Double-pulse test circuit and test method for H6 type inverter power device

Abstract

The invention provides a double-pulse test circuit and test method for an H6 type inverter power device, the double-pulse test circuit comprises an energy charging and discharging unit and an H6 type inverter unit, the energy charging and discharging unit charges a direct current bus capacitor and provides a direct current bus voltage for the H6 type inverter unit; and the H6 type inverter unit is connected with the charging and discharging unit, and switches a circuit commutation path by controlling the on and off of each switching tube in the H6 type inverter unit so as to carry out a double-pulse test. According to the invention, the problem that the actual working characteristics of the power device in the H6-type inverter cannot be accurately analyzed by a traditional double-pulse test circuit is solved.

Description

Technical Field

[0001] The invention relates to the technical field of electronic circuits, and in particular to a double pulse test circuit and a test method for an H6 type inverter power device. Background Art

[0002] Compared with isolated photovoltaic grid-connected inverters, non-isolated photovoltaic grid-connected inverters have the advantages of small size and high efficiency; however, the traditional H4 inverter has a large leakage current, and its efficiency and safety are not high. The H6 inverter has the advantages of small leakage current and high efficiency. In recent years, it has been widely used in photovoltaic grid-connected inverters.

[0003] Double pulse testing is an important means of analyzing the performance of power devices. Through double pulse testing, the switching characteristics, reverse recovery characteristics, and ultimate working capacity of power devices can be analyzed. It provides guidance for the selection of power devices and drive circuit design of inverters, and can also be used to analyze the failure mechanism of power devices.

[0004] The traditional double-pulse test circuit adopts a chopper topology, which can only simulate the commutation process between a single switch tube and a single diode, and test the switching characteristics, reverse recovery characteristics, temperature characteristics, etc. of the relevant power devices in the process; for complex topologies, such as the H6 inverter, the traditional double-pulse test circuit cannot accurately reflect the working characteristics of the power devices in the actual circuit.

[0005] In view of this, providing a new double-pulse test circuit and test method to analyze the actual working characteristics of power devices in the H6 inverter is a technical problem that technical personnel in this field are eager to solve. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a double pulse test circuit and test method for H6 type inverter power devices, so as to solve the problem that the traditional double pulse test circuit cannot accurately analyze the actual working characteristics of the power devices in the H6 type inverter.

[0007] To achieve the above-mentioned object and other related objects, the present invention provides a double pulse test circuit for an H6 type inverter power device, the double pulse test circuit comprising a charge and discharge unit and an H6 type inverter unit, wherein:

[0008] The charging and discharging unit provides a DC bus voltage to the H6 type inverter unit by charging the DC bus capacitor;

[0009] The H6 inverter unit is connected to the charging and discharging unit, and the circuit commutation path is switched by controlling the on and off of each switch tube therein to perform a double pulse test.

[0010] Optionally, the charging and discharging unit includes a DC power supply, a current limiting resistor, a first switch, a DC bus capacitor, a second switch and a discharge resistor;

[0011] The positive terminal of the DC power supply is connected to the upper plate of the DC bus capacitor via the current limiting resistor and the first switch, and the negative terminal is connected to the lower plate of the DC bus capacitor; the second switch and the discharge resistor are connected in series between the upper plate and the lower plate of the DC bus capacitor.

[0012] Optionally, the charging and discharging unit further includes a control module, which is used to generate a first control signal and a second control signal to control the opening and closing of the first switch and the second switch respectively.

[0013] Optionally, the charging and discharging unit further includes a monitoring module for monitoring the voltage of the DC bus capacitor; in this case, the control module is connected to the monitoring module for generating the first control signal and the second control signal according to the monitoring results.

[0014] Optionally, the H6 inverter unit includes a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube, a sixth switch tube, a first diode, a second diode and an inductor;

[0015] The first switch tube, the third switch tube and the fifth switch tube are connected in series at both ends of the charge and discharge unit, the second switch tube, the fourth switch tube and the sixth switch tube are connected in series at both ends of the charge and discharge unit, and the control end of each switch tube is connected to a corresponding drive signal;

[0016] The anode end of the first diode is connected to the connection node between the fourth switch tube and the sixth switch tube, and the cathode end is connected to the connection node between the first switch tube and the third switch tube;

[0017] The anode end of the second diode is connected to the connection node between the third switch tube and the fifth switch tube, and the cathode end is connected to the connection node between the second switch tube and the fourth switch tube;

[0018] The first end of the inductor is connected to a connection node between the first switch tube and the third switch tube, and the second end of the inductor is connected to a connection node between the second switch tube and the fourth switch tube.

