Direct-current bus capacitor active discharging method and device, electronic equipment and medium

Abstract

The invention provides a direct-current bus capacitor active discharging method and device, electronic equipment and a medium. The method comprises the following steps: acquiring a discharge feedback quantity between two adjacent moments according to voltage values of a bus capacitor at the two adjacent moments; according to the bus capacitance value, the preset initial voltage, the preset final voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments, the discharge reference quantity is calculated; obtaining a preset pulse width of a first switching tube of at least one bridge arm, and obtaining a target driving pulse width according to the discharge feedback quantity, the discharge reference quantity and the preset pulse width; and controlling the second switch tube of the bridge arm to be switched on, and driving the first switch tube of the bridge arm to be switched on and switched off alternately according to the target driving pulse width so as to discharge the bus capacitor. According to the invention, active discharge closed-loop control is carried out by adopting the energy difference between adjacent moments, so that the dependence on bus voltage sampling precision can be reduced; and the cost can be reduced, the area of the discharge control circuit is reduced, and the overall power density is improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicle control technology, and in particular to a method, device, electronic equipment and medium for active discharge of a DC bus capacitor. Background Art

[0002] As the power level of new energy vehicles continues to increase, the voltage level of the inverter DC bus is also increasing. The higher and higher DC bus voltage is bound to bring potential safety problems. In the fault and shutdown state, the excessively high DC bus voltage poses a great safety hazard. For example, after a vehicle fails, maintenance personnel open the cover for maintenance, and after a vehicle collision, the high-voltage bus may be exposed. Under these conditions, maintenance personnel have the opportunity to touch the DC bus, causing personal safety issues. Therefore, how to quickly and safely complete the discharge of the DC bus capacitor in the shutdown or fault state is becoming one of the technical problems that need to be solved in the design of new energy vehicles.

[0003] In order to solve the above problems, in the related art, there are two main active discharge solutions using the inverter bridge arm direct discharge solution: an open-loop discharge solution and a closed-loop discharge solution:

[0004] (1) The open-loop discharge scheme sets different discharge pulse widths based on voltage and temperature ranges, and discharges the bus capacitor according to the given pulse width. However, since the characteristic parameters of semiconductor power modules are not completely consistent, the pulse width set in the open loop is not universally applicable, and even active discharge cannot be performed under certain extreme samples.

[0005] (2) The closed-loop discharge scheme is currently based on the voltage fluctuation during the half-bridge switching process of the bridge arm as the feedback quantity, which is proportional to the peak current of a single discharge. By controlling the discharge peak current during the discharge process, closed-loop control of the constant discharge peak current is achieved, thereby completing the discharge of the bus capacitor. However, this scheme requires an additional sampling circuit for the bus voltage fluctuation to achieve peak current sampling. There are defects such as complex circuit structure, high cost, and additional failure rate.

[0006] It should be noted that the information disclosed in the background technology section of the invention is only intended to deepen the understanding of the general background technology of the invention, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0007] The object of the present invention is to provide a method, device, electronic device and medium for active discharge of a DC bus capacitor. The present invention uses the energy difference between adjacent moments to perform active discharge closed-loop control, which can reduce the dependence on the sampling accuracy of the bus voltage. It not only has good universality and good control accuracy, but also does not require a current sampling circuit. While significantly reducing costs, it can also reduce the area of ​​the discharge control circuit, thereby improving the overall power density.

[0008] In order to achieve the above object, the present invention is implemented by the following technical scheme: a method for actively discharging a DC bus capacitor, wherein the bus capacitor is connected in parallel with an input end of a bridge inverter, the bridge inverter includes at least one bridge arm, and each bridge arm includes a first switch tube and a second switch tube; the method for actively discharging a DC bus capacitor includes:

[0009] According to the voltage value of the bus capacitor at two adjacent moments, obtaining the discharge feedback amount between the adjacent moments;

[0010] Calculate the discharge reference amount between the adjacent moments according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments;

[0011] Acquire a preset pulse width of a first switch tube of at least one of the bridge arms, and obtain a target driving pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width;

[0012] The second switch tube of the bridge arm is controlled to be turned on and the first switch tube of the bridge arm is driven to be alternately turned on and off according to the target driving pulse width, so as to discharge the bus capacitor.

[0013] Optionally, acquiring the discharge feedback amount between two adjacent moments according to the voltage value of the bus capacitor at the two adjacent moments includes:

[0014] Respectively obtain a first voltage value at a first sampling moment and a second voltage value at a second sampling moment that are adjacent to each other;

[0015] Calculating the first capacitor energy at the first sampling moment according to the first voltage value and the bus capacitance value; and calculating the second capacitor energy at the second sampling moment according to the second voltage value and the bus capacitance value;

[0016] The actual discharge energy between the adjacent moments is calculated according to the first capacitor energy and the second capacitor energy, and the actual discharge energy is used as the discharge feedback amount.

[0017] Optionally, the calculating of the discharge reference amount between adjacent moments according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments comprises:

[0018] Calculating the energy that the bus capacitor needs to release according to the bus capacitance value, the preset initial voltage and the preset termination voltage;

[0019] Calculate the total number of discharges according to the target discharge time and the target discharge switching frequency;

[0020] Calculating a single discharge energy according to the energy that needs to be released by the bus capacitor and the total number of discharges;

[0021] Calculating the number of switches between the first sampling moment and the second sampling moment according to the time length between the first sampling moment and the second sampling moment and the target discharge switching frequency;

[0022] A target discharge energy is obtained according to the number of switching times and the single discharge energy, and the target discharge energy is used as the discharge reference amount.

