Pulse tracking system for IGBT (Insulated Gate Bipolar Translator) driving signal

Abstract

The invention provides a pulse tracking system for an IGBT driving signal, and relates to the technical field of IGBT detection, and the pulse tracking system comprises the steps: outputting a short-circuit signal when the detection voltage of an IGBT module is detected to be greater than a preset short-circuit voltage value; analyzing the pulse signal to drive an IGBT module; processing according to the detection voltage and the pulse signal to obtain a conduction state signal, processing according to the pulse signal and the short-circuit signal to obtain a fault signal, and uploading the fault signal to an upper control system; and the upper control system records the conduction state signal and the detection voltage in real time, and stops outputting the PWM signal when receiving the fault signal. The beneficial effects are that the IGBT conduction state can be monitored in real time to realize pulse tracking; when a short-circuit fault occurs, the pulse is blocked by software, so that the IGBT is protected and prevented from being damaged, the upper control system also receives the detection voltage, and the fault reason is quickly positioned by analyzing the voltage waveform during operation.

Description

Technical Field

[0001] The invention relates to the technical field of IGBT detection, and in particular to a pulse tracking system for an IGBT driving signal. Background Art

[0002] Although the existing large-capacity high-voltage inverters are widely used in the fields of steam turbine electrification (such as LNG equipment), BEST small machines and compressed air energy storage equipment, their IGBT drive technology still has significant deficiencies. Although 3300V and above high-voltage IGBT modules are usually used to increase the output voltage of the power unit and reduce the number of cascade units to enhance reliability, and multiple modules are connected in parallel to increase capacity, there is still room for improvement in the drive and monitoring of IGBTs. Although the IGBT driver boards currently on the market have integrated short-circuit protection functions, they lack the function of pulse tracking by detecting the voltage between the IGBT source (Source) and drain (Drain). This lack makes it impossible to effectively track the IGBT drive pulse signal and it is difficult to monitor the IGBT status in real time, which in turn affects the product optimization of high-power IGBTs. In particular, when an IGBT fails, it is difficult to quickly and accurately locate the fault due to the lack of voltage waveform data during operation, which greatly increases the difficulty of operation and maintenance of the inverter and the time to solve the problem. Therefore, the existing IGBT drive technology has obvious limitations in product optimization and fault analysis. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a pulse tracking system for an IGBT drive signal, comprising:

[0004] A voltage detection module, connected to the source and drain of the IGBT module, for detecting the voltage between the source and drain of the IGBT to obtain a detection voltage;

[0005] A detection voltage processing module, connected to the voltage detection module, configured to output a short-circuit signal when it is determined that the detection voltage is lower than a preset short-circuit voltage value;

[0006] A pulse processing module, connected to the host control system and the IGBT module, for analyzing the PWM signal sent by the host control system to obtain a pulse signal to drive the IGBT module;

[0007] a signal feedback module, connected to the voltage detection module, the upper control system, the detection voltage processing module and the pulse processing module, for obtaining a conduction state signal according to the detection voltage and the pulse signal, and obtaining a fault signal according to the pulse signal and the short-circuit signal, and uploading the conduction state signal, the fault signal and the detection voltage to the upper control system;

[0008] The upper control system records the conduction state signal and the detection voltage in real time, and stops outputting the PWM signal when receiving the fault signal.

[0009] Preferably, the voltage detection module includes:

[0010] A voltage dividing unit, connected to the source and drain of the IGBT module, for dividing the initial voltage between the source and drain;

[0011] The surge removal unit is connected to the voltage division unit and is used to remove the surge voltage in the initial voltage after voltage division to obtain the detection voltage.

[0012] Preferably, the detection voltage processing module includes a comparator connected to the voltage detection module, which is used to compare the detection voltage with the short-circuit voltage value, and output the short-circuit signal when the detection voltage is lower than a preset short-circuit voltage value.

[0013] Preferably, the signal feedback module includes:

[0014] A fault processing unit is used to generate the fault signal when the pulse signal indicates a short circuit or the short circuit signal exists.

[0015] Preferably, the signal feedback module includes:

[0016] A conduction state processing unit is used to generate a conduction state signal indicating that the IGBT module is turned on when the pulse signal is at a high level and the detection voltage is at a high level, and to generate a conduction state signal indicating that the IGBT module is turned off when the pulse signal is at a low level and the detection voltage is at a low level.

[0017] Preferably, it also includes an optical fiber module, which is connected between the upper control system and the pulse processing module, and between the upper control system and the signal feedback module, and is used to send the PWM signal output by the upper control system to the pulse processing module, and send the conduction state signal and the fault signal output by the signal feedback module to the upper control system.

[0018] Preferably, the signal feedback module is also used to feed back the drive signal to the upper control system.