[0019] Optionally, the double pulse test circuit further includes a waveform test unit connected to the H6 type inverter unit and used to test the electrical signal waveform of the corresponding power device in the H6 type inverter unit.

[0020] The present invention also provides a double pulse test method for an H6 inverter power device, the double pulse test method comprising:

[0021] The DC bus capacitor is charged to obtain a DC bus voltage and applied to both ends of the H6 inverter unit;

[0022] Controlling the on and off of each switch tube in the H6 inverter unit to switch the circuit commutation path to perform a double pulse test;

[0023] After the test is completed, the DC bus capacitor is discharged.

[0024] Optionally, by switching the circuit commutation path, a double pulse test is performed on the first switch tube, the fourth switch tube, the sixth switch tube and the first diode in the H6 inverter unit, and another double pulse test is performed on the second switch tube, the third switch tube, the fifth switch tube and the second diode in the H6 inverter unit.

[0025] Optionally, when a double pulse test is performed on the first switch tube, the fourth switch tube, the sixth switch tube and the first diode:

[0026] During the test, double pulses are applied to the first switch tube and the sixth switch tube, the fourth switch tube remains turned on, and the second switch tube, the third switch tube and the fifth switch tube remain turned off, and the working characteristics of the corresponding power devices when zero current is turned on, half current is turned off, half current is turned on and large current is turned off are tested by switching the circuit commutation path;

[0027] When a double pulse test is performed on the second switch tube, the third switch tube, the fifth switch tube and the second diode:

[0028] During the test, double pulses are applied to the second switch tube and the fifth switch tube, the third switch tube remains turned on, and the first switch tube, the fourth switch tube and the sixth switch tube remain turned off. The operating characteristics of the corresponding power devices at zero current turn-on, half current turn-off, half current turn-on and high current turn-off are tested by switching the circuit commutation path.

[0029] Optionally, before performing the double pulse test, the method further includes the step of obtaining the pulse width;

[0030] Among them, the pulse width satisfies the formula L is the inductance value, V DD is the DC bus voltage value, T on is the pulse width value, I Lmax is the maximum inductor current value.

[0031] As described above, the dual pulse test circuit and test method of the H6 inverter power device of the present invention directly perform a dual pulse test on the H6 inverter, and the test of all power devices can be completed using two sets of pulse timings, which can more quickly, more accurately and more realistically reflect the actual working characteristics of each power device (including each switch tube and each diode) in the H6 inverter, and is convenient for testing and analyzing the switching process, commutation process and limit characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Shown is a schematic diagram of a double pulse test circuit of the present invention.

[0033] Figure 2 It shows a timing diagram of the driving signal applied when the double pulse test circuit of the present invention performs a double pulse test on the first switch tube, the fourth switch tube, the sixth switch tube and the first diode.

[0034] Figure 3 It shows the corresponding schematic diagram when the first, fourth and sixth switch tubes are turned on and the other switch tubes are turned off.

[0035] Figure 4 The diagram shows a corresponding situation when the fourth switch tube is turned on and the other switch tubes are turned off.

[0036] Figure 5 It shows a timing diagram of the driving signal applied when the double pulse test circuit of the present invention performs a double pulse test on the second switch tube, the third switch tube, the fifth switch tube and the second diode.

[0037] Figure 6 The diagram shows the corresponding situation when the second, third and fifth switch tubes are turned on and the other switch tubes are turned off.

[0038] Figure 7 The diagram shows a corresponding situation when the third switch tube is turned on and the other switch tubes are turned off.

[0039] Component number description

[0040] 100 Double Pulse Test Circuit

[0041] 110 Charging and discharging unit

[0042] 111 Control module

[0043] 112 Monitoring Module

[0044] 120 H6 inverter unit

[0045] 130 Waveform Test Unit DETAILED DESCRIPTION

[0046] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0047] See also Figures 1 to 7 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the form, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0048] like Figure 1 As shown, this embodiment provides a double pulse test circuit 100 for an H6 type inverter power device, including a charge and discharge unit 110 and an H6 type inverter unit 120; further, it also includes a waveform test unit 130. Among them:

[0049] The charging and discharging unit 110 connects the DC bus capacitor C bus The H6 inverter unit 120 is charged to provide a DC bus voltage V DD .

