IGBT Collector-Emitter Saturation Voltage Detection Device

Abstract

The present invention discloses a saturation voltage detection device for the collector - emitter of an IGBT. The first output terminal of the trigger module of the device is electrically connected to the control terminal of the discharge control module, and the second output terminal is electrically connected to the base of the IGBT. The trigger module is used to send trigger signals to the discharge control module and the IGBT, and control the energy storage module to discharge to the IGBT through the discharge control module; the current setting and comparison module is used to output a trigger signal to the trigger module according to the magnitude relationship between the current collected by the current sampling module and the set current; the trigger module is used to send a sampling and holding signal to the sampling and holding module according to the trigger signal; the sampling and holding module is used to output the voltage difference between the collector and the emitter of the IGBT when receiving the sampling and holding signal. The present invention only needs to control the trigger module to send trigger signals to the discharge control module and the IGBT, and the saturation voltage of the collector - emitter of the IGBT can be obtained without the intervention of operators in the middle, realizing the automation of the detection process and improving the operation efficiency.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of detection technologies, and in particular, to a saturation voltage detection device for the collector-emitter of an IGBT. Background Art

[0002] As a power conversion device, an IGBT (Insulated Gate Bipolar Transistor) is one of the most important electrical components in AC drives, harmonious locomotives, and high-speed multiple units. Whether it works properly will directly affect the safety of railway operation.

[0003] However, there is currently no device for automatically measuring the saturation voltage between the collector and emitter of an IGBT. Summary of the Invention

[0004] The present invention provides a saturation voltage detection device for the collector-emitter of an IGBT to achieve automatic measurement of the saturation voltage between the collector and emitter of an IGBT.

[0005] The embodiments of the present invention provide a saturation voltage detection device for the collector-emitter of an IGBT, including: an energy storage module, a discharge control module, a trigger module, a current sampling module, a current setting comparison module, and a sample and hold module;

[0006] The first end of the discharge control module is electrically connected to the energy storage module, the second end of the discharge control module is electrically connected to the collector of the IGBT, and the emitter of the IGBT is electrically connected to the second end of the energy storage module through the current sampling module;

[0007] The first output end of the trigger module is electrically connected to the control end of the discharge control module, the second output end of the trigger module is electrically connected to the base of the IGBT, and the trigger module is used to send a trigger signal to the discharge control module and the IGBT to control the energy storage module to discharge to the IGBT through the discharge control module;

[0008] The first input end of the current setting comparison module is electrically connected to the current sampling module, the second input end of the current setting comparison module inputs a setting signal corresponding to a set current, the output end of the current setting comparison module is electrically connected to the input end of the trigger module, the current sampling module is used to collect the current in the loop where the IGBT is located, and the current setting comparison module is used to output a trigger signal to the trigger module according to the magnitude relationship between the current collected by the current sampling module and the set current;

[0009] The trigger module is used to send a sample and hold signal to the sample and hold module according to the trigger signal;

[0010] The first end of the sampling and holding module is electrically connected to the collector of the IGBT, the second end of the sampling and holding module is electrically connected to the emitter of the IGBT, and the third end of the sampling and holding module is electrically connected to the third output end of the triggering module. The sampling and holding module is configured to output the voltage difference between the collector and the emitter of the IGBT when receiving the sampling and holding signal.

[0011] Optionally, the discharge control module includes a control switch and an inductor;

[0012] The first end of the control switch serves as the first end of the discharge control module, the second end of the control switch is electrically connected to the first end of the inductor, the control end of the control switch serves as the control end of the discharge control module, and the second end of the inductor serves as the second end of the discharge control module.

[0013] Optionally, the triggering module includes a first triggering unit, a second triggering unit, and a third triggering unit;

[0014] The output end of the first triggering unit serves as the first output end of the triggering module, the output end of the second triggering unit serves as the second output end of the triggering module, the input end of the third triggering unit serves as the input end of the triggering module, and the output end of the third triggering unit serves as the third output end of the triggering module.

[0015] Optionally, the first triggering unit includes a first sub-trigger and a second sub-trigger;

[0016] The output end of the first sub-trigger is electrically connected to the input end of the second sub-trigger, and the output end of the second sub-trigger serves as the output end of the first triggering unit.

[0017] Optionally, the saturation voltage detection device for the IGBT collector-emitter further includes a power supply module, a power supply triggering module, and a rectification module. The power supply module is electrically connected to the power supply triggering module, the power supply triggering module is electrically connected to the control end of the rectification module, the first end of the rectification module is electrically connected to the first end of the energy storage module, and the second end of the rectification module is electrically connected to the second end of the energy storage module.

