Control method and device of brake device and brake device

Abstract

The invention discloses a control method and device of a braking device and the braking device, which are used for reducing the cost of a braking assembly of a multi-level inverter. The braking device comprises a first braking assembly, a second braking assembly and at least one third braking assembly. The first brake assembly, the at least one third brake assembly and the second brake assembly are connected in series; the first brake assembly is connected with a first bus capacitor in the inverter in parallel, the second brake assembly is connected with the last bus capacitor in the inverter in parallel, and each third brake assembly is connected with two bus capacitors in the inverter in parallel; the first brake assembly and the second brake assembly comprise bridge arms, the upper bridge arm of the first brake assembly and the lower bridge arm of the second brake assembly are diodes, and the diodes are connected with a brake resistor in parallel; each third brake assembly comprises a first bridge arm and a second bridge arm which are connected in series, a lower bridge arm of the first bridge arm and an upper bridge arm of the second bridge arm are diodes, and at least one brake resistor is connected between the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm in parallel.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a control method, apparatus, and braking device for a braking device. Background Technology

[0002] Currently, multilevel technology is widely used in various power electronic products with inverters due to its advantages such as low switching loss, high efficiency, and low output harmonic content.

[0003] If a power supply or load connected to the inverter fails, the bus voltage may rise, potentially damaging components. A braking component is typically incorporated into the inverter to dissipate bus energy when the bus voltage rises, thus lowering the bus voltage. In existing technology, a braking resistor and a half-bridge module consisting of multiple switching transistors are usually configured across each bus capacitor. The half-bridge module establishes an electrical connection between the DC bus and the braking resistor when a power failure causes the bus voltage to rise, allowing the braking resistor to dissipate the energy on the DC bus and preventing damage to the inverter and connected equipment due to overvoltage. However, during the operation of the braking component, only some of the switching transistors are active, leading to reduced utilization of the components within the braking component and increasing its cost. Summary of the Invention

[0004] The purpose of this application is to provide a control method, apparatus, and braking device for reducing the cost of braking components in a multilevel inverter and reducing the size of the braking device.

[0005] In a first aspect, this application provides a braking device that can be applied to a multilevel inverter with multiple bus capacitors and is connected in parallel with the multiple bus capacitors in the inverter. The braking device may include: a first braking component, a second braking component, and at least one third braking component. The first braking component, at least one third braking component, and the second braking component are connected in series.

[0006] Specifically, the first braking component is connected in parallel with the first bus capacitor in the inverter, the second braking component is connected in parallel with the last bus capacitor in the inverter, and each third braking component is connected in parallel with two bus capacitors in the inverter other than the first and last bus capacitors. The first and second braking components include bridge arms consisting of a switching transistor and a diode connected in series. The upper bridge arm of the first braking component is a diode, and the lower bridge arm of the second braking component is a diode. A braking resistor is connected in parallel with the diodes in the first and second braking components. Each third braking component includes a first bridge arm and a second bridge arm connected in series. The lower bridge arm of the first bridge arm is a diode, and the upper bridge arm of the second bridge arm is a diode. At least one braking resistor is connected in parallel between the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm.

[0007] Using the above scheme, the inverter is a multi-level inverter with multiple bus capacitors. Compared with configuring a half-bridge module with multiple switching transistors and a braking resistor for each bus capacitor, each bus capacitor only needs to be configured with one switching transistor, which reduces the number of switching transistor devices, improves the utilization rate of switching transistors, and also helps to reduce the wiring difficulty and wiring area of ​​the braking device due to the reduction in the number of switching transistors.

[0008] In one possible design, the first braking component includes: a first diode, a first braking resistor, and a first switching transistor. The cathode of the first diode is connected to a first terminal of the first bus capacitor and a first terminal of the first braking resistor; the anode of the first diode is connected to a first terminal of the first switching transistor and a second terminal of the first braking resistor; and the second terminal of the first switching transistor is connected to a second terminal of the first bus capacitor.