[0023] Optionally, obtaining a target driving pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width includes:

[0024] Determine whether the discharge feedback amount is greater than the discharge reference amount:

[0025] If yes, reducing the preset pulse width to obtain the target driving pulse width;

[0026] If not, it is determined whether the discharge feedback amount is less than the discharge reference amount. If so, the preset pulse width is increased to obtain the target drive pulse width; if not, the preset pulse width is used as the target drive pulse width.

[0027] Optionally, obtaining a preset pulse width of a first switch tube of at least one of the bridge arms includes:

[0028] Acquire the current voltage of the bus capacitor and the current temperature of the first switch tube;

[0029] The preset pulse width is obtained according to the current voltage, the current temperature and a preset corresponding relationship between bus voltage-switching tube temperature-driving pulse width.

[0030] Optionally, acquiring the discharge feedback amount between two adjacent moments according to the voltage value of the bus capacitor at the two adjacent moments includes:

[0031] Respectively obtain a first voltage value at a first sampling moment and a second voltage value at a second sampling moment that are adjacent to each other;

[0032] The actual equivalent discharge energy between adjacent moments is calculated according to the first voltage value and the second voltage value.

[0033] Optionally, the calculating of the discharge reference amount between adjacent moments according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments comprises:

[0034] Obtaining a single discharge energy according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, and the target discharge switching frequency;

[0035] The target equivalent discharge energy between the adjacent moments is calculated according to the duration between the first sampling moment and the second sampling moment, the target discharge switching frequency, the single discharge energy, and the bus capacitance value.

[0036] In order to achieve the above object, the present invention further provides a DC bus capacitor active discharge device, wherein the bus capacitor is connected in parallel with an input end of a bridge inverter, the bridge inverter comprises at least one bridge arm, each of the bridge arms comprises a first switch tube and a second switch tube; the DC bus capacitor active discharge device comprises:

[0037] A discharge feedback amount acquisition unit is configured to acquire the discharge feedback amount between two adjacent moments according to the voltage value of the bus capacitor at the two adjacent moments;

[0038] A discharge reference amount acquisition unit is configured to calculate a discharge reference amount between adjacent moments according to a pre-acquired bus capacitance value, a preset initial voltage, a preset termination voltage, a target discharge time, a target discharge switching frequency, and a duration between adjacent moments;

[0039] a driving pulse width acquisition unit, configured to acquire a preset pulse width of a first switch tube of at least one of the bridge arms, and obtain a target driving pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width;

[0040] The driving switch control unit is configured to control the second switch tube of the bridge arm to be turned on and drive the first switch tube of the bridge arm to be alternately turned on and off according to the target driving pulse width to discharge the bus capacitor.

[0041] In order to achieve the above-mentioned purpose, the present invention also provides an electronic device, which includes a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the active discharge method of the DC bus capacitor described in any one of the above items is implemented.

[0042] In order to achieve the above object, the present invention further provides a readable storage medium, wherein the readable storage medium stores a computer program, and when the computer program is executed by a processor, the DC bus capacitor active discharge method described in any one of the above items is implemented.

[0043] Compared with the prior art, the active discharge method, device, electronic device and medium of a DC bus capacitor provided by the present invention have the following advantages:

[0044] The active discharge method of the DC bus capacitor provided by the present invention obtains the discharge feedback amount (such as actual discharge energy) between the adjacent moments according to the voltage value of the bus capacitor at two adjacent moments, wherein the voltage value can be obtained by reusing the existing voltage information acquisition method, thereby eliminating the need for an additional peak current sampling circuit, not only significantly reducing the cost, but also effectively reducing the area of ​​the control circuit, thereby improving the overall power density. Further, the present invention calculates the discharge reference amount (such as target discharge energy) between the adjacent moments according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments, thereby laying a good foundation for achieving more accurate active discharge closed-loop control. Further, the present invention obtains the preset pulse width of the first switch tube of at least one of the bridge arms, and obtains the target drive pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width. In this configuration, the energy difference between adjacent moments is used for active discharge closed-loop control, which can reduce the dependence on the sampling accuracy of the bus voltage, and has good universality and good control accuracy.

[0045] Since the DC bus capacitor active discharge device, electronic device and medium provided by the present invention belong to the same inventive concept as the DC bus capacitor active discharge method provided by the present invention, the DC bus capacitor active discharge device, electronic device and medium provided by the present invention at least have all the advantages of the DC bus capacitor active discharge method provided by the present invention. For details of the beneficial effects of the DC bus capacitor active discharge device, electronic device and medium provided by the present invention, please refer to the above description of the beneficial effects of the DC bus capacitor active discharge method provided by the present invention, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a schematic diagram of the direct discharge principle of the bridge inverter;

[0047] Figure 2 A schematic diagram of the overall process of the active discharge method of a DC bus capacitor provided in the first embodiment of the present invention;

[0048] Figure 3 A schematic diagram of the principle of the active discharge method of a DC bus capacitor provided in the first embodiment of the present invention;

[0049] Figure 4 A schematic diagram of the principle of the active discharge method of the DC bus capacitor provided in the second embodiment of the present invention;

[0050] Figure 5 A schematic diagram of the principle of the active discharge method of the DC bus capacitor provided in the third embodiment of the present invention;

[0051] Figure 6 A block diagram of a DC bus capacitor active discharge device provided in Embodiment 4 of the present invention;

[0052] Figure 7 A schematic diagram of the block structure of an electronic device provided in Embodiment 5 of the present invention;

[0053] The reference numerals are as follows:

[0054] Bus capacitor-C, bridge inverter-100, bridge arms-110, 120, 130, first switch tubes-Q11, Q21, Q31, second switch tubes-Q12, Q22, Q32;