[0018] Optionally, the saturation voltage detection device for the IGBT collector-emitter further includes a first comparison module, an inverter, and a charging indication module;

[0019] The first input terminal of the first comparison module is connected to the set signal of the set current. The second input terminal of the first comparison module is electrically connected to the voltage acquisition module connected to the energy storage module. The output terminal of the first comparison module is electrically connected to the input terminal of the inverter. The output terminal of the inverter is electrically connected to one end of the charging indication module, and the other end of the charging indication module is grounded.

[0020] Optionally, the saturation voltage detection device for the IGBT collector-emitter further includes a charging control module;

[0021] The first input terminal of the charging control module is electrically connected to the power trigger module. The second input terminal of the charging control module is electrically connected to the output terminal of the first comparison module. The output terminal of the charging control module is electrically connected to the control terminal of the rectification module. The charging control module is used to control the power module to charge the energy storage module when the voltage value corresponding to the set current is greater than the voltage value corresponding to the energy storage module.

[0022] Optionally, the saturation voltage detection device for the IGBT collector-emitter is characterized by further including a button module;

[0023] The button module is respectively electrically connected to the input terminal of the first trigger unit, the input terminal of the second trigger unit, and the third input terminal of the charging control module. The button module is used to send corresponding level signals to the first trigger unit, the second trigger unit, and the charging control module according to the state of the charging indication module.

[0024] Optionally, the saturation voltage detection device for the IGBT collector-emitter is characterized by further including a second comparison module, a discharge switch, and a discharge resistor;

[0025] The first input terminal of the second comparison module is electrically connected to the voltage acquisition module. The second input terminal of the second comparison module is connected to the threshold setting signal of the set current. The output terminal of the second comparison module is electrically connected to the control terminal of the discharge switch;

[0026] The first end of the discharge resistor is electrically connected to the first end of the energy storage module. The second end of the discharge resistor is electrically connected to the first end of the discharge switch. The second end of the discharge switch is electrically connected to the second end of the energy storage module. The discharge switch is used to control the energy storage module to discharge to the discharge resistor when the voltage value output by the voltage acquisition module is greater than the voltage value corresponding to the maximum value of the set current.

[0027] Optionally, the saturation voltage detection device for the IGBT collector-emitter is characterized by further including a display module;

[0028] The display module is electrically connected to the output end of the sampling and holding module.

[0029] The IGBT collector-emitter saturation voltage detection device provided by the embodiment of the present invention includes: an energy storage module, a discharge control module, a trigger module, a current sampling module, a current setting and comparison module, and a sampling and holding module; the energy storage module is electrically connected to the discharge control module, the trigger module is electrically connected to the discharge control module, the IGBT, and the sampling and holding module respectively, and the sampling and holding module is electrically connected to the collector and emitter of the IGBT. When detecting the saturation voltage of the collector-emitter of the IGBT, the energy storage module is controlled by the trigger module to discharge to the IGBT. When the IGBT discharges, the trigger module sends a sampling and holding signal to the sampling and holding module according to the trigger signal output based on the magnitude relationship between the current in the loop where the IGBT is located input by the current setting and comparison module and the set current. When the sampling and holding module receives the sampling and holding signal, it outputs the voltage difference between the collector and emitter of the IGBT. In the embodiment of the present invention, only after controlling the trigger module to send trigger signals to the discharge control module and the IGBT, the voltage difference between the collector and emitter of the IGBT can be obtained. There is no need for the intervention of operators in the middle, realizing the automation of the detection process, saving manpower, and improving work efficiency. Description of the Drawings

[0030] Figure 1 It is a schematic structural diagram of an IGBT collector-emitter saturation voltage detection device provided by an embodiment of the present invention.

[0031] Figure 2 It is a schematic waveform diagram of the current in the loop where the IGBT is located provided by an embodiment of the present invention.

[0032] Figure 3 It is a schematic structural diagram of another IGBT collector-emitter saturation voltage detection device provided by an embodiment of the present invention.

[0033] Figure 4 It is a schematic structural diagram of another IGBT collector-emitter saturation voltage detection device provided by an embodiment of the present invention.

[0034] Figure 5 It is a schematic structural diagram of another IGBT collector-emitter saturation voltage detection device provided by an embodiment of the present invention.

[0035] Figure 6 It is a schematic structural diagram of another IGBT collector-emitter saturation voltage detection device provided by an embodiment of the present invention.

[0036] Figure 7 It is a schematic structural diagram of another IGBT collector-emitter saturation voltage detection device provided by an embodiment of the present invention. Detailed implementation manners

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only the parts related to the present invention rather than all the structures are shown in the accompanying drawings.

