Inductance measuring circuit and inductance measuring device

Abstract

The embodiment of the utility model provides an inductance measuring circuit and an inductance measuring device, and relates to the technical field of inductors. The inductance measuring circuit comprises a capacitor unit, a switch unit, a to-be-measured power unit and a load unit, one end of the capacitor unit is connected with the first end of the switch unit, the second end of the switch unit is connected with one end of the to-be-tested power unit, and the other end of the to-be-tested power unit is connected with the other end of the capacitor unit; the load unit is connected in parallel with the to-be-tested power unit. Based on the content of the invention, an effect of accurately measuring the stray inductance parameter of the measured power unit is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inductance, and particularly to an inductance measurement circuit and an inductance measurement device. BACKGROUND

[0002] With the rapid development of power electronics technology, power modules, as representatives of power electronics technology, have been widely used in new energy, power generation and other industries; the power module belongs to a power driver, and has a very high requirement on internal parasitic stray inductance; therefore, it is particularly important to measure the stray inductance of the power module.

[0003] Therefore, there is an urgent need for a measurement circuit capable of accurately measuring the stray inductance of the power module. CONTENT OF THE INVENTION

[0004] The embodiments of the present application provide an inductance measurement circuit and an inductance measurement device, so as to accurately measure the stray inductance of the power module.

[0005] In a first aspect, the embodiments of the present application provide an inductance measurement circuit, which comprises a capacitor unit, a switch unit, a to-be-measured power unit and a load unit; one end of the capacitor unit is connected to a first end of the switch unit, a second end of the switch unit is connected to one end of the to-be-measured power unit, and the other end of the to-be-measured power unit is connected to the other end of the capacitor unit; the load unit is connected in parallel with the to-be-measured power unit; the switch unit is configured to receive a pulse signal and change a switching state according to the pulse signal; the to-be-measured power unit is configured to output a first voltage value and a current value of the to-be-measured power unit according to the switching state of the switch unit; and the first voltage value and the current value are used to obtain an inductance value of the to-be-measured power unit.

[0006] In a possible implementation, the switch unit is a MOS switch or an IGBT switch.

[0007] In a possible implementation, the inductance measurement circuit further comprises a first driving unit; the first driving unit is connected to a third end of the switch unit; and the first driving unit is configured to send the pulse signal to the switch unit.

[0008] In a possible implementation, when the switch unit is a MOS switch, the first end of the switch unit is a drain electrode, the second end of the switch unit is a source electrode, and the third end of the switch unit is a gate electrode.

[0009] Alternatively, when the switch unit is an IGBT switch, the first end of the switch unit is a collector electrode, the second end of the switch unit is an emitter electrode, and the third end of the switch unit is a gate electrode.

[0010] In a possible implementation, the switch unit is configured to be closed in response to the pulse signal being a high-level signal, or to be opened in response to the pulse signal being a low-level signal.

[0011] In a possible implementation, the first driving unit comprises a driving module and a signal generator; one end of the driving module is connected with the third end of the switch unit, and the other end of the driving module is connected with the signal generator; the signal generator is configured to send the pulse signal to the switch unit through the driving module.

[0012] In a possible implementation, the inductance measurement circuit further comprises a second driving unit; one end of the second driving unit is connected with the power unit to be measured, and the other end of the second driving unit is grounded; the second driving unit is configured to control the power unit to be measured to be in a non-working state.

[0013] In a possible implementation, the inductance measurement circuit further comprises a signal acquisition unit and a signal analysis unit; the signal acquisition unit is connected with the power unit to be measured, the third end of the switch unit and the signal analysis unit simultaneously; the signal analysis unit is configured to acquire the first voltage value, the current value and the second voltage value output by the third end of the switch unit through the signal acquisition unit, and obtain the inductance value of the power unit to be measured according to the first voltage value, the current value and the second voltage value.

[0014] In a possible implementation, the inductance measurement circuit further comprises a signal acquisition unit and a signal analysis unit; the signal acquisition unit is connected with the power unit to be measured, the third end of the switch unit and the signal analysis unit simultaneously; the signal analysis unit is configured to acquire the first voltage value, the current value and the second voltage value output by the third end of the switch unit through the signal acquisition unit, and obtain the inductance value of the power unit to be measured according to the first voltage value, the current value and the second voltage value.

