Frequency converter short circuit protection circuit, short circuit detection method and related equipment

Abstract

The invention discloses a frequency converter short-circuit protection circuit, a short-circuit detection method and related equipment, and relates to the technical field of frequency converter protection, and the frequency converter short-circuit protection circuit comprises a short-circuit-to-ground protection circuit, a short-circuit-to-ground detection circuit, a rectifier bridge circuit, a bus capacitor circuit and a controller. The short-circuit-to-ground protection circuit comprises a first switch, a second switch and a first resistor and is used for protecting the frequency converter when a short-circuit-to-ground fault occurs in the frequency converter, and the short-circuit-to-ground detection circuit is connected with the second switch of the short-circuit-to-ground protection circuit and is used for detecting whether the short-circuit-to-ground fault occurs in the frequency converter to obtain a detection result; and the controller is electrically connected with the ground short circuit detection circuit and is used for carrying out ground short circuit processing corresponding to a detection result on the frequency converter based on the detection result obtained by the ground short circuit detection circuit. According to the invention, short-circuit protection of the frequency converter is realized based on the frequency converter short-circuit protection circuit, and a short-circuit fault is timely detected and correspondingly processed when the short-circuit fault occurs.

Description

Technical Field

[0001] This application relates to the field of frequency converter protection technology, and in particular to frequency converter short-circuit protection circuits, short-circuit detection methods and related equipment. Background Technology

[0002] In the short-circuit protection of frequency converters, current detection is usually used to detect whether the current in the frequency converter changes, so that the frequency converter can be protected in time when a short circuit occurs based on the current change.

[0003] When a frequency converter is powered on, if a short-circuit fault occurs, such as a DC bus short circuit, output phase-to-phase short circuit, or output-to-ground short circuit, the current will change significantly. Existing current detection methods can detect this current change to identify related short-circuit faults and provide short-circuit protection when a short-circuit fault is detected. However, for short-circuit faults to ground, if a short-circuit fault to ground exists before the frequency converter is powered on, at the moment of power-on, current may flow to ground from other branches (i.e., the main current may not change), and the relevant detection devices and control systems are not powered on. This makes it difficult for the relevant detection devices to detect the presence of a short-circuit fault to ground by detecting the current. Summary of the Invention

[0004] In view of the above problems, this application provides a short-circuit protection circuit, a short-circuit detection method, and related equipment for frequency converters to achieve the purpose of short-circuit protection. The specific solution is as follows:

[0005] The first aspect of this application provides a short-circuit protection circuit for a frequency converter, including: a short-circuit protection circuit to ground, a short-circuit detection circuit to ground, a rectifier bridge circuit, a bus capacitor circuit, and a controller;

[0006] The ground short-circuit protection circuit includes: a first switch, a second switch, and a first resistor;

[0007] One end of the first switch and one end of the first resistor are connected to one end of the rectifier bridge circuit; the other end of the first switch, the other end of the first resistor, and one end of the second switch are connected to one end of the bus capacitor circuit; the other end of the second switch and the other end of the bus capacitor circuit are connected to the other end of the rectifier bridge circuit.

[0008] The ground short circuit detection circuit is connected to the second switch of the ground short circuit protection circuit, and is used to detect whether the frequency converter has a ground short circuit fault and obtain the detection result;

[0009] The controller is electrically connected to the ground short-circuit detection circuit and is used to perform ground short-circuit processing on the frequency converter based on the detection result obtained by the ground short-circuit detection circuit.

[0010] Furthermore, one end of the ground short circuit detection circuit is connected to one end of the second switch, and the other end of the ground short circuit detection circuit is connected to the other end of the second switch. The ground short circuit detection circuit is used to detect the voltage across the second switch, so as to detect whether the frequency converter has a ground short circuit fault based on the voltage across the second switch.