[0019] The above technical solution has the following advantages or beneficial effects: on the one hand, by feeding back the conduction state of the IGBT to the upper control system, the conduction state of the IGBT can be monitored in real time to achieve the purpose of pulse tracking; at the same time, when a short-circuit fault occurs in the IGBT module, the pulse tracking system will latch the conduction state of the IGBT when the fault occurs, and will transmit the fault signal to the upper control system, thereby timely blocking the drive signal of the IGBT. The pulse processing module cannot receive the PWM signal and cannot parse the drive signal, thereby realizing software blocking of the pulse, thereby protecting the IGBT from damage, and the upper control system also receives the detection voltage, and quickly locates the cause of the fault by analyzing the voltage waveform during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a schematic structural diagram of a pulse tracking system for an IGBT driving signal in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment, and other embodiments may also fall within the scope of the present invention as long as they conform to the gist of the present invention.

[0022] In a preferred embodiment of the present invention, based on the above problems existing in the prior art, a pulse tracking system for an IGBT driving signal is provided. Figure 1 As shown, including:

[0023] The voltage detection module 1 is connected to the source and drain of the IGBT module 2 and is used to detect the voltage between the source and drain of the IGBT module 2 to obtain a detection voltage;

[0024] A detection voltage processing module 3, connected to the voltage detection module 1, for outputting a short-circuit signal when it is determined that the detection voltage is lower than a preset short-circuit voltage value;

[0025] The pulse processing module 4 is connected to the upper control system 6 and the IGBT module 2 and is used to analyze the PWM signal sent by the upper control system to obtain a pulse signal to drive the IGBT module 2;

[0026] The signal feedback module 7 is connected to the voltage detection module 1, the upper control system 6, the detection voltage processing module 3 and the pulse processing module 4, and is used to obtain a conduction state signal according to the detection voltage and the pulse signal, and to obtain a fault signal according to the pulse signal and the short-circuit signal, and to upload the conduction state signal, the fault signal and the detection voltage to the upper control system 6;

[0027] The upper control system 6 records the conduction state signal and the detection voltage in real time, and stops outputting the PWM signal when receiving a fault signal.

[0028] Specifically, the present embodiment provides a pulse tracking system for an IGBT drive signal. On the one hand, the system can monitor the on-state of the IGBT in real time to achieve the purpose of pulse tracking by feeding back the on-state of the IGBT to the upper control system 6. At the same time, when a short-circuit fault occurs in the IGBT module 2, the pulse tracking system will latch the on-state of the IGBT when the fault occurs, and will transmit the fault signal to the upper control system 6 to implement software blocking of the PWM signal, thereby timely blocking the drive signal of the IGBT. The pulse processing module 4 cannot receive the PWM signal and cannot parse the drive signal, thereby implementing software blocking of the pulse. In addition, a short-circuit protection circuit can be set, and the fault signal is input to the short-circuit protection circuit to implement hardware protection, thereby protecting the IGBT from damage. The upper control system 6 also receives the detection voltage, and quickly locates the cause of the fault by analyzing the voltage waveform during operation.

[0029] In a preferred embodiment of the present invention, Figure 1 As shown, the voltage detection module 1 includes:

[0030] A voltage dividing unit 11, connected to the source and drain of the IGBT module, for dividing the initial voltage between the source and the drain;

[0031] The surge removal unit 12 is connected to the voltage division unit 11 and is used for removing the surge voltage from the initial voltage after voltage division to obtain the detection voltage.

[0032] Specifically, in this embodiment, the voltage between the source (Source) and the drain (Drain) of the IGBT is divided by a voltage divider unit (mainly including multiple voltage divider resistors, and a voltage divider circuit in the prior art can be used), and the surge voltage is removed by a surge removal unit (mainly including a capacitor, and a surge removal circuit in the prior art can be used), thereby converting the high-voltage unit into a measurable low voltage to obtain a detection voltage between the source (Source) and the drain (Drain).

[0033] In a preferred embodiment of the present invention, the detection voltage processing module 3 includes a comparator connected to the voltage detection module 1, which is used to compare the detection voltage with the short-circuit voltage value and output a short-circuit signal when the detection voltage is lower than a preset short-circuit voltage value.

[0034] Specifically, the detection voltage processing module includes a comparator, which compares the detection voltage sampled by the voltage detection module with the set short-circuit voltage. Under normal conditions, the detection voltage of the IGBT module should be in a state of constantly alternating between high and low levels (low level when turned on and high level when turned off). In the event of a short circuit, the IGBT module always remains in the on state, and the corresponding detection voltage will continue to be a low level, so the short-circuit voltage value is set to a lower value. If the detection voltage obtained by real-time detection is continuously lower than the set short-circuit power value, it indicates that a short circuit has occurred in the IGBT module. In the event of a short circuit, the analog signal (detection voltage) is converted into a digital signal (generally O / 1 to represent the state).

[0035] In a preferred embodiment of the present invention, the signal feedback module 7 includes:

[0036] The fault processing unit 71 is used to generate a fault signal when a pulse signal is missing or a short-circuit signal exists.

[0037] Specifically, in this embodiment, the pulse signal can reflect whether the IGBT module 2 is driven normally, and the short-circuit signal obtained by the comparator in the aforementioned embodiment can also indicate whether the IGBT module is short-circuited, so the two are subjected to an "or" logic operation in the signal feedback module, that is, when either the pulse signal indicates a short circuit or the short-circuit signal exists, both indicate a short circuit, and one is obtained through input judgment and the other is obtained through output feedback judgment, which can improve the accuracy of short-circuit detection.

