Discharging device and method of direct current bus capacitor, electrical equipment and storage medium

Abstract

The embodiment of the invention discloses a discharging device and method of a direct-current bus capacitor, electrical equipment and a storage medium. The discharging device comprises a resistor which is connected in series with a DC bus capacitor of the converter; a brake IGBT connected between the positive electrode (DCP) and the negative electrode (DCN) of the DC bus capacitor; the switch is respectively connected with the brake IGBT and the resistor; and the control unit is configured to switch on the braking IGBT and control the state of the switch so as to switch on a discharge loop of the direct current bus capacitor when power failure of the power supply system of the converter is detected, and the discharge loop comprises the resistor and the braking IGBT. When the power supply system of the converter is detected to be powered off, the braking IGBT is reused to realize rapid discharge of the direct current bus capacitor, so that the discharge time is reduced.

Description

Technical Field

[0001] The present invention relates to the field of electrical technology, in particular to a discharge device, a method, an electrical device and a storage medium for a DC bus capacitor. Background Art

[0002] A converter, also known as an electronic power converter, is an electrical device that changes the voltage, frequency, number of phases, and other electrical quantities or characteristics of a power system. The DC bus capacitor of a converter may consist of one or more capacitors connected in series.

[0003] In order to ensure that the voltage shared by each capacitor in series is the same, a voltage-equalizing resistor is usually connected in parallel to each capacitor. Under the premise of meeting the voltage equalization requirement, in order to ensure that the voltage-equalizing resistor does not consume too much energy, the resistance value of the voltage-equalizing resistor is usually relatively large.

[0004] In the prior art, when the converter is shut down, the DC bus capacitor is discharged through the voltage-equalizing resistor. However, due to the large resistance of the voltage-equalizing resistor, the discharge time is relatively long (for example, 5 minutes). Summary of the invention

[0005] The embodiments of the present invention provide a discharge device, a discharge method, an electrical device and a storage medium for a DC bus capacitor.

[0006] According to a first aspect, an embodiment of the present invention provides a discharge device for a DC bus capacitor. The device comprises:

[0007] A resistor connected in series with the DC bus capacitor of the converter;

[0008] a braking insulated gate bipolar transistor (IGBT), connected between the positive electrode (DCP) and the negative electrode (DCN) of the DC bus capacitor;

[0009] A switch, connected to the brake IGBT and the resistor respectively;

[0010] The control unit is configured to turn on the braking IGBT and control the state of the switch to turn on the discharge circuit of the DC bus capacitor when it is detected that the power supply system of the converter is powered off, wherein the discharge circuit includes the resistor and the braking IGBT.

[0011] Therefore, when a power failure of the power supply system of the converter is detected, the braking IGBT is reused to achieve rapid discharge of the DC bus capacitor, thereby reducing the discharge time.

[0012] Preferably, the control unit is configured to turn off the braking IGBT and control the state of the switch to turn on the charging circuit of the DC bus capacitor when detecting that the DC bus capacitor is in a charging state, wherein the charging circuit includes the resistor and a rectifier module of the converter.

[0013] Therefore, when it is detected that the DC bus capacitor is in a charging state, the braking IGBT is turned off, and a resistor in series with the DC bus capacitor is introduced into the charging circuit. The resistor can limit the current charging at the moment of power-on, thereby protecting components such as the rectifier module.

[0014] Preferably, the control unit is configured to control the state of the switch to short-circuit the resistor when detecting that the converter is in a normal working state.

[0015] Therefore, when the converter operates normally, the resistor is short-circuited, thereby saving energy.

[0016] Preferably, the switch includes a single-pole double-throw switch, which includes a first static contact, a second static contact and a moving contact, the first static contact is connected between the first end of the resistor and the DC bus capacitor, the second static contact is connected to the braking IGBT, and the moving contact is connected to the second end of the resistor.

[0017] Therefore, through the coordinated control of the single-pole double-throw switch and the brake IGBT, flexible switching between the charging state, normal working state and discharge state can be achieved.

[0018] Preferably, the braking IGBT comprises a gate, a collector and an emitter, wherein the gate is connected to the control unit, the collector is connected to the positive electrode of the DC bus capacitor via a diode, and the emitter is connected to the negative electrode (DCN) of the DC bus capacitor.

[0019] It can be seen that the braking IGBT can be conveniently reused through the control unit.