[0011] Furthermore, one end of the first switch and one end of the first resistor are connected to the positive output terminal of the rectifier bridge circuit; the other end of the first switch, the other end of the first resistor, and one end of the second switch are connected to the positive terminal of the bus capacitor circuit; the other end of the second switch and the negative terminal of the bus capacitor circuit are connected to the negative input terminal of the rectifier bridge circuit.

[0012] Alternatively, one end of the first switch and one end of the first resistor are connected together to the negative output terminal of the rectifier bridge circuit; the other end of the first switch, the other end of the first resistor, and one end of the second switch are connected together to the negative terminal of the bus capacitor circuit; the other end of the second switch and the positive terminal of the bus capacitor circuit are connected together to the positive input terminal of the rectifier bridge circuit.

[0013] Furthermore, the first switch includes: a first relay switch, a first thyristor switch, or a first MOSFET switch;

[0014] The second switch includes: a second relay switch, a second thyristor switch, or a second MOSFET switch.

[0015] Furthermore, the controller is connected to the first switch and the second switch of the short-circuit-to-ground detection circuit, respectively;

[0016] If the detection result obtained by the short-circuit detection circuit to ground is that no short-circuit fault to ground has occurred, the controller will engage the first switch and the second switch to enable the inverter to operate normally.

[0017] If the detection result obtained by the short-circuit detection circuit to ground indicates that a short-circuit fault to ground has occurred, the controller will issue a short-circuit fault alarm to ground.

[0018] Furthermore, it also includes: a short-circuit detection circuit; the short-circuit detection circuit is connected to the output terminal of the inverter and is used to detect the current at the output terminal of the inverter when the inverter is powered on, so as to perform short-circuit detection on the inverter.

[0019] A second aspect of this application provides a short-circuit detection method for a frequency converter, applied to the controller of the short-circuit protection circuit of the frequency converter; the short-circuit detection method for the frequency converter includes:

[0020] Before powering on the frequency converter, disconnect the first switch and the second switch of the short-circuit protection circuit to ground;

[0021] After the inverter is powered on, the ground short-circuit detection circuit is controlled to detect the voltage across the second switch;

[0022] Based on the voltage across the second switch, determine whether the inverter has experienced a short circuit to ground.

[0023] If the inverter experiences a short-circuit fault to ground, a short-circuit fault alarm will be triggered.

[0024] If the inverter does not experience the ground short-circuit fault, then the first switch and the second switch are engaged to allow the inverter to operate normally.

[0025] A third aspect of this application provides a short-circuit protection device for a frequency converter, comprising: at least one processor and a memory connected to the processor, wherein:

[0026] The memory is used to store computer programs;

[0027] The processor is used to execute the computer program so that the inverter short-circuit protection device can implement the inverter short-circuit detection method.

[0028] A fourth aspect of this application provides a computer program product, comprising: computer-readable instructions that, when executed on an electronic device, cause the inverter short-circuit protection device to implement the inverter short-circuit detection method of the first aspect or any implementation thereof.

[0029] The fifth aspect of this application provides a computer storage medium carrying one or more computer programs, which, when executed by an electronic device, enable the inverter short-circuit protection device to implement the inverter short-circuit detection method of the first aspect or any implementation thereof.

[0030] By employing the above technical solution, the inverter short-circuit protection circuit provided in this application can, through the first switch, second switch, and first resistor of the ground short-circuit protection circuit, achieve the following: before the inverter is powered on, the first switch and second switch are turned off, so that when the inverter is powered on and a ground short-circuit fault exists, the current path of the ground short circuit is cut off or limited by the first switch, second switch, and first resistor, thereby ensuring that the relevant components of the inverter are not damaged by short circuit. The ground short-circuit detection circuit detects whether the inverter has a ground short-circuit fault based on the second switch of the ground short-circuit protection circuit, and outputs the corresponding ground short-circuit fault detection result, so that the controller can perform corresponding ground short-circuit processing on the inverter based on the detection result, ensuring the safety of the inverter. Attached Figure Description

[0031] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0032] Figure 1 A circuit diagram of a short-circuit protection circuit for a frequency converter provided in this application;

[0033] Figure 2 A short-circuit current path diagram to ground for a frequency converter short-circuit protection circuit provided in this application;

[0034] Figure 3 A flowchart illustrating a short-circuit detection method for a frequency converter provided in this application. Detailed Implementation

[0035] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is for explaining specific embodiments only and is not intended to limit the scope of this application.