[0009] In one possible design, the second braking assembly includes: a second switching transistor, a second diode, and a second braking resistor. A first terminal of the second switching transistor is connected to a first terminal of the last bus capacitor, and a second terminal of the second switching transistor is connected to the cathode of the second diode. The cathode of the second diode is connected to a first terminal of the second braking resistor, and the anode of the second diode is connected to both a second terminal of the second braking resistor and a second terminal of the last bus capacitor.

[0010] In one possible design, each third braking component includes: a third switching transistor, a third diode, a fourth diode, a fourth switching transistor, and a third braking resistor.

[0011] Specifically, the first terminal of the third switching transistor is connected to the first terminal of the first bus capacitor of the two bus capacitors connected in parallel with the third braking assembly, and the second terminal of the third switching transistor is connected to the cathode of the third diode; the cathode of the fourth diode is connected to the anode of the third diode, and the anode of the fourth diode is connected to the first terminal of the fourth switching transistor; the second terminal of the fourth switching transistor is connected to the second terminal of the second bus capacitor of the two bus capacitors connected in parallel with the third braking assembly; the first terminal of the third braking resistor is connected to the cathode of the third diode, and the second terminal of the third braking resistor is connected to the anode of the fourth diode.

[0012] Using the above design, for braking components with parallel DC buses (excluding the first and last DC buses), a single braking resistor can be configured to regulate the voltage of the two bus capacitors, thereby reducing the wiring complexity and size of the braking device. Furthermore, for scenarios with DC bus imbalance, a three-port regulating resistor, such as a sliding resistor, can be used to meet the voltage regulation requirements of a single DC bus while reducing the number of wires required.

[0013] In one possible design, the third braking resistor can be a three-port resistor such as a sliding resistor. The third braking resistor then includes a third terminal, which is the middle port of the sliding resistor. This third terminal is connected to the middle node of the two bus capacitors connected in parallel with the third braking component. Using a sliding resistor can meet the braking requirements of the two bus capacitors without requiring a connecting wire between the two resistors, further reducing the number and complexity of wiring in the braking device.

[0014] In one possible design, for scenarios where the DC bus needs to be braked individually, each third braking component also includes a fourth braking resistor, which is connected between the second end of the third braking resistor and the anode of the fourth diode, and the second end of the third braking resistor is connected to the middle node of the two bus capacitors connected in parallel with the third braking component.

[0015] Secondly, embodiments of this application provide a control method for a braking device. This control method can be applied to an inverter equipped with a braking device. The control method can be executed by a controller of the braking device or a controller of the power circuit in the inverter, and specifically includes the following steps:

[0016] The system detects the bus voltage and the inverter's operating status, which includes a fault operating status and a normal operating status. When the bus voltage is detected to be greater than a first preset threshold and the inverter is in a fault operating status, the system controls the braking component in the inverter to operate. When the bus voltage is detected to be greater than a second preset threshold and the inverter is in a normal operating status, the system controls the braking component in the inverter to operate, where the first preset threshold is greater than the second preset threshold.

[0017] With the above design, during the operation of the inverter, a power supply or load failure will cause the bus voltage to rise. Control of the power circuit or other reasons will also cause the bus voltage to become unbalanced and exceed its normal voltage range. When a power supply or load failure connected to the inverter is detected that causes the bus voltage to become unbalanced, the inverter can be made to operate at a lower voltage range than the normal bus voltage range to avoid frequent activation of the braking device. It can also provide protection when the bus voltage rises due to control strategy errors.

[0018] In one possible design, the method further includes: when controlling the braking component in the inverter to operate, if the bus voltage is detected to be less than a third preset threshold, controlling the braking component in the inverter to stop operating.