[0050] As an example, the charging and discharging unit 110 includes a DC power supply DC, a current limiting resistor R1, a first switch SW1, a DC bus capacitor C bus , the second switch SW2 and the discharge resistor R2; the positive terminal of the DC power supply DC is connected to the DC bus capacitor C through the current limiting resistor R1 and the first switch SW1 bus The negative terminal is connected to the DC bus capacitor C bus The second switch SW2 and the discharge resistor R2 are connected in series to the DC bus capacitor C bus between the upper and lower plates.

[0051] The DC power supply DC is an adjustable DC power supply, which is convenient for designing the DC bus voltage V according to actual application requirements. DD The first switch SW1 and the second switch SW2 are of the same switch type, including a bidirectional switch or a mechanical switch (such as a relay or a circuit breaker, etc.) formed by a back-to-back connection of MOSFETs. Of course, the different switch types of the two have no substantial impact on this embodiment. The resistance values ​​of the current limiting resistor R1 and the bleeder resistor R2 are set according to actual application requirements, and this embodiment does not limit this.

[0052] When the first switch SW1 is closed and the second switch SW2 is open, the DC bus capacitor C bus Charging, the capacitor voltage increases until it reaches the DC bus voltage V DD During the charging process, the charging current is controlled by designing the resistance value of the current limiting resistor R1, thereby controlling the charging speed. When the first switch SW1 is opened and the second switch SW2 is closed, the DC bus capacitor C is discharged through the discharge resistor R2. bus During discharge, the capacitor voltage drops to zero volts. During the discharge process, the discharge current is controlled by designing the resistance value of the discharge resistor R2, thereby controlling the discharge speed.

[0053] In this example, the charging and discharging unit 110 further includes a control module 111 for generating a first control signal and a second control signal to control the opening and closing of the first switch SW1 and the second switch SW2 respectively.

[0054] Furthermore, the charging and discharging unit 110 further includes a monitoring module 112 for monitoring the DC bus capacitor C bus voltage; at this time, the control module 111 is connected to the monitoring module 112 for generating a first control signal and a second control signal according to the monitoring result.

[0055] Take the example that the first switch SW1 and the second switch SW2 are controlled to be closed when the corresponding control signal is at a high level and controlled to be opened when the corresponding control signal is at a low level;

[0056] During the charging process: If the DC bus capacitor C bus The voltage across the two ends does not reach the DC bus voltage V DD , the monitoring module 112 generates a high-level first control signal and a low-level second control signal to control the first switch SW1 to be closed and the second switch SW2 to be opened; if the DC bus capacitor C bus The voltage at both ends reaches the DC bus voltage V DD , the monitoring module 112 generates a low-level first control signal and a low-level second control signal to control the first switch SW1 and the second switch SW2 to open;

[0057] During the discharge process: If the DC bus capacitor C bus The voltage at both ends does not reach zero volts, the monitoring module 112 generates a low-level first control signal and a high-level second control signal to control the first switch SW1 to open and the second switch SW2 to close; if the DC bus capacitor C bus When the voltage across both ends reaches zero volts, the monitoring module 112 generates a low-level first control signal and a low-level second control signal to control the first switch SW1 and the second switch SW2 to open.

[0058] The H6 inverter unit 120 is connected to the charging and discharging unit 110, and switches the circuit commutation path by controlling the on and off of each switch tube therein to perform a double pulse test.