[0038] Figure 1 The following is a schematic structural diagram of a saturation voltage detection device for the collector-emitter of an IGBT provided by an embodiment of the present invention. Refer to Figure 1 , the saturation voltage detection device for the collector-emitter of an IGBT includes: an energy storage module 01, a discharge control module 02, a trigger module 03, a current sampling module 04, a current setting comparison module 05, and a sample and hold module 06;

[0039] The first end of the discharge control module 02 is electrically connected to the energy storage module 01, the second end of the discharge control module 02 is electrically connected to the collector of the IGBT, and the emitter of the IGBT is electrically connected to the second end of the energy storage module 01 through the current sampling module 04;

[0040] The first output end of the trigger module 03 is electrically connected to the control end of the discharge control module 02, the second output end of the trigger module 03 is electrically connected to the base of the IGBT, and the trigger module 03 is used to send a trigger signal to the discharge control module 02 and the IGBT to control the energy storage module 01 to discharge to the IGBT through the discharge control module 02;

[0041] The first input end of the current setting comparison module 05 is electrically connected to the current sampling module 04, a setting signal corresponding to a set current is input to the second input end of the current setting comparison module 05, the output end of the current setting comparison module 05 is electrically connected to the input end of the trigger module 03, the current sampling module 04 is used to collect the current in the loop where the IGBT is located, and the current setting comparison module 05 is used to output a trigger signal to the trigger module 03 according to the magnitude relationship between the current collected by the current sampling module 04 and the set current;

[0042] The trigger module 03 is used to send a sample and hold signal to the sample and hold module 06 according to the trigger signal;

[0043] The first end of the sample and hold module 06 is electrically connected to the collector of the IGBT, the second end of the sample and hold module 06 is electrically connected to the emitter of the IGBT, and the third end of the sample and hold module 06 is electrically connected to the third output end of the trigger module 03. The sample and hold module 06 is used to output the voltage difference between the collector and emitter of the IGBT when receiving the sample and hold signal.

[0044] The energy storage module 01 can be a capacitor, and the capacitor is equivalent to a power supply. After the capacitor is charged, the capacitor can be regarded as a power supply and can discharge to the IGBT. The discharge control module 02 can be an electronic switch. After receiving the trigger signal sent by the trigger module 03, the electronic switch conducts. After the IGBT base also receives the trigger signal, a closed loop is formed among the energy storage module 01, the discharge control module 02, the IGBT, and the current sampling module 04, and the energy storage module 01 discharges to the IGBT. Among them, the trigger signal sent by the trigger module 03 to the discharge control module 02 and the IGBT is the first trigger signal, and the first trigger signal can be a high-level or low-level signal. The trigger module 03 can be a monostable flip-flop, and the monostable flip-flop is used to send pulses. The current sampling module 04 can be a current sampler, which is used to collect the current in the loop where the IGBT is located and convert the current into a corresponding voltage value for output when the energy storage module 01 discharges to the IGBT, that is, the output of the current sampling module 04 is a voltage value.

[0045] The current setting comparison module 05 can include a comparator. Exemplarily, the non-inverting input terminal of the comparator can be used as the first input terminal of the current setting comparison module 05, the inverting input terminal of the comparator can be used as the second input terminal of the current setting comparison module 05, the non-inverting input terminal of the comparator is connected to the voltage signal corresponding to the current in the loop where the IGBT is located, and the inverting input terminal of the comparator is connected to the setting signal of the set current. Among them, the setting signal is a voltage value, and the set current can be the saturation current of the IGBT, so the setting signal is the voltage value corresponding to the set current. The setting signal can be obtained by a current setting potentiometer, and the current setting potentiometer outputs the voltage value corresponding to the set current.

[0046] Figure 2 This is a waveform schematic diagram of the current in the loop where the IGBT is located provided by the embodiment of the present invention. Refer to Figure 2, the curve represents the waveform of the current in the circuit where the IGBT is located. The abscissa is the time t, and the ordinate is the current I. The dotted line represents the magnitude of the set current, which is set to I0. There are two intersections between the current in the circuit where the IGBT is located and the set current, namely the first intersection point a and the second intersection point b. During the process of the current in the circuit where the IGBT is located increasing from small to large, the current setting comparison module 05 outputs a low-level signal when the current in the circuit where the IGBT is located is less than the set current, and the current setting comparison module 05 outputs a high-level signal when the current in the circuit where the IGBT is located is greater than the set current. That is, near the first intersection point a, the current setting comparison module O5 will output a rising edge. During the process of the current in the circuit where the IGBT is located decreasing from large to small, the current setting comparison module 05 outputs a low-level signal again when the current in the circuit where the IGBT is located is less than the set current. That is, near the second intersection point b, the current setting comparison module O5 will output a falling edge. Therefore, the trigger signal sent by the current setting comparison module 05 to the trigger module 03 can be a rising edge or a falling edge, and this embodiment does not make specific limitations here. Among them, the trigger signal output by the current setting comparison module 05 is the second trigger signal, and the second trigger signal is a rising edge or a falling edge.

