IGBT pass-through testing methods, devices, frequency converters, and storage media
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SUZHOU INOVANCE CONTROL TECH CO LTD
- Filing Date
- 2022-06-01
- Publication Date
- 2026-06-30
Smart Images
Figure CN114994490B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of frequency converter fault detection technology, and in particular to an IGBT shoot-through detection method, device, frequency converter, and storage medium. Background Technology
[0002] A frequency converter is a power control device that uses frequency conversion technology and microelectronics to control a motor by changing the frequency of the power supply. It has a wide range of applications in industrial control. An IGBT (Insulated Gate Bipolar Transistor) is a key component of a frequency converter.
[0003] In related technologies, IGBT shoot-through faults in frequency converters are typically detected by equipping the IGBTs with VCE (voltage between the collector and emitter) detection devices and combining this with a control unit within the frequency converter that has a preset program. However, current low-power frequency converters generally do not equip their IGBTs with VCE detection devices. Therefore, relying solely on the preset program in the control unit is insufficient to detect IGBT shoot-through faults. Consequently, existing frequency converters without VCE detection suffer from the problem of being unable to detect IGBT shoot-through faults. Summary of the Invention
[0004] The main objective of this invention is to provide an IGBT shoot-through detection method, device, frequency converter, and storage medium, aiming to solve the technical problem that frequency converters without VCE detection cannot detect IGBT shoot-through faults in the prior art.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] In a first aspect, the present invention provides an IGBT shoot-through detection method for detecting a full-bridge inverter unit, the inverter unit including a first phase, wherein the first phase is any phase of the inverter unit; the method includes:
[0007] Obtain the first bus voltage of the inverter unit;
[0008] Control the first bridge arm IGBT of the first phase to conduct for a first preset time to obtain the second bus voltage of the inverter unit, wherein the first bridge arm IGBT is an upper bridge arm IGBT or a lower bridge arm IGBT.
[0009] The bus voltage drop is obtained based on the first bus voltage and the second bus voltage;
[0010] Based on the bus voltage drop, the shoot-through detection result of the second bridge arm IGBT of the first phase is obtained. When the first bridge arm IGBT is the upper bridge arm IGBT, the second bridge arm IGBT is the lower bridge arm IGBT, and when the first bridge arm IGBT is the lower bridge arm IGBT, the second bridge arm IGBT is the upper bridge arm IGBT.
[0011] Optionally, in the above IGBT pass-through detection method, the first preset duration is 5 to 15 µs;
[0012] The steps for controlling the first arm IGBT of the first phase to conduct for a first preset duration include:
[0013] Generate driving pulse width signal;
[0014] The drive pulse width signal is sent to the gate of the first bridge arm IGBT of the first phase to control the first bridge arm IGBT of the first phase to be turned on.
[0015] When the first IGBT of the first phase is turned on for a first preset duration, the transmission of the drive pulse width signal is stopped.
[0016] Optionally, in the above IGBT shoot-through detection method, the step of obtaining the shoot-through detection result of the second arm IGBT of the first phase based on the bus voltage drop includes:
[0017] Determine whether the bus voltage drop exceeds a preset threshold;
[0018] If the bus voltage drops below a preset threshold, it is determined that the second bridge arm IGBT of the first phase has an IGBT shoot-through fault.
[0019] If the bus voltage drop does not exceed the preset threshold, it is determined that there is no IGBT shoot-through fault in the second bridge arm IGBT of the first phase.
[0020] Optionally, in the above IGBT shoot-through detection method, after the step of obtaining the shoot-through detection result of the second bridge arm IGBT of the first phase based on the bus voltage drop, the method further includes:
[0021] If the shoot-through detection result of the second bridge arm IGBT is that there is no IGBT shoot-through fault, then the third bus voltage of the inverter unit and the fourth bus voltage of the inverter unit when the second bridge arm IGBT is turned on for a second preset time are obtained to obtain the shoot-through detection result of the first bridge arm IGBT.
[0022] Optionally, in the above IGBT shoot-through detection method, the inverter unit further includes a second phase, which is any phase other than the first phase in the inverter unit;
[0023] After obtaining the shoot-through test result of the first bridge arm IGBT, the method further includes:
[0024] When the shoot-through detection result of the first bridge arm IGBT is that there is no IGBT shoot-through fault, the fifth bus voltage of the inverter unit and the sixth bus voltage of the inverter unit when the third bridge arm IGBT of the second phase is turned on for a third preset time are obtained.
[0025] Based on the voltage of the fifth bus and the voltage of the sixth bus, the shoot-through test result of the fourth arm IGBT of the second phase is obtained;
[0026] If the shoot-through test result of the fourth bridge arm IGBT is that there is no IGBT shoot-through fault, then the seventh bus voltage of the inverter unit and the eighth bus voltage of the inverter unit when the fourth bridge arm IGBT is turned on for a fourth preset time are obtained to obtain the shoot-through test result of the third bridge arm IGBT.
[0027] Optionally, in the above IGBT direct-through detection method, the inverter unit further includes a third phase, which is any phase other than the first phase in the inverter unit;
[0028] After obtaining the shoot-through test result of the first bridge arm IGBT, the method further includes:
[0029] When the shoot-through detection result of the first bridge arm IGBT is that there is no IGBT shoot-through fault, obtain the VCE voltage of any bridge arm IGBT in the third phase.
[0030] Based on the VCE voltage, the shoot-through detection result of any IGBT in the third phase is obtained.
[0031] Optionally, in the above IGBT shoot-through detection method, the step of obtaining the first bus voltage of the inverter unit includes:
[0032] When the inverter unit is detected to be powered on, in standby mode, or in fault condition, the first bus voltage of the inverter unit is obtained.
[0033] Secondly, the present invention provides an IGBT pass-through detection device for detecting a full-bridge inverter unit, the inverter unit including a first phase, wherein the first phase is any phase of the inverter unit; the device includes:
[0034] The voltage sampling module is used to obtain the first bus voltage and the second bus voltage of the inverter unit. The second bus voltage is the bus voltage of the inverter unit when the first bridge arm IGBT of the first phase is turned on for a first preset time. The first bridge arm IGBT is either the upper bridge arm IGBT or the lower bridge arm IGBT.
[0035] The IGBT driver module is used to drive the first bridge arm IGBT to turn on and off.
[0036] The logic judgment module is a control chip, including any one of a digital signal processor, microcontroller, field-programmable gate array, or complex programmable logic device. It is used to obtain the shoot-through detection result of the second bridge arm IGBT of the first phase based on the voltage drop of the first bus voltage and the second bus voltage. When the first bridge arm IGBT is the upper bridge arm IGBT, the second bridge arm IGBT is the lower bridge arm IGBT, and when the first bridge arm IGBT is the lower bridge arm IGBT, the second bridge arm IGBT is the upper bridge arm IGBT.
[0037] Thirdly, the present invention provides a frequency converter, the frequency converter comprising:
[0038] Inverter unit, the inverter unit is a full-bridge inverter unit;
[0039] The control unit, connected to the inverter unit, is used to implement the IGBT shoot-through detection method described above.