[0059] As an example, the H6 inverter unit 120 includes a first switch tube T1, a second switch tube T2, a third switch tube T3, a fourth switch tube T4, a fifth switch tube T5, a sixth switch tube T6, a first diode D1, a second diode D2 and an inductor L; the first switch tube T1, the third switch tube T3 and the fifth switch tube T5 are connected in series at both ends of the charging and discharging unit 110, the second switch tube T2, the fourth switch tube T4 and the sixth switch tube T6 are connected in series at both ends of the charging and discharging unit 110, and the control end of each switch tube is connected to the corresponding drive signal The anode end of the first diode D1 is connected to the connection node of the fourth switch tube T4 and the sixth switch tube T6, and the cathode end is connected to the connection node of the first switch tube T1 and the third switch tube T3; the anode end of the second diode D2 is connected to the connection node of the third switch tube T3 and the fifth switch tube T5, and the cathode end is connected to the connection node of the second switch tube T2 and the fourth switch tube T4; the first end of the inductor L is connected to the connection node of the first switch tube T1 and the third switch tube T3, and the second end is connected to the connection node of the second switch tube T2 and the fourth switch tube T4.

[0060] It should be noted that the control end of each switch tube is connected to the corresponding drive signal means: the control end of the first switch tube T1 is connected to the first drive signal V g1 The control end of the second switch tube T2 is connected to the second drive signal V g2 The control end of the third switch tube T3 is connected to the third drive signal V g3 The control end of the fourth switch tube T4 is connected to the fourth drive signal V g4 The control end of the fifth switch tube T5 is connected to the fifth drive signal V g5 The control end of the sixth switch tube T6 is connected to the sixth drive signal V g6 .

[0061] Among them, each switch tube is a fully controlled power device with the same device type, including IGBT (insulated gate bipolar transistor) or MOSFET (metal-oxide semiconductor field effect transistor). Of course, the different device types of each switch tube have no substantial impact on this embodiment; the first diode D1 and the second diode D2 have the same device type, including FRD (recovery diode) or SBD (Schottky diode). Of course, the different device types of the two have no substantial impact on this embodiment; the inductor L is an inductor with low magnetic permeability, such as a hollow inductor.

[0062] The waveform testing unit 130 is connected to the H6 inverter unit 120 and is used to test the electrical signal waveform of the corresponding power device in the H6 inverter unit 120 .

[0063] As an example, the waveform test unit 130 is implemented by an oscilloscope. By connecting the specific port of the corresponding power device in the H6 inverter unit 120 to the corresponding test channel of the oscilloscope, the electrical signal waveform of the corresponding power device can be tested; for example, the gate voltage v of each switch tube ge , collector-emitter voltage v ce , collector current i c The waveform test of each diode's forward conduction current i F , forward conduction voltage v F Waveform test.

[0064] This embodiment also provides a double pulse test method for an H6 inverter power device, which can be implemented using the double pulse test circuit 100 as described above, including steps S1 to S3, and further including step S0.

[0065] Step S0: Obtain pulse width.

[0066] As an alternative, the double pulse test involves two pulses with the same pulse width, satisfying the formula Where L is the inductance, V DD is the DC bus voltage value, T on is the pulse width value, I Lmax is the maximum inductor current value. In practical applications, according to test requirements, the DC bus voltage value V DD , Maximum inductor current value I Lmax and inductance L are known values. Thus, substituting the three known values ​​into the above formula can obtain the pulse width T on The value of .

[0067] Step S1: DC bus capacitor C bus Charging to obtain DC bus voltage V DD And applied to both ends of the H6 type inverter unit 120.

[0068] For example, the first switch SW1 is controlled to be closed by the first control signal, and the second switch SW2 is controlled to be opened by the second control signal, and the DC bus capacitor C is connected to the DC bus capacitor C by the DC power supply DC. bus When the capacitor voltage reaches the DC bus voltage V DD When the first switch SW1 is controlled by the first control signal to open, the charging is completed.

[0069] Step S2: Control the on and off of each switch tube in the H6 inverter unit 120 to switch the circuit commutation path to perform a double pulse test.

[0070] Specifically, by switching the circuit commutation path, a double pulse test is performed on the first switch tube T1, the fourth switch tube T4, the sixth switch tube T6 and the first diode D1 in the H6 inverter unit 120, and another double pulse test is performed on the second switch tube T2, the third switch tube T3, the fifth switch tube T5 and the second diode D2 in the H6 inverter unit 120.

[0071] Among them, when the double pulse test is performed on the first switch tube T1, the fourth switch tube T4, the sixth switch tube T6 and the first diode D1: during the test, the double pulse is applied to the first switch tube T1 and the sixth switch tube T6, the fourth switch tube T4 remains turned on, and the second switch tube T2, the third switch tube T3 and the fifth switch tube T5 remain turned off, and the working characteristics of the corresponding power devices at zero current turn-on, half current turn-off, half current turn-on and high current turn-off are tested by switching the circuit commutation path.