[0015] In a possible implementation, the fixing structure comprises at least two pressure rods; each pressure rod is fixedly arranged on the two sides of the switch unit in the inductance measurement circuit, and the switch unit is fixedly installed on the bottom plate through each pressure rod.

[0016] The inductance measurement circuit and the inductance measurement device provided in the embodiments of the present application have the following advantages: one end of the capacitor unit is connected with the first end of the switch unit, the second end of the switch unit is connected with one end of the power unit to be measured, and the other end of the power unit to be measured is connected with the other end of the capacitor unit; the load unit is connected with the power unit to be measured in parallel to form a loop; based on the switch unit of the loop, the switch state is changed according to the received pulse signal, so that the power unit to be measured outputs the first voltage value and the current value, and the inductance value of the power unit to be measured is obtained, thereby the effect of accurately measuring the stray inductance of the power module can be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate embodiments consistent with the application and, together with the description, serve to explain the principles of the application.

[0018] Figure 1 A structural schematic diagram of a stray inductance measuring circuit of a power loop provided in the present application;

[0019] Figure 2 A structural schematic diagram of a stray inductance measuring circuit provided in the present application Figure 1 ;

[0020] Figure 3 A structural schematic diagram of a stray inductance measuring circuit provided in the present application Figure 1 ;

[0021] Figure 4 A structural schematic diagram of a stray inductance measuring circuit provided in the present application Figure 3 ;

[0022] Figure 5 A structural schematic diagram of a stray inductance measuring circuit provided in the present application Figure 2 ;

[0023] Figure 6 A structural schematic diagram of a stray inductance measuring circuit provided in the present application Figure 3 ;

[0024] Figure 7 A structural schematic diagram of a stray inductance measuring device provided in the present application;

[0025] Figure 8 An exploded view of a stray inductance measuring device provided in the present application.

[0026] Reference signs:

[0027] Capacitance unit 11;

[0028] Switching unit 12;

[0029] Power unit 13 to be measured;

[0030] Load unit 14;

[0031] MOS switch 15;

[0032] First driving unit 16;

[0033] Driving module 161;

[0034] Signal generator 162;

[0035] Second driving unit 17;

[0036] Signal acquisition unit 18;

[0037] Signal analysis unit 19;

[0038] Bottom plate 21;

[0039] Fixing structure 22;

[0040] Inductive measurement circuit 23;

[0041] Pressure bar 221;

[0042] Insulating clamp 222.

[0043] Through the above drawings, the specific embodiments of the present application have been shown, and will be described in more detail hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0044] The exemplary embodiments will be described in detail herein with reference to the accompanying drawings. In the following description, unless otherwise indicated, like numbers in the different drawings represent the same or similar elements. The following exemplary embodiments described in the following description are not meant to be limiting of the present application in any way, but are merely to illustrate some aspects of the present application in which the application resides.

[0045] With the rapid development of power electronics technology, power modules as the representative of power electronics technology have been widely used in new energy, power generation and other industries; power modules belong to power driving devices, and the internal parasitic stray inductance is extremely high; therefore, it is particularly important to measure the stray inductance of the power module.

[0046] In one example, Figure 1 A structure diagram of a stray inductance measurement circuit of a power loop provided by the present application is shown in FIG. 1. Figure 1 As shown in FIG. 1, an external power supply is connected in parallel with a DC support capacitor DCLINK, one end of the DCLINK is connected to a first end of a device under test (DUT), a second end of the DUT is connected to a first end of a half-bridge switching circuit, a second end of the half-bridge switching circuit is connected to another end of the DCLINK, one of the switches in the half-bridge switching circuit is connected in parallel with a load inductance L-Load to form a stray inductance measurement circuit of the DUT, and based on the circuit, Figure 2 The present application Figure 1 A schematic diagram of a measurement data acquisition process in the present application is shown in FIG. 2. Figure 2 As shown in FIG. 2, a plurality of pulse signals HSS, HSG, HS, LS of a double-pulse model in a half-bridge state can be used to collect a current IDUT and the voltage U DUT and the internal gate voltage U of the DUT at the time of testing G , the current change rate di / dt of the measured object, i.e. the current / time and the voltage peak U generated on the measured object at the time of turn-off DUT _Peak to calculate the stray inductance in the loop, i.e. L = U DUT _Peak / (di / dt).