[0036] The embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0037] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

[0038] In the short-circuit protection of frequency converters, current detection is usually used to detect whether the current in the frequency converter changes, so that the frequency converter can be protected in time when a short circuit occurs based on the current change.

[0039] When a frequency converter is powered on, if a short-circuit fault occurs, such as a DC bus short circuit, output phase-to-phase short circuit, or output-to-ground short circuit, the current will change significantly. Existing current detection methods can detect related short-circuit faults in the frequency converter based on this current change and provide short-circuit protection when a short-circuit fault is detected. Specifically, for a ground fault, if a ground fault exists before the frequency converter is powered on, at the moment of power-on, current may flow to ground from other branches (i.e., the main circuit current may not change), and the relevant detection devices and control systems are not powered on, making it difficult for the relevant detection devices to detect whether a ground fault exists in the frequency converter by detecting the current. In view of this, the present invention provides a frequency converter short-circuit protection circuit, a short-circuit detection method, and related equipment.

[0040] For details, please refer to Figure 1 In some embodiments of this application, the provided inverter short-circuit protection circuit specifically includes: three-phase input terminals (R, S, T in the figure), rectifier bridge circuit, ground short-circuit protection circuit, bus capacitor circuit, ground short-circuit detection circuit, braking circuit, inverter bridge circuit, control circuit, short-circuit detection circuit, and three-phase output terminals (U, V, W in the figure).

[0041] The rectifier bridge circuit includes: a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, and a sixth diode D6. The rectifier bridge circuit is mainly used to convert the AC power input from the three-phase input terminal into DC power. The anode of the first diode D1 is connected to the R-phase input terminal of the three-phase input terminal, the anode of the second diode D2 is connected to the S-phase input terminal of the three-phase input terminal, the anode of the third diode D3 is connected to the T-phase input terminal of the three-phase input terminal, the cathode of the fourth diode D4 is connected to the R-phase input terminal of the three-phase input terminal, the cathode of the fifth diode D5 is connected to the S-phase input terminal of the three-phase input terminal, and the cathode of the sixth diode D6 is connected to the T-phase input terminal of the three-phase input terminal. The cathodes of the first diode D1, the second diode D2, and the third diode D3 together serve as the positive output terminal of the rectifier bridge circuit, and the anodes of the fourth diode D4, the fifth diode D5, and the sixth diode D6 together serve as the negative input terminal of the rectifier bridge circuit.

[0042] The short-circuit protection circuit to ground includes: a first switch PLY1, a first resistor R1, and a second switch PLY2. This circuit primarily ensures that no large current is generated in any branch of the inverter when a short circuit to ground occurs, preventing damage to related components. The bus capacitor circuit includes: a first bus capacitor C1 and a second bus capacitor C2. This circuit stores and smooths the DC energy of the circuit. The braking circuit includes: a seventh diode D7 and a seventh switch Q7. This circuit actively discharges energy when the bus voltage is too high, preventing overvoltage damage to the inverter. The inverter bridge circuit includes: a first switch Q1. The second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6 form the inverter bridge circuit, which is mainly used to convert the DC power output from the bus capacitor circuit into AC power that meets the actual working requirements. The short-circuit detection circuit is connected to the three-phase output terminal and is mainly used to detect the current at the output terminal of the inverter when the inverter is powered on, so as to perform short-circuit detection (including non-to-ground short-circuit detection and ground short-circuit detection) on the inverter. The controller is electrically connected to the ground short-circuit detection circuit and is used to perform ground short-circuit processing on the inverter based on the detection results obtained by the ground short-circuit detection circuit.

