CN115112957A

CN115112957A - Intelligent power module with capacity value self-checking function

Info

Publication number: CN115112957A
Application number: CN202210610392.8A
Authority: CN
Inventors: 冯宇翔; 左安超; 华庆; 王文建
Original assignee: Guangdong Huixin Semiconductor Co Ltd
Current assignee: Guangdong Huixin Semiconductor Co Ltd
Priority date: 2022-05-31
Filing date: 2022-05-31
Publication date: 2022-09-27

Abstract

The invention discloses an intelligent power module with a capacity value self-checking function, which comprises a power unit and a test unit, wherein the power unit is connected with the test unit through a power line; the testing unit comprises a micro control unit, a display unit, a power supply circuit, a signal generating circuit, a sampling circuit and a capacitance value testing circuit, the capacitance value testing circuit is electrically connected with a first capacitor in the power unit and used for detecting the capacitance value of the first capacitor, the first end of the first capacitor is electrically connected with an ITRIP pin in the power unit, and the second end of the first capacitor is electrically connected with a VSS pin in the power unit. The intelligent power module with the capacitance value self-checking function realizes the capacitance value test of the first capacitor connected with the ITRIP pin in parallel in the intelligent power module, and further can screen the intelligent power module with the first capacitor or the welding defect, so that the flow of the bad intelligent power module is avoided.

Description

Intelligent power module with capacity value self-checking function

Technical Field

The invention relates to the technical field of power modules, in particular to an intelligent power module with a capacity value self-checking function.

Background

The intelligent power module is a power driving electronic module combining power electronics and integrated circuit technology, and mainly integrates a power switch device and a high-voltage driving circuit together so as to be applied to variable frequency motor servo driving or household appliance variable frequency control and the like.

The capacitor connected with the ITRIP end (current signal detection end) in parallel in the intelligent power module is used for filtering external interference signals of the ITRIP end so as to avoid false triggering of components of module fault protection, the larger the capacitance value is, the better the performance of filtering interference signals is, but the larger the capacitance value is, the fault signals can be filtered out transiently, the longer the trigger protection delay time is, and therefore the capacitor connected with the ITRIP end in parallel plays a vital role in the intelligent power module.

However, in the test program of the conventional intelligent power module, the capacitance value of the capacitor connected in parallel with the conventional intelligent power module is not tested by the test program of the ITRIP terminal, so that the conventional intelligent power module cannot control the defect caused by the capacitor connected in parallel with the ITRIP terminal or welding, and the defective product is easily caused to flow out.

Disclosure of Invention

The invention aims to provide an intelligent power module with a capacitance value self-checking function, and aims to solve the problem that a traditional intelligent power module cannot control a capacitor connected with an ITRIP end in parallel or is welded to cause defects, so that a poor product flows out.

In order to solve the above problems, the present invention provides an intelligent power module with a capacity value self-checking function, which includes a power unit and a test unit; the test unit comprises a micro control unit, a display unit, a power supply circuit, a signal generating circuit, a sampling circuit and a capacitance value test circuit, the power supply circuit and the sampling circuit are electrically connected with the power unit, the signal generating circuit is electrically connected with an ITRIP pin of the power unit, the display unit, the power supply circuit, the signal generating circuit, the sampling circuit and the capacitance value testing circuit are all electrically connected with the micro-control unit, the signal generating circuit is also electrically connected with the power supply circuit, the sampling circuit is respectively electrically connected with the signal generating circuit and the capacitance value testing circuit, the capacitance value test circuit is used for detecting the capacitance value of a first capacitor in the power unit, a first end of the first capacitor is electrically connected with an ITRIP pin in the power unit, and a second end of the first capacitor is electrically connected with a VSS pin in the power unit.

Preferably, the capacitance test circuit comprises a first resistor; the first end of the first resistor is electrically connected with the signal generating circuit, and the second end of the first resistor is electrically connected with the sampling circuit and the first end of the first capacitor respectively.