[0019] In one possible design, controlling the braking component in the inverter to operate when the bus voltage is detected to be greater than a first preset threshold and the inverter is in a fault operation state includes:

[0020] The voltage of each bus capacitor in the inverter is detected. When the voltage across the target bus capacitor exceeds the first preset threshold and the inverter is in a fault operation state, the braking component connected to the target bus capacitor is controlled to operate. With this design, when bus voltage imbalance occurs due to a fault or control strategy error, some bus capacitors may have normal voltages while others are unbalanced. Individual braking components can be controlled to operate, allowing for individual adjustment of the voltage of some bus capacitors.

[0021] Thirdly, embodiments of this application provide a control device for a braking device, the control device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the methods provided in the second aspect of this application and any possible design thereof.

[0022] Furthermore, the technical effects of the third aspect and any of its possible designs can be found in the technical effects of different designs in the first and second aspects of the embodiments of this application, and will not be repeated here. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings introduced below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of a braking device provided for related technologies;

[0025] Figure 2 A schematic diagram of the structure of a braking device provided in this application embodiment. Figure 1 ;

[0026] Figure 3 A schematic diagram of the packaging of internal components of a braking assembly provided in an embodiment of this application;

[0027] Figure 4 A schematic diagram of a switching transistor provided in an embodiment of this application;

[0028] Figure 5 A schematic diagram of the structure of a third braking component provided in this application embodiment;

[0029] Figure 6 A schematic diagram of the structure of a third braking component provided in this application embodiment. Figure 2 ;

[0030] Figure 7 A schematic diagram of the structure of a braking device provided in this application embodiment. Figure 3 ;

[0031] Figure 8 A schematic flowchart illustrating a control method for a braking device provided in an embodiment of this application;

[0032] Figure 9 This is a schematic diagram of the structure of a control device for a braking device provided in an embodiment of this application. Detailed Implementation

[0033] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0034] The terminology used in the implementation section of this application is only for explaining specific embodiments of this application and is not intended to limit this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0035] The application scenarios of the braking device in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0036] The braking device provided in this application embodiment can be applied to an inverter with multiple bus capacitors and is used to start when the voltage of the bus capacitor exceeds the normal voltage range. It consumes the electrical energy on the bus capacitor through the internal braking resistor, thereby reducing the bus voltage and restoring the bus voltage to the normal voltage range.

[0037] See Figure 1 The diagram shown is a structural schematic of a braking device using a three-level inverter. (See attached image.) Figure 1 As shown, the braking assembly includes two series-connected first and second bridge arms, and braking resistors R1 and R2 connected in parallel with the upper bridge arm of each bridge arm. The first bridge arm consists of switches Q1 and Q2 connected in series, and the second bridge arm consists of switches Q3 and Q4 connected in series. When the braking assembly needs to operate, the switches in the bridge arms can be controlled to conduct, forming an electrical connection between the bus capacitor and the braking resistor. When the braking assembly is officially started, taking the first bridge arm as an example, the upper bridge arm switch Q1 and the lower bridge arm switch Q2 are not operating. Instead, the parasitic diodes of the two switches operate, forming a power-consuming branch with the braking resistor R1. This reduces the utilization rate of the switches in the braking assembly, and the aforementioned switching devices increase the wiring difficulty and wiring area of ​​the inverter.

[0038] To address the aforementioned issues, this application provides a control method, apparatus, and braking device for reducing the cost of braking components in multilevel inverters and decreasing the size of the inverter.

[0039] See Figure 2 As shown, this application provides a schematic diagram of the structure of a braking device. Figure 2 As shown, this braking device can be applied to a multilevel inverter with multiple bus capacitors. The braking device includes at least a first braking component, a second braking component, and at least one third braking component. The first braking component, at least one third braking component, and the second braking component are connected in series.

[0040] Specifically, the first braking component is connected in parallel with the first bus capacitor in the inverter, the second braking component is connected in parallel with the last bus capacitor in the inverter, and each third braking component is connected in parallel with two bus capacitors in the inverter except for the first bus capacitor and the last component, which include a bridge arm consisting of a switching transistor and a diode connected in series. The upper bridge arm of the first braking component is a diode bus capacitor. The first braking component and the second braking transistor are connected in parallel, and the lower bridge arm of the second braking component is a diode. A braking resistor is connected in parallel between the diodes in the first braking component and the second braking component. Each third braking component includes a first bridge arm and a second bridge arm connected in series. The lower bridge arm of the first bridge arm is a diode, the upper bridge arm of the second bridge arm is a diode, and at least one braking resistor is connected in parallel between the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm.