[0040] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by one or more processors, implements the IGBT pass-through detection method as described above.
[0041] The above-described one or more technical solutions provided by this invention can have the following advantages or at least achieve the following technical effects:
[0042] This invention proposes an IGBT shoot-through detection method, device, inverter, and storage medium. By controlling the first arm IGBT of any phase in the inverter unit to conduct for a first preset duration, the bus voltage before and after the IGBT's conduction is acquired sequentially. The bus voltage drop is calculated, and the shoot-through detection result of the second arm IGBT of the same phase is obtained based on this voltage drop. This achieves the goal of detecting IGBT shoot-through faults without VCE detection. This method is particularly suitable for inverters without VCE detection, enabling rapid detection of shoot-through faults in each IGBT of the inverter unit at low cost, avoiding faults such as bus short circuits caused by IGBT shoot-through, and even safety accidents such as unit explosions. This invention can also be combined with existing methods for detecting IGBT shoot-through faults using VCE to achieve even faster detection of shoot-through faults in all IGBTs of the inverter. Attached Figure Description
[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0044] Figure 1 This is a flowchart illustrating the first embodiment of the IGBT pass-through detection method of the present invention;
[0045] Figure 2 This is a connection block diagram of the frequency converter involved in the present invention;
[0046] Figure 3 for Figure 2 A schematic diagram of the circuit principle of a frequency converter;
[0047] Figure 4 for Figure 2 A schematic diagram of the hardware structure of the control unit;
[0048] Figure 5 This is a schematic flowchart of the first embodiment of the IGBT pass-through detection method of the present invention;
[0049] Figure 6 This is a flowchart illustrating the second embodiment of the IGBT pass-through detection method of the present invention;
[0050] Figure 7 This is a flowchart illustrating the third embodiment of the IGBT pass-through detection method of the present invention;
[0051] Figure 8 This is a functional module diagram of the first embodiment of the IGBT pass-through detection device of the present invention.
[0052] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0054] It should be noted that in this invention, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element. Furthermore, in this invention, unless otherwise expressly specified and limited, the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two elements or an interaction between two elements.
[0055] In this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. In this invention, the use of suffixes such as "module," "component," or "unit" to denote elements is solely for illustrative purposes and has no specific meaning in itself. Therefore, "module," "component," or "unit" may be used interchangeably.
[0056] For those skilled in the art, the specific meanings of the above terms in this invention can be understood according to the specific circumstances. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis that those skilled in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.
[0057] A frequency converter is a power control device that uses frequency conversion technology and microelectronics to control a motor by changing the frequency of the power supply. It has a wide range of applications in industrial control. A frequency converter mainly consists of a rectifier unit, a filter unit, an inverter unit, a control unit, and a drive unit. The inverter unit adjusts the output voltage and frequency by switching the IGBTs (Insulated Gate Bipolar Transistors) on and off, providing the motor with the required power supply voltage, thereby achieving energy saving and speed regulation. Therefore, the IGBT is a key component of the frequency converter.
[0058] Analysis of relevant technologies reveals that IGBT shoot-through faults in frequency converters are typically detected by equipping the IGBTs with VCE (voltage between the collector and emitter) detection devices and combining this with a control unit within the frequency converter that has a preset program. However, due to cost considerations, current low-power frequency converters generally do not equip their IGBTs with VCE detection devices. Therefore, IGBT shoot-through faults cannot be detected solely through the preset program in the control unit. Moreover, there are currently no frequency converters on the market that can perform IGBT shoot-through detection solely through the program in the control unit without VCE detection.
[0059] In view of the technical problem that existing frequency converters without VCE detection cannot detect IGBT shoot-through faults, this invention provides an IGBT shoot-through detection method, the overall idea of which is as follows:
[0060] Obtain the first bus voltage of the inverter unit; control the first bridge arm IGBT of the first phase to conduct for a first preset time, and obtain the second bus voltage of the inverter unit, wherein the first bridge arm IGBT is either the upper bridge arm IGBT or the lower bridge arm IGBT, and the first phase is any phase of the inverter unit; obtain the bus voltage drop based on the first bus voltage and the second bus voltage; obtain the shoot-through detection result of the second bridge arm IGBT of the first phase based on the bus voltage drop, wherein when the first bridge arm IGBT is the upper bridge arm IGBT, the second bridge arm IGBT is the lower bridge arm IGBT, and when the first bridge arm IGBT is the lower bridge arm IGBT, the second bridge arm IGBT is the upper bridge arm IGBT.
[0061] The above technical solution achieves the goal of detecting IGBT shoot-through faults without requiring VCE detection. This method is particularly suitable for frequency converters without VCE detection, enabling rapid and cost-effective detection of shoot-through faults in each IGBT of the inverter unit, thus preventing bus short circuits and even safety accidents such as generator failures caused by IGBT shoot-through. This invention can also be combined with existing methods for configuring VCE detection for IGBT shoot-through to achieve even faster detection of shoot-through faults in all IGBTs of the frequency converter.
[0062] The IGBT pass-through detection method, device, inverter, and storage medium provided by the present invention will be described in detail below with reference to the accompanying drawings and through specific embodiments and implementation methods.
[0063] Example 1
[0064] Reference Figure 1 The flowchart illustrates the first embodiment of the IGBT shoot-through detection method of the present invention. The IGBT shoot-through detection method is applied to a frequency converter 100, which is used to perform frequency conversion control on a load 200, which may be a motor device.
[0065] like Figure 2 The diagram shown is a connection block diagram of a frequency converter 100, which includes:
[0066] Inverter unit 110, which is a full-bridge inverter unit;
[0067] The control unit 120 is connected to the inverter unit 110 and is used to implement the IGBT shoot-through detection method.
[0068] This IGBT shoot-through detection method is used to detect whether there is a shoot-through fault in the IGBTs of the full-bridge inverter unit.
[0069] The full-bridge inverter unit can be either a three-phase full-bridge inverter unit or a single-phase full-bridge inverter unit. This embodiment uses a three-phase full-bridge inverter unit for illustration.
[0070] like Figure 3 The diagram shown is a schematic diagram of the circuit principle of the inverter unit 110 in this embodiment; the inverter unit 110 may include: a detection circuit and a drive circuit;
[0071] The detection circuit is connected to the positive and negative terminals of the bus of the inverter unit 110. It can detect the bus voltage by detecting a resistor or by detecting a voltage sensor. The detection circuit is also connected to the control unit 120 to send the detected bus voltage to the control unit 120 in real time.