Preferably, the capacitance value of the first capacitor is obtained by calculating according to the following calculation formula:

C＝R*Ln[(V1-V0)/(V1-Vt)]/t；

wherein t is time, C is a capacitance value of the first capacitor, R is a resistance value of the first resistor, V0 is an initial voltage value of the first capacitor, V1 is a voltage value at which the first capacitor can be finally charged or discharged, and Vt is a voltage value of the first capacitor at the time t.

Preferably, the capacitance value test circuit includes a constant current diode, an anode of the constant current diode is electrically connected to the signal generation circuit, and a cathode of the constant current diode is electrically connected to the sampling circuit and the first end of the first capacitor, respectively.

Preferably, the capacitance value of the first capacitor is calculated and obtained through the following calculation formula:

C＝It/U；

the t is time, the C is a capacitance value of the first capacitor, the I is a current value of the power unit, and the U is a voltage value of the first capacitor at the t time.

Preferably, the power unit includes a driving chip, three inverter subunits and the first capacitor; each inverter subunit comprises a first three-level transistor, a first diode, a second three-level transistor and a second diode, wherein the source electrode of the first three-level transistor is electrically connected with the drain electrode of the second three-level transistor, the drain electrode of the first three-level transistor is electrically connected with the P pin of the power unit, the source electrode of the first three-level transistor is also electrically connected with the anode electrode of the first diode, the cathode electrode of the first diode is electrically connected with the drain electrode of the first three-level transistor, the source electrode of the second three-level transistor is electrically connected with the anode electrode of the second diode, and the cathode electrode of the second diode is electrically connected with the drain electrode of the second three-level transistor; the gates of the first three-stage transistors in the three inverter sub-units are respectively and electrically connected with three high-side output ends of the driving chip, the gates of the second three-stage transistors in the three inverter sub-units are respectively and electrically connected with three low-side output ends of the driving chip, the sources of the first three-stage transistors and the drains of the second three-stage transistors in the three inverter sub-units are respectively and electrically connected with three VS ends of the driving chip, the sources of the first three-stage transistors and the drains of the second three-stage transistors in the three inverter sub-units are also respectively and electrically connected with a U pin, a V pin and a W pin of the power unit, and the sources of the second three-stage transistors in the three inverter sub-units are respectively and electrically connected with a UN pin of the power unit, the VN pin and the WN pin are electrically connected; the first end of the first capacitor is also electrically connected with the ITRIP end of the driving chip.

Preferably, each of the inverter subunits further includes three second resistors and three third resistors, gates of the first three-stage transistors in the three inverter subunits are electrically connected to the high-side output terminal of the driver chip through one of the second resistors, respectively, and gates of the second three-stage transistors in the three inverter subunits are electrically connected to the low-side output terminal of the driver chip through one of the third resistors, respectively.

Preferably, the first and second three-level transistors are both one of insulated gate bipolar transistors, reverse conducting insulated gate bipolar transistors and field effect transistors.

Preferably, the power unit further includes a fourth resistor and a second capacitor, a first end of the fourth resistor is electrically connected to the RCIN terminal of the driver chip and a first end of the second capacitor, a second end of the fourth resistor is electrically connected to the VDD terminal of the driver chip and the VDD pin of the power unit, and a second end of the third capacitor is electrically connected to the VSS pin of the power unit.

Preferably, an over-temperature protection switch, an under-voltage protection circuit, an over-current protection circuit and an over-voltage protection circuit are arranged in the driving chip.