[0043] In this circuit, the positive terminal of the first bus capacitor C1 is connected to the positive output terminal of the rectifier bridge circuit, and the negative terminal of the first bus capacitor C1 is connected to the positive terminal of the second bus capacitor C2. One end of the first switch PLY1 and one end of the first resistor R1 are connected to the negative input terminal of the rectifier bridge circuit. The other end of the first switch PLY1, the other end of the first resistor R1, one end of the second switch PLY2, and one end of the short-circuit detection circuit to ground are connected to the negative terminal of the second bus capacitor C2. The other end of the second switch PLY2 and the other end of the short-circuit detection circuit to ground are connected to the seventh switch Q7, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6. The emitter of the first switch Q1, the collector of the seventh switch Q7 is connected to the anode of the seventh diode D7, the cathode of the seventh diode D7 is connected to the positive terminal of the first bus capacitor C1, the collectors of the first switch Q1, the second switch Q2 and the third switch Q3 are all connected to the positive terminal of the first bus capacitor C1, the emitter of the first switch Q1 and the collector of the fourth switch Q4 are all connected to the U-phase output terminal of the three-phase output terminal, the emitter of the second switch Q2 and the collector of the fifth switch Q5 are all connected to the V-phase output terminal of the three-phase output terminal, and the emitter of the third switch Q3 and the collector of the sixth switch Q6 are all connected to the W-phase output terminal of the three-phase output terminal.

[0044] To better understand how the embodiments of this application implement ground short-circuit protection for the frequency converter based on the ground short-circuit protection circuit and the ground short-circuit detection circuit, please refer to [link / reference needed]. Figure 2The short circuit to ground in the frequency converter mainly occurs at the three-phase output terminal. For example, if a short circuit to ground occurs at the U-phase output terminal of the three-phase output terminal (i.e., a PE short circuit occurs, Protective Earthing), specifically, if the frequency converter is powered on again after a short circuit to ground, the main short circuit path (current flow) in the frequency converter circuit is usually divided into two paths. The first short circuit path to ground is (corresponding to the positive half-cycle of the input AC current, the black arrow part in the figure): three-phase input terminal → positive output terminal of rectifier bridge circuit → bus capacitor circuit → second switch PLY2 → body diode of fourth switch Q4 → PE terminal (grounded); the second short circuit path to ground is (corresponding to the negative half-cycle of the input AC current, the gray arrow part in the figure): PE terminal → body diode of first switch Q1 → bus capacitor circuit → first resistor R1 → negative input terminal of rectifier bridge circuit → three-phase input terminal. Among them, the first resistor R1 has a relatively large resistance value. Before the inverter is powered on, the first switch PLY1 and the second switch PLY2 are in the open state. If the inverter already has a short circuit to ground, when the inverter is powered on, the current of the first short circuit path to ground is cut off because the second switch PLY2 is in the open state. The related devices of the short circuit path to ground will not be damaged due to the short circuit to ground. In addition, due to the presence of the first resistor R1 (this resistor is set to a large resistance, and the specific resistance value can be determined based on the rated current of the related devices and the rated voltage of the inverter), the current of the second short circuit path to ground is limited to an acceptable current level for the related devices. The related devices of the short circuit path to ground will not be damaged due to the short circuit to ground.

[0045] It is understandable that, apart from the U-phase output terminal of the three-phase output terminal experiencing a short circuit to ground, if the other two phase output terminals of the three-phase output terminal experience a short circuit to ground, this short circuit protection circuit can also provide short circuit protection to the inverter when a short circuit to ground fault occurs.