[0055] Discharge feedback amount acquisition unit-210, discharge reference amount acquisition unit-220, drive pulse width acquisition unit-230, drive switch control unit-240;

[0056] Processor-310, memory-320, communication interface-330, communication bus-340. DETAILED DESCRIPTION

[0057] The following is a further detailed description of a DC bus capacitor active discharge method, device, electronic device and medium proposed by the present invention in conjunction with the accompanying drawings. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Any modification of the structure, change of the proportional relationship or adjustment of the size, under the same or similar conditions as the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. The specific design features of the present invention disclosed herein include, for example, specific dimensions, directions, positions and shapes, which will be determined in part by the specific environment to be applied and used. And, in the embodiments described below, sometimes the same figure mark is used in common between different drawings to represent the same part or part with the same function, and its repeated description is omitted. In this specification, similar reference numerals and letters are used to refer to similar items, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures. In addition, if the method described herein includes a series of steps, the order of these steps presented herein is not necessarily the only order in which these steps can be performed, and some of the steps described may be omitted and / or some other steps not described herein may be added to the method.

[0058] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements. The singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in a sense including "and / or", the term "several" is generally used in a sense including "at least one", and the term "at least two" is generally used in a sense including "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and are not to be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features.

[0059] The core idea of ​​the present invention is to provide a method, device, electronic device and medium for active discharge of a DC bus capacitor. The present invention uses the energy difference between adjacent moments to perform active discharge closed-loop control, which can reduce the dependence on the sampling accuracy of the bus voltage. It not only has good universality and good control accuracy, but also does not require a current sampling circuit. While significantly reducing costs, it can also reduce the area of ​​the discharge control circuit, thereby improving the overall power density.

[0060] It should be noted that the DC bus capacitor active discharge method and readable storage medium provided by the present invention can be applied to the electronic device provided by the present invention, and the DC bus capacitor active discharge method, device, electronic device and medium provided by the present invention can be applied to vehicles. It should be understood that the terms "vehicle" or "vehicle" or other similar terms used herein include general motor vehicles, such as passenger vehicles including sports utility vehicles (SUVs), buses, trucks, and various commercial vehicles.

[0061] Embodiment 1

[0062] In order to realize the above idea, this embodiment provides a DC bus capacitor active discharge method. For example, see Figure 1 , Figure 2 and Figure 3 ,in, Figure 1 This is a schematic diagram of the direct discharge principle of the bridge inverter; Figure 2A schematic diagram of the overall process of the active discharge method of a DC bus capacitor provided in the first embodiment of the present invention; Figure 3 The schematic diagram of the principle of the active discharge method of the DC bus capacitor provided in the first embodiment of the present invention. Figure 1 It can be seen that the bus capacitor C is connected in parallel with the input end of a bridge inverter 100, and the bridge inverter 100 includes at least one bridge arm ( Figure 1 In the example, the three-phase AC of U, V, and W corresponds to the three bridge arms 110, 120, and 130, each of which includes a first switch tube and a second switch tube (such as Figure 1 As shown, the bridge arm 110 includes a first switch tube Q11 and a second switch tube Q12, the bridge arm 120 includes a first switch tube Q21 and a second switch tube Q22, and the bridge arm 130 includes a first switch tube Q31 and a second switch tube Q32). Figure 2 and Figure 3 It can be seen that the DC bus capacitor active discharge method includes:

[0063] S100: acquiring a discharge feedback amount between two adjacent moments according to a voltage value of the bus capacitor C at the two adjacent moments;

[0064] S200: Calculating a discharge reference amount between adjacent moments according to a pre-acquired bus capacitance value, a preset initial voltage, a preset termination voltage, a target discharge time, a target discharge switching frequency, and a duration between adjacent moments;

[0065] S300: Obtain at least one of the bridge arms ( Figure 1 The preset pulse width of the first switch tube Q11 (taking the bridge arm 110 as an example), and obtaining the target driving pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width;

[0066] S400: Control the second switch tube Q12 of the bridge arm 110 to be turned on and drive the first switch tube Q11 of the bridge arm 110 to be alternately turned on and off according to the target driving pulse width, so as to discharge the bus capacitor C.

[0067] The active discharge method of the DC bus capacitor provided by the present invention obtains the discharge feedback amount (such as actual discharge energy) between the adjacent moments according to the voltage value of the bus capacitor C at two adjacent moments, wherein the voltage value can be obtained by reusing the existing voltage information acquisition method, thereby eliminating the need for an additional peak current sampling circuit, which can not only significantly reduce the cost, but also effectively reduce the area of ​​the control circuit, thereby improving the overall power density. Further, the present invention calculates the discharge reference amount (such as target discharge energy) between the adjacent moments according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments, thereby laying a good foundation for achieving more accurate active discharge closed-loop control. Further, the present invention obtains the preset pulse width of the first switch tube Q11 of at least one of the bridge arms 110, and obtains the target drive pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width. In this configuration, the energy difference between adjacent moments is used for active discharge closed-loop control, which can reduce the dependence on the sampling accuracy of the bus voltage, and has good universality and good control accuracy.

[0068] It should be noted that, as can be understood by those skilled in the art, the present invention does not impose too many restrictions on the execution order of step S100 and step S200. For example, in some embodiments, step S100 can be executed first to obtain the discharge feedback amount, and then step S200 can be executed to obtain the discharge reference amount; in other embodiments, step S200 can be executed first to obtain the discharge reference amount, and then step S100 can be executed to obtain the discharge feedback amount; or in some other systems that support parallel computing, step S100 can be executed simultaneously to obtain the discharge feedback amount and step S200 to obtain the discharge reference amount. In addition, it should be understood that the present invention does not limit the duration between two adjacent moments, and it can be reasonably set according to actual needs. It should be particularly noted that those skilled in the art should be able to understand that, preferably, the above steps S100, S200, S300 and step S400 are iteratively executed during the entire discharge process of the DC bus capacitor C, that is, in the entire process from the start of discharge of the DC bus capacitor C to the completion of discharge, the above steps can be repeatedly executed multiple times.