[0041] In practical applications, the diodes and switches in the aforementioned braking assembly can be electrically connected using laminated busbars or copper busbars, and the number of diodes and switches in the braking assembly can be configured according to the application scenario of the inverter. For example, when the inverter is used in a high-power power supply scenario, since the current allowed to pass through a single diode and switch is limited, multiple diodes and multiple switches can be configured in the braking assembly to meet the high current transmission requirements during braking. These multiple diodes and multiple switches are all connected in parallel. Each diode and each switch can be individually packaged; see [reference needed]. Figure 3 As shown, multiple diodes connected in parallel can also be packaged into a single device, as well as multiple switching transistors connected in parallel, for example, in a 62mm package, an Economual package, or a PrimePACK package.

[0042] The braking device provided in this application embodiment can be applied to an inverter with multiple bus capacitors. The inverter's input terminal is connected to an AC power source, converting the AC power output from the AC power source into DC power, and then outputting the DC power to the downstream connected equipment to power it. Multiple braking components in the braking device are connected in series and then in parallel with the bus capacitors within the inverter, thus configuring one braking component for each bus capacitor or two adjacent bus capacitors in the inverter. Each braking component is equipped with a braking resistor. When an AC power failure or controller logic causes the bus voltage to rise, the bus capacitors can be electrically connected to the braking resistor. The braking resistor consumes the energy of the bus capacitors to prevent damage to the components due to high voltage until the AC power failure is resolved and the bus voltage returns to normal.

[0043] Specifically, each braking component is equipped with a switching transistor, which controls the connection of the bus capacitor and the braking resistor. The braking device may include a controller, or the control device may be connected to the controller in the inverter. This controller may be directly connected to the switching transistor or connected via a drive circuit. See also... Figure 4As shown, the controller drives the switching devices to turn on and off by sending drive signals. Since the braking assembly is used to protect the circuit when the bus voltage rises, the switching devices can be controlled to turn on when the bus voltage rises, so that the braking resistor is connected to the bus capacitor and consumes the electrical energy of the bus capacitor, thereby reducing the bus voltage and preventing the inverter and devices connected to the inverter from being damaged by high voltage.

[0044] In practical applications, the controller sends a corresponding drive signal to each switching transistor to control its on and off states. Therefore, the PCB containing the drive unit needs to be configured with drive cables between the controller and each switching transistor. To reduce the length of the drive cables, the controller's PCB needs to be mounted above or as close as possible to the PCB containing the switching transistors. The drive cables can also be installed using a single-board connector or a flexible PCB.

[0045] use Figure 2 The braking device shown has a bridge arm in each braking component connected to the bus capacitor composed of a diode and a switching transistor. The switching transistor enables the operation of the braking component. Compared with the prior art, which uses two switching transistors connected in series to form a braking component, this increases the utilization rate of the switching transistor. Furthermore, since the diode is a unidirectional conducting device, there is no need to configure a control circuit, which also helps to reduce the wiring difficulty of the braking component and thus reduce the size of the braking component.

[0046] In practical applications, to reduce the wiring difficulty of the braking device, for the bus capacitors in a multi-level inverter other than the first and last bus capacitors, a third braking component can be reused between adjacent bus capacitors. The braking resistor in the third braking component can meet the braking requirements of the two bus capacitors. For example, the braking resistor in the third braking component can be a sliding resistor. The second end of the first terminal of the sliding resistor can be connected to the first bus capacitor through the first bridge arm, and the second and third terminals of the sliding resistor can be connected to the second bus capacitor through the second bridge arm. Therefore, the braking resistors corresponding to the two bus capacitors only need to be configured with three ports. Compared to configuring a braking resistor with two external interfaces for each bus capacitor, this reduces the number of connection lines between the two braking resistors and the number of connection lines between the braking resistor and the bus capacitor, which helps to reduce the wiring difficulty of the braking device and reduce the size of the braking resistor.