[0047] The sampling and holding module 06 can be a sample and hold circuit. The sampling and holding module 06 will only output the voltage difference between the collector and emitter of the IGBT at the current moment when it receives the sampling and holding signal sent by the trigger module 03. This voltage difference is the saturation voltage corresponding to the required saturation current. Among them, the sampling and holding signal is a high-level or low-level signal.

[0048] The working principle of the saturation voltage detection device for the IGBT collector-emitter is as follows: When it is necessary to detect the saturation voltage of the IGBT collector-emitter, the trigger module 03 sends pulses to the discharge control module 02 and the IGBT to make the discharge control module 02 and the IGBT conduct. After the discharge control module 02 and the IGBT conduct, the energy storage module 01 automatically discharges to the IGBT. When the IGBT discharges, the current setting comparison module 05 outputs a rising edge or a falling edge according to the relationship between the magnitude of the current in the circuit where the IGBT is located and the magnitude of the set current. After receiving this rising edge or falling edge, the trigger module 03 sends a pulse to the sampling and holding module 06 to make it output the voltage difference between the two ends of the collector and emitter of the IGBT at the current moment, that is, the measured saturation voltage of the IGBT collector-emitter.

[0049] The saturation voltage detection device for the IGBT collector - emitter provided in this embodiment includes: an energy storage module, a discharge control module, a trigger module, a current sampling module, a current setting comparison module, and a sample - and - hold module; the energy storage module is electrically connected to the discharge control module, the trigger module is electrically connected to the discharge control module, the IGBT, and the sample - and - hold module respectively, and the sample - and - hold module is electrically connected to the collector and emitter of the IGBT. When detecting the saturation voltage of the IGBT collector - emitter, the trigger module controls the energy storage module to discharge to the IGBT. When the IGBT discharges, the trigger module sends a sample - and - hold signal to the sample - and - hold module according to the trigger signal output based on the magnitude relationship between the current in the loop where the IGBT is located and the set current input by the current setting comparison module. When the sample - and - hold module receives the sample - and - hold signal, it outputs the voltage difference between the collector and emitter of the IGBT. In this embodiment, only after controlling the trigger module to send trigger signals to the discharge control module and the IGBT, the voltage difference between the collector and emitter of the IGBT can be obtained. There is no need for the intervention of operators in the middle, realizing the automation of the detection process, saving manpower, and improving work efficiency.

[0050] Figure 3 is a schematic structural diagram of another saturation voltage detection device for the IGBT collector - emitter provided by an embodiment of the present invention. Refer to Figure 3 , optionally, the discharge control module 02 includes a control switch Q1 and an inductor L;

[0051] The first end of the control switch Q1 serves as the first end of the discharge control module 02, the second end of the control switch Q1 is electrically connected to the first end of the inductor L, the control end of the control switch Q1 serves as the control end of the discharge control module 02, and the second end of the inductor L serves as the second end of the discharge control module 02.

[0052] The control switch Q1 can be a thyristor, and the gate of the thyristor serves as the control end of the control switch Q1. Exemplarily, the thyristor conducts when its gate receives a high level. When the trigger module 03 sends a pulse to the control end of the control switch Q1, the control switch Q1 conducts during the high - level stage of the pulse. After the IGBT conducts and the control switch Q1 conducts, the energy storage module 01 can discharge to the IGBT. At the same time, the energy storage module 01 and the inductor L form an oscillating circuit, making the current waveform in the loop where the IGBT is located as Figure 2 shown.

[0053] Continue to refer to Figure 3 , optionally, the trigger module 03 includes a first trigger unit 031, a second trigger unit 032, and a third trigger unit 033;

[0054] The output terminal of the first trigger unit 031 serves as the first output terminal of the trigger module 03, the output terminal of the second trigger unit 032 serves as the second output terminal of the trigger module 03, the input terminal of the third trigger unit 033 serves as the input terminal of the trigger module 03, and the output terminal of the third trigger unit 033 serves as the third output terminal of the trigger module 03.

[0055] The first trigger unit 031, the second trigger unit 032, and the third trigger unit 033 can all be monostable flip-flops, and the working processes among the first trigger unit 031, the second trigger unit 032, and the third trigger unit 033 are independent of each other and do not affect each other.

[0056] The first trigger unit 031 and the second trigger unit 032 respectively send pulse signals to the control switch Q1 and the IGBT. Exemplarily, when the control terminal of the control switch Q1 receives a high-level signal, the control switch Q1 conducts. When the control terminal of the IGBT receives a high-level signal, the IGBT conducts. After the control switch Q1 and the IGBT conduct, the energy storage module 01 discharges to the IGBT.

[0057] Exemplarily, the third trigger unit 033 is a monostable flip-flop triggered by a falling edge. That is, after the input terminal of the third trigger unit 033 receives a falling edge, a pulse will be output at the output terminal. Refer to Figure 2 and Figure 3 , the current setting comparison module 05 generates a falling edge at the second intersection point b. When the third trigger unit 033 receives the falling edge, it immediately outputs a sample and hold signal to the sample and hold module 06, so that the sample and hold module 06 samples the voltage between the collector and emitter of the IGBT at the current moment, that is, the saturation voltage of the IGBT collector-emitter.