[0069] It should be noted that the present invention does not impose too many restrictions on the method for obtaining the bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, and the target discharge switching frequency. For example, in some embodiments, the bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, and the target discharge switching frequency can be preset values. For example, the bus capacitance value is the rated capacitance value of the bus capacitor C, the preset initial voltage is the highest voltage of the bus, the preset termination voltage is 0, the target discharge time is a first calibrated value, and the target discharge switching frequency is a second calibrated value, etc. In other embodiments, the bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, and the target discharge switching frequency can also be dynamically configured according to actual needs.

[0070] In addition, the present invention does not impose too many restrictions on the bridge arm for implementing the discharge of the bus capacitor C. For example, in some exemplary embodiments, the bus capacitor can be discharged only by controlling the first switch tube Q11 (or the second switch tube Q12) of the bridge arm 110. In other exemplary embodiments, the bus capacitor can be discharged by controlling the first switch tube Q11 (or the second switch Q12) of the bridge arm 110 and the first switch tube Q21 (or the second switch Q22) of the bridge arm 120. In some other exemplary embodiments, the bus capacitor can be discharged by controlling the first switch tube Q11 (or the second switch Q12) of the bridge arm 110, the first switch tube Q21 (or the second switch Q22) of the bridge arm 120, and the first switch tube Q31 (or the second switch Q32) of the bridge arm 130.

[0071] Preferably, in some exemplary implementations, the step S100 of obtaining the discharge feedback amount between two adjacent moments according to the voltage value of the bus capacitor C at the two adjacent moments includes:

[0072] S111: Acquire a first voltage value at a first sampling moment and a second voltage value at a second sampling moment respectively.

[0073] S112: Calculate the first capacitor energy at the first sampling moment according to the first voltage value and the bus capacitance value, and calculate the second capacitor energy at the second sampling moment according to the second voltage value and the bus capacitance value.

[0074] Exemplarily, the first capacitor energy at the first sampling time is calculated by the following formula (1):

[0075] E 1 =0.5×C×U 1 2 (1)

[0076] In formula (1), E 1 is the first capacitor energy, C is the bus capacitance value, U 1 is the first voltage value of the bus capacitor at the first sampling moment.

[0077] Exemplarily, the second capacitor energy at the second sampling time is calculated by the following formula (2):

[0078] E 2 =0.5×C×U 2 2 (2)

[0079] In formula (2), E 2 is the second capacitor energy, C is the bus capacitance value, U 2 is the second voltage value of the bus capacitor at the second sampling moment.

[0080] S113: calculating actual discharge energy between adjacent moments according to the first capacitor energy and the second capacitor energy, and using the actual discharge energy as the discharge feedback amount.

[0081] Exemplarily, the actual discharge energy can be calculated by the following formula (3):

[0082] E r =E 1 -E 2 (3)

[0083] In formula (3), E r is the actual discharge energy, E 1 is the first capacitance energy of the bus capacitor at the first sampling moment, E 2 is the second capacitance energy of the bus capacitance at the second sampling moment.

[0084] Preferably, in some exemplary embodiments, in step S200, the discharge reference amount between the adjacent moments is calculated according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments, including:

[0085] S211: Calculate the energy that the bus capacitor C needs to release according to the bus capacitance value, the preset initial voltage and the preset termination voltage.

[0086] Exemplarily, the energy that needs to be released by the bus capacitor C can be calculated by the following formula (4):

[0087] E DC.link =0.5×C×Uss 2 -0.5×C×U se 2 (4)

[0088] In formula (4), E DC.link is the energy that the bus capacitor C needs to release, C is the bus capacitor value, U ss is the preset initial voltage, U se is the preset termination voltage.

[0089] S212: Calculate the total number of discharges according to the target discharge time and the target discharge switching frequency.

[0090] Exemplarily, the total number of discharges can be calculated by the following formula (5):

[0091] n piece =t total ×f discharge (5)

[0092] In formula (5), n piece is the total number of discharges, t total is the target discharge time, f discharge is the target discharge switching frequency.

[0093] S213: Calculate a single discharge energy according to the energy that needs to be released by the bus capacitor C and the total number of discharges.

[0094] Exemplarily, the single discharge energy can be calculated by the following formula (6):

[0095] E piece =E DC.link ÷n piece (6)

[0096] In formula (6), E piece is the single discharge energy, E DC.link is the energy that the bus capacitor C needs to release, n piece is the total number of discharges.

[0097] S214: Calculate the number of switches (ie, the number of discharges) between the first sampling moment and the second sampling moment according to the duration between the first sampling moment and the second sampling moment and the target discharge switching frequency.

[0098] Exemplarily, the number of switching times between the first sampling time and the second sampling time can be calculated by the following formula (7):

[0099] m=(t 2 -t1 )×f discharge (7)

[0100] In formula (7), m is the number of switches between the first sampling time and the second sampling time, t 2 -t 1 is the duration between the first sampling moment and the second sampling moment, f discharge is the target discharge switching frequency.

[0101] S215: Obtaining a target discharge energy according to the number of switching times and the single discharge energy, and using the target discharge energy as the discharge reference amount.

[0102] E g =m×E piece (8)

[0103] In formula (8), E g is the target discharge energy, m is the number of switches between the first sampling time and the second sampling time, E piece is the single discharge energy.

