the switching devices.

[0040] Furthermore, in the single-phase half-bridge main circuit 1, the induced voltage generated by the parasitic inductance L1 is U1. The voltage acquisition and conversion device 2 acquires the induced voltage U1 generated by the parasitic inductance L1 and reverses the acquired induced voltage U1 to obtain the compensation voltage U2 required by the compensation transformer 3. In order to reduce or eliminate the influence of the induced voltage U1 on the switching devices, the optimal value of the compensation voltage U2 should be the same phase and opposite in amplitude as the induced voltage U1 generated by the parasitic inductance L1, and the frequency of the compensation voltage U2 should be the same as the frequency of the induced voltage U1 so as to completely cancel the induced voltage U1. With the above settings, the single-phase half-bridge main circuit of the integrated absorption circuit can be unaffected by the change in the switching frequency of the power devices, meeting the application requirements of the power devices in the electric drive system at different switching frequencies.

[0041] Specifically, the primary winding of the compensation transformer 3 has N3 turns, and the secondary winding has N2 turns. The primary and secondary voltages of the compensation transformer 3 satisfy the following relationship: the ratio of the secondary voltage to the primary voltage is the same as the ratio of the secondary winding turns N2 to the primary winding turns N3. Therefore, when the primary voltage is determined, the secondary voltage can be adjusted by adjusting the turns ratio of the primary and secondary windings of the compensation transformer 3. In other words, by adjusting the turns ratio of the primary and secondary windings of the compensation transformer 3, the compensation voltage U2 output to the main circuit can be adjusted so that the magnitude of the compensation voltage U2 is in phase with the induced voltage U1 generated by the parasitic inductor L1, but opposite in amplitude, and the frequency of the compensation voltage U2 is the same as the frequency of the induced voltage U1, thereby satisfying the requirements of the absorption circuit for the compensation voltage U2.

[0042] Three single-phase half-bridge circuits are connected in parallel to form a three-phase full-bridge circuit for the inverter, such as... Figure 3As shown, the U-phase half-bridge circuit, V-phase half-bridge circuit, and W-phase half-bridge circuit are connected in parallel across the DC voltage to form a three-phase full-bridge circuit. This circuit consists of six IGBT power switches, with the upper bridge arm consisting of IGBT power switches Q1, Q3, and Q5, and the lower bridge arm consisting of IGBT power switches Q2, Q4, and Q6. The collectors of IGBT power switches Q1, Q3, and Q5 in the upper bridge arm are connected to the positive terminal of the power supply. The emitters of IGBT power switches Q2, Q4, and Q6 in the lower bridge arm are connected to the negative terminal of the power supply. Parasitic inductance L1 is connected in series with the secondary inductance L2 of the compensation transformer between the positive terminal of the DC voltage and the collector of IGBT power switch Q1. Parasitic inductance L4 is connected in series with the secondary inductance L5 of the compensation transformer between the positive terminal of the DC voltage and the collector of IGBT power switch Q1. Parasitic inductance L7 is connected in series with the secondary inductance L8 of the compensation transformer between the positive terminal of the DC voltage and the collector of IGBT power switch Q1. The U-phase half-bridge circuit, V-phase half-bridge circuit, and W-phase half-bridge circuit each lead out an AC output terminal for outputting AC voltage. The parasitic inductors L1, L4, and L7 are all connected to voltage acquisition and conversion devices. These devices acquire the induced voltage generated by the parasitic inductors and reverse-convert the induced voltage to output a converted voltage. The compensation transformer outputs a compensation voltage to the secondary side of the transformer, i.e., the main circuit, based on the converted voltage, to reduce or eliminate the influence of the induced voltage generated by the parasitic inductors on the switching devices.

[0043] The compensation voltage output by the compensation transformer can effectively eliminate the voltage spikes generated by the switching devices in the three-phase full-bridge circuit of the inverter, such as... Figure 4 As shown, Figure 4 This diagram illustrates the effect of the absorption circuit provided in this disclosure on induced voltage spikes. Within a single cycle, the induced voltage U1 generated by the parasitic inductance L1 in the single-phase half-bridge main circuit 1 produces spikes in both the upper and lower directions of the bus voltage. To effectively suppress the spikes when the switching devices are disconnected, a compensation voltage U2 is injected into the circuit through the compensation transformer 3. The magnitude of the compensation voltage U2 is in phase with the peak value of the induced voltage U2 but opposite in amplitude, thereby eliminating the spikes. Figure 4As can be seen, by setting voltage acquisition and conversion devices and compensation transformers in the single-phase half-bridge circuit of each switching component of the inverter, the induced voltage generated during the switching process can be reduced and eliminated. At the same time, this circuit is not affected by the switching frequency of the power devices, and can achieve the elimination of induced voltage in the electric drive system at different switching frequencies of the power devices, reduce the electrical stress and electromagnetic emission during the operation of the power devices, and improve the safety of the power devices and the output performance of the system.