[0058] Continue to refer to Figure 3 , optionally, the first trigger unit 031 includes a first sub-trigger 0311 and a second sub-trigger 0312;

[0059] The output terminal of the first sub-trigger 0311 is electrically connected to the input terminal of the second sub-trigger 0312, and the output terminal of the second sub-trigger 0312 serves as the output terminal of the first trigger unit 031.

[0060] When controlling the conduction of the control switch Q1 and the IGBT, the conduction time of the IGBT can be controlled to be earlier than that of the control switch Q1. Exemplarily, the IGBT can be controlled to conduct 500 us earlier than the control switch Q1. According to the time when the IGBT conducts earlier than the control switch Q1, the specification of the first sub-trigger 0311 is selected, that is, the width of the pulse sent by the first sub-trigger 0311 is 500 us. The second sub-trigger 0312 can be triggered by the falling edge. The second trigger unit 032 and the first sub-trigger 0311 send pulses simultaneously. The second trigger unit 032 sends a pulse to the control terminal of the IGBT to make the IGBT conduct. At the same time, the first sub-trigger 0311 sends a 500-us pulse to the second sub-trigger 0312. After 500 us, when the second sub-trigger 0312 receives the falling edge sent by the first sub-trigger 0311, the second sub-trigger 0312 sends a pulse to the control terminal of the control switch Q1, thereby controlling the conduction of the control switch Q1. Thus, through the first sub-trigger 0311 and the second sub-trigger 0312, the control switch Q1 can conduct later than the IGBT.

[0061] Continue to refer to Figure 3 , optionally, the saturation voltage detection device of the IGBT collector-emitter further includes a power supply module 07, a power supply trigger module 08, and a rectification module 09. The power supply module 07 is electrically connected to the power supply trigger module 08. The power supply trigger module 08 is electrically connected to the control terminal of the rectification module 09. The first end of the rectification module 09 is electrically connected to the first end of the energy storage module 01. The second end of the rectification module 09 is electrically connected to the second end of the energy storage module 01.

[0062] The power supply module 07 can include an AC power supply 071, a transformer 072, and a shaping circuit 073. The AC power supply 071 is electrically connected to the transformer 072. The transformer 072 is electrically connected to the shaping circuit 073. The shaping circuit 073 is electrically connected to the power supply trigger module 08. The AC power supply 071 can be 220V AC. The voltage provided by the 220V AC is relatively large and cannot be directly supplied to the IGBT. Therefore, it needs to be stepped down by the transformer 072 to a smaller voltage that the IGBT can bear. After the shaping circuit 073, the voltage waveform output by the transformer 072 is shaped.

[0063] The power supply trigger module 08 can be a monostable flip-flop. The rectification module 09 can be a single-phase semi-controlled bridge rectification circuit. The rectification module 09 is used to convert the alternating current of the AC power supply 071 into direct current to supply to the energy storage module 01. The rectification module 09 includes a plurality of thyristors. The control terminals of the thyristors are electrically connected to the power supply trigger module 08. When the power supply trigger module 08 sends a pulse to the rectification module 09, the thyristors of the rectification module 09 conduct, rectifying the AC power supply 071, so that the rectification module 09 can output direct current to the energy storage module 01, thereby enabling the energy storage module 01 to complete the charging process.

[0064] The saturation voltage detection device for the IGBT collector-emitter also includes a current-limiting resistor R1. One end of the current-limiting resistor R1 is electrically connected to the first end of the rectification module 09, and the other end of the current-limiting resistor R1 is electrically connected to the first end of the energy storage module 01. The current-limiting resistor R1 reduces the current in the charging circuit during the process of the power supply module 07 charging the energy storage module 01, avoiding damage to the device due to excessive current.

[0065] Figure 4 The following is a schematic structural diagram of another saturation voltage detection device for the IGBT collector-emitter provided by the embodiment of the present invention. Refer to Figure 4 Optionally, the saturation voltage detection device for the IGBT collector-emitter further includes a first comparison module 10, an inverter 11, and a charging indication module 12;

[0066] The first input terminal of the first comparison module 10 accesses the set signal of the set current. The second input terminal of the first comparison module 10 is electrically connected to the voltage acquisition module 13 connected to the energy storage module 01. The output terminal of the first comparison module 10 is electrically connected to the input terminal of the inverter 11. The output terminal of the inverter 11 is electrically connected to one end of the charging indication module 12, and the other end of the charging indication module 12 is grounded.