[0047] In some implementations, since the devices at the connection points of two adjacent braking components are switching transistors, i.e., two switching transistors connected in series, in order to reduce the wiring difficulty of the braking device, the two switching transistors can be packaged into a half-bridge module. The first end of the first switching transistor and the second end of the second switching transistor are the AC ports of the half-bridge module, and the connection point of the first switching transistor and the second switching transistor is the neutral point of the half-bridge module. In this case, the half-bridge module is only configured with three external interfaces, and the PCB board on which the braking device is located only needs to be configured with the connection lines of the above three interfaces, which can further reduce the wiring difficulty of the braking device.

[0048] The structure of each braking component in the braking device will be described below with reference to the embodiments.

[0049] In one possible implementation, see Figure 5 As shown, the first braking assembly includes a first diode D1, a first braking resistor R1, and a first switching transistor Q1; the second braking assembly includes a second switching transistor Q2, a second diode D2, and a second braking resistor R2; and each third braking assembly includes a third switching transistor Q3, a third diode D3, a fourth diode D4, a fourth switching transistor Q4, and a third braking resistor R3. To facilitate understanding of the technical solution claimed in this application, a five-level inverter is used as an example for illustration.

[0050] Specifically, the cathode of the first diode D1 is connected to the first terminal of the first bus capacitor C1 and the first terminal of the first braking resistor R1; the anode of the first diode D2 is connected to the first terminal of the first switch Q1 and the second terminal of the first braking resistor R1; the second terminal of the first switch Q1 is connected to the second terminal of the first bus capacitor C1. The first terminal of the second switch Q2 is connected to the first terminal of the last bus capacitor C4; the second terminal of the second switch Q2 is connected to the cathode of the second diode D2; the cathode of the second diode D2 is connected to the first terminal of the second braking resistor R2; and the anode of the second diode D2 is connected to the second terminal of the second braking resistor R2 and the second terminal of the last bus capacitor C4. The first terminal of the third switch R3 is connected to the first terminal of the first bus capacitor C1 of the two bus capacitors connected in parallel with the third braking assembly. The second terminal of the third switch Q3 is connected to the cathode of the third diode D3. The cathode of the fourth diode D4 is connected to the anode of the third diode D3, and the anode of the fourth diode D4 is connected to the first terminal of the fourth switch Q4. The second terminal of the fourth switch Q4 is connected to the second terminal of the second bus capacitor C3 of the two bus capacitors connected in parallel with the third braking assembly. The first terminal of the third braking resistor R3 is connected to the cathode of the third diode D3, the second terminal of the third braking resistor R3 is connected to the anode of the fourth diode D4, and the third terminal of the third braking resistor R3 is connected to the middle node of the two bus capacitors connected in parallel with the third braking assembly.

[0051] In one example, in order to brake the bus capacitors individually while reducing the number of wirings for the braking resistor, the third braking resistor R3 can be a resistor with three output ports. The third terminal of the third braking resistor R3 is connected to the middle node of the two bus capacitors connected in parallel with the third braking component. For example, the third braking resistor R3 is a sliding resistor. The resistance wire connected to the first and third terminals of the sliding resistor provides braking resistance for the bus capacitor C2, and the second and third terminals of the sliding resistor provide sliding resistance for the bus capacitor C3. When the bus capacitors C2 and C3 are braked, the current during the braking process flows through the third port of the sliding resistor, thereby realizing the reuse of the port and the port connection line, reducing the number of wirings in the braking device, which is beneficial to reducing the cost and size of the braking device.