[0046] In the above circuit setup, the current path to ground short circuit is cut off or limited by the first switch PLY1, the second switch PLY2, and the first resistor R1, which can effectively ensure that the relevant components of the frequency converter are not damaged by short circuit. Furthermore, it introduces few additional circuit components, does not increase the circuit burden of the frequency converter, is easy to implement, simple, and efficient. In addition, the use of a resistor to limit the current in the second short circuit path to ground can facilitate the charging of the bus capacitor by the rectifier bridge circuit, ensuring that the working efficiency of the frequency converter is not affected when ground protection is implemented.

[0047] Furthermore, based on the aforementioned ground short-circuit protection circuit, some embodiments of this application also provide a corresponding ground short-circuit detection circuit. One end of the ground short-circuit detection circuit is connected to one end of the second switch PLY2 of the ground short-circuit protection circuit, and the other end of the ground short-circuit detection circuit is connected to the other end of the second switch PLY2 of the ground short-circuit protection circuit. The ground short-circuit detection circuit can detect the voltage across the second switch PLY2, thereby detecting whether the inverter has a ground short-circuit fault based on the voltage across the second switch PLY2. Specifically, when the inverter is fault-free and the second switch PLY2 is not closed, when the inverter is powered on, there will be a standard voltage value when the voltage across the second switch PLY2 is detected. If the inverter has a short circuit to ground (i.e., grounding in the current path, affecting the voltage across the second switch PLY2), and the second switch PLY2 is not closed, the inverter will detect the voltage across the second switch PLY2 when powered on. This voltage will be abnormal. Therefore, the short circuit to ground detection circuit can determine whether the inverter has a short circuit to ground based on the voltage across the second switch PLY2 and output the corresponding detection result. If the detection result obtained by the short circuit to ground detection circuit is that no short circuit to ground has occurred, the first switch PLY1 and the second switch PLY2 can be closed to enable the inverter to operate normally. If the detection result obtained by the short circuit to ground detection circuit is that a short circuit to ground has occurred, a short circuit to ground fault alarm can be triggered.

[0048] Based on the above-mentioned ground short circuit detection circuit, the voltage characteristics of the second switch PLY2 of the ground short circuit protection circuit can be fully utilized to quickly detect whether the frequency converter has experienced a ground short circuit, thereby outputting the corresponding ground short circuit fault detection result, and performing corresponding operations based on the detection result, thereby ensuring the safe operation of the frequency converter.

[0049] Furthermore, based on the above, it can be understood that in other embodiments of this application, the ground short-circuit protection circuit and the ground short-circuit detection module can also be set in other locations. For example, the first switch PLY1 and the first resistor R1 can be set between the positive output terminal of the rectifier bridge circuit and the first bus capacitor C1, while the second switch PLY2 can be set between the first bus capacitor C1 and the seventh diode D7. Specifically, one end of the first switch PLY1 and one end of the first resistor R1 are connected to the positive output terminal of the rectifier bridge circuit; the other end of the first switch PLY1, the other end of the first resistor R1, one end of the ground short-circuit detection module, and the second... One end of switch PLY2 is connected to the positive terminal of the first bus capacitor C1 in the bus capacitor circuit; the other end of the second switch PLY2 and the other end of the short-circuit detection module to ground are connected to the cathode of the seventh diode D7 (which can be equivalent to connecting to the negative input terminal of the rectifier bridge circuit); the first switch PLY1 and the first resistor R1 are usually placed between the rectifier bridge circuit and the bus capacitor circuit (either on the upper or lower side between them), and the second switch PLY2 can be placed on the same side as the first switch PLY1 and the first resistor R1. Its position can be adjusted according to actual needs to ensure that the circuits of the two short-circuit paths to ground mentioned above are switched or restricted.

[0050] Furthermore, it is understood that the first switch and the second switch mentioned above can be relay switches, thyristor switches, MOSFET switches, or related circuits or devices with switching functions, and no limitation is made here.