[0072] The drive circuit includes six IGBTs, designated as VT1, VT2, VT3, VT4, VT5, and VT6. VT1, VT3, and VT5 are the upper arm IGBTs for phase U, phase V, and phase W, respectively. VT2, VT4, and VT6 are the lower arm IGBTs for phase U, phase V, and phase W, respectively. The gates of T6 are all connected to the control unit 120. The drains of VT1, VT3 and VT5 are all connected to the positive terminal of the bus. The source of VT1 is connected to the drain of VT2, the source of VT3 is connected to the drain of VT4, the source of VT5 is connected to the drain of VT6, and the sources of VT2, VT4 and VT6 are all connected to the negative terminal of the bus. The common connection point of the source of VT1 and the drain of VT2, the common connection point of the source of VT3 and the drain of VT4, and the common connection point of the source of VT5 and the drain of VT6 are respectively connected to the load 200.
[0073] The control unit 120 refers to a terminal device or control device that can achieve communication connection. It can be a terminal device such as an embedded industrial control computer, or a control device for on-site control or remote control.
[0074] like Figure 4 The diagram shown is a hardware structure diagram of the control unit 120 in this embodiment; the control unit 120 may include: a processor 1201, such as a CPU (Central Processing Unit), a communication bus 1202, a user interface 1203, a communication interface 1204, and a memory 1205.
[0075] Those skilled in the art will understand that Figure 2 , Figure 3 and Figure 4 The structure shown does not constitute a limitation on the inverter 100 of the present invention, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.
[0076] Specifically, the communication bus 1202 is used to realize the connection and communication between these components; the user interface 1203 is used to connect to the client and communicate data with the client. The user interface 1203 may include output units, such as a display screen, and input units, such as a keyboard; the communication interface 1204 is used to connect to the control panel and communicate data with the control panel. The communication interface 1204 may include input / output interfaces, such as standard wired interfaces and wireless interfaces; the memory 1205 is used to store various types of data. This data may include, for example, instructions of any application or method in the control unit 120, as well as application-related data. The memory 1205 may be a high-speed RAM memory or a stable memory, such as a disk storage device. Optionally, the memory 1205 may also be a storage device independent of the processor 1201.
[0077] For details, please refer to... Figure 4 The memory 1205 may include an operating system, a data communication module, a user interface module, and an IGBT pass-through detection program. The data communication module is mainly used to connect to the inverter unit 110 and communicate with the inverter unit 110.
[0078] The processor 1201 is used to call the IGBT pass-through detection program stored in the memory 1205 and perform the following operations:
[0079] Obtain the first bus voltage of inverter unit 110;
[0080] Control the first bridge arm IGBT of the first phase to conduct for a first preset time to obtain the second bus voltage of the inverter unit 110, wherein the first bridge arm IGBT is an upper bridge arm IGBT or a lower bridge arm IGBT.
[0081] The bus voltage drop is obtained based on the first bus voltage and the second bus voltage;
[0082] Based on the bus voltage drop, the shoot-through detection result of the second bridge arm IGBT of the first phase is obtained. When the first bridge arm IGBT is the upper bridge arm IGBT, the second bridge arm IGBT is the lower bridge arm IGBT, and when the first bridge arm IGBT is the lower bridge arm IGBT, the second bridge arm IGBT is the upper bridge arm IGBT.
[0083] Based on the aforementioned frequency converter 100, the following is combined with... Figure 1 The flowchart shown illustrates the IGBT shoot-through detection method of this embodiment in detail. This method can be used to detect shoot-through faults in single-phase or three-phase full-bridge inverter units. Using any phase in the inverter unit as the first phase, this method can detect shoot-through faults in IGBTs on any phase of the inverter unit.
[0084] In this embodiment, it is used to detect such as Figure 3 The full-bridge inverter unit shown includes three phases: U-phase, V-phase, and W-phase. The method may include the following steps:
[0085] Step S10: Obtain the first bus voltage of the inverter unit.
[0086] Specifically, the first bus voltage is the bus voltage that needs to be detected before the first bridge arm IGBT on any phase is turned on when performing a shoot-through detection on any bridge arm IGBT on any phase in the inverter unit. Specifically, it can be detected by a detection resistor or a voltage sensor. The detected first bus voltage is transmitted to the control unit in real time. Correspondingly, the control unit obtains the first bus voltage of the inverter unit.
[0087] In a specific implementation, step S10 may include:
[0088] Step S11: When the inverter unit is detected to be powered on, ready to run, or has a fault, the first bus voltage of the inverter unit is obtained.
[0089] Specifically, the IGBT shoot-through detection method for detecting IGBT shoot-through faults on the inverter unit can be as follows: it can start automatically when the inverter is powered on and the corresponding inverter unit is powered on; it can also start automatically when other devices have started working after the inverter is powered on and are about to control the inverter unit to start working, i.e., when the inverter unit is waiting to start running; or it can start automatically when the control unit detects other fault conditions in the inverter unit during the control operation of the inverter unit, depending on the user selection.
[0090] This enables automatic detection of different stages of the inverter unit, which can be achieved in practical applications by configuring the function codes of the control unit.
[0091] like Figure 5 The diagram shown is a detailed flowchart of this embodiment, based on... Figure 3 The inverter unit shown uses six IGBTs to control the motor. If one of these IGBTs fails to shut down due to shoot-through, turning on another IGBT in the same phase as the faulty IGBT will cause both the upper and lower IGBTs of that phase to conduct, resulting in a short circuit between the positive and negative buses. This can easily lead to a huge energy release, causing the inverter to explode and potentially severely impacting the site, even rendering the entire unit unusable and irreparable. Therefore, in this embodiment, before operating the inverter unit, a shoot-through test is performed on each IGBT using the method described in this embodiment.
[0092] In this embodiment, as Figure 5 As shown, assuming that the lower IGBT of phase U, i.e. VT2, is first detected for fault, the inverter unit first detects the first bus voltage and sends the first bus voltage to the control unit, and the control unit obtains the first bus voltage of the inverter unit.
[0093] Step S20: Control the first bridge arm IGBT of the first phase to conduct for a first preset time to obtain the second bus voltage of the inverter unit, wherein the first bridge arm IGBT is an upper bridge arm IGBT or a lower bridge arm IGBT.
[0094] Specifically, the first preset duration can be 5 to 15 microseconds;
[0095] Since it is unclear at this time whether the second arm IGBT of the first phase has a shoot-through fault, the preset duration should not be too long, generally in microseconds (µs). This way, even if the second arm IGBT of the first phase has a shoot-through fault, the short-circuit time of the inverter unit is very short. According to the IGBT datasheet, a short shoot-through of 10µs will not damage the IGBT.
[0096] The first IGBT can be either the upper or lower IGBT of the first phase. When shoot-through detection is required for the upper IGBT of the first phase, the lower IGBT of the first phase is controlled to conduct. Conversely, when shoot-through detection is required for the lower IGBT of the first phase, the upper IGBT of the first phase is controlled to conduct. In practice, each phase of the inverter unit can be tested sequentially, so any IGBT on any phase can be selected for initial control.
[0097] The second bus voltage is the bus voltage detected after the first bridge arm IGBT of the first phase is turned on. Specifically, it is also detected by a detection resistor or voltage sensor. The detected second bus voltage is transmitted to the control unit in real time. Correspondingly, the control unit obtains the second bus voltage of the inverter unit.