[0052] In one example, to achieve independent braking of the two bus capacitors, each third braking component includes a fourth braking resistor R4 in addition to the third braking resistor R3. See [link to example]. Figure 6 As shown, the fourth braking resistor R4 is connected between the second terminal of the third braking resistor R3 and the anode of the fourth diode D4, and the second terminal of the third braking resistor R3 is connected to the second terminal of the first bus capacitor C2 of the two bus capacitors connected in parallel with the third braking component. The third and fourth braking resistors R3 can be packaged into a single device, and the first terminal, the second terminal, and the third terminal of the fourth braking resistor R4 are the three external interfaces of this device.

[0053] It should be noted that, Figures 2 to 6 The switching transistors in the braking assembly shown can be voltage-type switching transistors. Each of these switching transistors is equipped with a control port. A controller can connect to the control port of the switching transistor and control the switching transistor's on and off states by providing a corresponding level signal to the control port. For example, if the switching transistor is a MOSFET, the control terminal is the gate, and the first and second terminals are the drain and source, respectively. Of course, other voltage-type driving switching transistors can also be used, and the two switching transistors can be of different switching types; this application does not impose further limitations here.

[0054] Of course, the above description of the braking device is only an example. In practical applications, the braking device can also adopt other structures. For example, inverters of different power levels have different braking requirements. According to the power level of the inverter, multiple parallel architectures can be configured, that is, multiple parallel first braking components, second braking components, and third braking components can be configured respectively, such as... Figure 7 The diagram shows the structure of a braking device with three sets of parallel braking components. Of course, other devices with the aforementioned functions can also be used within the braking device; this application does not impose any limitations on this.

[0055] Based on the same inventive concept, this application also provides an inverter, which may include a power circuit, multiple bus capacitors, and the aforementioned braking device. The power circuit has an external AC power supply at its input terminal and multiple output terminals. The first output terminal of the power circuit is connected to the first terminal of one of the multiple bus capacitors, the second output terminal of the power circuit is connected to the second terminal of the first bus capacitor, and so on, with the last output terminal of the power circuit connected to the second terminal of the last of the multiple bus capacitors. The braking device is connected in parallel with the multiple bus capacitors.

[0056] Based on the above description of the braking device structure, the following section provides a detailed explanation of the braking device's operation. The control process of the braking device can be executed by the controller inside the braking device or the controller of the inverter. (See [link to relevant documentation]). Figure 8 As shown, the main steps include:

[0057] Step S801: Detect the bus voltage and the inverter's operating status. The operating status includes fault operation status and normal operation status.

[0058] In practical applications, the equipment containing the inverter is generally equipped with a monitoring system. This system can detect the operating parameters of the inverter and the AC power supply connected to the inverter, and determine the inverter's operating status based on these parameters. For example, when it detects that the voltage output of the AC power supply connected to the inverter exceeds the rated voltage of the AC power supply, it is determined that the inverter is in a fault operating state. These operating parameters include, but are not limited to, voltage, current, and power.

[0059] Step S802: When the bus voltage is detected to be greater than the first preset threshold and the inverter is in fault operation state, control the braking component in the inverter to work.

[0060] Specifically, since the inverter has multiple bus capacitors, each of which can output a bus voltage, the bus voltage across each bus capacitor can be detected. When the detected bus voltage across any bus capacitor is greater than a first preset threshold and the inverter is in a fault operation state, the braking component in the inverter is controlled to work.

[0061] It should be noted that the above explanation is based on the example that the rated voltage of each bus capacitor is the same. When the rated voltages across each bus capacitor are different during normal operation, it is necessary to configure a corresponding first preset threshold for each bus capacitor and use it as the starting condition for the braking component connected in parallel with the bus capacitors, so as to avoid the braking component from being mis-energized.

[0062] In practical applications, when the AC power supply connected to the inverter fails, even if the braking component connected to the bus capacitor operates and adjusts the bus voltage to the normal operating voltage range before the AC power supply failure is resolved, the bus voltage will still rise when the braking component stops operating. To avoid frequent starting and stopping of the braking device, the first preset threshold can be set to a value greater than the stable operating voltage of the bus capacitor, thereby frequently starting it until the AC power supply failure is resolved. For example, if the bus voltage range corresponding to the normal operation of the bus capacitor is [800V, 900V], the first preset threshold can be set to 1200V.