[0047] However, in the above manner, in combination Figure 1 By calculating the stray inductance of the power loop through the double-pulse model in the half-bridge state, the stray inductance L obtained includes all stray inductances in the power loop, such as the bus capacitor L_cap, the copper bar (Lbusbar1+Lbusbar2), and the measured power module, the half-bridge switch circuit (L_HS+L_LS), etc., and the stray inductance of the measured power module obtained is not accurate.

[0048] In view of the above technical problems, the present application proposes the following technical concept: one end of a capacitor unit is connected to a first end of a switch unit, a second end of the switch unit is connected to one end of a to-be-measured power unit, the other end of the to-be-measured power unit is connected to the other end of the capacitor unit; a load unit is connected in parallel with the to-be-measured power unit to form a loop, and based on the switch unit of the loop, the switch state is changed according to the received pulse signal, so that the to-be-measured power unit outputs a first voltage value and a current value, to obtain the inductance value of the to-be-measured power unit. In this way, the problem of inaccurate stray inductance of the measured power module obtained in the prior art can be solved.

[0049] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0050] Figure 3 A structure diagram of an inductance measurement circuit provided by an embodiment of the present application Figure 1 For example, Figure 3As shown, the inductance measurement circuit includes: a capacitor unit 11, a switch unit 12, a power under test unit 13, and a load unit 14; one end of the capacitor unit 11 is connected to the first end of the switch unit 12, the second end of the switch unit 12 is connected to one end of the power under test unit 13, and the other end of the power under test unit 13 is connected to the other end of the capacitor unit 11; the load unit 14 is connected in parallel with the power under test unit 13; the switch unit 12 is used to receive pulse signals and change the switching state according to the pulse signals; the power under test unit 13 is used to output a first voltage value and a current value of the power under test unit 13 according to the switching state of the switch unit 12; wherein, the first voltage value and the current value are used to obtain the inductance value of the power under test unit 13.

[0051] For example, to test the stray inductance of the power unit under test 13, an inductance measurement circuit is provided. This circuit includes: an additional DC power supply, a capacitor unit 11 (e.g., a DC capacitor), a switching unit 12 (e.g., a general-purpose semiconductor switch), a load unit 14 (e.g., a load inductor), and the power unit under test 13 (e.g., a power semiconductor device in a single-element, half-bridge, or full-bridge package). The capacitor unit 11 is connected in parallel with the DC power supply; one end of the capacitor unit 11 is connected to the first end of the switching unit 12; the second end of the switching unit 12 is connected to one end of the power unit under test 13; and the other end of the power unit under test 13 is connected to the other end of the capacitor unit 11. The load unit 14 is connected in parallel with the power unit under test 13, forming a power loop. The power supply can be a low-voltage DC power supply (such as 48V~60V) to ensure the safety of the entire device for the human body. The capacitor unit 11 is used to stably transmit the low-voltage DC voltage of the external power supply to the entire circuit and maintain the low stray inductance of the power supply circuit. The switching unit 12 can be a semiconductor switch to receive pulse signals and change its own switching state, such as closed or open, according to the pulse signals. The load inductor is used to generate a continuous current flowing through the power unit under test 13. The power unit under test 13 will output a first voltage value across its terminals and a current value flowing through it, depending on the switching state of the switching unit 12. By collecting and analyzing the first voltage value and the current value, the inductance value of the power unit under test 13 can be calculated.

[0052] For example, Figure 4 Provided for the embodiments of this application Figure 3 A schematic diagram of the measurement data acquisition process, as shown below. Figure 4As shown, based on the pulse signal, the general semiconductor switch is in the on state, the current flows through the positive pole of the capacitor, the general semiconductor switch and the load inductor, and then flows back to the negative pole of the capacitor; based on the pulse signal, the general semiconductor switch is closed, the inductor current flows through the measured power unit for reverse freewheeling; based on the pulse signal, the general semiconductor switch is turned on again, the freewheeling current of the measured power unit gradually decreases linearly, and the voltage on both sides of the measured power unit will appear a voltage platform caused by the decrease of the freewheeling current ; then the voltage V of the measured power unit will rise to the bus voltage, the freewheeling current I of the measured power unit returns to 0 ampere, based on the pulse signal, the operation ends; according to the collected measured power unit freewheeling current drop slope / and the measured power unit voltage platform , through Ls= / ( / ), the stray inductance Ls inside the measured power unit body can be obtained.