[0044] It should be noted that the embodiments disclosed herein are illustrated using multiple IGBT power switches to eliminate parasitic inductance in a three-phase full-bridge circuit composed of multiple IGBT power switches. The absorption circuit provided in the embodiments of this disclosure can also be applied to the case of a three-phase full-bridge circuit composed of other devices, including but not limited to multiple MOSFET modules or multiple SiC MOSFET modules.

[0045] Therefore, this disclosure can reduce and eliminate the induced voltage that accompanies the switching process by setting a voltage acquisition and conversion device and a compensation transformer in the single-phase half-bridge circuit of each switching component of the inverter. At the same time, the circuit is not affected by the switching frequency of the power device, and can realize the elimination of induced voltage in the electric drive system at different switching frequencies of the power device, reduce the electrical stress and electromagnetic emission in the operation of the power device, and improve the safety of the power device and the output performance of the system.

[0046] Example 2

[0047] Based on the same inventive concept, the second aspect of this disclosure also provides an inverter 10 for an electric drive system, the inverter 10 being used to convert direct current into alternating current, the inverter 10 having the absorption circuit provided in the first aspect of this disclosure.

[0048] The absorption circuit includes three parallel half-bridge topologies. In each half-bridge topology, a voltage acquisition and conversion device and a compensation transformer are provided in the single-phase half-bridge circuit. The voltage acquisition and conversion device is used to acquire the induced voltage generated by the parasitic inductance in the single-phase half-bridge circuit and reverse the induced voltage to output a converted voltage. The compensation transformer is used to output a compensation voltage to the single-phase half-bridge circuit based on the converted voltage.

[0049] This embodiment of the invention reduces and eliminates the induced voltage generated during the switching process by setting a voltage acquisition and conversion device and a compensation transformer in the single-phase half-bridge circuit of each switching component of the inverter. At the same time, the circuit is not affected by the switching frequency of the power device, and can achieve the elimination of induced voltage in the electric drive system at different switching frequencies of the power device. This reduces the electrical stress and electromagnetic emission during the operation of the power device, and improves the safety of the power device and the output performance of the system.

[0050] Example 3

[0051] Based on the same inventive concept, a third aspect of this disclosure also provides an electric drive system, such as... Figure 5 As shown, the electric drive system 100 includes at least components such as an inverter 10 and a transmission mechanism 20. Those skilled in the art will understand that the electric drive system structure shown in the figure does not constitute a limitation on the structure of the electric drive system, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0052] The inverter 10 is the core of the electric drive system 100. Its function is to convert the DC power provided by the power battery into sinusoidal AC power that the motor can use, and it also controls the speed and torque of the AC motor. Specifically, the inverter 10 of this disclosure includes an absorption circuit, which includes three parallel half-bridge topologies. In each half-bridge topology, a voltage acquisition and conversion device and a compensation transformer are provided in a single-phase half-bridge circuit. The voltage acquisition and conversion device is used to acquire the induced voltage generated by the parasitic inductance in the single-phase half-bridge circuit and reverse-convert the induced voltage to output a converted voltage. The compensation transformer is used to output a compensation voltage to the single-phase half-bridge circuit based on the converted voltage.

[0053] This embodiment of the invention reduces and eliminates the induced voltage generated during the switching process by setting a voltage acquisition and conversion device and a compensation transformer in the single-phase half-bridge circuit of each switching component of the inverter. At the same time, the circuit is not affected by the switching frequency of the power device, and can achieve the elimination of induced voltage in the electric drive system at different switching frequencies of the power device. This reduces the electrical stress and electromagnetic emission during the operation of the power device, and improves the safety of the power device and the output performance of the system.

[0054] Example 4

[0055] Based on the same inventive concept, the fourth aspect of this disclosure also provides a vehicle, such as... Figure 6 As shown, the vehicle includes at least components such as an electric drive system 100, a battery system 200, and an electronic control system 300. Those skilled in the art will understand that the vehicle structure shown in the figure does not constitute a limitation on the vehicle structure and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0056] The electric drive system 100 converts the energy of the power battery into the kinetic energy of the wheels. The electric drive system 100 includes the inverter 10 provided in the second aspect of this disclosure. Therefore, the electric drive system 100 provided in the embodiments of this disclosure includes the technical features of the inverter and absorption circuit provided in the embodiments of this disclosure, and can achieve the beneficial effects of the absorption circuit provided in the embodiments of this disclosure. The similarities can be referred to the above description of the absorption circuit provided in the embodiments of this disclosure, and will not be repeated here.

[0057] Example 5

[0058] To better implement the absorption circuit, a fifth aspect of this disclosure also provides a voltage compensation method corresponding to the absorption circuit. For example... Figure 7 As shown, the voltage compensation method specifically includes the following steps:

[0059] S101 collects the induced voltage generated by the parasitic inductance in the switching component.