Compared with the prior art, the intelligent power module with the capacitance value self-checking function is additionally provided with the capacitance value testing circuit, and the capacitance value testing circuit is electrically connected with the first capacitor connected in parallel with the ITRIP pin in the power unit to be used for detecting the capacitance value of the first capacitor, so that the capacitance value testing of the first capacitor connected in parallel with the ITRIP pin in the intelligent power module is realized, the first capacitor or the intelligent power module with defects in welding can be screened, and the phenomenon that the bad intelligent power module flows out is avoided.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic diagram illustrating a frame connection of an intelligent power module having a capacity self-checking function according to an embodiment of the present invention;

fig. 2 is an electrical schematic diagram of a power unit in an intelligent power module with a capacitance value self-checking function according to an embodiment of the present invention;

fig. 3 is a schematic diagram illustrating a connection of a frame of a first test unit in an intelligent power module having a capacity self-checking function according to an embodiment of the present invention;

fig. 4 is a schematic diagram illustrating a connection of a frame of a second test unit in an intelligent power module having a capacitance value self-checking function according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a conventional smart power module connected to a frame of an electrical parameter testing machine;

fig. 6 is a connection diagram illustrating a filter time testing principle of an ITRIP pin in a conventional smart power module.

100, a power unit; 101. an inverter sub-unit; 200. a test unit; 201. a micro control unit; 202. a display unit; 203. a power supply circuit; 204. a signal generating circuit; 205. a sampling circuit; 206. a capacitance value test circuit;

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

An embodiment of the present invention provides an intelligent power module with a capacitance value self-checking function, which is shown in fig. 1 to 4 and includes a power unit 100 and a test unit 200; the test unit 200 includes a micro control unit 201(MCU), a display unit 202, a power circuit 203, a signal generation circuit 204, a sampling circuit 205, and a capacitance test circuit 206, the power supply circuit 203 and the sampling circuit 205 are electrically connected to the power unit 100, the signal generating circuit 204 is electrically connected to an itrep pin of the power unit 100, the display unit 202, the power supply circuit 203, the signal generating circuit 204, the sampling circuit 205 and the capacitance value testing circuit 206 are electrically connected to the micro control unit 201, the signal generating circuit 204 is also electrically connected to the power supply circuit 203, the sampling circuit 205 is electrically connected to the signal generating circuit 204 and the capacitance value testing circuit 206, the capacitance value testing circuit 206 is also electrically connected to a first capacitor C1 in the power unit 100 for detecting a capacitance value of the first capacitor C1, a first end of the first capacitor C1 is electrically connected to the itrep pin of the power unit 100, and a second end of the first capacitor C1 is electrically connected to a VSS pin of the power unit 100.

The micro control unit 201, the display unit 202, the power circuit 203, the signal generating circuit 204 and the sampling circuit 205 are all conventional circuits used in a testing machine 400 for testing the conventional intelligent power module 300 in the conventional intelligent power module 300, and are not described in detail herein.

In this embodiment, the display unit 202 is further configured to display the capacitance value of the first capacitor C1 detected by the capacitance value test circuit 206.

In this embodiment, the power unit 100 includes a driving chip U1, three inverter sub-units 101, and a first capacitor C1; each inverter sub-unit 101 includes a first three-pole transistor Q1, a first diode D2, a second three-pole transistor Q2, and a second diode D3, a source of the first three-pole transistor Q1 is electrically connected to a drain of the second three-pole transistor Q2, a drain of the first three-pole transistor Q1 is electrically connected to the P pin of the power unit 100, a source of the first three-pole transistor Q1 is also electrically connected to an anode of the first diode D2, a cathode of the first diode D2 is electrically connected to a drain of the first three-pole transistor Q1, a source of the second three-pole transistor Q2 is electrically connected to an anode of the second diode D3, and a cathode of the second diode D3 is electrically connected to a drain of the second three-pole transistor Q2; the gates of the first three-pole transistor Q1 in the three inverter sub units 101 are electrically connected with three high-side output terminals (H01, H02, H03) of the driving chip U1, respectively, the gates of the second three-pole transistor Q2 in the three inverter sub units 101 are electrically connected with three low-side output terminals (L01, L02, LO3) of the driving chip U1, respectively, the sources of the first and second three-pole transistors Q1 and Q2 in the three inverter sub units 101 are electrically connected with three VS terminals of the driving chip U1, respectively, the sources of the first and second three-pole transistors Q1 and Q2 in the three inverter sub units 101 are also electrically connected with the U, V and W pins of the power unit 100, respectively, and the sources of the second three-pole transistor Q2 in the three inverter sub units 101 are electrically connected with the UN, VN and WN pins of the power unit 100, respectively; the first terminal of the first capacitor C1 is also electrically connected to the ITRIP terminal of the driver chip U1.