[0053] In this embodiment, one end of the capacitor unit 11 is connected to the first end of the switch unit 12, the second end of the switch unit 12 is connected to one end of the measured power unit 13, the other end of the measured power unit 13 is connected to the other end of the capacitor unit 11; the load unit 14 is connected in parallel with the measured power unit 13 to form a loop, based on the switch unit 12 of the loop, the switch state is changed according to the received pulse signal, so that the measured power unit 13 outputs a first voltage value and a current value, so as to obtain the inductance value of the measured power unit 13, and then the effect of accurately measuring the stray inductance of the power module can be achieved.

[0054] Figure 5 The structure of an inductance measurement circuit provided in the embodiment of the present application is shown in Figure 2 Fig. 1. Figure 5 As shown in the above structure, the inductance measurement circuit comprises: a capacitor unit 11, a switch unit 12, a measured power unit 13 and a load unit 14; one end of the capacitor unit 11 is connected to the first end of the switch unit 12, the second end of the switch unit 12 is connected to one end of the measured power unit 13, the other end of the measured power unit 13 is connected to the other end of the capacitor unit 11; the load unit 14 is connected in parallel with the measured power unit 13; the switch unit 12 is used for receiving a pulse signal and changing the switch state according to the pulse signal; the measured power unit 13 is used for outputting a first voltage value and a current value of the measured power unit 13 according to the switch state of the switch unit 12; wherein the first voltage value and the current value are used to obtain the inductance value of the measured power unit 13. Wherein, the switch unit 12 is a MOS switch 15 or an IGBT switch.

[0055] In one possible implementation, when the switching unit 12 is a MOS switch 15 or an IGBT switch, the first terminal of the switching unit 12 is a drain, the second terminal of the switching unit 12 is a source, and the third terminal of the switching unit 12 is a gate.

[0056] Alternatively, when the switching unit is an IGBT switch, the first terminal of the switching unit is a collector, the second terminal of the switching unit is an emitter, and the third terminal of the switching unit is a gate.

[0057] Exemplarily, in order to test the stray inductance of the power unit 13 to be tested, an inductance measuring circuit is arranged, which comprises: an additional DC power supply, a capacitor unit 11, a switch unit 12 such as a general semiconductor switch, a load unit 14, and the power unit 13 to be tested; wherein the switch unit 12 is a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) MOS switch 15, and can also be a semiconductor switch such as an Insulate-Gate Bipolar Transistor (IGBT); the capacitor unit 11 is connected in parallel with the DC power supply, one end of the capacitor unit 11 is connected to the drain of the MOS switch 15, the source of the MOS switch 15 is connected to one end of the power unit 13 to be tested, and the other end of the power unit 13 to be tested is connected to the other end of the capacitor unit 11; the load unit 14 is connected in parallel with the power unit 13 to be tested, thereby forming a power loop, wherein the low-voltage DC power supply is used to ensure that the entire device is safe for human body, the capacitor unit 11 is used to stably transmit the low-voltage DC voltage of the external power supply to the entire loop, and maintain the low stray inductance of the power supply loop, the gate of the MOS switch 15 is used to receive a pulse signal, and change the switching state such as closing or opening according to the pulse signal, the load inductance is used to generate a continuous current flowing through the power unit 13 to be tested, and the power unit 13 to be tested will output a first voltage value between the two ends of the power unit 13 to be tested and a current value flowing through the power unit 13 to be tested according to the switching state of the MOS switch 15, and by collecting and analyzing the first voltage value and the current value, the inductance value of the power unit 13 to be tested can be accurately calculated.When the switch unit is an IGBT switch, the first end of the switch unit is a collector, the second end of the switch unit is an emitter, and the third end of the switch unit is a gate; at this time, the one end of the capacitor unit 11 is connected to the collector of the IGBT switch in parallel with the DC power supply, the emitter of the IGBT switch is connected to one end of the to-be-measured power unit 13, and the other end of the to-be-measured power unit 13 is connected to the other end of the capacitor unit 11; the load unit 14 is connected in parallel with the to-be-measured power unit 13 to form a power loop, wherein the DC power supply is to ensure that the entire device is safe to the human body, the capacitor unit 11 is to stably transmit the low-voltage direct-current voltage of the external power supply to the entire loop and maintain the low-stray inductance of the power loop, the gate of the IGBT switch is to receive a pulse signal and change the switching state of the IGBT switch such as closing or opening according to the pulse signal, and the load inductance is to generate a continuous current flowing through the to-be-measured power unit 13; the to-be-measured power unit 13 outputs a first voltage value between the two ends of the to-be-measured power unit 13 and a current value flowing through the to-be-measured power unit 13 according to the switching state of the IGBT switch; by collecting and analyzing the first voltage value and the current value, the inductance value of the to-be-measured power unit 13 can be accurately calculated.