[0098] like Figure 5 The diagram shown is a detailed flowchart of this embodiment, based on... Figure 3 The inverter unit shown assumes that the lower bridge arm IGBT VT2 of phase U is first detected for fault. Correspondingly, after the control unit obtains the first bus voltage, it controls the upper bridge arm IGBT VT1 of phase U to be turned on for 10us and obtains the second bus voltage at this time.
[0099] Specifically, step S20 may include:
[0100] Step S21: Generate the driving pulse width signal;
[0101] Step S22: Send the drive pulse width signal to the gate of the first bridge arm IGBT of the first phase to control the first bridge arm IGBT of the first phase to turn on.
[0102] Step S23: When the first bridge arm IGBT of the first phase is turned on for a first preset time, stop sending the drive pulse width signal;
[0103] Step S24: Obtain the second bus voltage of the inverter unit.
[0104] In the specific implementation process, the control unit generates a drive pulse width signal and sends it to the gate of the first bridge arm IGBT of the first phase, controlling the first bridge arm IGBT of the first phase to turn on. After the IGBT remains on for a first preset time, the control unit stops sending the drive pulse width signal to the inverter unit and detects the current bus voltage (i.e., the second bus voltage) through a detection resistor or voltage sensor in the inverter unit. The inverter unit then sends this second bus voltage to the control unit, and the control unit accordingly acquires the second bus voltage of the inverter unit. The drive pulse width signal can be a test signal with different pulse widths.
[0105] In this embodiment, as Figure 5 As shown, the control unit controls VT1 to be turned on for 10us. Specifically, the control unit generates a drive pulse width signal. VT1 is normally in the off state. The control unit sends the drive pulse width signal to the gate of VT1, and VT1 is turned on. When the on-time reaches 10us, the control unit stops sending the drive pulse width signal, and VT1 is turned off. At this time, the bus voltage of the inverter unit is detected, that is, the second bus voltage is detected, and the second bus voltage is sent to the control unit. The control unit obtains the second bus voltage of the inverter unit.
[0106] Step S30: Obtain the bus voltage drop based on the first bus voltage and the second bus voltage.
[0107] Specifically, the bus voltage sag can be calculated based on the first bus voltage and the second bus voltage, or it can be calculated based on the effective values of the first and second bus voltages. Alternatively, the bus voltage sag can be obtained by calculating either the difference between the first and second bus voltages or by calculating the percentage of that difference.
[0108] In this embodiment, as Figure 5 As shown, the control unit obtains the first bus voltage and controls VT1 to conduct for 10us. After obtaining the second bus voltage, it calculates the bus voltage drop based on the obtained first and second bus voltages, and then proceeds to the next step.
[0109] Step S40: Based on the bus voltage drop, obtain the shoot-through detection result of the second bridge arm IGBT of the first phase. Wherein, when the first bridge arm IGBT is the upper bridge arm IGBT, the second bridge arm IGBT is the lower bridge arm IGBT, and when the first bridge arm IGBT is the lower bridge arm IGBT, the second bridge arm IGBT is the upper bridge arm IGBT.
[0110] Specifically, when the first bridge arm IGBT of the aforementioned first phase is the upper bridge arm IGBT, the result obtained here is the shoot-through test result of the lower bridge arm IGBT of the first phase; when the first bridge arm IGBT of the aforementioned first phase is the lower bridge arm IGBT, the result obtained here is the shoot-through test result of the upper bridge arm IGBT of the first phase.
[0111] Specifically, step S40 may include:
[0112] Step S41: Determine whether the bus voltage drop exceeds the preset threshold.
[0113] In the specific implementation process, based on the bus voltage drop value obtained in step S30 and the preset threshold value stored in the control unit, it is determined whether there is a shoot-through fault in the second bridge arm IGBT of the first phase, thereby realizing shoot-through detection, specifically determining whether the bus voltage drop value exceeds the preset threshold value.
[0114] Step S42: If the bus voltage drops below a preset threshold, it is determined that the second bridge arm IGBT of the first phase has an IGBT shoot-through fault.
[0115] In the specific implementation process, if the bus voltage drop value obtained in step S30 exceeds the preset threshold, it is determined that the second bridge arm IGBT of the first phase has a shoot-through fault, and the shoot-through detection result of the second bridge arm IGBT of the first phase is that there is an IGBT shoot-through fault. Correspondingly, the control unit can also provide fault prompts, or retrieve and display the corresponding solution based on the pre-stored fault solutions.
[0116] Step S43: If the bus voltage drop does not exceed the preset threshold, it is determined that there is no IGBT shoot-through fault in the second bridge arm IGBT of the first phase.
[0117] In the specific implementation process, if the bus voltage drop value obtained in step S30 does not exceed the preset threshold, it is determined that the second bridge arm IGBT of the first phase does not have a shoot-through fault, and the shoot-through detection result of the second bridge arm IGBT of the first phase is that there is no IGBT shoot-through fault. Correspondingly, the control unit can continue to detect other bridge arm IGBTs. For example, it can perform fault detection on the first bridge arm IGBT of the first phase. Specifically, it can control the second bridge arm IGBT of the first phase to be turned on for a first preset time, and continue to calculate the bus voltage drop based on the bus voltage of the inverter unit before and after the turn-on, thereby obtaining the shoot-through detection result of the first bridge arm IGBT of the first phase. Of course, the shoot-through detection result of no IGBT shoot-through fault can also be displayed, so that users can know the current detection process in a timely manner and know the detection results of each IGBT in the inverter unit in a timely manner.
[0118] Specifically, after step S42, the method may also include:
[0119] Step S44: If there is an IGBT shoot-through fault in the second bridge arm IGBT of the first phase, issue a fault prompt or alarm reminder.
[0120] In practice, when the shoot-through detection result of the second arm IGBT of the first phase indicates that there is an IGBT shoot-through fault, the control unit can generate an alarm control signal and send it to the alarm unit or external alarm connected to the control unit to provide fault indication or alarm reminder.
[0121] Specifically, after step S40, the method may also include:
[0122] Step S50: If the shoot-through detection result of the second bridge arm IGBT is that there is no IGBT shoot-through fault, then obtain the third bus voltage of the inverter unit and the fourth bus voltage of the inverter unit when the second bridge arm IGBT is turned on for a second preset time, so as to obtain the shoot-through detection result of the first bridge arm IGBT.
[0123] In the specific implementation process, if a short-time conduction control is performed on the first bridge arm IGBT of a certain phase to obtain the shoot-through detection result of the second bridge arm IGBT on that phase, and the shoot-through detection result is that there is no IGBT shoot-through fault, then a short-time conduction control can be performed on the second bridge arm IGBT of that phase to obtain the aforementioned shoot-through detection result of the first bridge arm IGBT.