Among them, the first three-pole transistor Q1 in the three inverter sub-units 101 is an upper arm, and the second three-pole transistor Q2 is a lower arm.

The pins (also called ports or terminals) of the power driver module include a high voltage input terminal P, lower bridge arm pulse signal input terminals (UN, VN, WN) in the three inverter subunits 101, floating power supply terminals (VB1, VB2, VB3), a three-phase terminal (U, V, W), a three-channel high-side driver circuit input terminal (HIN1, HIN2, HIN3), a three-channel low-side driver circuit input terminal (LIN1, LIN2, LIN3), a FAULT signal output terminal FAULT, a current signal detection terminal ITRIP, a power supply output terminal VDD, and a ground terminal VSS.

The corresponding driver chip U1 is also provided with corresponding ports (also called pins or terminals), such as floating power terminals (VB1, VB2, VB3), three-phase terminals (U, VS1, V, VS2, W, VS3), three-channel high-side driver input terminals (HIN1, HIN2, HIN3), three-channel low-side driver input terminals (LIN1, LIN2, LIN3), FAULT signal output terminals FAULT, current signal detection terminal ITRIP, power output terminals VDD, and ground terminals VSs, and of course, it is also provided with other ports, such as a COM terminal connected to the RCIN terminal, and a VSs terminal.

Of course, according to actual requirements, the power unit 100 in this embodiment may also be a conventional smart power module 300 as shown in fig. 5 or other similar power modules.

In the present embodiment, each inverter subunit 101 further includes three second resistors R2 and three third resistors R3, the gates of the first triode transistors Q1 in the three inverter subunits 101 are electrically connected to the high-side output terminal of the driver chip U1 through one second resistor R2, respectively, and the gates of the second triode transistors Q2 in the three inverter subunits 101 are electrically connected to the low-side output terminal of the driver chip U1 through one third resistor R3, respectively.

In the present embodiment, each of the first three-pole transistor Q1 and the second three-pole transistor Q2 is one of an insulated gate bipolar transistor (IGBT transistor), a reverse conducting insulated gate bipolar transistor (reverse conducting IGBT transistor), and a field effect transistor (MOSFET transistor).

In this embodiment, the power unit 100 further includes a fourth resistor R4 and a second capacitor C2, a first end of the fourth resistor R4 is electrically connected to the RCIN terminal of the driving chip U1 and a first end of the second capacitor C2, a second end of the fourth resistor R4 is electrically connected to the VDD terminal of the driving chip U1 and the VDD pin of the power unit 100, and a second end of the third capacitor is electrically connected to the VSS pin of the power unit 100.

In this embodiment, an over-temperature protection switch, an under-voltage protection circuit, an over-current protection circuit, and an over-voltage protection circuit are disposed in the driver chip U1.

The over-temperature protection switch, the under-voltage protection circuit, the over-current protection circuit, and the over-voltage protection circuit are all circuits conventionally arranged in the conventional intelligent power module 300, and are not specifically described herein.

The first setting manner of the capacitance test circuit 206 in this embodiment is as follows: the capacitance test circuit 206 includes a first resistor R1; a first end of the first resistor R1 is electrically connected to the signal generating circuit 204, and a second end of the first resistor R1 is electrically connected to the sampling circuit 205 and a first end of the first capacitor C1, respectively. At this time, the first capacitor C1 can be charged through the first resistor R1.