[0104] Combining equations (4), (5), (6), (7) and (8), we can deduce:

[0105] The discharge reference amount can be calculated by the following formula (9):

[0106] E g =[(t 2 -t 1 )×(0.5×C×U ss 2 -0.5×C×U se 2 )]÷t total (9)

[0107] The meaning of each parameter in formula (9) can be found in the relevant descriptions of formula (4), formula (5) and formula (7), which will not be repeated here.

[0108] Preferably, in some exemplary implementations, obtaining the target driving pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width in step S300 includes:

[0109] Determine whether the discharge feedback amount is greater than the discharge reference amount:

[0110] If yes, reducing the preset pulse width to obtain the target driving pulse width;

[0111] If not, it is determined whether the discharge feedback amount is less than the discharge reference amount. If so, the preset pulse width is increased to obtain the target drive pulse width; if not, the preset pulse width is used as the target drive pulse width.

[0112] Therefore, the active discharge method of the DC bus capacitor provided by the present invention can reduce the dependence on the bus voltage sampling accuracy by adopting the energy difference between adjacent moments to perform dynamic control of the active discharge closed loop, and has good universality and good control accuracy.

[0113] It should be particularly noted that the present invention does not limit the specific value of the preset pulse width. For example, in some of the embodiments, the preset pulse width can be a non-zero value obtained based on experience or calibration; in other embodiments, the value of the preset pulse width can also be 0. In addition, it should be understood that the present invention does not place too many restrictions on the specific strategy of increasing or decreasing the preset pulse width. For example, in some of the exemplary embodiments, no matter how large the deviation between the discharge feedback amount and the discharge reference amount is, as long as there is a deviation between the discharge feedback amount and the discharge reference amount, a preset value is increased or decreased on the basis of the preset pulse width; in other exemplary embodiments, the increase or decrease value of the preset pulse width can also be determined based on the deviation between the discharge feedback amount and the discharge reference amount.

[0114] In order to facilitate the understanding of the present invention, the following Figure 3 The basic principle of the active discharge method for the DC bus capacitor provided in this embodiment is briefly described as follows:

[0115] like Figure 3 As shown, the target driving pulse width is obtained according to the target discharge energy (i.e., the discharge reference amount) and the actual discharge energy (i.e., the discharge feedback amount); the driving controller controls the on / off state of the driving switch according to the target driving pulse width, thereby discharging the bus capacitor C. Among them, the target discharge energy between the first sampling time t1 and the second sampling time t2 is m×E piece (That is, [(t 2 -t 1 )×(0.5×C×U ss 2 -0.5×C×U se 2 )]÷t total , please refer to the above for the specific calculation process), the actual discharge energy is 0.5×C×U 1 2 -0.5×C×U 2 2 (Please refer to the above for the specific calculation process).

[0116] Embodiment 2

[0117] This embodiment provides another method for active discharge of DC bus capacitors. The basic principle of the method for active discharge of DC bus capacitors provided in this embodiment is similar to that of the method for active discharge of DC bus capacitors provided in the first embodiment. In order to avoid redundant description, only the differences from the first embodiment are described below. For the parts not mentioned in this embodiment, please refer to the relevant description of the first embodiment for adaptive understanding. For example, please refer to Figure 4 , Figure 4 The schematic diagram of the principle of the active discharge method of the DC bus capacitor provided in this embodiment. Figure 3 and Figure 4 It can be found that the DC bus capacitor active discharge method provided in this embodiment is different from that in the first embodiment in that the manner of obtaining the preset pulse width of the first switch tube Q11 of at least one of the bridge arms 110 in step S200 is different.

[0118] Preferably, in some exemplary embodiments, the step S200 of obtaining a preset pulse width of a first switch tube Q11 of at least one of the bridge arms 110 includes:

[0119] S201: Obtaining the current voltage of the bus capacitor C (ie, the current bus voltage) and the current temperature of the first switch tube Q11;

[0120] S202: Obtain the preset pulse width according to the current voltage, the current temperature, and a preset correspondence relationship between bus voltage-switch tube temperature-drive pulse width.

[0121] The DC bus capacitor active discharge method provided by the present invention obtains the current voltage of the bus capacitor C and the current temperature of the first switch tube Q11 in real time, and determines the preset pulse width according to the current voltage, the current temperature and the preset correspondence relationship between the bus voltage-switch tube temperature-drive pulse width. It can be seen that in this embodiment, the preset pulse width is dynamically determined according to the current voltage of the bus capacitor C and the current temperature of the first switch tube Q11, so that the actual discharge energy can follow the target discharge energy more quickly, and has a faster closed-loop control response speed.

[0122] It should be noted that, as those skilled in the art can understand, the present invention does not impose too many restrictions on the method of obtaining the preset corresponding relationship of bus voltage-switch tube temperature-drive pulse width. For example, it can be obtained through calibration.

[0123] In order to facilitate the understanding of the present invention, the following Figure 4 The basic principle of the active discharge method for the DC bus capacitor provided in this embodiment is briefly described as follows:

[0124] like Figure 4 As shown, the target driving pulse width is obtained according to the target discharge energy (i.e., discharge reference), the actual discharge energy (i.e., discharge feedback), the current voltage of the bus capacitor C, the current temperature of the first switch tube Q11, and the preset correspondence relationship between the bus voltage-switch tube temperature-driving pulse width; the driving controller controls the on / off state of the driving switch according to the target driving pulse width, thereby discharging the bus capacitor C. Among them, the target discharge energy between the first sampling time t1 and the second sampling time t2 is m×E piece (That is, [(t 2 -t 1 )×(0.5×C×U ss 2 -0.5×C×U se 2 )]÷t total , please refer to the above for the specific calculation process), the actual discharge energy is 0.5×C×U 1 2 -0.5×C×U 2 2 (Please refer to the above for the specific calculation process).