[0063] Step S803: When the bus voltage is detected to be greater than the second preset threshold and the inverter is in normal operation, control the braking component in the inverter to operate. The first preset threshold is greater than the second preset threshold. The second preset threshold can be set to the maximum value within the normal operating range of the bus capacitor, or it can be set to other values. For example, if the inverter is equipped with a display panel, the first preset threshold can be configured through touchscreen signals received by the display panel.

[0064] In practical applications, the above steps describe the operation of the braking component when an abnormal rise in bus voltage is detected. When the bus voltage is within the normal operating range, the braking component needs to be stopped to prevent the bus voltage from becoming too low.

[0065] Specifically, when controlling the operation of the braking component in the inverter, if the bus voltage is detected to be less than a third preset threshold, the braking component in the inverter will stop operating.

[0066] Based on the same inventive concept, this application also provides a control device for a braking device, which can execute the aforementioned control method for the braking device. See [link to relevant documentation]. Figure 9 As shown, the control device for the braking system includes:

[0067] At least one processor 901 and a memory 902 connected to at least one processor 901. In this embodiment, the specific connection medium between the processor 901 and the memory 902 is not limited. Figure 9 The example shown is the connection between processor 901 and memory 902 via bus 900. Bus 900 is... Figure 9 The connections between other components are indicated by thick lines and are for illustrative purposes only, not as limiting information. The Bus 900 can be divided into address bus, data bus, control bus, etc., for ease of representation. Figure 9 The term is represented by a single thick line, but this does not imply that there is only one bus or one type of bus. Alternatively, the processor 901 can also be called a controller; there is no restriction on the name.

[0068] In this embodiment of the application, the memory 902 stores instructions that can be executed by at least one processor 901. By executing the instructions stored in the memory 902, at least one processor 901 can execute the control method of the braking device discussed above.

[0069] The processor 901 is the control center of the device. It can connect to various parts of the control device through various interfaces and lines. By running or executing instructions stored in memory 902 and calling data stored in memory 902, the processor can perform various functions and process data, thereby monitoring the device as a whole.

[0070] The processor 901 can be a general-purpose processor, such as a central processing unit (CPU), digital signal processor, application-specific integrated circuit, field-programmable gate array or other programmable logic device, discrete gate circuit or transistor logic device, or discrete hardware component, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the control method for the braking device disclosed in the embodiments of this application can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0071] Memory 902, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. Memory 902 may include at least one type of storage medium, such as flash memory, hard disk, multimedia card, card-type memory, random access memory (RAM), static random access memory (SRAM), programmable read-only memory (PROM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic storage, magnetic disk, optical disk, etc. Memory 902 can be any other medium capable of carrying or storing desired program code in the form of instructions or data structures that can be accessed by a computer, but is not limited thereto. In the embodiments of this application, memory 902 can also be a circuit or any other device capable of implementing storage functions for storing program instructions and / or data.

[0072] By designing and programming the processor 901, the code corresponding to the control method of the braking device described in the foregoing embodiments can be embedded into the chip, thereby enabling the chip to execute the steps of the control method of the braking device described in the foregoing embodiments during operation. How to design and program the processor 901 is a technique well known to those skilled in the art, and will not be described in detail here.