[0124] In this embodiment, as Figure 5 As shown, after the control unit calculates the bus voltage drop, it compares the bus voltage drop with a preset threshold to obtain the shoot-through detection result of the lower bridge arm IGBT VT2 of phase U. Specifically, it determines whether the bus voltage drop exceeds the preset threshold. If so, it determines that VT2 has an IGBT shoot-through fault and issues a fault warning. If not, it determines that VT2 does not have an IGBT shoot-through fault, and it can continue to detect the fault of the upper bridge arm IGBT VT1 of phase U. The specific process is similar to the process of detecting VT2. First, the third bus voltage is detected, then VT2 is controlled to conduct for 10us, the fourth bus voltage is detected, and then the bus voltage drop of the third bus voltage and the fourth bus voltage is calculated. It determines whether the bus voltage drop exceeds the preset threshold. If so, it determines that VT1 has an IGBT shoot-through fault and issues a fault warning. If not, it determines that VT1 does not have an IGBT shoot-through fault.
[0125] Specifically, the first preset duration and the second preset duration can be the same, or different durations can be set according to actual needs. For example, control VT1 to conduct for 10us and control VT2 to conduct for 9us. However, the unit of the preset duration is us. That is, the first bridge arm IGBT cannot be conducted for too long. Otherwise, the second bridge arm IGBT may have a shoot-through fault, which may lead to a short circuit on the bus or even a safety accident such as a machine explosion.
[0126] Most IGBT shoot-through faults are caused by abnormal drive optocouplers or drive circuit failures. If this method is used to inspect all IGBTs in the inverter unit of the frequency converter before production or use, IGBT shoot-through faults can be detected in time, and the staff can be notified to perform further tests or repairs on the drive circuit in a timely manner. This can prevent other accidents such as machine explosion or even scrapping of the entire machine due to IGBT shoot-through faults. This method can also be used for frequency converter quality inspection, effectively improving the yield rate of frequency converter production lines.
[0127] The IGBT shoot-through detection method provided in this embodiment controls the first arm IGBT of any phase of the inverter unit to conduct for a first preset duration, sequentially acquiring the bus voltage before and after the IGBT's conduction, calculating the bus voltage drop, and then obtaining the shoot-through detection result of the second arm IGBT of the same phase based on the bus voltage drop. This achieves the goal of detecting IGBT shoot-through faults without VCE detection, meaning that IGBT shoot-through detection can be implemented solely through software methods in the absence of VCE protection. This method is particularly suitable for inverters without VCE detection, such as some low-power, low-cost inverters, enabling rapid detection of shoot-through faults in each IGBT of the inverter unit in a low-cost manner, avoiding faults such as bus short circuits caused by IGBT shoot-through, and even safety accidents such as unit explosions. This invention can also be combined with existing methods for configuring VCE detection for IGBT shoot-through to achieve even faster detection of shoot-through faults in all IGBTs of the inverter.
[0128] Example 2
[0129] Based on the same inventive concept, referring to Figure 6 Based on the first embodiment, a second embodiment of the IGBT shoot-through detection method of the present invention is proposed. This IGBT shoot-through detection method is also applied to the detection of full-bridge inverter units.
[0130] Furthermore, the inverter unit also includes a second phase, which is any other phase in the inverter unit besides the first phase.
[0131] The following is combined Figure 6 The flowchart shown illustrates the IGBT pass-through detection method of this embodiment in detail. In one embodiment, after step 50, the method may further include:
[0132] Step S60: When the shoot-through detection result of the first bridge arm IGBT is that there is no IGBT shoot-through fault, obtain the fifth bus voltage of the inverter unit and the sixth bus voltage of the inverter unit when the third bridge arm IGBT of the second phase is turned on for a third preset time.
[0133] Specifically, the third preset duration can be different from or the same as the aforementioned first and second preset durations. The fifth bus voltage is the bus voltage of the inverter unit before the third bridge arm IGBT of the second phase is turned on, and the sixth bus voltage is the bus voltage of the inverter unit after the third bridge arm IGBT of the second phase is turned on.
[0134] In the specific implementation process, after the control unit obtains the shoot-through detection result of the first bridge arm IGBT and finds that there is no IGBT shoot-through fault, it continues to acquire the bus voltage of the inverter unit, namely the fifth bus voltage; then, it generates a drive pulse width signal and sends the drive pulse width signal to the gate of the third bridge arm IGBT of the second phase to control the third bridge arm IGBT of the second phase to turn on. When the third bridge arm IGBT of the second phase has been turned on for a third preset time, it stops sending the drive pulse width signal and acquires the bus voltage of the inverter unit, namely the sixth bus voltage.
[0135] Step S70: Based on the fifth bus voltage and the sixth bus voltage, obtain the shoot-through test result of the fourth bridge arm IGBT of the second phase.
[0136] Specifically, the fourth IGBT of the second phase can be in a corresponding position to the second IGBT of the first phase, or they can be in different positions. For example, when the second IGBT is the upper arm of the first phase, the fourth IGBT can be the lower arm of the second phase.
[0137] In the specific implementation process, after the control unit obtains the voltage of the fifth bus and the voltage of the sixth bus, it calculates the bus voltage drop based on the obtained voltage of the fifth bus and the sixth bus, and then determines whether the bus voltage drop exceeds the preset threshold. If it exceeds the preset threshold, it is determined that there is an IGBT shoot-through fault in the fourth bridge arm IGBT of the second phase. If it does not exceed the preset threshold, it is determined that there is no IGBT shoot-through fault in the fourth bridge arm IGBT of the second phase, and the next step is continued.
[0138] Step S80: If the shoot-through detection result of the fourth bridge arm IGBT is that there is no IGBT shoot-through fault, then obtain the seventh bus voltage of the inverter unit and the eighth bus voltage of the inverter unit when the fourth bridge arm IGBT is turned on for a fourth preset time, so as to obtain the shoot-through detection result of the third bridge arm IGBT.
[0139] Specifically, the fourth preset duration can be different from or the same as the aforementioned preset duration. The seventh bus voltage is the bus voltage of the inverter unit before the fourth bridge arm IGBT of the second phase is turned on, and the eighth bus voltage is the bus voltage of the inverter unit after the fourth bridge arm IGBT of the second phase is turned on.
[0140] In the specific implementation process, after the control unit obtains the shoot-through detection result of the fourth bridge arm IGBT and finds that there is no IGBT shoot-through fault, it continues to acquire the bus voltage of the inverter unit, i.e., the seventh bus voltage. Then, it generates a drive pulse width signal and sends the drive pulse width signal to the gate of the fourth bridge arm IGBT of the second phase to control the fourth bridge arm IGBT of the second phase to turn on. When the fourth bridge arm IGBT of the second phase has been turned on for a fourth preset time, it stops sending the drive pulse width signal and acquires the bus voltage of the inverter unit, i.e., the eighth bus voltage. Then, it calculates the bus voltage drop based on the obtained seventh bus voltage and eighth bus voltage, and then determines whether the bus voltage drop exceeds a preset threshold. If it exceeds the preset threshold, it is determined that the third bridge arm IGBT of the second phase has an IGBT shoot-through fault. If it does not exceed the preset threshold, it is determined that the third bridge arm IGBT of the second phase does not have an IGBT shoot-through fault.