[0051] Further, see Figure 3 This application embodiment also provides a short-circuit detection method for a frequency converter, which can be applied to the above-mentioned short-circuit protection circuit of the frequency converter. The short-circuit detection method for the frequency converter includes:

[0052] 301. Before powering on the frequency converter, disconnect the first and second switches of the short-circuit protection circuit to ground;

[0053] Before powering on the frequency converter, disconnecting the first and second switches of the ground short-circuit protection circuit ensures that even if a ground short-circuit fault occurs when the frequency converter is powered on, there will be no large current that could damage the relevant components.

[0054] 302. After the frequency converter is powered on, the control ground short circuit detection circuit detects the voltage across the second switch;

[0055] If the inverter has a short circuit to ground fault after being powered on, the voltage across the second switch will be abnormal. You can determine whether the inverter has a short circuit to ground fault by detecting the voltage across the second switch.

[0056] 303. Based on the voltage across the second switch, determine whether the frequency converter has a short circuit to ground fault;

[0057] Whether the frequency converter has a short circuit to ground fault can be determined by detecting the voltage across the second switch and comparing it with a standard voltage.

[0058] 304. If a short circuit to ground fault occurs in the frequency converter, a short circuit to ground fault alarm will be triggered;

[0059] If the voltage is abnormal and inconsistent with the standard voltage, it indicates that the inverter has a short circuit to ground fault. At this time, a short circuit to ground fault alarm can be triggered, thereby prompting relevant operators to carry out corresponding repairs.

[0060] 305. If the inverter does not experience a short circuit to ground, then activate the first and second switches to allow the inverter to operate normally.

[0061] If the voltage is consistent with the standard voltage, it indicates that the inverter has not experienced a short circuit to ground. The first and second switches are then activated to ensure that the normal current path of the inverter is not switched or restricted, so that the inverter can operate normally.

[0062] The above control method is simple and easy to implement, and can ensure that the inverter will not be damaged by a short circuit to ground when powered on, thus ensuring the safe operation of the inverter.

[0063] In addition, after the inverter is running normally, the short-circuit detection module in this embodiment can detect the current status of each output terminal of the inverter during operation, so as to provide timely short-circuit protection for the inverter when a non-to-ground short circuit or a ground short circuit occurs.

[0064] This application embodiment also provides a frequency converter short-circuit protection device, including: the above-described frequency converter short-circuit protection circuit, at least one processor, and a memory connected to the processor, wherein:

[0065] The processor is electrically connected to the inverter's short-circuit protection circuit, and the memory is used to store the computer program.

[0066] The processor is used to execute computer programs so that the inverter short-circuit protection device can implement the inverter short-circuit detection method described above.

[0067] This application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are run on a frequency converter short-circuit protection device or other electronic device, the frequency converter short-circuit protection device or other electronic device implements the frequency converter short-circuit detection method provided in this application.

[0068] This application also provides a computer-readable storage medium carrying one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement the inverter short-circuit detection method provided in this application.

[0069] It should also be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. In addition, in the device embodiment drawings provided in this application, the connection relationship between modules indicates that they have a communication connection, which can be implemented as one or more communication buses or signal lines.

[0070] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware, or it can be implemented by special-purpose hardware including application-specific integrated circuits, special-purpose CPUs, special-purpose memory, special-purpose components, etc. Generally, any function performed by a computer program can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be diverse, such as analog circuits, digital circuits, or special-purpose circuits. However, for this application, software program implementation is more often the preferred implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium, such as a computer floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk, or optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, training equipment, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0071] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product.

[0072] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, training device, or data center to another website, computer, training device, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

Claims

1. A short-circuit protection circuit for a frequency converter, characterized in that, include: Short circuit to ground protection circuit, short circuit to ground detection circuit, rectifier bridge circuit, bus capacitor circuit and controller; The ground short-circuit protection circuit includes: a first switch, a second switch, and a first resistor; One end of the first switch and one end of the first resistor are connected to one end of the rectifier bridge circuit; the other end of the first switch, the other end of the first resistor, and one end of the second switch are connected to one end of the bus capacitor circuit; the other end of the second switch and the other end of the bus capacitor circuit are connected to the other end of the rectifier bridge circuit. The ground short circuit detection circuit is connected to the second switch of the ground short circuit protection circuit, and is used to detect whether the frequency converter has a ground short circuit fault and obtain the detection result; The controller is electrically connected to the ground short-circuit detection circuit and is used to perform ground short-circuit processing on the frequency converter based on the detection result obtained by the ground short-circuit detection circuit.