[0058] In the embodiment, on the basis of the above embodiment, one end of the capacitor unit 11 is connected to the drain of the MOS switch 15, the source of the MOS switch 15 is connected to one end of the to-be-measured power unit 13, and the other end of the to-be-measured power unit 13 is connected to the other end of the capacitor unit 11; the load unit 14 is connected in parallel with the to-be-measured power unit 13 to form a loop, the gate of the MOS switch 15 in the loop receives a pulse signal, changes the switching state of the MOS switch 15 according to the received pulse signal, and causes the to-be-measured power unit 13 to output a first voltage value and a current value to obtain the inductance value of the to-be-measured power unit 13; further, the effect of accurately measuring the stray inductance of the power module can be achieved.

[0059] Figure 6 A structure diagram of an inductance measurement circuit provided in the embodiment of the present application Figure 3 As shown in Figure 6 The inductance measurement circuit includes a capacitor unit 11, a switch unit 12, a to-be-measured power unit 13, and a load unit 14; one end of the capacitor unit 11 is connected to the first end of the switch unit 12, the second end of the switch unit 12 is connected to one end of the to-be-measured power unit 13, and the other end of the to-be-measured power unit 13 is connected to the other end of the capacitor unit 11; the load unit 14 is connected in parallel with the to-be-measured power unit 13; the switch unit 12 is used to receive a pulse signal and change the switching state according to the pulse signal; the to-be-measured power unit 13 is used to output a first voltage value and a current value of the to-be-measured power unit 13 according to the switching state of the switch unit 12; wherein the first voltage value and the current value are used to obtain the inductance value of the to-be-measured power unit 13.

[0060] In a possible implementation, the inductance measurement circuit further comprises a first driving unit 16; the first driving unit 16 is connected to the third end of the switch unit 12; the first driving unit 16 is configured to send a pulse signal to the switch unit 12.

[0061] In a possible implementation, the switch unit 12 is configured to be closed in response to the pulse signal being a high-level signal, or to be opened in response to the pulse signal being a low-level signal.

[0062] Exemplarily, an inductance measurement circuit is provided, which comprises a direct current power supply, a capacitor unit 11, a switch unit 12, a load unit 14, a power unit 13 to be measured, and a first driving unit 16; the capacitor unit 11 is connected in parallel to the direct current power supply, one end of the capacitor unit 11 is connected to the first end of the switch unit 12, the second end of the switch unit 12 is connected to one end of the power unit 13 to be measured, the other end of the power unit 13 to be measured is connected to the other end of the capacitor unit 11; the load unit 14 is connected in parallel to the power unit 13 to be measured, and the first driving unit 16 is connected to the third end of the switch unit 12 to form a power loop; wherein the capacitor unit 11 is configured to stably transmit low-voltage direct current voltage of an external power supply to the entire loop and maintain low stray inductance of the power loop, the first driving unit 16 is configured to send a pulse signal to the switch unit 12, the pulse signal comprising a high-level signal and a low-level signal, the third end of the switch unit 12 is configured to receive the pulse signal sent by the first driving unit 16, and the switch unit 12 is configured to be closed according to the pulse signal of the high-level signal or to be opened according to the pulse signal of the low-level signal, and the load inductance is configured to generate a continuous current flowing through the power unit 13 to be measured, the power unit 13 to be measured is configured to output a first voltage value between two ends of the power unit 13 to be measured and a current value flowing through the power unit 13 to be measured according to a switching state of the switch unit 12, and the inductance value of the power unit 13 to be measured can be calculated by collecting and analyzing the first voltage value and the current value.