[0020] According to a second aspect, an embodiment of the present invention provides a method for discharging a DC bus capacitor of a converter. The converter comprises: a resistor connected in series with the DC bus capacitor of the converter; a braking IGBT connected between the positive electrode and the negative electrode of the DC bus capacitor; and a switch connected to the braking IGBT and the resistor, respectively. The method comprises:

[0021] detecting an electrical connection state between the converter and a power supply system of the converter;

[0022] When the electrical connection state indicates that the power supply system is powered off, turning on the brake IGBT;

[0023] The state of the switch is controlled to conduct a discharge loop of the DC bus capacitor, wherein the discharge loop includes the resistor and the brake IGBT.

[0024] Therefore, when a power failure of the power supply system of the converter is detected, the braking IGBT is reused to achieve rapid discharge of the DC bus capacitor, thereby reducing the discharge time.

[0025] Preferably, it also includes:

[0026] When it is detected that the DC bus capacitor is in a charging state, turning off the braking IGBT;

[0027] The state of the switch is controlled to conduct a charging circuit of the DC bus capacitor, wherein the charging circuit includes the resistor and a rectifier module of the converter.

[0028] Therefore, when it is detected that the DC bus capacitor is in a charging state, the braking IGBT is turned off, and a resistor in series with the DC bus capacitor is introduced into the charging circuit. The resistor can limit the current charging at the moment of power-on, thereby protecting components such as the rectifier module.

[0029] Preferably, it also includes:

[0030] When it is detected that the converter is in a normal working state, the state of the switch is controlled to short-circuit the resistor.

[0031] Therefore, when the converter operates normally, the resistor is short-circuited, thereby saving energy.

[0032] Preferably, the switch comprises a single-pole double-throw switch, the single-pole double-throw switch comprises a first static contact, a second static contact and a moving contact, the first static contact is connected between the first end of the resistor and the DC bus capacitor, the second static contact is connected to the brake IGBT, and the moving contact is connected to the second end of the resistor;

[0033] The step of controlling the state of the switch to conduct the discharge circuit of the DC bus capacitor includes: controlling the movable contact to be in electrical contact with the second static contact.

[0034] Therefore, the converter can be flexibly controlled through the coordinated control of the single-pole double-throw switch and the brake IGBT.

[0035] Preferably, the switch comprises a single-pole double-throw switch, the single-pole double-throw switch comprises a first static contact, a second static contact and a moving contact, the first static contact is connected between the first end of the resistor and the DC bus capacitor, the second static contact is connected to the brake IGBT, and the moving contact is connected to the second end of the resistor;

[0036] The step of controlling the state of the switch to conduct the charging circuit of the DC bus capacitor includes: controlling the moving contact to be in electrical contact with the second static contact.

[0037] Therefore, the charging process of the DC bus capacitor can be controlled by the single-pole double-throw switch. Preferably, the switch comprises a single-pole double-throw switch, the single-pole double-throw switch comprises a first static contact, a second static contact and a moving contact, the first static contact is connected between the first end of the resistor and the DC bus capacitor, the second static contact is connected to the brake IGBT, and the moving contact is connected to the second end of the resistor;

[0038] The controlling the state of the switch to short-circuit the resistor includes: controlling the movable contact to be in electrical contact with the first stationary contact.

[0039] Therefore, the resistor can be shorted by a single-pole double-throw switch, saving energy.

[0040] According to a third aspect, an embodiment of the present invention provides an electrical device. The electrical device includes:

[0041] processor;

[0042] A memory, configured to store executable instructions of the processor;

[0043] The processor is used to read the executable instructions from the memory, and execute the executable instructions to implement the method for discharging a DC bus capacitor of a converter as described in any one of the above items.

[0044] According to a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having computer instructions stored thereon, wherein the computer instructions, when executed by a processor, implement the method for discharging a DC bus capacitor of a converter as described in any one of the above items.

[0045] According to a fifth aspect, an embodiment of the present invention provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the method for discharging a DC bus capacitor of a converter as described in any one of the above items is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the above and other features and advantages of the present invention will be more apparent to those skilled in the art. In the accompanying drawings:

[0047] Figure 1 It is a configuration diagram of a discharge device for a DC bus capacitor of a converter according to an embodiment of the present invention.

[0048] Figure 2 Schematic diagram of the discharge state of the DC bus capacitor according to the embodiment of the present invention.