The capacitance value of the first capacitor C1 is obtained by the following calculation formula (1):

C＝R*Ln[(V1-V0)/(V1-Vt)]/t (1)；

where t is time, C is a capacitance (capacitance) of the first capacitor C1, R is a resistance (resistance) of the first resistor R1, V0 is an initial voltage of the first capacitor C1, V1 is a voltage that the first capacitor C1 can be charged or discharged, and Vt is a voltage of the first capacitor C1 at time t.

During testing, the mcu 201 first obtains the voltage value of the first capacitor C1 at time t through the sampling circuit 205, and then obtains the capacitance value of the first capacitor C1 through the above formula (1), so as to complete testing, and thus select a bad smart power module, and avoid the bad smart power module from flowing out.

The second setting manner of the capacitance test circuit 206 in this embodiment is as follows: the capacitance test circuit 206 comprises a constant current diode D1, the anode of the constant current diode D1 is electrically connected with the signal generation circuit 204, and the cathode of the constant current diode D1 is electrically connected with the sampling circuit 205 and the first end of the first capacitor C1 respectively. At this time, the first capacitor C1 can be stably charged through the constant current diode D1.

The capacitance value of the first capacitor C1 is obtained by calculating the following calculation formula (2):

C＝It/U (2)；

where t is time, C is a capacitance (capacitance) of the first capacitor C1, I is a current value of the power unit 100, and U is a voltage value of the first capacitor C1 at time t.

During testing, the mcu 201 first obtains the voltage value of the first capacitor C1 at time t through the sampling circuit 205, and then obtains the capacitance value of the first capacitor C1 through the above formula (2), so as to complete testing, and thus select a bad smart power module, and avoid the bad smart power module from flowing out.

Compared with the prior art, the intelligent power module with the capacitance value self-checking function is additionally provided with the capacitance value testing circuit 206, and the capacitance value testing circuit 206 is electrically connected with the first capacitor C1 which is connected in parallel with the ITRIP pin in the power unit 100 to detect the capacitance value of the first capacitor C1, so that the capacitance value testing of the first capacitor C1 which is connected in parallel with the ITRIP pin in the intelligent power module is realized, the first capacitor C1 or an intelligent power module with defects in welding can be screened, and the phenomenon that bad intelligent power modules flow out is avoided.

Fig. 5 is a schematic diagram illustrating a frame connection between a conventional intelligent power module 300 and a conventional tester 400, where the conventional tester 400 includes only a micro control unit 401, a display unit 402, a power circuit 403, a signal generation circuit 404, and a sampling circuit 405, and the corresponding connection manner is the same as or similar to that of the intelligent power module with a self-test function, and is not repeated herein.

Fig. 6 is a schematic connection diagram illustrating a filter time test principle of the ITRIP pin in the conventional smart power module 300, where voltage waveforms of VCC, VB1, VB2, and VB3 are 301, signal waveforms of LIN1, LIN2, and LIN3 are 302, a pulse waveform of the ITRIP pin is 303, a voltage waveform of VCE at two ends of the inverter power device is 304, and a current waveform flowing through the inverter power device is 305.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. An intelligent power module with a capacity value self-checking function is characterized by comprising a power unit and a test unit; the test unit comprises a micro control unit, a display unit, a power circuit, a signal generation circuit, a sampling circuit and a capacitance value test circuit, wherein the power circuit and the sampling circuit are electrically connected with the power unit, the signal generation circuit is electrically connected with an ITRIP pin of the power unit, the display unit, the power circuit, the signal generation circuit, the sampling circuit and the capacitance value test circuit are electrically connected with the micro control unit, the signal generation circuit is also electrically connected with the power circuit, the sampling circuit is respectively electrically connected with the signal generation circuit and the capacitance value test circuit, the capacitance value test circuit is also electrically connected with a first capacitor in the power unit to be used for detecting the capacitance value of the first capacitor, and the first end of the first capacitor is electrically connected with the ITRIP pin in the power unit, the second end of the first capacitor is electrically connected with a VSS pin in the power unit.