[0063] For example, by the first drive unit 16 sends a high level pulse wave, the general semiconductor switch is in the on state, the current flows through the capacitor positive pole, the general semiconductor switch and the load inductance, and then flows back to the capacitor negative pole, and the first drive unit 16 sends a low level, the general semiconductor switch is closed, and the inductance current flows through the reverse diode or body diode of the power unit 13 to be tested; the first drive unit 16 sends a second high level pulse wave, and the general semiconductor switch is turned on again, and the diode freewheeling current of the power unit 13 to be tested gradually decreases linearly, and the voltage on both sides of the power unit 13 to be tested, i.e. the first voltage value, will appear a voltage platform caused by the decrease of the freewheeling current; then the voltage of the power unit 13 to be tested will rise to the bus voltage, and the diode freewheeling current of the power unit 13 to be tested, i.e. the current value, returns to 0 ampere; the first drive unit 16 sends a low level to end the operation; the diode freewheeling current of the power unit 13 to be tested in the above decreases at a slope / and the voltage platform of the power unit 13 to be tested will be based on Ls= / / , and the stray inductance Ls of the power unit 13 to be tested will be calculated.

[0064] In a possible implementation, the first drive unit 16 comprises: a drive module 161 and a signal generator 162; one end of the drive module 161 is connected with the third end of the switch unit 12, and the other end of the drive module 161 is connected with the signal generator 162; the signal generator 162 is configured to send a pulse signal to the switch unit 12 through the drive module 161.

[0065] Exemplarily, the first drive unit 16 comprises: a drive module 161 and a signal generator 162 such as a pulse generator; one end of the drive module 161 is connected with the third end of the switch unit 12, and the other end of the drive module 161 is connected with the signal generator 162; wherein the signal generator 162 is configured to send a pulse signal to the drive module 161, so that the drive module 161 sends the pulse signal to the switch unit 12 to control the switch unit 12 to close or open.

[0066] For example, the pulse generator sends a high level pulse wave, through the driving module 161 to make the general semiconductor switch in the on state, the current flows through the positive electrode of the capacitor, the general semiconductor switch and the load inductor, and then flows back to the negative electrode of the capacitor, the pulse generator outputs low level, the general semiconductor switch is closed, and the inductor current flows through the reverse diode or body diode of the to-be-measured power unit 13; the pulse generator sends a second high level pulse wave, the general semiconductor switch is turned on again, the diode freewheeling current of the to-be-measured power unit 13 gradually decreases linearly, and the voltage on both sides of the to-be-measured power unit 13, i.e. the first voltage value, appears a voltage platform caused by the decrease of the freewheeling current; then the voltage of the to-be-measured power unit 13 rises to the bus voltage, the diode freewheeling current of the to-be-measured power unit 13, i.e. the current value, returns to 0 ampere; the pulse generator outputs low level, and the operation is ended; the diode freewheeling current of the to-be-measured power unit 13 in the above decreases at a slope / and the voltage platform of the to-be-measured power unit 13 will be based on Ls= / / , to calculate the stray inductance Ls of the to-be-measured power unit 13.

[0067] In a possible implementation, the inductance measurement circuit further comprises: a second driving unit 17; one end of the second driving unit 17 is connected with the to-be-measured power unit 13, and the other end of the second driving unit 17 is grounded; the second driving unit 17 is used to control the to-be-measured power unit 13 to be in a non-working state.

[0068] In a possible implementation, the inductance measurement circuit further comprises: a signal acquisition unit 18 and a signal analysis unit 19; the signal acquisition unit 18 is connected with the to-be-measured power unit 13, the third end of the switch unit 12 and the signal analysis unit 19 simultaneously; the signal analysis unit 19 is used to obtain the first voltage value, the current value and the second voltage value output by the third end of the switch unit 12 through the signal acquisition unit 18, and obtain the inductance value of the to-be-measured power unit 13 according to the first voltage value, the current value and the second voltage value.

[0069] For example, the inductance measurement circuit further includes a second driving unit 17, one end of which is connected to the power unit under test 13, and the other end of which is grounded. The second driving unit 17, such as a gate driver, controls the gate drive of the power unit under test 13, such as the internal gate of a MOS switch 15, so that the MOS switch 15 is in a non-operating state. The inductance measurement circuit also includes a signal acquisition unit 18 and a signal analysis unit 19. The signal acquisition unit 18 is connected to the power unit under test 13, such as connecting the voltage test terminal and the current test terminal of the power unit under test 13, and is used to acquire the first voltage value and current value of the power unit under test 13 through the voltage test terminal and the current test terminal. The signal acquisition unit 18 is also connected to the third terminal of the switching unit 12, and is used to acquire the voltage value of the pulse signal received by the third terminal of the switching unit 12 and the second voltage value, so as to record the acquisition time of the second voltage value as the test time. The signal acquisition unit 18 is also connected to the signal analysis unit 19. The signal acquisition unit 18 is also connected to the signal analysis unit 19, and transmits the acquired first voltage value, current value and the second voltage value output by the third terminal of the switching unit 12 to the signal analysis unit 19 through a communication protocol (such as CAN, Modbus), so that the signal analysis unit 19 can obtain the stray inductance value of the power unit 13 under test based on the first voltage value, the current value and the second voltage value. It is worth noting that the signal analysis unit 19 can also be connected to the signal generator 162 to control the output logic of the pulse signal emitted by the signal generator 162.