[0072] For example, the following is applied to each switch tube in the H6 inverter unit 120: Figure 2 The driving signal shown, that is, applying double pulses to the first switch tube T1 and the sixth switch tube T6, the fourth switch tube T4 remains turned on, and the second switch tube T2, the third switch tube T3 and the switch tube device T5 remain turned off;

[0073] At time t0, the first switch tube T1, the fourth switch tube T4, and the sixth switch tube T6 are turned on, and the DC bus capacitor C bus The inductor L starts to be charged through the first switch tube T1, the fourth switch tube T4, and the sixth switch tube T6. The circuit flow path is as follows: Figure 3 As shown; at this time, the gate voltage v of the first switch tube T1, the fourth switch tube T4, and the sixth switch tube T6 when the zero current is turned on can be tested. ge Oscillation, collector current i c The current peak and di / dt, collector-emitter voltage v ce Voltage drop and dv / dt, zero current turn-on loss, etc.

[0074] At time t1, the first switch tube T1 and the sixth switch tube T6 are turned off, and the fourth switch tube T4 remains turned on. The inductor current is commutated from the conductive channels of the first switch tube T1 and the sixth switch tube T6 to the first diode D1. The inductor current continues to flow in the conductive channel of the fourth switch tube T4 and the first diode D1. The circuit flow path is as follows: Figure 4 As shown; at this time, the gate voltage v of the first switch tube T1 and the sixth switch tube T6 when the half current is turned off can be tested. ge Oscillation, collector current i c The current peak and di / dt, collector-emitter voltage v ce Voltage spikes and dv / dt, half-current turn-off losses, etc.

[0075] At time t2, the first switch tube T1 and the sixth switch tube T6 are turned on again, and the fourth switch tube T4 remains turned on. The inductor current is commutated by the first diode D1 to the conductive channel of the first switch tube T1 and the sixth switch tube T6 again. At this time, the gate voltage v of the first switch tube T1 and the sixth switch tube T6 when the half current is turned on can be tested. ge Oscillation, collector current i c The current peak and di / dt, collector-emitter voltage v ce The voltage drop and dv / dt, half-current turn-on loss, etc. can also be tested for the reverse recovery of the first diode D1;

[0076] At time t3, the first switch tube T1 and the sixth switch tube T6 are turned off, and the fourth switch tube T4 continues to be turned on. The inductor current is commutated from the conductive channel of the first switch tube T1 and the sixth switch tube T6 to the first diode D1 again, and the inductor current continues to flow in the conductive channel of the fourth switch tube T4 and the first diode D1. At this time, the gate voltage v of the first switch tube T1 and the sixth switch tube T6 when the large current is turned off can be tested. ge Oscillation, collector current i c The current peak and di / dt, collector-emitter voltage v ce Voltage spikes and dv / dt, large current turn-off losses, etc.

[0077] At time t4, the fourth switch tube T4 is turned off, and the first switch tube T1 and the sixth switch tube T6 remain turned off. At this time, the gate voltage v of the fourth switch tube T4 when the large current is turned off can be tested. ge Oscillation, collector current i c The current peak and di / dt, collector-emitter voltage v ce Voltage spikes and dv / dt, high current turn-off losses, etc.

[0078] Among them, when the double pulse test is performed on the second switch tube T2, the third switch tube T3, the fifth switch tube T5 and the second diode D2: during the test, the double pulse is applied to the second switch tube T2 and the fifth switch tube T5, the third switch tube T3 remains turned on, and the first switch tube T1, the fourth switch tube T4 and the sixth switch tube T6 remain turned off, and the working characteristics of the corresponding power devices at zero current turn-on, half current turn-off, half current turn-on and large current turn-off are tested by switching the circuit commutation path.