[0067] The set signal of the set current can be obtained by a current setting potentiometer 101 and a first proportional operator 102. The output terminal of the current setting potentiometer 101 is electrically connected to the input terminal of the first proportional operator 102. The first output terminal of the first proportional operator 102 is electrically connected to the first input terminal of the first comparison module 10. The voltage output by the current setting potentiometer 101 is a multiple voltage of the voltage value corresponding to the set current. Exemplarily, the voltage output by the current setting potentiometer 101 is one-tenth of the voltage value corresponding to the set current. Therefore, the first proportional operator 102 is also required to amplify the voltage output by the current setting potentiometer 101 by 10 times to the voltage value corresponding to the set current. The voltage acquisition module 13 can be a voltage sensor for acquiring the voltage of the energy storage module 01.

[0068] The first comparison module 10 is a comparator. The non-inverting input terminal of the comparator serves as the first input terminal of the first comparison module 10. The inverting input terminal of the comparator serves as the second input terminal of the first comparison module 10. The output terminal of the comparator serves as the output terminal of the first comparison module 10. The voltage acquisition module 13 is electrically connected to the second input terminal of the first comparison module 10 through a second proportional operator 103. The charging indication module 12 can be a light-emitting diode. Exemplarily, the charging indication module 12 can emit green light.

[0069] The power supply module 07 continuously charges the energy storage module 01, causing the voltage across the energy storage module 01 to continuously increase. When the voltage of the energy storage module 01 amplified by the second proportional arithmetic unit 103 is greater than the voltage value corresponding to the set current, the first comparison module 10 outputs a low level. This low level is inverted by the inverter 11 and then outputs a high level to the charging indication module 12, which is lit, indicating that the charging process of the energy storage module 01 is completed.

[0070] Figure 5 The figure is a schematic structural diagram of another IGBT collector-emitter saturation voltage detection device provided by an embodiment of the present invention. Refer to Figure 5 Optionally, the IGBT collector-emitter saturation voltage detection device further includes a charging control module 14. The first input terminal of the charging control module 14 is electrically connected to the power trigger module 08, the second input terminal of the charging control module 14 is electrically connected to the output terminal of the first comparison module 10, and the output terminal of the charging control module 14 is electrically connected to the control terminal of the rectification module 09. The charging control module 14 is configured to control the power supply module 07 to charge the energy storage module 01 when the voltage value corresponding to the set current is greater than the voltage value corresponding to the energy storage module 01.

[0071] The charging control module 14 can be an AND gate. The power trigger module 08 continuously sends out pulses. When the voltage input to the first input terminal of the first comparison module 10 is greater than the voltage input to the second input terminal of the first comparison module 10, that is, the voltage value corresponding to the set current is greater than the voltage across the energy storage module 01, the first comparison module 10 outputs a high level. At this time, the voltage across the energy storage module 01 has not reached the voltage value corresponding to the set current and needs to continue charging. A high level is input to the second input terminal of the AND gate. At this time, the pulses sent by the power trigger module 08 can be transmitted through the AND gate to the control terminal of the rectification module 09, enabling the rectification module 09 to rectify the alternating current of the power supply module 07 into direct current and supply it to the energy storage module 01, so that the energy storage module 01 continues to charge until the voltage across the energy storage module 01 is greater than the voltage value corresponding to the set current. At this time, the first comparison module 10 outputs a low level to the second input terminal of the AND gate. At this time, the AND gate blocks the pulses of the power trigger module 08 from continuing to be transmitted to the rectification module 09, and the rectification module 09 cannot complete rectification and no longer outputs direct current, and the energy storage module 01 stops charging.

[0072] Figure 6 The figure is a schematic structural diagram of another IGBT collector-emitter saturation voltage detection device provided by an embodiment of the present invention. Refer to Figure 6 Optionally, the IGBT collector-emitter saturation voltage detection device further includes a button module 15;

[0073] The button module 15 is electrically connected to the input terminal of the first trigger unit 031, the input terminal of the second trigger unit 032, and the third input terminal of the charging control module 14 respectively. The button module 15 is configured to send corresponding level signals to the first trigger unit 031, the second trigger unit 032, and the charging control module 14 according to the state of the charging indication module 12.

[0074] When the button module 15 is pressed, the button module 15 outputs a level signal, such as a low level signal. When the charging indication module 12 is a light-emitting diode, the states of the charging indication module 12 are two states of the light on and the light off. When the charging indication module 12 is on, the energy storage module 01 is fully charged. At this time, the saturation voltage of the IGBT collector-emitter can be detected. When the button module 15 is pressed, the detection starts. At this time, the button module 15 sends low level signals to the second trigger unit 032 and the first sub-trigger 0311 simultaneously, so that the second trigger unit 032 immediately controls the IGBT to conduct, and after a period of time, the second sub-trigger 0312 controls the control switch Q1 to conduct, and the energy storage module 01 discharges to the IGBT. In the initial detection stage, the power supply module 07 does not need to continue to supply power to the energy storage module 01. When the button module 15 is pressed, the charging control module 14 inputs a low level, thereby blocking the power trigger module 07 from sending a pulse to the rectification module 09, so that the rectification module 09 no longer rectifies, that is, no longer outputs direct current to the energy storage module 01, and the energy storage module 01 stops charging.