[0141] Specifically Figure 5 In this embodiment, after determining that VT1 does not have an IGBT shoot-through fault, fault detection can continue to be performed on the lower arm IGBT of phase V, namely VT4. Specifically, VT3 is controlled to conduct for 10µs, the bus voltage of the inverter unit before and after VT3 conduction is detected, and the bus voltage drop is calculated to obtain the shoot-through detection result of VT4. If VT4 does not have an IGBT shoot-through fault, fault detection can continue to be performed on the upper arm IGBT of phase V, namely VT3, the lower arm IGBT of phase W, namely VT6, and the upper arm IGBT of phase W, namely VT5. This completes the shoot-through fault detection for all phases or all IGBTs in the inverter unit.
[0142] For more details on the specific implementation of the above method steps, please refer to the description of the specific implementation in Example 1. For the sake of brevity, these details will not be repeated here.
[0143] The IGBT shoot-through detection method provided in this embodiment, based on the fact that the shoot-through detection results of the two bridge arm IGBTs of the first phase show no IGBT shoot-through faults, can continue to control the conduction of the bridge arm IGBTs of other phases to obtain the shoot-through detection results of the IGBTs of other phases on the inverter unit, thus achieving the effect of inspecting all IGBT devices.
[0144] In another embodiment, after step S40, the method may further include:
[0145] Step A1: Obtain the ninth bus voltage and the tenth bus voltage of the inverter unit. The ninth bus voltage is obtained based on the fifth preset duration of the control of the first bridge arm IGBT of the first phase to conduct. The fifth preset duration is longer than the first preset duration.
[0146] Specifically, after step S40, if the shoot-through detection result of the second arm IGBT of the first phase is that there is no IGBT shoot-through fault, the conduction control of the first arm IGBT of the first phase can continue to be performed to obtain the shoot-through detection results of the second arm IGBTs of other phases. That is to say, based on... Figure 5 For example, if it is determined that there is no IGBT shoot-through fault in VT2, the conduction control of VT1 can continue to be performed to obtain the shoot-through detection results of VT4 and VT6.
[0147] The fifth preset duration is longer than the first preset duration, and the fifth preset duration can be in the millisecond range. Since it has been determined that the second arm IGBT of the first phase does not have a shoot-through fault, the first arm IGBT of the first phase can be controlled to be turned on for a longer time, thereby sequentially performing shoot-through detection on the second arm IGBTs of other phases, thus saving the overall detection time.
[0148] In the specific implementation process, the ninth bus voltage is the bus voltage before the second conduction control after the first bridge arm IGBT of the first phase has undergone the first conduction control and the shoot-through detection result of the second bridge arm IGBT of the first phase has been obtained. The tenth bus voltage is the bus voltage after the first bridge arm IGBT of the first phase has undergone the second conduction control.
[0149] Step A2: Based on the voltage of the ninth bus and the voltage of the tenth bus, obtain the shoot-through test result of the second bridge arm IGBT of the second phase.
[0150] Specifically, the second IGBT of the second phase corresponds to the second IGBT of the first phase in step S40. For example, if step S40 obtains the shoot-through test result of the upper IGBT of the first phase, the result obtained here is for the upper IGBT of the second phase; similarly, if step S40 obtains the shoot-through test result of the lower IGBT of the first phase, the result obtained here is for the lower IGBT of the second phase. This allows for shoot-through test results of the lower IGBTs of all phases by controlling the conduction of only the upper IGBT of the first phase.
[0151] Based on the voltages of the ninth and tenth busbars, the corresponding busbar voltage drop is obtained, and then it is determined whether the busbar voltage drop exceeds a preset threshold. If the busbar voltage drop exceeds the preset threshold, it is determined that the second IGBT of the second phase has an IGBT shoot-through fault; if the busbar voltage drop does not exceed the preset threshold, it is determined that the second IGBT of the second phase does not have an IGBT shoot-through fault. It should be noted that the second phase can be any one or more phases other than the first phase on the inverter unit.
[0152] In this embodiment, as Figure 5As shown, following the first stage of the process, if VT1 is controlled to conduct for 10µs and the bus voltage drop is determined not to exceed the preset threshold (meaning VT2 does not have an IGBT shoot-through fault), the ninth bus voltage can continue to be monitored. After VT1 is controlled to conduct for 5ms, the tenth bus voltage is monitored, and the bus voltage drops of the ninth and tenth bus voltages are calculated to determine whether they exceed the preset threshold, thus obtaining the IGBT shoot-through detection results for VT4 and / or VT6. Similarly, if VT2 is controlled to conduct for 10µs and the bus voltage drop is determined not to exceed the preset threshold (meaning VT1 does not have an IGBT shoot-through fault), VT2 is controlled to conduct for another 5ms to obtain the IGBT shoot-through detection results for VT3 and VT5. In this way, by controlling the conduction of the upper and lower IGBTs of the first phase, IGBT shoot-through fault detection can be achieved for the upper and lower IGBTs of all phases.
[0153] For more details on the specific implementation of the above method steps, please refer to the description of the specific implementation in Example 1. For the sake of brevity, these details will not be repeated here.
[0154] The IGBT shoot-through detection method provided in this embodiment, based on the fact that the shoot-through detection result of the second bridge arm IGBT of the first phase is that there is no IGBT shoot-through fault, obtains the bus voltage before and after the first bridge arm IGBT of the first phase is turned on for a second preset time, and obtains the IGBT shoot-through detection result of the second bridge arm IGBT of other phases on the inverter unit. This saves the time of the whole process and can inspect all IGBT devices more quickly.
[0155] Example 3
[0156] Based on the same inventive concept, referring to Figure 7 Based on Embodiment 1 and / or Embodiment 2, a third embodiment of the IGBT shoot-through detection method of the present invention is proposed, which is also applied to the detection of full-bridge inverter units.
[0157] The following is combined Figure 7 The flowchart shown illustrates the IGBT pass-through detection method of this embodiment in detail. Further, the inverter unit also includes a third phase, which can be any phase other than the first phase in the inverter unit; after step S50, the method may further include:
[0158] Step S91: When the shoot-through detection result of the first bridge arm IGBT is that there is no IGBT shoot-through fault, obtain the VCE voltage of any bridge arm IGBT of the third phase;
[0159] Step S92: Based on the VCE voltage, obtain the shoot-through detection result of any IGBT in the third phase.
[0160] Specifically, in some frequency converters, if a certain bridge arm IGBT or several bridge arm IGBTs are equipped with VCE detection, the method of Example 1 or Example 2 can be combined with the method of detecting IGBT shoot-through faults through VCE. That is, based on the detected VCE voltage of the bridge arm IGBT, it can be determined whether the bridge arm IGBT has an IGBT shoot-through fault. By combining multiple methods, it can be applied to more frequency converters. Therefore, the method of the present invention can be applied not only to frequency converters without VCE detection, but also to frequency converters equipped with VCE detection.