2. The intelligent power module with self-checking function of capacitance value according to claim 1, wherein the capacitance value test circuit comprises a first resistor; the first end of the first resistor is electrically connected with the signal generating circuit, and the second end of the first resistor is electrically connected with the sampling circuit and the first end of the first capacitor respectively.

3. The intelligent power module with the capacitance value self-checking function according to claim 2, wherein the capacitance value of the first capacitor is obtained by calculating according to the following calculation formula:

C＝R*Ln[(V1-V0)/(V1-Vt)]/t；

4. The intelligent power module with the capacitance value self-checking function according to claim 1, wherein the capacitance value testing circuit comprises a constant current diode, an anode of the constant current diode is electrically connected with the signal generating circuit, and a cathode of the constant current diode is electrically connected with the sampling circuit and the first end of the first capacitor respectively.

5. The intelligent power module with the capacitance value self-checking function according to claim 4, wherein the capacitance value of the first capacitor is obtained by calculating according to the following calculation formula:

C＝It/U；

6. The intelligent power module with the capacitance value self-checking function according to claim 1, wherein the power unit comprises a driving chip, three inverter subunits and the first capacitor; each inverter subunit comprises a first three-level transistor, a first diode, a second three-level transistor and a second diode, wherein the source electrode of the first three-level transistor is electrically connected with the drain electrode of the second three-level transistor, the drain electrode of the first three-level transistor is electrically connected with the P pin of the power unit, the source electrode of the first three-level transistor is also electrically connected with the positive electrode of the first diode, the negative electrode of the first diode is electrically connected with the drain electrode of the first three-level transistor, the source electrode of the second three-level transistor is electrically connected with the positive electrode of the second diode, and the negative electrode of the second diode is electrically connected with the drain electrode of the second three-level transistor; the gates of the first three-stage transistors in the three inverter sub-units are respectively and electrically connected with three high-side output ends of the driving chip, the gates of the second three-stage transistors in the three inverter sub-units are respectively and electrically connected with three low-side output ends of the driving chip, the sources of the first three-stage transistors and the drains of the second three-stage transistors in the three inverter sub-units are respectively and electrically connected with three VS ends of the driving chip, the sources of the first three-stage transistors and the drains of the second three-stage transistors in the three inverter sub-units are also respectively and electrically connected with a U pin, a V pin and a W pin of the power unit, and the sources of the second three-stage transistors in the three inverter sub-units are respectively and electrically connected with a UN pin of the power unit, the VN pin and the WN pin are electrically connected; the first end of the first capacitor is also electrically connected with the ITRIP end of the driving chip.

7. The intelligent power module with the self-checking function according to claim 6, wherein each of the inverter sub-units further includes three second resistors and three third resistors, gates of the first three-stage transistors in the three inverter sub-units are electrically connected to the high-side output terminal of the driver chip through one of the second resistors, respectively, and gates of the second three-stage transistors in the three inverter sub-units are electrically connected to the low-side output terminal of the driver chip through one of the third resistors, respectively.

8. The intelligent power module with the capacitance value self-checking function according to claim 6, wherein the first three-level transistor and the second three-level transistor are both one of an insulated gate bipolar transistor, a reverse conducting insulated gate bipolar transistor and a field effect transistor.

9. The intelligent power module with the self-checking function of capacitance value according to claim 6, wherein the power unit further comprises a fourth resistor and a second capacitor, a first end of the fourth resistor is electrically connected to the RCIN terminal of the driver chip and a first end of the second capacitor, a second end of the fourth resistor is electrically connected to the VDD terminal of the driver chip and the VDD pin of the power unit, and a second end of the third capacitor is electrically connected to the VSS pin of the power unit.

10. The intelligent power module with the self-checking function of the capacitance value according to any one of claims 6 to 9, wherein an over-temperature protection switch, an under-voltage protection circuit, an over-current protection circuit and an over-voltage protection circuit are arranged in the driving chip.