[0125] Embodiment 3

[0126] This embodiment provides another method for active discharge of DC bus capacitors. The basic principle of the method for active discharge of DC bus capacitors provided in this embodiment is similar to that of the method for active discharge of DC bus capacitors provided in Embodiment 1. In order to avoid redundant description, only the differences from Embodiment 1 are described below. For the parts not mentioned in this embodiment, please refer to the relevant description of Embodiment 1 for adaptive understanding. Figure 5 , Figure 5 The schematic diagram of the principle of the active discharge method of the DC bus capacitor provided in this embodiment. Figure 3 and Figure 5 It can be found that the DC bus capacitor active discharge method provided in this embodiment is different from the first embodiment in that the method of obtaining the discharge feedback amount in step 100 and the method of obtaining the discharge reference amount in step S200 are different. The first embodiment is based on the formula for storing electric energy of the capacitor, and the discharge feedback amount and the discharge reference amount are both calculated based on the bus capacitance value. However, the DC bus capacitor active discharge method provided in this embodiment eliminates the bus capacitance value when calculating the discharge feedback amount and the discharge reference amount. For ease of understanding, Figure 5 The discharge feedback amount is represented by the actual equivalent discharge energy, and the discharge reference amount is represented by the target equivalent discharge energy.

[0127] Preferably, in some exemplary implementations, the step S100 of obtaining the discharge feedback amount between two adjacent moments according to the voltage value of the bus capacitor C at the two adjacent moments includes:

[0128] S121: Acquire a first voltage value at a first sampling moment and a second voltage value at a second sampling moment respectively;

[0129] S122: Calculate actual equivalent discharge energy between adjacent moments according to the first voltage value and the second voltage value.

[0130] Exemplarily, the actual equivalent discharge energy can be calculated by the following formula (10):

[0131] R r =0.5×U 1 2 -0.5×U 2 2 (10)

[0132] In formula (9), R r is the actual equivalent discharge energy, U 1 is the first voltage value of the bus capacitor at the first sampling moment, U 2 is the second voltage value of the bus capacitor at the second sampling moment.

[0133] Correspondingly, the step S200 calculates the discharge reference amount between the adjacent moments according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments, including:

[0134] S221: Obtain a single discharge energy according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, and the target discharge switching frequency.

[0135] For example, for details on how to obtain the single discharge energy based on the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, and the target discharge switching frequency, please refer to the relevant contents of Formula (4), Formula (5), and Formula (6) above, which will not be repeated here.

[0136] S222: Calculate the target equivalent discharge energy between the adjacent moments according to the duration between the first sampling moment and the second sampling moment, the target discharge switching frequency, the single discharge energy, and the bus capacitance value.

[0137] For example, for details on how to calculate the number of switches between the first sampling moment and the second sampling moment based on the duration between the first sampling moment and the second sampling moment and the target discharge switching frequency, please refer to the relevant content of formula (7) above, which will not be repeated here.

[0138] Furthermore, the target equivalent discharge energy is calculated by the following formula (11):

[0139] R g =(m×E piece )÷C (11)

[0140] In formula (11), R g is the target equivalent discharge energy, m is the number of switches between the first sampling time and the second sampling time, E piece The single discharge energy.

[0141] Combining equations (4), (5), (6), (7) and (11), it can be deduced that the target equivalent discharge energy can be calculated by the following equation (12):

[0142] E g =[(t 2 -t 1 )×(0.5×U ss 2 -0.5×U se 2 )]÷t total (12)

[0143] For the meaning of each parameter in formula (12), please refer to the relevant description of formula (4), formula (5) and formula (7), which will not be repeated here. In the active discharge method of the DC bus capacitor provided in this embodiment, the actual equivalent discharge energy and the target equivalent discharge energy no longer contain the bus capacitance value, which can eliminate the deviation of the discharge time caused by the deviation of the bus capacitance C (for example, due to the manufacturing process and other reasons, the actual capacitance value of the bus capacitance C has a significant deviation from the rated capacitance value), and can make the discharge time more accurate.

[0144] In order to facilitate the understanding of the present invention, the following Figure 5 The basic principle of the active discharge method for the DC bus capacitor provided in this embodiment is briefly described as follows:

[0145] like Figure 5As shown in FIG. 1 , the target driving pulse width is obtained according to the target equivalent discharge energy (i.e., the discharge reference amount) and the actual equivalent discharge energy (i.e., the discharge feedback amount); the driving controller controls the on / off state of the driving switch according to the target driving pulse width, thereby discharging the bus capacitor C. The target equivalent discharge energy between the first sampling time t1 and the second sampling time t2 is (m×E piece )÷C(that is, [(t 2 -t 1 )×(0.5×U ss 2 -0.5×U se 2 )]÷t total , please refer to the above for the specific calculation process), the actual equivalent discharge energy is 0.5×U 1 2 -0.5×U 2 2 (Please refer to the above for the specific calculation process).