[0075] Figure 7 It is a schematic structural diagram of another saturation voltage detection device for the IGBT collector-emitter provided by an embodiment of the present invention. Refer to Figure 7 Optionally, the saturation voltage detection device for the IGBT collector-emitter further includes a second comparison module 16, a discharge switch Q2, and a discharge resistor R2;

[0076] The first input terminal of the second comparison module 16 is electrically connected to the voltage acquisition module 13, the second input terminal of the second comparison module 16 accesses a threshold setting signal of a set current, and the output terminal of the second comparison module 16 is electrically connected to the control terminal of the discharge switch Q2;

[0077] The first end of the discharge resistor R2 is electrically connected to the first end of the energy storage module 01, the second end of the discharge resistor R2 is electrically connected to the first end of the discharge switch Q2, and the second end of the discharge switch Q2 is electrically connected to the second end of the energy storage module 01. The discharge switch Q2 is configured to control the energy storage module 01 to discharge to the discharge resistor R2 when the voltage value output by the voltage acquisition module 13 is greater than the voltage value corresponding to the maximum value of the set current.

[0078] When the power supply module 07 charges the energy storage module 01, the voltage across the energy storage module 01 should not be too large. Exemplarily, it can be set that the voltage across the energy storage module 01 should not be greater than 1.1 times the voltage value corresponding to the set current. That is, the voltage value of 1.1 times the voltage value corresponding to the set current is the threshold voltage. The threshold setting signal of the set current can be obtained from the current setting potentiometer 101, the first proportional arithmetic unit 102, and the third proportional arithmetic unit 104. The amplification factor of the third proportional arithmetic unit 104 is 1.1 times in this embodiment. The input end of the third proportional arithmetic unit 104 is electrically connected to the second output end of the first proportional arithmetic unit 102, and the output end of the third proportional arithmetic unit 104 is electrically connected to the second input end of the second comparison module 16. The second comparison module 16 can be a comparator. The non-inverting input end of the comparator serves as the first input end of the second comparison module 16, the inverting input end of the comparator serves as the second input end of the second comparison module 16, and the output end of the comparator serves as the output end of the second comparison module 16.

[0079] The discharge switch Q2 can be a transistor, and the base of the transistor serves as the control end of the discharge switch Q2.

[0080] When the voltage across the energy storage module 01 is greater than the threshold voltage, the second comparison module 16 outputs a high level to the control end of the discharge switch Q2, and the discharge switch Q2 conducts. A closed loop is formed among the energy storage module 01, the discharge resistor R2, and the discharge switch Q2. The energy storage module 01 discharges through the discharge resistor R2 to reduce the voltage across itself.

[0081] The saturation voltage detection device for the IGBT collector-emitter also includes a discharge indication module 17. One end of the discharge indication module 17 is electrically connected to the output end of the first comparison module 16, and the other end of the discharge indication module 17 is grounded. The discharge indication module 17 can be a light-emitting diode, and the corresponding light-emitting diode of the discharge indication module 17 can emit red light, making its light-emitting color different from that of the charging indication module 12. When the voltage across the energy storage module 01 is greater than the threshold voltage, the second comparison module 16 outputs a high level to the discharge indication module 17 to make it conduct and emit light. That is, when the discharge indication module 17 is on, it indicates that the voltage across the energy storage module 01 is higher than the threshold voltage. At this time, the button module 15 cannot be pressed for detection.

[0082] Continue to refer to Figure 7 , optionally, the saturation voltage detection device for the IGBT collector-emitter further includes a display module 18;

[0083] The display module 18 is electrically connected to the output end of the sample and hold module 06.

[0084] The display module 18 can be a digital tube or other devices with a display function. This embodiment does not make specific limitations here.

[0085] The output terminal of the sampling and holding module can also be connected to the background master station, and the saturation voltage of the IGBT collector-emitter output can be transmitted to the background master station.