[0070] In this embodiment, based on the above embodiment, a first driving unit 16 is set in the inductance measurement circuit. The first driving unit 16 includes a driving module 161 and a signal generator 162, so that the signal generator 162 is used to send a pulse signal to the driving module 161, so that the driving module 161 sends the pulse signal to the switching unit 12 to control the switching unit 12 to close or open. The voltage value and current value of the power unit 13 under test are obtained through the signal acquisition unit 18 and the signal analysis unit 19 to obtain the inductance value of the power unit 13 under test. Thus, the stray inductance of the power unit 13 under test can be measured conveniently, safely and accurately.

[0071] Figure 7 This is a schematic diagram of the structure of an inductance measuring device provided in an embodiment of this application, as shown below. Figure 7 As shown, the inductance measuring device includes: a base plate 21, a fixing structure 22, and an inductance measuring circuit 23 as described above; the inductance measuring circuit 23 is fixedly mounted on the base plate 21 via the fixing structure 22.

[0072] Exemplarily, in order to measure the inductance of the power unit 13 to be measured, an inductance measuring device 20 is provided, which comprises a bottom plate 21, a fixing structure 22, and the inductance measuring circuit 23 as described above. In the inductance measuring circuit 23, one end of the capacitor unit 11 is connected to the first end of the switch unit 12, the second end of the switch unit 12 is connected to one end of the power unit 13 to be measured, and the other end of the power unit 13 to be measured is connected to the other end of the capacitor unit 11. The load unit 14 is connected in parallel with the power unit 13 to be measured. The switch unit 12, the capacitor unit 11, the power unit 13 to be measured, and the load unit 14 in the inductance measuring circuit 23 are fixed on the bottom plate 21 by the fixing structure 22, so as to obtain the inductance measuring device. When measuring the inductance, the switch unit 12 changes the switch state according to the received pulse signal, so that the power unit 13 to be measured outputs the first voltage value and the current value, so as to obtain the inductance value of the power unit 13 to be measured.

[0073] Figure 8 An exploded view of an inductance measuring device provided by the embodiment of the present application is shown in FIG. 1. The inductance measuring device comprises a bottom plate 21, a fixing structure 22, and an inductance measuring circuit 23 as described above. The inductance measuring circuit 23 is fixedly arranged on the bottom plate 21 by the fixing structure 22. Figure 8

[0074] In a possible implementation, the fixing structure 22 comprises at least two pressure rods 221. Each pressure rod 221 is fixedly arranged on the two sides of the switch unit 12 in the inductance measuring circuit 23, and the switch unit 12 is fixedly installed on the bottom plate 21 by the pressure rods 221.

[0075] ​Exemplarily, in order to measure the inductance of the to-be-measured power unit 13, an inductance measuring device is provided, which comprises the bottom plate 21, the fixing structure 22, and the inductance measuring circuit 23 as described above. In the inductance measuring circuit 23, one end of the capacitor unit 11 is connected to the first end of the switch unit 12, the second end of the switch unit 12 is connected to one end of the to-be-measured power unit 13 through the transmission bus, and the other end of the to-be-measured power unit 13 is connected to the other end of the capacitor unit 11. The load unit 14 is connected in parallel with the to-be-measured power unit 13, and the switch module, the capacitor unit 11, the to-be-measured power unit 13, and the load unit 14 in the inductance measuring circuit 23 are fixed on the bottom plate 21 through the fixing structure 22, so as to obtain the inductance measuring device. The fixing structure 22 comprises at least two pressure rods 221 and at least one insulation clamp 222. The pressure rods are respectively fixedly arranged on the two sides of the switch unit 12, and the switch unit 12 is fixedly installed on the bottom plate 21 through the pressure rods 221. One end of the drive module 161 in the inductance measuring circuit 23 is fixedly arranged on the bottom plate 21 through the insulation clamp. The other end of the drive module 161 is fixedly installed on the pressure rod through the insulation clamp 222, so that the drive module 161 is arranged above the switch unit 12. In addition, the fixing structure 22 further comprises at least two other pressure rods. The other pressure rods are respectively fixedly arranged on the two sides of the to-be-measured power unit 13, and the to-be-measured power unit 13 is fixedly installed on the bottom plate 21 through the other pressure rods. The second drive unit 17 and the signal acquisition unit 18 in the inductance measuring circuit 23 are integrally arranged on an integrated circuit board. One end of the integrated circuit board is fixedly installed on the bottom plate 21 through the insulation clamp 222, and the other end of the integrated circuit board and the other end of the second drive unit 17 are respectively fixedly installed on the other pressure rods through the insulation clamp 222.