[0146] Embodiment 4

[0147] Based on the same inventive concept, this embodiment provides a DC bus capacitor active discharge device, please continue to refer to Figure 1 and Figure 6 ,in, Figure 6 A block diagram of the DC bus capacitor active discharge device provided in this embodiment. Figure 6 It can be seen that the DC bus capacitor active discharge device includes: a discharge feedback amount acquisition unit 210, a discharge reference amount acquisition unit 220, a drive pulse width acquisition unit 230 and a drive switch control unit 240. Exemplarily, the discharge feedback amount acquisition unit 210 is configured to acquire the discharge feedback amount between the adjacent moments according to the voltage value of the bus capacitor C at two adjacent moments. The discharge reference amount acquisition unit 220 is configured to calculate the discharge reference amount between the adjacent moments according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments. The drive pulse width acquisition unit 230 is configured to acquire the preset pulse width of the first switch tube (such as the first switch tube Q11 of the bridge arm 110) of at least one of the bridge arms (such as the bridge arm 110), and obtain the target drive pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width. The driving switch control unit 240 is configured to control the second switch tube (such as the first switch tube Q12 of the bridge arm 110) of the bridge arm (such as the bridge arm 110) to be turned on and drive the first switch tube (such as the first switch tube Q11 of the bridge arm 110) of the bridge arm (such as the bridge arm 110) to be alternately turned on and off according to the target driving pulse width to discharge the bus capacitor C.

[0148] It can be seen that the DC bus capacitor active discharge device provided by the present invention can reduce the dependence on the bus voltage sampling accuracy by adopting the energy difference between adjacent moments to perform active discharge closed-loop control. It not only has good universality and good control accuracy, but also does not require a current sampling circuit. While significantly reducing costs, it can also reduce the area of ​​the discharge control circuit, thereby improving the overall power density.

[0149] Since the active discharge device of the DC bus capacitor provided by the present invention has the same principle as the active discharge method of the DC bus capacitor provided by the present invention, in order to avoid redundancy, the active discharge device of the DC bus capacitor provided by the present invention will not be described in detail here. For the parts not described in this embodiment, please refer to the description of the active discharge method of the DC bus capacitor in this article for adaptive understanding.

[0150] Embodiment 5

[0151] This embodiment provides an electronic device. For example, see Figure 7 , Figure 7 Schematic diagram of the block structure of the electronic device provided in this embodiment. Figure 7 As shown, the electronic device provided in this embodiment includes a processor 310 and a memory 320, and a computer program is stored in the memory 320. When the computer program is executed by the processor 310, the DC bus capacitor active discharge method provided in any of the above embodiments is implemented. Since the electronic device provided in this embodiment and the DC bus capacitor active discharge method provided in the present invention belong to the same inventive concept, the electronic device provided in this embodiment at least has all the advantages of the DC bus capacitor active discharge method provided in the present invention. For details, please refer to the above description of the beneficial effects of the DC bus capacitor active discharge method, which will not be repeated here.

[0152] For example, Figure 7 As shown, the electronic device may also include a communication interface 330 and a communication bus 340, wherein the processor 310, the communication interface 330, and the memory 320 communicate with each other through the communication bus 340. The communication bus 340 includes but is not limited to a CAN bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus. The communication interface 330 is used for communication between the above-mentioned electronic device and other controllers. The communication bus 340 connects the above-mentioned electronic device and other dispersed nodes such as other controllers into a closed-loop system, so that each controller can communicate and transmit data in multiple working states, thereby realizing the control function of the vehicle.

[0153] The processor 310 referred to in the present invention may be a microcontroller unit (MCU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor 310 is the control center of the electronic device, and uses various interfaces and lines to connect various parts of the entire electronic device.

[0154] The memory 320 may be used to store the computer program, and the processor 310 implements various functions of the electronic device by running or executing the computer program stored in the memory 320 and calling the data stored in the memory 320 .

[0155] The memory 320 may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0156] Embodiment 6

[0157] This embodiment provides a readable storage medium, in which a computer program is stored, and when the computer program is executed by a processor, the DC bus capacitor active discharge method described above can be implemented. Since the readable storage medium provided by the present invention and the DC bus capacitor active discharge method provided by the present invention belong to the same inventive concept, the readable storage medium provided by the present invention at least has all the advantages of the DC bus capacitor active discharge method provided by the present invention. For details of the beneficial effects of the readable storage medium provided by the present invention, please refer to the above description of the beneficial effects of the DC bus capacitor active discharge method provided by the present invention, which will not be repeated here.

[0158] The readable storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared or semiconductor, or any combination of the above. More specific examples (non-exhaustive examples) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer hard disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this article, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, a device or a device or used in combination with it.

[0159] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0160] Computer program code for performing the operation of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0161] Compared with the prior art, the active discharge method, device, electronic device and medium of a DC bus capacitor provided by the present invention have the following advantages:

[0162] The active discharge method of the DC bus capacitor provided by the present invention obtains the discharge feedback amount (such as actual discharge energy) between the adjacent moments according to the voltage value of the bus capacitor at two adjacent moments, wherein the voltage value can be obtained by reusing the existing voltage information acquisition method, thereby eliminating the need for an additional peak current sampling circuit, not only significantly reducing the cost, but also effectively reducing the area of ​​the control circuit, thereby improving the overall power density. Further, the present invention calculates the discharge reference amount (such as target discharge energy) between the adjacent moments according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments, thereby laying a good foundation for achieving more accurate active discharge closed-loop control. Further, the present invention obtains the preset pulse width of the first switch tube of at least one of the bridge arms, and obtains the target drive pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width. In this configuration, the energy difference between adjacent moments is used for active discharge closed-loop control, which can reduce the dependence on the sampling accuracy of the bus voltage, and has good universality and good control accuracy.

[0163] It should be noted that the devices and methods disclosed in the embodiments of this article can also be implemented in other ways. The device implementation described above is only schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of this article. In this regard, each box in the flowchart or block diagram can represent a part of a module, program or code, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented by a dedicated hardware-based system for performing a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0164] In addition, the functional modules in the various embodiments of this document may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0165] The above description is only a description of a preferred embodiment of a DC bus capacitor active discharge method, device, electronic device and medium provided by the present invention, and is not any limitation on the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure content belong to the protection scope of the present invention. Obviously, technicians in this field can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations fall within the scope of the present invention and its equivalent technology, the present invention is also intended to include these modifications and variations.