[0049] Figure 3 Schematic diagram of the charging state of the DC bus capacitor according to the embodiment of the present invention.

[0050] Figure 4 Schematic diagram of the normal working state of the converter according to the embodiment of the present invention.

[0051] Figure 5 This is a flowchart of a method for discharging a DC bus capacitor of a converter according to an embodiment of the present invention.

[0052] Figure 6 is an exemplary structural diagram of an electrical device according to an embodiment of the present invention.

[0053] The reference numerals are as follows:

[0054] Label meaning 11 Resistors 12 DC bus capacitors 13 Brake IGBT 14 switch 15 Control unit 16 Power supply system 17 Rectifier module 18 diode 21 First static contact 22 Second static contact 23 Moving contact 501～503 step 600 Electrical Equipment 601 processor 602 Memory DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail with reference to the following embodiments.

[0056] For the sake of brevity and intuitiveness in description, the scheme of the present invention is explained below by describing several representative implementations. A large number of details in the implementations are only used to help understand the scheme of the present invention. However, it is obvious that the technical scheme of the present invention may not be limited to these details when implemented. In order to avoid unnecessarily obscuring the scheme of the present invention, some implementations are not described in detail, but only a framework is given. Hereinafter, "including" means "including but not limited to", and "according to..." means "at least according to..., but not limited to only according to...". Due to the language habits of Chinese, when the number of a component is not specifically specified below, it means that the component can be one or more, or can be understood as at least one.

[0057] Figure 1 1 is a structural diagram of a discharge device for a DC bus capacitor of a converter according to an embodiment of the present invention. The device comprises:

[0058] A resistor 11 is connected in series with a DC bus capacitor 12 of the converter;

[0059] A braking IGBT 13 is connected between a positive electrode (DCP) and a negative electrode (DCN) of a DC bus capacitor 12;

[0060] The switch 14 is connected to the brake IGBT 13 and the resistor 11 respectively;

[0061] The control unit 15 is configured to turn on the braking IGBT 13 and control the state of the switch 14 to turn on the discharge circuit of the DC bus capacitor 12 when detecting that the power supply system 16 of the converter is powered off, wherein the discharge circuit includes the resistor 11 and the braking IGBT 13 .

[0062] The resistor 11 may be implemented as an anti-surge resistor to suppress a charging surge current.

[0063] The converter includes a rectifier module 17 (eg, an AC / DC converter), a DC bus capacitor 12 and an inverter module ( Figure 1 The inverter module can be implemented as a DC / AC converter. The rectifier module 17 converts the AC power provided by the power supply system 16 into DC power; the DC bus capacitor 12 filters the DC power provided by the rectifier module 17; the inverter module converts the filtered DC power into a DC current for driving the motor ( Figure 1 An alternating current (not shown) is provided.

[0064] The switch 14 is an electronic component that interrupts the current or allows it to flow to other circuits. The switch 14 may include one or more electronic contacts. When the switch is closed, it means that the electronic contacts are conducting, allowing current to flow through the switch 14, also known as the switch "ON state"; when the switch is open, it means that the electronic contacts are not conducting, forming an open circuit, and current is not allowed to flow through the switch 14, also known as the switch "OFF state". Specifically, the switch 14 may be implemented as a solid-state switch or an electromagnetic relay, etc.

[0065] Preferably, the switch 14 comprises a single-pole double-throw switch. The single-pole double-throw switch comprises a first static contact 21, a second static contact 22 and a moving contact 23, wherein the first static contact 21 is connected between the first end of the resistor 11 and the DC bus capacitor 12, the second static contact 22 is connected to the brake IGBT 13, and the moving contact 23 is connected to the second end of the resistor 11.

[0066] The switch 14 is described above by taking a single-pole double-throw switch as an example. Those skilled in the art will appreciate that such description is merely exemplary and is not intended to limit the protection scope of the embodiments of the present invention.

[0067] The converter also includes a braking IGBT 13. The braking IGBT 13 is used to discharge the feedback energy provided by the motor connected to the converter when the converter is operating normally. For example, the braking IGBT 13 includes a gate, a collector and an emitter, wherein the gate is connected to the control unit 15, the collector is connected to the positive electrode (DCP) of the DC bus capacitor 12 via a diode 18, and the emitter is connected to the negative electrode (DCN) of the DC bus capacitor 12. A channel is formed by applying a positive gate voltage, providing a base current to the PNP transistor, turning on the IGBT 13. Conversely, applying a reverse gate voltage eliminates the channel, cuts off the base current, and turns off the IGBT 13.