[0079] For example, the following is applied to each switch tube in the H6 inverter unit 120: Figure 5 The driving signal shown, that is, a double pulse is applied to the second switch tube T2 and the fifth switch tube T5, the third switch tube T3 remains turned on, and the first switch tube T1, the fourth switch tube T4 and the sixth switch tube T6 remain turned off;

[0080] At time t0, the second switch tube T2, the third switch tube T3, and the fifth switch tube T5 are turned on, and the DC bus capacitor C bus The inductor L starts to be charged through the second switch tube T2, the third switch tube T3, and the fifth switch tube T5. The circuit flow path is as follows: Figure 6 As shown; at this time, the gate voltage v of the second switch tube T2, the third switch tube T3, and the fifth switch tube T5 when the zero current is turned on can be tested. ge Oscillation, collector current i c The current peak and di / dt, collector-emitter voltage v ce Voltage drop and dv / dt, zero current turn-on loss, etc.

[0081] At time t1, the second switch tube T2 and the fifth switch tube T5 are turned off, and the third switch tube T3 remains turned on. The inductor current is commutated from the conductive channel of the second switch tube T2 and the fifth switch tube T5 to the second diode D2. The inductor current continues to flow in the conductive channel of the third switch tube T3 and the second diode D2. The circuit flow path is as follows: Figure 7 As shown; at this time, the gate voltage v of the second switch tube T2 and the fifth switch tube T5 when the half current is turned off can be tested ge Oscillation, collector current i c The current peak and di / dt, collector-emitter voltage v ce Voltage spikes and dv / dt, half-current turn-off losses, etc.

[0082] At time t2, the second switch tube T2 and the fifth switch tube T5 are turned on again, and the third switch tube T3 remains turned on. The inductor current is commutated by the second diode D2 to the conductive channel of the second switch tube T2 and the fifth switch tube T5 again. At this time, the gate voltage v of the second switch tube T2 and the fifth switch tube T5 when the half current is turned on can be tested. ge Oscillation, collector current i c The current peak and di / dt, collector-emitter voltage v ce The voltage drop and dv / dt, half-current turn-on loss, etc. can also be tested for the reverse recovery of the second diode D2;

[0083] At time t3, the second switch tube T2 and the fifth switch tube T5 are turned off, and the third switch tube T3 continues to be turned on. The inductor current is commutated from the conductive channel of the second switch tube T2 and the fifth switch tube T5 to the second diode D2 again, and the inductor current continues to flow in the conductive channel of the third switch tube T3 and the second diode D2. At this time, the gate voltage v of the second switch tube T2 and the fifth switch tube T5 when the large current is turned off can be tested. ge Oscillation, collector current i c The current peak and di / dt, collector-emitter voltage v ceVoltage spikes and dv / dt, large current turn-off losses, etc.

[0084] At time t4, the third switch tube T3 is turned off, and the second switch tube T2 and the fifth switch tube T5 remain turned off. At this time, the gate voltage v of the third switch tube T3 when the high current is turned off can be tested. ge Oscillation, collector current i c The current peak and di / dt, collector-emitter voltage v ce Voltage spikes and dv / dt, high current turn-off losses, etc.

[0085] Step S3: After the test is completed, the DC bus capacitor C bus Discharge.

[0086] For example, the first switch SW1 is controlled to be opened by the first control signal, and the second switch SW2 is controlled to be closed by the second control signal, and the DC bus capacitor C is connected to the DC bus capacitor C by the discharge resistor R2. bus Discharge, and when the capacitor voltage reaches zero volts, the second switch SW2 is controlled by the second control signal to open, thereby completing the energy discharge.

[0087] It should be noted that, although all the switch tubes are turned off when this step is executed, the inductor current still continues to flow through the parasitic diodes of each switch tube, the first diode D1 and the second diode D2.

[0088] In summary, the double pulse test circuit and test method of the H6 inverter power device of the present invention directly performs double pulse test on the H6 inverter, and can complete the test of all power devices by using two sets of pulse timings, which can more quickly, more accurately and more truly reflect the actual working characteristics of each power device (including each switch tube and each diode) in the H6 inverter, and is convenient for testing and analyzing the switching process, commutation process and limit characteristics. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0089] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A double pulse test circuit for H6 inverter power devices, characterized in that: The double pulse test circuit includes a charging and discharging unit and an H6 type inverter unit, wherein: The charging and discharging unit provides a DC bus voltage to the H6 type inverter unit by charging the DC bus capacitor; The H6 inverter unit is connected to the charging and discharging unit, and the circuit commutation path is switched by controlling the on and off of each switch tube therein to perform a double pulse test.