Claims

1. A method for active discharge of a DC bus capacitor, characterized in that: The bus capacitor is connected in parallel with an input end of a bridge inverter, the bridge inverter includes at least one bridge arm, each of the bridge arms includes a first switch tube and a second switch tube; the DC bus capacitor active discharge method includes: According to the voltage value of the bus capacitor at two adjacent moments, obtaining the discharge feedback amount between the adjacent moments; Calculate the discharge reference amount between the adjacent moments according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments; Acquire a preset pulse width of a first switch tube of at least one of the bridge arms, and obtain a target driving pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width; The second switch tube of the bridge arm is controlled to be turned on and the first switch tube of the bridge arm is driven to be alternately turned on and off according to the target driving pulse width, so as to discharge the bus capacitor.

2. The DC bus capacitor active discharge method according to claim 1, characterized in that: The step of obtaining the discharge feedback amount between two adjacent moments according to the voltage value of the bus capacitor at the two adjacent moments includes: Respectively obtain a first voltage value at a first sampling moment and a second voltage value at a second sampling moment that are adjacent to each other; Calculating the first capacitor energy at the first sampling moment according to the first voltage value and the bus capacitance value; and calculating the second capacitor energy at the second sampling moment according to the second voltage value and the bus capacitance value; The actual discharge energy between the adjacent moments is calculated according to the first capacitor energy and the second capacitor energy, and the actual discharge energy is used as the discharge feedback amount.

3. The DC bus capacitor active discharge method according to claim 2, characterized in that: The calculating of the discharge reference amount between the adjacent moments according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments comprises: Calculating the energy that the bus capacitor needs to release according to the bus capacitance value, the preset initial voltage and the preset termination voltage; Calculate the total number of discharges according to the target discharge time and the target discharge switching frequency; Calculating a single discharge energy according to the energy that needs to be released by the bus capacitor and the total number of discharges; Calculating the number of switches between the first sampling moment and the second sampling moment according to the time length between the first sampling moment and the second sampling moment and the target discharge switching frequency; A target discharge energy is obtained according to the number of switching times and the single discharge energy, and the target discharge energy is used as the discharge reference amount.

4. The DC bus capacitor active discharge method according to claim 1, characterized in that: The step of obtaining a target driving pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width includes: Determine whether the discharge feedback amount is greater than the discharge reference amount: If yes, reducing the preset pulse width to obtain the target driving pulse width; If not, it is determined whether the discharge feedback amount is less than the discharge reference amount. If so, the preset pulse width is increased to obtain the target drive pulse width; if not, the preset pulse width is used as the target drive pulse width.

5. The DC bus capacitor active discharge method according to claim 1, characterized in that: The obtaining of a preset pulse width of a first switch tube of at least one of the bridge arms comprises: Acquire the current voltage of the bus capacitor and the current temperature of the first switch tube; The preset pulse width is obtained according to the current voltage, the current temperature and a preset corresponding relationship between bus voltage-switching tube temperature-driving pulse width.

6. The DC bus capacitor active discharge method according to claim 1, characterized in that: The step of obtaining the discharge feedback amount between two adjacent moments according to the voltage value of the bus capacitor at the two adjacent moments includes: Respectively obtain a first voltage value at a first sampling moment and a second voltage value at a second sampling moment that are adjacent to each other; The actual equivalent discharge energy between adjacent moments is calculated according to the first voltage value and the second voltage value.

7. The DC bus capacitor active discharge method according to claim 6, characterized in that: The calculating of the discharge reference amount between the adjacent moments according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, the target discharge switching frequency and the duration between the adjacent moments comprises: Obtaining a single discharge energy according to the pre-acquired bus capacitance value, the preset initial voltage, the preset termination voltage, the target discharge time, and the target discharge switching frequency; The target equivalent discharge energy between the adjacent moments is calculated according to the duration between the first sampling moment and the second sampling moment, the target discharge switching frequency, the single discharge energy, and the bus capacitance value.

8. A DC bus capacitor active discharge device, characterized in that: The bus capacitor is connected in parallel with an input end of a bridge inverter, the bridge inverter includes at least one bridge arm, each of the bridge arms includes a first switch tube and a second switch tube; the DC bus capacitor active discharge device includes: A discharge feedback amount acquisition unit is configured to acquire the discharge feedback amount between two adjacent moments according to the voltage value of the bus capacitor at the two adjacent moments; A discharge reference amount acquisition unit is configured to calculate a discharge reference amount between adjacent moments according to a pre-acquired bus capacitance value, a preset initial voltage, a preset termination voltage, a target discharge time, a target discharge switching frequency, and a duration between adjacent moments; a driving pulse width acquisition unit, configured to acquire a preset pulse width of a first switch tube of at least one of the bridge arms, and obtain a target driving pulse width according to the discharge feedback amount, the discharge reference amount and the preset pulse width; The driving switch control unit is configured to control the second switch tube of the bridge arm to be turned on and drive the first switch tube of the bridge arm to be alternately turned on and off according to the target driving pulse width to discharge the bus capacitor.

9. An electronic device, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method for active discharge of a DC bus capacitor according to any one of claims 1 to 8 is implemented.

10. A readable storage medium, characterized in that: The readable storage medium stores a computer program, and when the computer program is executed by a processor, the DC bus capacitor active discharge method according to any one of claims 1 to 8 is implemented.

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