2. The inverter short-circuit protection circuit according to claim 1, characterized in that, One end of the ground short circuit detection circuit is connected to one end of the second switch, and the other end of the ground short circuit detection circuit is connected to the other end of the second switch. The ground short circuit detection circuit is used to detect the voltage across the second switch, so as to detect whether the frequency converter has a ground short circuit fault based on the voltage across the second switch.

3. The inverter short-circuit protection circuit according to claim 1, characterized in that, One end of the first switch and one end of the first resistor are connected to the positive output terminal of the rectifier bridge circuit; the other end of the first switch, the other end of the first resistor, and one end of the second switch are connected to the positive terminal of the bus capacitor circuit; the other end of the second switch and the negative terminal of the bus capacitor circuit are connected to the negative input terminal of the rectifier bridge circuit. Alternatively, one end of the first switch and one end of the first resistor are connected together to the negative output terminal of the rectifier bridge circuit; the other end of the first switch, the other end of the first resistor, and one end of the second switch are connected together to the negative terminal of the bus capacitor circuit; the other end of the second switch and the positive terminal of the bus capacitor circuit are connected together to the positive input terminal of the rectifier bridge circuit.

4. The inverter short-circuit protection circuit according to claim 1, characterized in that, The first switch includes: a first relay switch, a first thyristor switch, or a first MOSFET switch; The second switch includes: a second relay switch, a second thyristor switch, or a second MOSFET switch.

5. The inverter short-circuit protection circuit according to claim 1, characterized in that, The controller is connected to the first switch and the second switch of the short-circuit to ground detection circuit, respectively. If the detection result obtained by the short-circuit detection circuit to ground is that no short-circuit fault to ground has occurred, the controller will engage the first switch and the second switch to enable the inverter to operate normally. If the detection result obtained by the short-circuit detection circuit to ground indicates that a short-circuit fault to ground has occurred, the controller will issue a short-circuit fault alarm to ground.

6. The inverter short-circuit protection circuit according to claim 1, characterized in that, It also includes: short-circuit detection circuit; The short-circuit detection circuit is connected to the output terminal of the frequency converter and is used to detect the current at the output terminal of the frequency converter when the frequency converter is powered on, so as to perform short-circuit detection on the frequency converter.

7. A method for detecting short circuits in a frequency converter, characterized in that, A controller applied to the inverter short-circuit protection circuit as described in any one of claims 1 to 6; The inverter short-circuit detection method includes: Before powering on the frequency converter, disconnect the first switch and the second switch of the short-circuit protection circuit to ground; After the inverter is powered on, the ground short-circuit detection circuit is controlled to detect the voltage across the second switch; Based on the voltage across the second switch, determine whether the inverter has experienced a short circuit to ground. If the inverter experiences a short-circuit fault to ground, a short-circuit fault alarm will be triggered. If the inverter does not experience the ground short-circuit fault, then the first switch and the second switch are engaged to allow the inverter to operate normally.

8. A short-circuit protection device for a frequency converter, characterized in that, include: At least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is used to execute the computer program so that the inverter short-circuit protection device can implement the inverter short-circuit detection method as described in claim 7.

9. A computer program product, characterized in that, include: A computer-readable instruction, when executed on an electronic device, causes the electronic device to implement the inverter short-circuit detection method as described in claim 7.

10. A computer storage medium, characterized in that, The storage medium carries one or more computer programs, which, when executed by an electronic device, enable the electronic device to implement the inverter short-circuit detection method as described in claim 7.

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