[0076] In the inductance measurement, the switch unit 12 changes the switch state according to the received pulse signal, so that the to-be-measured power unit 13 outputs the first voltage value and the current value. The signal acquisition unit 17 acquires the first voltage value and the current value, and transmits the acquired first voltage value and the current value to the signal analysis unit 18 through the signal connector 17, so as to obtain the inductance value of the to-be-measured power unit 13.

[0077] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction related hardware. The foregoing program can be stored in a computer readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed.

[0078] It should be understood that many variations can be made in the embodiments described and shown which should be considered within the scope of the present application as defined by the appended claims.

Claims

1. An inductance measuring circuit, characterized by, The inductance measurement circuit comprises a capacitor unit, a switch unit, a power unit to be measured and a load unit; one end of the capacitor unit is connected to a first end of the switch unit, a second end of the switch unit is connected to one end of the power unit to be measured, the other end of the power unit to be measured is connected to the other end of the capacitor unit; the load unit is connected in parallel with the power unit to be measured; The switch unit is configured to receive a pulse signal and change a switching state according to the pulse signal. The power unit to be measured is configured to output a first voltage value and a current value of the power unit to be measured according to the switching state of the switch unit; wherein the first voltage value and the current value are used to obtain an inductance value of the power unit to be measured.

2. The electrical sense circuit of claim 1, wherein, The switch unit is a MOS switch or an IGBT switch.

3. The electrical sense circuit of claim 1, wherein, The inductance measurement circuit further comprises a first driving unit; the first driving unit is connected to a third end of the switch unit. The first driving unit is configured to send the pulse signal to the switch unit.

4. The electrical sense circuit of claim 3, wherein, When the switch unit is a MOS switch, the first end of the switch unit is a drain, the second end of the switch unit is a source, and the third end of the switch unit is a gate. Alternatively, when the switch unit is an IGBT switch, the first end of the switch unit is a collector, the second end of the switch unit is an emitter, and the third end of the switch unit is a gate.

5. The electrical sense circuit of claim 3, wherein, The switch unit is configured to be closed in response to the pulse signal being a high-level signal, or to be opened in response to the pulse signal being a low-level signal.

6. The electrical sense circuit of claim 3, wherein, The first driving unit comprises a driving module and a signal generator; one end of the driving module is connected to the third end of the switch unit, and the other end of the driving module is connected to the signal generator. The signal generator is configured to send the pulse signal to the switch unit through the driving module.

7. The electrical sense circuit of claim 1, wherein, The inductance measurement circuit further comprises a second driving unit; one end of the second driving unit is connected to the power unit to be measured, and the other end of the second driving unit is grounded. The second driving unit is configured to control the power unit to be measured to be in a non-working state.

8. The electrical sensing circuit of any one of claims 1-7, wherein, The inductance measurement circuit further comprises a signal acquisition unit and a signal analysis unit; the signal acquisition unit is connected to the power unit to be measured, the third end of the switch unit and the signal analysis unit simultaneously. The signal analysis unit is configured to acquire a first voltage value, a current value and a second voltage value output by the third end of the switch unit through the signal acquisition unit, and obtain an inductance value of the power unit to be measured according to the first voltage value, the current value and the second voltage value.

9. An inductance measuring device characterized by comprising: The inductance measurement device comprises a bottom plate, a fixing structure and the inductance measurement circuit according to any one of claims 1-8; the inductance measurement circuit is fixedly arranged on the bottom plate through the fixing structure.

10. The electrical sensing device of claim 9, wherein, The fixing structure comprises at least two pressure rods; each pressure rod is fixedly arranged on both sides of the switch unit in the inductance measurement circuit, and the switch unit is fixedly installed on the bottom plate through each pressure rod.

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