[0073] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0074] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0075] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0076] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0077] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A braking device, characterized in that, include: A first braking assembly, a second braking assembly, and at least one third braking assembly; wherein the first braking assembly, the at least one third braking assembly, and the second braking assembly are connected in series; The first braking assembly is connected in parallel with the first bus capacitor in the inverter, the second braking assembly is connected in parallel with the last bus capacitor in the inverter, and each third braking assembly is connected in parallel with two bus capacitors in the inverter other than the first bus capacitor and the last bus capacitor. The first braking assembly and the second braking assembly each include a bridge arm consisting of a switching transistor and a diode connected in series. The upper bridge arm of the first braking assembly is a diode, and the lower bridge arm of the second braking assembly is a diode. A braking resistor is connected in parallel with the diodes in the first braking assembly and the second braking assembly. Each third braking assembly includes a first bridge arm and a second bridge arm connected in series, the lower bridge arm of the first bridge arm being a diode, the upper bridge arm of the second bridge arm being a diode, and at least one braking resistor connected in parallel between the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm.

2. The braking device according to claim 1, characterized in that, The first braking component includes: a first diode, a first braking resistor, and a first switching transistor; The cathode of the first diode is connected to the first terminal of the first bus capacitor and the first terminal of the first braking resistor, and the anode of the first diode is connected to the first terminal of the first switching transistor and the second terminal of the first braking resistor. The second terminal of the first switching transistor is connected to the second terminal of the first bus capacitor.

3. The braking device according to claim 1, characterized in that, The second braking assembly includes: a second switching transistor, a second diode, and a second braking resistor; The first terminal of the second switching transistor is connected to the first terminal of the last bus capacitor, and the second terminal of the second switching transistor is connected to the cathode of the second diode. The cathode of the second diode is connected to the first end of the second braking resistor, and the anode of the second diode is connected to the second end of the second braking resistor and the second end of the last bus capacitor.

4. The braking device according to any one of claims 1 to 3, characterized in that, Each third braking component includes: a third switching transistor, a third diode, a fourth diode, a fourth switching transistor, and a third braking resistor; The first terminal of the third switch is connected to the first terminal of the first bus capacitor of the two bus capacitors connected in parallel with the third braking assembly, and the second terminal of the third switch is connected to the cathode of the third diode. The cathode of the fourth diode is connected to the anode of the third diode, and the anode of the fourth diode is connected to the first terminal of the fourth switching transistor. The second terminal of the fourth switching transistor is connected to the second terminal of the second bus capacitor of the two bus capacitors connected in parallel with the third braking assembly. The first end of the third braking resistor is connected to the cathode of the third diode, and the second end of the third braking resistor is connected to the anode of the fourth diode.

5. The braking device according to claim 4, characterized in that, The third braking resistor also includes a third terminal, which is connected to the middle node of the two bus capacitors connected in parallel with the third braking assembly.

6. The braking device according to claim 4, characterized in that, Each third braking assembly also includes a fourth braking resistor, which is connected between the second end of the third braking resistor and the anode of the fourth diode, and the second end of the third braking resistor is connected to the middle node of the two bus capacitors connected in parallel with the third braking assembly.

7. A control method for a braking device, characterized in that, Applied to the braking device as described in any one of claims 1 to 6, the method comprises: Detect bus voltage and inverter operating status, including fault operating status and normal operating status; When the bus voltage is detected to be greater than the first preset threshold and the inverter is in a fault operation state, the braking component in the inverter is controlled to work. When the bus voltage is detected to be greater than the second preset threshold and the inverter is in normal operation, the braking component in the inverter is controlled to work, wherein the first preset threshold is greater than the second preset threshold.

8. The method according to claim 7, characterized in that, The method further includes: When controlling the braking component in the inverter to operate, if the bus voltage is detected to be less than a third preset threshold, the braking component in the inverter is controlled to stop operating.

9. The method according to claim 8, characterized in that, When the bus voltage is detected to be greater than a first preset threshold and the inverter is in a fault operation state, controlling the braking component in the inverter to operate includes: Detect the voltage of each bus capacitor in the inverter; When the voltage across the target bus capacitor is detected to be greater than the first preset threshold, and the inverter is in a fault operation state, the braking component connected to the target bus capacitor is controlled to work.

10. A control device for a braking system, characterized in that, include: At least one processor; The at least one processor is also connected in communication with a memory, wherein the memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform a control method for the braking device as described in any one of claims 6-9.

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