[0068] The switch 14 and the brake IGBT are described above by taking a single-pole double-throw switch and a specific IGBT structure as examples, respectively. Those skilled in the art will appreciate that such description is merely exemplary and is not intended to limit the protection scope of the embodiments of the present invention.

[0069] When the control unit 15 detects that the power supply system 16 is powered off, the control unit 15 introduces the braking IGBT 13 into the discharge circuit of the DC bus capacitor 12, thereby reusing the braking IGBT 13 to achieve rapid discharge of the DC bus capacitor and thereby reduce the discharge time.

[0070] In one embodiment, the control unit 15 is configured to turn off the braking IGBT 13 and control the state of the switch 14 to conduct the charging circuit of the DC bus capacitor 12 when detecting that the DC bus capacitor 12 is in a charging state. The charging circuit includes a resistor 11 and a rectifier module 17 of the converter.

[0071] Therefore, when it is detected that the DC bus capacitor 12 is in a charging state, the braking IGBT 13 is turned off, and the resistor 11 connected in series with the DC bus capacitor 12 is introduced into the charging circuit. The resistor 11 can limit the current and charge at the moment of power-on, thereby protecting components such as the rectifier module 16.

[0072] In one embodiment, the control unit 15 is configured to control the state of the switch 14 to short-circuit the resistor 11 when it is detected that the DC bus capacitor 12 is in a power-using state. Therefore, when the converter operates normally, the resistor is short-circuited, thereby saving energy.

[0073] Figure 2 Schematic diagram of the discharge state of the DC bus capacitor according to the embodiment of the present invention.

[0074] exist Figure 2In the embodiment, when the control unit 15 detects that the power supply system 16 of the converter is powered off, the control unit 15 turns on the braking IGBT 13 and controls the moving contact 23 of the switch 14 to be in electrical contact with the second static contact 22. According to the direction indicated by the arrow, the electricity discharged from the DC bus capacitor 12 passes through the resistor 11 and the control switch 14 (the moving contact 23 is in electrical contact with the second static contact 22) in sequence, reaches the braking IGBT 13 in the on state, and returns to the negative electrode (DCN) of the DC bus capacitor 12 to form a discharge circuit. It can be seen that the surge-resistant resistor 11 and the braking IGBT 13 are both introduced into the discharge circuit of the DC bus capacitor 12, so as to realize the rapid discharge of the DC bus capacitor and thereby reduce the discharge time.

[0075] Figure 3 It is a schematic diagram of the charging state of the DC bus capacitor according to the embodiment of the present invention.

[0076] exist Figure 3 In the embodiment, when the control unit 15 detects that the DC bus capacitor 12 is in a charging state (at this time, the rectifier module 17 charges the DC bus capacitor 12), the braking IGBT 13 is turned off. The control unit 15 also controls the moving contact 23 of the switch 14 to be in electrical contact with the second static contact 22. In the direction indicated by the arrow, the electricity provided by the rectifier module 17 passes through the resistor 11 and the DC bus capacitor 12 in sequence, and then returns to the rectifier module 17 to form a charging circuit. It can be seen that since the braking IGBT 13 has been turned off, the braking IGBT 13 is not included in the charging circuit. By introducing the resistor 11 into the charging circuit of the DC bus capacitor, the resistor 11 can be charged with current limiting at the moment of power-on, thereby protecting components such as the rectifier module.

[0077] Figure 4 Schematic diagram of the normal working state of the converter according to the embodiment of the present invention.

[0078] exist Figure 4 In the embodiment, when the control unit 15 detects that the DC bus capacitor 12 is in a normal working state to provide electric energy to the motor, the moving contact 23 of the control switch 14 contacts the first static contact 21, thereby short-circuiting the resistor 11. When the converter is in a normal working state, the braking IGBT 13 is used to discharge the feedback energy provided by the motor connected to the converter. The turning on or off of the braking IGBT 13 can be determined based on known mature logic. In the direction indicated by the arrow, the DC bus capacitor 12 can provide electricity to both ends of the DC bus to supply normal power to the motor through the path provided by the switch 14 (the moving contact 23 is in electrical contact with the first static contact 21). Moreover, the resistor 11 is short-circuited, thereby saving energy.