2. The double pulse test circuit of the H6 inverter power device according to claim 1, characterized in that: The charging and discharging unit includes a DC power supply, a current limiting resistor, a first switch, a DC bus capacitor, a second switch and a discharge resistor; The positive terminal of the DC power supply is connected to the upper plate of the DC bus capacitor via the current limiting resistor and the first switch, and the negative terminal is connected to the lower plate of the DC bus capacitor; the second switch and the discharge resistor are connected in series between the upper plate and the lower plate of the DC bus capacitor.

3. The double pulse test circuit of the H6 inverter power device according to claim 2, characterized in that: The charging and discharging unit further includes a control module for generating a first control signal and a second control signal to control the opening and closing of the first switch and the second switch respectively.

4. The double pulse test circuit of the H6 inverter power device according to claim 3, characterized in that: The charging and discharging unit also includes a monitoring module for monitoring the voltage of the DC bus capacitor; at this time, the control module is connected to the monitoring module to generate the first control signal and the second control signal according to the monitoring results.

5. The double pulse test circuit of the H6 inverter power device according to claim 1, characterized in that: The H6 type inverter unit includes a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube, a sixth switch tube, a first diode, a second diode and an inductor; The first switch tube, the third switch tube and the fifth switch tube are connected in series at both ends of the charge and discharge unit, the second switch tube, the fourth switch tube and the sixth switch tube are connected in series at both ends of the charge and discharge unit, and the control end of each switch tube is connected to a corresponding drive signal; The anode end of the first diode is connected to the connection node between the fourth switch tube and the sixth switch tube, and the cathode end is connected to the connection node between the first switch tube and the third switch tube; The anode end of the second diode is connected to the connection node between the third switch tube and the fifth switch tube, and the cathode end is connected to the connection node between the second switch tube and the fourth switch tube; The first end of the inductor is connected to a connection node between the first switch tube and the third switch tube, and the second end of the inductor is connected to a connection node between the second switch tube and the fourth switch tube.

6. The double pulse test circuit of the H6 inverter power device according to any one of claims 1 to 5, characterized in that: The double pulse test circuit also includes a waveform test unit connected to the H6 type inverter unit and used to test the electrical signal waveform of the corresponding power device in the H6 type inverter unit.

7. A double pulse test method for H6 inverter power device, characterized in that: The double pulse test method comprises: The DC bus capacitor is charged to obtain a DC bus voltage and applied to both ends of the H6 inverter unit; Controlling the on and off of each switch tube in the H6 inverter unit to switch the circuit commutation path to perform a double pulse test; After the test is completed, the DC bus capacitor is discharged.

8. The double pulse test method for H6 inverter power device according to claim 7, characterized in that: By switching the circuit commutation path, a double pulse test is performed on the first switch tube, the fourth switch tube, the sixth switch tube and the first diode in the H6 inverter unit, and another double pulse test is performed on the second switch tube, the third switch tube, the fifth switch tube and the second diode in the H6 inverter unit.

9. The double pulse test method for H6 inverter power device according to claim 8, characterized in that: When a double pulse test is performed on the first switch tube, the fourth switch tube, the sixth switch tube and the first diode: During the test, double pulses are applied to the first switch tube and the sixth switch tube, the fourth switch tube remains turned on, and the second switch tube, the third switch tube and the fifth switch tube remain turned off, and the working characteristics of the corresponding power devices when zero current is turned on, half current is turned off, half current is turned on and large current is turned off are tested by switching the circuit commutation path; When a double pulse test is performed on the second switch tube, the third switch tube, the fifth switch tube and the second diode: During the test, double pulses are applied to the second switch tube and the fifth switch tube, the third switch tube remains turned on, and the first switch tube, the fourth switch tube and the sixth switch tube remain turned off. The operating characteristics of the corresponding power devices at zero current turn-on, half current turn-off, half current turn-on and high current turn-off are tested by switching the circuit commutation path.

10. The double pulse test method for H6 inverter power device according to claim 9, characterized in that: Before performing the double pulse test, the step of obtaining the pulse width is also included; Among them, the pulse width satisfies the formula L is the inductance value, V DD is the DC bus voltage value, T on is the pulse width value, I Lmax is the maximum inductor current value.

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