[0161] By detecting the voltage drop across the CE terminal of the IGBT in the drive circuit, i.e., obtaining the VCE voltage, if the instantaneous current flowing through the IGBT is large and desaturation occurs, the VCE voltage will increase sharply. This can determine whether the IGBT has a short circuit, and thus whether the IGBT has a shoot-through fault.
[0162] The IGBT shoot-through detection method provided in this embodiment can detect the shoot-through detection results of some IGBTs in the inverter unit using the method of the present invention, and can also detect the shoot-through detection results of other IGBTs in the inverter unit using VCE detection, thus having a wider range of applications and more applicable scenarios.
[0163] Example 4
[0164] Based on the same inventive concept, referring to Figure 8 The present invention provides a first embodiment of the IGBT direct-through detection device, which is applied in a frequency converter for detecting a full-bridge inverter unit. The inverter unit includes a first phase, which can be any phase of the inverter unit.
[0165] The following is combined Figure 8 The functional module diagram shown illustrates the IGBT pass-through detection device provided in this embodiment in detail. The device may include:
[0166] The voltage sampling module is used to obtain the first bus voltage and the second bus voltage of the inverter unit. The second bus voltage is the bus voltage of the inverter unit when the first bridge arm IGBT of the first phase is turned on for a first preset time. The first bridge arm IGBT is either the upper bridge arm IGBT or the lower bridge arm IGBT.
[0167] The IGBT driver module is used to drive the first bridge arm IGBT to turn on and off.
[0168] The logic judgment module is a control chip, including any one of a digital signal processor, microcontroller, field-programmable gate array, or complex programmable logic device. It is used to obtain the shoot-through detection result of the second bridge arm IGBT of the first phase based on the voltage drop of the first bus voltage and the second bus voltage. When the first bridge arm IGBT is the upper bridge arm IGBT, the second bridge arm IGBT is the lower bridge arm IGBT, and when the first bridge arm IGBT is the lower bridge arm IGBT, the second bridge arm IGBT is the upper bridge arm IGBT.
[0169] Furthermore, the first preset duration is 5–15 µs; the device may also include:
[0170] The signal generation module is used to generate the drive pulse width signal;
[0171] The signal transmission module is used to send a drive pulse width signal to the gate of the first bridge arm IGBT of the first phase to control the first bridge arm IGBT of the first phase to turn on; and to stop sending the drive pulse width signal when the first bridge arm IGBT of the first phase is turned on for a first preset time.
[0172] Furthermore, the logic judgment module may include:
[0173] The judgment unit is used to determine whether the bus voltage drop exceeds a preset threshold.
[0174] The first result unit is used to determine that the second bridge arm IGBT of the first phase has an IGBT shoot-through fault if the bus voltage drops below a preset threshold.
[0175] The second result unit is used to determine that the second bridge arm IGBT of the first phase does not have an IGBT shoot-through fault if the bus voltage drop does not exceed a preset threshold.
[0176] Furthermore, the voltage sampling module is also used to obtain the third bus voltage of the inverter unit and the fourth bus voltage of the inverter unit when the IGBT drive module drives the second arm IGBT to conduct for a second preset time if the shoot-through detection result of the second arm IGBT is that there is no IGBT shoot-through fault, so as to obtain the shoot-through detection result of the first arm IGBT through the logic judgment module.
[0177] Furthermore, the inverter unit also includes a second phase, which is any other phase in the inverter unit besides the first phase;
[0178] The voltage sampling module is also used to acquire the fifth bus voltage of the inverter unit and the sixth bus voltage of the inverter unit when the shoot-through detection result of the first bridge arm IGBT is that there is no IGBT shoot-through fault.
[0179] The logic judgment module is also used to obtain the shoot-through detection result of the fourth bridge arm IGBT of the second phase based on the voltage of the fifth bus and the voltage of the sixth bus.
[0180] The voltage sampling module is also used to obtain the seventh bus voltage of the inverter unit and the eighth bus voltage of the inverter unit when the IGBT of the fourth bridge arm is turned on for a fourth preset time if the shoot-through detection result of the fourth bridge arm IGBT is that there is no IGBT shoot-through fault, so as to obtain the shoot-through detection result of the third bridge arm IGBT through the logic judgment module.
[0181] Furthermore, the inverter unit also includes a third phase, which is any phase other than the first phase in the inverter unit; the device may also include:
[0182] The VCE acquisition module is used to acquire the VCE voltage of any IGBT in the third phase when the shoot-through detection result of the first IGBT arm is that there is no IGBT shoot-through fault.
[0183] The logic judgment module is also used to obtain the shoot-through detection result of any IGBT arm of the third phase based on the VCE voltage.
[0184] Furthermore, the first acquisition module is specifically used to acquire the first bus voltage of the inverter unit when it is detected that the inverter unit is powered on, ready to run, or has a fault.
[0185] It should be noted that the functions and corresponding technical effects of each module in the IGBT pass-through detection device provided in this embodiment can be referred to the description of the specific implementation methods in the various embodiments of the IGBT pass-through detection method of this invention. For the sake of brevity, they will not be repeated here.
[0186] Example 5
[0187] Based on the same inventive concept, referring to Figure 2 This is a connection block diagram of the frequency converter involved in various embodiments of the present invention. This embodiment provides a frequency converter 100, which may include:
[0188] Inverter unit 110, which is a full-bridge inverter unit;
[0189] The control unit 120 is connected to the inverter unit 110 and is used to implement all or part of the steps of the various embodiments of the IGBT pass-through detection method of the present invention.
[0190] The full-bridge inverter unit can be a three-phase full-bridge inverter unit or a single-phase full-bridge inverter unit. The control unit 120 refers to a terminal device or control device that can realize communication connection, which can be a terminal device such as an embedded industrial control computer, or a control device for on-site control or remote control.
[0191] like Figure 4 The diagram shows the hardware structure of the control unit 120 in the inverter 100 of this embodiment. The control unit 120 may include a processor and a memory. The memory stores an IGBT pass-through detection program. When the IGBT pass-through detection program is executed by the processor, it implements all or part of the steps of the various embodiments of the IGBT pass-through detection method of the present invention.
[0192] It is understood that the control unit 120 may also include a communication bus, a user interface, and a communication interface.
[0193] The communication bus is used to enable communication between these components. The user interface is used to connect to the client and communicate data with the client. The user interface may include output units, such as a display screen, and input units, such as a keyboard. The communication interface is used to connect to the control panel and communicate data with the control panel. The communication interface may include input / output interfaces, such as standard wired interfaces and wireless interfaces.
[0194] The memory is used to store various types of data, which may include, for example, instructions for any application or method in the control unit 120, as well as application-related data. The memory can be implemented using any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Random Access Memory (RAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. Optionally, the memory can also be a processor-independent storage device.