[0079] The embodiment of the present invention also provides a method for discharging a DC bus capacitor of a converter. Figure 51 is a flow chart of a method for discharging a DC bus capacitor of a converter according to an embodiment of the present invention. The converter comprises: a resistor connected in series with the DC bus capacitor of the converter; a braking IGBT connected between the positive and negative electrodes of the DC bus capacitor; and a switch connected to the braking IGBT and the resistor, respectively. Figure 5 As shown, the method includes:

[0080] Step 501: Detect the electrical connection status between the converter and the power supply system of the converter.

[0081] Step 502: When the electrical connection state indicates that the power supply system is powered off, turn on the braking IGBT.

[0082] Step 503: Control the state of the switch to conduct the discharge loop of the DC bus capacitor, where the discharge loop includes a resistor and a braking IGBT.

[0083] In one embodiment, it further includes: when it is detected that the DC bus capacitor is in a charging state, turning off the braking IGBT; controlling the state of the switch to turn on the charging circuit of the DC bus capacitor, the charging circuit including a resistor and a rectifier module of the converter.

[0084] In one embodiment, the invention further comprises: when the current transformer is detected to be in a normal working state, controlling the state of the switch to short-circuit the resistor.

[0085] In one embodiment, the switch includes a single-pole double-throw switch, the single-pole double-throw switch includes a first static contact, a second static contact and a moving contact, the first static contact is connected between the first end of the resistor and the DC bus capacitor, the second static contact is connected to the brake IGBT, and the moving contact is connected to the second end of the resistor. Controlling the state of the switch to conduct the discharge circuit of the DC bus capacitor includes: controlling the moving contact to be in electrical contact with the second static contact. Controlling the state of the switch to conduct the charging circuit of the DC bus capacitor includes: controlling the moving contact to be in electrical contact with the second static contact. Controlling the state of the switch to short-circuit the resistor includes: controlling the moving contact to be in electrical contact with the first static contact.

[0086] The embodiment of the present invention further provides an electrical device having a processor-memory architecture. Figure 6 is an exemplary structural diagram of an electrical device according to an embodiment of the present invention.

[0087] like Figure 6As shown, the electrical device 600 includes a processor 601, a memory 602, and a computer program stored in the memory 602 and executable on the processor 601. When the computer program is executed by the processor 601, the discharge method of the DC bus capacitor of the converter as described above is implemented. Among them, the memory 602 can be specifically implemented as a variety of storage media such as an electrically erasable programmable read-only memory (EEPROM), a flash memory (Flash memory), and a programmable program read-only memory (PROM). The processor 601 can be implemented as including one or more central processing units or one or more field programmable gate arrays, wherein the field programmable gate array integrates one or more central processing unit cores. Specifically, the central processing unit or the central processing unit core can be implemented as a CPU or an MCU or a DSP, and so on.

[0088] It should be noted that not all steps and modules in the above processes and structure diagrams are necessary, and some steps or modules can be ignored according to actual needs. The execution order of each step is not fixed and can be adjusted as needed. The division of each module is only for the convenience of describing the functional division adopted. In actual implementation, a module can be implemented by multiple modules, and the functions of multiple modules can also be implemented by the same module. These modules can be located in the same device or in different devices.

[0089] The hardware modules in each embodiment can be implemented mechanically or electronically. For example, a hardware module may include a specially designed permanent circuit or logic device (such as a dedicated processor, such as an FPGA or ASIC) for performing a specific operation. The hardware module may also include a programmable logic device or circuit (such as a general-purpose processor or other programmable processor) temporarily configured by software to perform a specific operation. As for whether to implement the hardware module mechanically, or using a dedicated permanent circuit, or using a temporarily configured circuit (such as configured by software), it can be decided based on cost and time considerations.

[0090] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A discharge device for a DC bus capacitor, characterized in that: include: A resistor (11) is connected in series with a DC bus capacitor (12) of the converter; A braking IGBT (13) connected between a positive electrode (DCP) and a negative electrode (DCN) of the DC bus capacitor (12); A switch (14) connected to the brake IGBT (13) and the resistor (11) respectively; A control unit (15) is configured to, when detecting that a power supply system (16) of the converter is powered off, turn on the braking IGBT (13) and control the state of the switch (14) to turn on a discharge circuit of the DC bus capacitor (12), wherein the discharge circuit includes the resistor (11) and the braking IGBT (13).