[0086] Note that the above is only the preferred embodiment of the present invention and the applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An IGBT collector-emitter saturation voltage detection device, characterized in that, Including: Energy storage module, discharge control module, trigger module, current sampling module, current setting comparison module, and sample and hold module; The first end of the discharge control module is electrically connected to the energy storage module, the second end of the discharge control module is electrically connected to the collector of the IGBT, and the emitter of the IGBT is electrically connected to the second end of the energy storage module through the current sampling module; The first output end of the trigger module is electrically connected to the control end of the discharge control module, the second output end of the trigger module is electrically connected to the base of the IGBT, and the trigger module is used to send a trigger signal to the discharge control module and the IGBT to control the energy storage module to discharge to the IGBT through the discharge control module; The first input end of the current setting comparison module is electrically connected to the current sampling module, the second input end of the current setting comparison module inputs a setting signal corresponding to a set current, the output end of the current setting comparison module is electrically connected to the input end of the trigger module, the current sampling module is used to collect the current in the loop where the IGBT is located, and the current setting comparison module is used to output a trigger signal to the trigger module according to the magnitude relationship between the current collected by the current sampling module and the set current; The trigger module is used to send a sample and hold signal to the sample and hold module according to the trigger signal; The first end of the sample and hold module is electrically connected to the collector of the IGBT, the second end of the sample and hold module is electrically connected to the emitter of the IGBT, the third end of the sample and hold module is electrically connected to the third output end of the trigger module, and the sample and hold module is used to output the voltage difference between the collector and emitter of the IGBT when receiving the sample and hold signal; The saturation voltage detection device of the IGBT collector-emitter further includes a second comparison module, a discharge switch, and a discharge resistor; The first input end of the second comparison module is electrically connected to the voltage acquisition module connected to the energy storage module, the second input end of the second comparison module accesses a threshold setting signal of the set current, and the output end of the second comparison module is electrically connected to the control end of the discharge switch; The first end of the discharge resistor is electrically connected to the first end of the energy storage module, the second end of the discharge resistor is electrically connected to the first end of the discharge switch, the second end of the discharge switch is electrically connected to the second end of the energy storage module, and the discharge switch is used to control the energy storage module to discharge to the discharge resistor when the voltage value output by the voltage acquisition module is greater than the voltage value corresponding to the maximum value of the set current.

2. The saturation voltage detection device for the IGBT collector-emitter according to claim 1, characterized in that, The discharge control module includes a control switch and an inductor; The first end of the control switch serves as the first end of the discharge control module, the second end of the control switch is electrically connected to the first end of the inductor, the control end of the control switch serves as the control end of the discharge control module, and the second end of the inductor serves as the second end of the discharge control module.

3. The saturation voltage detection device for the IGBT collector-emitter according to claim 2, characterized in that, The trigger module includes a first trigger unit, a second trigger unit, and a third trigger unit; The output terminal of the first trigger unit serves as the first output terminal of the trigger module, the output terminal of the second trigger unit serves as the second output terminal of the trigger module, the input terminal of the third trigger unit serves as the input terminal of the trigger module, and the output terminal of the third trigger unit serves as the third output terminal of the trigger module.

4. The saturation voltage detection device for the IGBT collector-emitter according to claim 3, characterized in that, The first trigger unit includes a first sub-trigger and a second sub-trigger; The output terminal of the first sub-trigger is electrically connected to the input terminal of the second sub-trigger, and the output terminal of the second sub-trigger serves as the output terminal of the first trigger unit.

5. The saturation voltage detection device for the IGBT collector-emitter according to claim 3, characterized in that, It further includes a power supply module, a power supply trigger module, and a rectification module. The power supply module is electrically connected to the power supply trigger module, the power supply trigger module is electrically connected to the control terminal of the rectification module, the first end of the rectification module is electrically connected to the first end of the energy storage module, and the second end of the rectification module is electrically connected to the second end of the energy storage module.

6. The IGBT collector-emitter saturation voltage detection device according to claim 5, characterized in that, It further includes a first comparison module, an inverter, and a charging indication module; The first input terminal of the first comparison module receives the set signal of the set current, the second input terminal of the first comparison module is electrically connected to the voltage acquisition module connected to the energy storage module, the output terminal of the first comparison module is electrically connected to the input terminal of the inverter, the output terminal of the inverter is electrically connected to one end of the charging indication module, and the other end of the charging indication module is grounded.

7. The saturation voltage detection device for the IGBT collector-emitter according to claim 6, wherein It further includes a charging control module; The first input terminal of the charging control module is electrically connected to the power supply trigger module, the second input terminal of the charging control module is electrically connected to the output terminal of the first comparison module, the output terminal of the charging control module is electrically connected to the control terminal of the rectification module, and the charging control module is used to control the power supply module to charge the energy storage module when the voltage value corresponding to the set current is greater than the voltage value corresponding to the energy storage module.

8. The saturation voltage detection device for the IGBT collector-emitter according to claim 7, characterized in that, It further includes a button module; The button module is respectively electrically connected to the input terminal of the first trigger unit, the input terminal of the second trigger unit, and the third input terminal of the charging control module, and the button module is used to send corresponding level signals to the first trigger unit, the second trigger unit, and the charging control module according to the state of the charging indication module.

9. The saturation voltage detection device for the IGBT collector-emitter according to claim 1, wherein It further includes a display module; The display module is electrically connected to the output terminal of the sample and hold module.

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