[0038] In a preferred embodiment of the present invention, Figure 1 As shown, the signal feedback module 7 includes:

[0039] The on-state processing unit 72 is used to generate an on-state signal indicating that the IGBT module is on when the pulse signal is at a high level and the detection voltage is at a low level, and to generate an on-state signal indicating that the IGBT module is off when the pulse signal is at a low level and the detection voltage is at a high level.

[0040] Specifically, the pulse signal is obtained by outputting a PWM signal to the upper control system. When the pulse signal is at a high level, it indicates that the IGBT module is turned on, and when the pulse signal is at a low level, it indicates that the IGBT module is turned off. Furthermore, when the detection voltage is at a low level, it indicates that the IGBT module is turned on, and when the detection voltage is at a high level, it indicates that the IGBT module is turned off. By performing logical operations on the high and low levels of the pulse signal and the detection voltage, the on-state of the IGBT module can be accurately determined.

[0041] In a preferred embodiment of the present invention, it also includes an optical fiber module 5, which is connected between the upper control system 6 and the pulse processing module 4, and between the upper control system 6 and the signal feedback module 7, and is used to send the PWM signal output by the upper control system 6 to the pulse processing module 4, and to send the conduction state signal and fault signal output by the signal feedback module 7 to the upper control system 6.

[0042] Specifically, in this embodiment, optical fiber is used to transmit signals, thereby avoiding external interference and having a good isolation effect.

[0043] In a preferred embodiment of the present invention, Figure 1 As shown, the signal feedback module 7 is also used to feed back the drive signal to the upper control system.

[0044] Specifically, in this embodiment, the driving signal obtained by the pulse processing module based on the PWM signal analysis is also uploaded to the upper control system. The upper control system can quickly locate the cause of the fault by analyzing the voltage waveform and the corresponding driving signal during the operation of the IGBT. Under normal circumstances, when the driving signal indicates that the IGBT module is turned on, the IGBT will be turned on and the corresponding detection voltage cannot be detected. When the driving signal indicates that the IGBT module is turned off, the IGBT will be turned off and the corresponding detection voltage can be detected. If the driving signal and the detection voltage are inconsistent, it means that there is a fault and the cause of the fault is analyzed.

[0045] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of this specification and illustrations should be included in the protection scope of the present invention.

Claims

1. A pulse tracking system for an IGBT drive signal, characterized in that: include: A voltage detection module, connected to the source and drain of the IGBT module, and used to detect the voltage between the source and drain of the IGBT module to obtain a detection voltage; A detection voltage processing module, connected to the voltage detection module, configured to output a short-circuit signal when it is determined that the detection voltage is lower than a preset short-circuit voltage value; A pulse processing module, connected to the upper control system and the IGBT module, for analyzing the PWM signal sent by the upper control system to obtain a pulse signal to drive the IGBT module; a signal feedback module, connected to the voltage detection module, the upper control system, the detection voltage processing module and the pulse processing module, for obtaining a conduction state signal according to the detection voltage and the pulse signal, and obtaining a fault signal according to the pulse signal and the short-circuit signal, and uploading the conduction state signal, the fault signal and the detection voltage to the upper control system; The upper control system records the conduction state signal and the detection voltage in real time, and stops outputting the PWM signal when receiving the fault signal.

2. The pulse tracking system according to claim 1, characterized in that The voltage detection module comprises: A voltage dividing unit, connected to the source and drain of the IGBT module, for dividing the initial voltage between the source and drain; The surge removal unit is connected to the voltage division unit and is used to remove the surge voltage in the initial voltage after voltage division to obtain the detection voltage.

3. The pulse tracking system according to claim 1, characterized in that: The detection voltage processing module includes a comparator connected to the voltage detection module, and is used to compare the detection voltage with the short-circuit voltage value, and output the short-circuit signal when the detection voltage is lower than a preset short-circuit voltage value.

4. The pulse tracking system according to claim 1, characterized in that: The signal feedback module comprises: A fault processing unit is used to generate the fault signal when the pulse signal indicates a short circuit or the short circuit signal exists.

5. The pulse tracking system according to claim 1, characterized in that: The signal feedback module comprises: A conduction state processing unit is used to generate a conduction state signal indicating that the IGBT module is turned on when the pulse signal is at a high level and the detection voltage is at a low level, and to generate a conduction state signal indicating that the IGBT module is turned off when the pulse signal is at a low level and the detection voltage is at a high level.

6. The pulse tracking system according to claim 1, characterized in that: It also includes an optical fiber module, which is connected between the upper control system and the pulse processing module, and between the upper control system and the signal feedback module, and is used to send the PWM signal output by the upper control system to the pulse processing module, and to send the conduction state signal and the fault signal output by the signal feedback module to the upper control system.

7. The pulse tracking system according to claim 1, characterized in that: The signal feedback module is also used to feed back the drive signal to the upper control system.

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