2. The device according to claim 1, characterized in that The control unit (15) is configured to, when detecting that the DC bus capacitor (12) is in a charging state, turn off the braking IGBT (13) and control the state of the switch (14) to turn on a charging circuit of the DC bus capacitor (12), wherein the charging circuit includes the resistor (11) and a rectifier module (17) of the converter.

3. The device according to claim 1, characterized in that The control unit (15) is configured to control the state of the switch (14) to short-circuit the resistor (11) when detecting that the converter (12) is in a normal working state.

4. The device according to claim 1, characterized in that The switch (14) comprises a single-pole double-throw switch, the single-pole double-throw switch comprising a first static contact (21), a second static contact (22) and a moving contact (23), the first static contact (21) being connected between a first end of the resistor (11) and the DC bus capacitor (12), the second static contact (22) being connected to the brake IGBT (13), and the moving contact (23) being connected to a second end of the resistor (11).

5. The device according to claim 1, characterized in that The brake IGBT (13) comprises a gate, a collector and an emitter, wherein the gate is connected to the control unit (15), the collector is connected to the positive electrode (DCP) of the DC bus capacitor (12) via a diode (18), and the emitter is connected to the negative electrode (DCN) of the DC bus capacitor (12).

6. A method for discharging a DC bus capacitor of a converter, characterized in that: The converter comprises: a resistor connected in series with a DC bus capacitor of the converter; a braking IGBT connected between a positive electrode and a negative electrode of the DC bus capacitor; and a switch connected to the braking IGBT and the resistor respectively; and the method comprises: Detecting the electrical connection state between the converter and the power supply system of the converter (501); When the electrical connection state indicates that the power supply system is powered off, turning on the brake IGBT (502); The state of the switch is controlled to conduct a discharge loop of the DC bus capacitor, wherein the discharge loop includes the resistor and the brake IGBT (503).

7. The method according to claim 6, characterized in that Also includes: When it is detected that the DC bus capacitor is in a charging state, turning off the braking IGBT; The state of the switch is controlled to conduct a charging circuit of the DC bus capacitor, wherein the charging circuit includes the resistor and a rectifier module of the converter.

8. The method according to claim 6, characterized in that Also includes: When it is detected that the converter is in a normal working state, the state of the switch is controlled to short-circuit the resistor.

9. The method according to claim 6, characterized in that The switch comprises a single-pole double-throw switch, the single-pole double-throw switch comprises a first static contact, a second static contact and a moving contact, the first static contact is connected between the first end of the resistor and the DC bus capacitor, the second static contact is connected to the brake IGBT, and the moving contact is connected to the second end of the resistor; The step of controlling the state of the switch to conduct the discharge circuit of the DC bus capacitor includes: controlling the movable contact to be in electrical contact with the second static contact.

10. The method according to claim 7, characterized in that The switch comprises a single-pole double-throw switch, the single-pole double-throw switch comprises a first static contact, a second static contact and a moving contact, the first static contact is connected between the first end of the resistor and the DC bus capacitor, the second static contact is connected to the brake IGBT, and the moving contact is connected to the second end of the resistor; The step of controlling the state of the switch to conduct the charging circuit of the DC bus capacitor includes: controlling the moving contact to be in electrical contact with the second static contact.

11. The method according to claim 8, characterized in that The switch comprises a single-pole double-throw switch, the single-pole double-throw switch comprises a first static contact, a second static contact and a moving contact, the first static contact is connected between the first end of the resistor and the DC bus capacitor, the second static contact is connected to the brake IGBT, and the moving contact is connected to the second end of the resistor; The controlling the state of the switch to short-circuit the resistor includes: controlling the movable contact to be in electrical contact with the first stationary contact.

12. An electrical device, characterized in that: include: Processor (601); A memory (602) for storing executable instructions of the processor; The processor (601) is used to read the executable instructions from the memory (602), and execute the executable instructions to implement the method for discharging a DC bus capacitor of a converter according to any one of claims 6 to 11.

13. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the computer instructions are executed by the processor, the method for discharging a DC bus capacitor of a converter according to any one of claims 6 to 11 is implemented.

14. A computer program product, characterized in that The method comprises a computer program, which, when executed by a processor, implements the method for discharging a DC bus capacitor of a converter according to any one of claims 6 to 11.

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