[0060] Specifically, the voltage acquisition and conversion device 2 acquires the induced voltage U generated by the parasitic inductance L in each single-phase half-bridge circuit of the three-phase full-bridge circuit.

[0061] S102, the induced voltage is reverse-converted to output a converted voltage.

[0062] Specifically, the voltage acquisition and conversion device 2 reverses the induced voltage U across the parasitic inductor L to obtain a voltage with opposite amplitude.

[0063] S103, based on the conversion voltage, output a compensation voltage to the single-phase half-bridge circuit.

[0064] Specifically, the compensation transformer 3 outputs a compensation voltage to the single-phase half-bridge circuit based on the conversion voltage, so as to reduce or eliminate the influence of the induced voltage U generated by the parasitic inductance L on the switching devices.

[0065] The compensation transformer 3 has N3 turns on its primary side and N2 turns on its secondary side. The primary and secondary voltages of the compensation transformer 3 satisfy the following relationship: the ratio of the secondary voltage to the primary voltage is the same as the ratio of the number of turns on the secondary side to the number of turns on the primary side. Therefore, when the primary voltage is determined, the secondary voltage can be adjusted by changing the turns ratio of the primary and secondary sides of the compensation transformer 3. In other words, by adjusting the turns ratio of the primary and secondary sides of the compensation transformer 3, the compensation voltage U2 output to the main circuit can be adjusted so that the magnitude of the compensation voltage U2 is in phase with, and opposite in amplitude to, the induced voltage U1 generated by the parasitic inductor L1, and the frequency of the compensation voltage U2 is the same as the frequency of the induced voltage U1. This satisfies the absorption circuit's requirement for the compensation voltage U2 and reduces or eliminates the influence of the induced voltage U on the switching devices.

[0066] As can be seen from the above, the absorption circuit, inverter, electric drive system, vehicle, and voltage compensation method provided in this disclosure can reduce and eliminate the induced voltage generated during the switching process by setting a voltage acquisition and conversion device and a compensation transformer in the single-phase half-bridge circuit of each switching component of the inverter. At the same time, the circuit is not affected by the switching frequency of the power device, and can achieve the elimination of induced voltage in the electric drive system at different switching frequencies of the power device, reduce the electrical stress and electromagnetic emission during the operation of the power device, and improve the safety of the power device and the output performance of the system.

[0067] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0068] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0069] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0070] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0071] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0072] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0073] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An absorption circuit comprising three half-bridge topology circuits arranged in parallel, characterized in that, The voltage acquisition conversion device and the compensation transformer are arranged in each single-phase half-bridge circuit of the half-bridge topology circuit, wherein the half-bridge topology circuit comprises an IGBT power switch Q1 and an IGBT power switch Q2, the collector of the IGBT power switch Q1 is connected with the positive pole of a direct current voltage, the emitter of the IGBT power switch Q2 is connected with the negative pole of the direct current voltage, the voltage acquisition conversion device is used for acquiring an induced voltage generated by a parasitic inductance in the single-phase half-bridge circuit and reversely converting the induced voltage to output a converted voltage, the compensation transformer is used for outputting a compensation voltage to the single-phase half-bridge circuit based on the converted voltage, the parasitic inductance and a secondary inductance of the compensation transformer are arranged in series between the positive pole of the direct current voltage and the collector of the IGBT power switch, and the voltage acquisition device is connected across the parasitic inductance.

2. The absorption circuit of claim 1, wherein, The compensation voltage is determined by a turns ratio of a primary side and a secondary side of the compensation transformer.

3. The absorption circuit of claim 1, wherein, The compensation voltage is opposite in phase to the induced voltage and has the same amplitude.

4. An inverter of an electric drive system for converting direct current into alternating current, characterized in that The inverter comprises the snubber circuit of any one of claims 1-3.

5. An electric drive system characterized by, The inverter comprises the snubber circuit of claim 4.

6. A vehicle characterized by comprising: The electric drive system comprises the inverter of claim 5.

7. A voltage compensation method, characterized by, The method is applied to the snubber circuit of any one of claims 1-3, and the method comprises: The voltage acquisition conversion device acquires an induced voltage generated by a parasitic inductance in a switching component; The voltage acquisition conversion device reversely converts the induced voltage to output a converted voltage; The compensation transformer outputs a compensation voltage to the single-phase half-bridge circuit based on the converted voltage output by the voltage acquisition conversion device.

8. The voltage compensation method according to claim 7, characterized in that, The compensation voltage is determined by a turns ratio of a primary side and a secondary side of the compensation transformer.

9. The voltage compensation method of claim 7, wherein, The compensation voltage is opposite in phase to the induced voltage and has the same amplitude.

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