[0195] The processor is used to call the IGBT pass-through detection program stored in the memory and execute the IGBT pass-through detection method as described above. The processor can be an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a complex programmable logic device (CPLD), a field programmable gate array (FPGA), a microcontroller unit (MCU), a microprocessor, or other electronic components, and is used to execute all or part of the steps of the various embodiments of the IGBT pass-through detection method described above.
[0196] Example 6
[0197] Based on the same inventive concept, this embodiment provides a computer-readable storage medium, such as flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic memory, disk, optical disk, server, etc. The storage medium stores a computer program, which can be executed by one or more processors. When the computer program is executed by the processor, it can implement all or part of the steps of the various embodiments of the IGBT pass-through detection method of the present invention.
[0198] It should be noted that the sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.
[0199] The above are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct or indirect applications in other related technical fields, are included within the patent protection scope of the present invention.
Claims
1. A method for detecting IGBT pass-through, characterized in that, A method for detecting a full-bridge inverter unit, the inverter unit including a first phase, wherein the first phase is any phase of the inverter unit; the method includes: Obtain the first bus voltage of the inverter unit; Control the first bridge arm IGBT of the first phase to conduct for a first preset time, and obtain the second bus voltage of the inverter unit, wherein the first bridge arm IGBT is an upper bridge arm IGBT or a lower bridge arm IGBT. The bus voltage drop is obtained based on the first bus voltage and the second bus voltage; Based on the bus voltage drop, the shoot-through detection result of the second bridge arm IGBT of the first phase is obtained, wherein when the first bridge arm IGBT is the upper bridge arm IGBT, the second bridge arm IGBT is the lower bridge arm IGBT, and when the first bridge arm IGBT is the lower bridge arm IGBT, the second bridge arm IGBT is the upper bridge arm IGBT. The step of obtaining the shoot-through detection result of the second arm IGBT of the first phase based on the bus voltage drop includes: Determine whether the bus voltage drop exceeds a preset threshold; If the bus voltage drops below the preset threshold, it is determined that the second bridge arm IGBT of the first phase has an IGBT shoot-through fault. If the bus voltage drop does not exceed the preset threshold, it is determined that the second bridge arm IGBT of the first phase does not have an IGBT shoot-through fault.
2. The IGBT pass-through detection method as described in claim 1, characterized in that, The first preset duration is 5~15us; The step of controlling the first bridge arm IGBT of the first phase to conduct for a first preset duration includes: Generate driving pulse width signal; The drive pulse width signal is sent to the gate of the first bridge arm IGBT of the first phase to control the first bridge arm IGBT of the first phase to be turned on. When the first IGBT of the first phase is turned on for a first preset duration, the transmission of the drive pulse width signal is stopped.
3. The IGBT pass-through detection method as described in claim 1, characterized in that, After the step of determining that the second bridge arm IGBT of the first phase has an IGBT shoot-through fault if the bus voltage drops below the preset threshold, the method further includes: If the second arm IGBT of the first phase has an IGBT shoot-through fault, a fault indication or alarm will be issued.
4. The IGBT pass-through detection method as described in claim 1, characterized in that, After the step of obtaining the shoot-through detection result of the second arm IGBT of the first phase based on the bus voltage drop, the method further includes: If the shoot-through detection result of the second bridge arm IGBT is that there is no IGBT shoot-through fault, then the third bus voltage of the inverter unit and the fourth bus voltage of the inverter unit when the second bridge arm IGBT is turned on for a second preset time are obtained, so as to obtain the shoot-through detection result of the first bridge arm IGBT.
5. The IGBT pass-through detection method as described in claim 4, characterized in that, The inverter unit further includes a second phase, which is any other phase in the inverter unit besides the first phase; After the step of obtaining the shoot-through detection result of the first bridge arm IGBT, the method further includes: When the shoot-through detection result of the first bridge arm IGBT is that there is no IGBT shoot-through fault, the fifth bus voltage of the inverter unit and the sixth bus voltage of the inverter unit when the third bridge arm IGBT of the second phase is turned on for a third preset time are obtained. Based on the fifth bus voltage and the sixth bus voltage, the shoot-through detection result of the fourth bridge arm IGBT of the second phase is obtained; If the shoot-through detection result of the fourth bridge arm IGBT is that there is no IGBT shoot-through fault, then the seventh bus voltage of the inverter unit and the eighth bus voltage of the inverter unit when the fourth bridge arm IGBT is turned on for a fourth preset time are obtained, so as to obtain the shoot-through detection result of the third bridge arm IGBT.
6. The IGBT pass-through detection method as described in claim 4, characterized in that, The inverter unit further includes a third phase, which is any other phase in the inverter unit besides the first phase; After the step of obtaining the shoot-through detection result of the first bridge arm IGBT, the method further includes: When the shoot-through detection result of the first bridge arm IGBT is that there is no IGBT shoot-through fault, the VCE voltage of any bridge arm IGBT of the third phase is obtained. Based on the VCE voltage, the shoot-through detection result of any IGBT arm of the third phase is obtained.
7. The IGBT pass-through detection method according to any one of claims 1 to 6, characterized in that, The step of obtaining the first bus voltage of the inverter unit includes: When the inverter unit is detected to be powered on, ready to run, or has a fault, the first bus voltage of the inverter unit is obtained.
8. An IGBT pass-through detection device, characterized in that, A device for detecting a full-bridge inverter unit, the inverter unit including a first phase, wherein the first phase is any phase of the inverter unit; the device includes: The voltage sampling module is used to acquire the first bus voltage and the second bus voltage of the inverter unit. The second bus voltage is the bus voltage of the inverter unit when the first bridge arm IGBT of the first phase is turned on for a first preset time. The first bridge arm IGBT is either the upper bridge arm IGBT or the lower bridge arm IGBT. The IGBT driver module is used to drive the first bridge arm IGBT to turn on and off. The logic judgment module, which is a control chip, includes any one of a digital signal processor, a microcontroller, a field-programmable gate array, or a complex programmable logic device, and is used to obtain the shoot-through detection result of the second bridge arm IGBT of the first phase based on the bus voltage drop of the first bus voltage and the second bus voltage. Wherein, when the first bridge arm IGBT is the upper bridge arm IGBT, the second bridge arm IGBT is the lower bridge arm IGBT, and when the first bridge arm IGBT is the lower bridge arm IGBT, the second bridge arm IGBT is the upper bridge arm IGBT. The logic judgment module includes: The judgment unit is used to determine whether the bus voltage drop exceeds a preset threshold. The first result unit is used to determine that the second bridge arm IGBT of the first phase has an IGBT shoot-through fault if the bus voltage drops below the preset threshold. The second result unit is used to determine that the second bridge arm IGBT of the first phase does not have an IGBT shoot-through fault if the bus voltage drop does not exceed the preset threshold.
9. A frequency converter, characterized in that, The frequency converter includes: Inverter unit, wherein the inverter unit is a full-bridge inverter unit; A control unit, connected to the inverter unit, is used to implement the IGBT pass-through detection method as described in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when executed by one or more processors, implements the IGBT pass-through detection method as described in any one of claims 1 to 7.