阅读说明：本技术 一种应用于变频器的集成制动器件 (Integrated brake device applied to frequency converter ) 是由 车湖深 吕冬洋 方庆 郭小波 于 2019-09-10 设计创作，主要内容包括：本发明提供一种应用于变频器的集成制动器件,涉及变频器技术领域,包括：基板,基板上设有：第一陶瓷覆铜板,焊接有至少一快恢复二极管；第二陶瓷覆铜板,第二陶瓷覆铜板上焊接有至少一绝缘栅双极型晶体管以及至少一温度电阻；若干功率端子,分别设置于第一陶瓷覆铜板和第二陶瓷覆铜板上；若干信号端子,分别设置于第一陶瓷覆铜板和第二陶瓷覆铜板上；外壳,盖合于基板上,且外壳上设有各功率端子和各信号端子伸出的孔洞；印刷电路板,放置于外壳的背离基板一侧的一第一凹槽内,且印刷电路板通过各信号端子与第一陶瓷覆铜板和第二陶瓷覆铜板连接。本发明具有更高的集成度,体积小,成本低,且具有更高的可靠性和使用的便捷性。(The invention provides an integrated brake device applied to a frequency converter, which relates to the technical field of frequency converters and comprises the following components: a substrate on which are provided: the first ceramic copper-clad plate is welded with at least one fast recovery diode; the second ceramic copper-clad plate is welded with at least one insulated gate bipolar transistor and at least one temperature resistor; the power terminals are respectively arranged on the first ceramic copper-clad plate and the second ceramic copper-clad plate; the signal terminals are respectively arranged on the first ceramic copper-clad plate and the second ceramic copper-clad plate; the shell covers the substrate, and holes for the power terminals and the signal terminals to extend out are formed in the shell; the printed circuit board is placed in a first groove on one side of the shell, which is far away from the substrate, and the printed circuit board is connected with the first ceramic copper-clad plate and the second ceramic copper-clad plate through signal terminals. The invention has the advantages of higher integration level, small volume, low cost, higher reliability and convenience for use.)

1. An integrated brake device applied to a frequency converter is characterized by specifically comprising:

a substrate, on which:

the first ceramic copper-clad plate is welded on the substrate, and at least one fast recovery diode is welded on the first ceramic copper-clad plate;

the second ceramic copper-clad plate is welded on the substrate, the second ceramic copper-clad plate is positioned on the right side of the first ceramic copper-clad plate, and at least one insulated gate bipolar transistor and at least one temperature resistor positioned on the left side of the insulated gate bipolar transistor are welded on the second ceramic copper-clad plate;

the power terminals are respectively arranged on the first ceramic copper-clad plate and the second ceramic copper-clad plate;

the signal terminals are respectively arranged on the first ceramic copper-clad plate and the second ceramic copper-clad plate; the shell covers the substrate, and holes extending out of the power terminals and the signal terminals are formed in the shell; the printed circuit board is placed in a first groove on one side of the shell, which is far away from the substrate, and the printed circuit board is connected with the first ceramic copper-clad plate and the second ceramic copper-clad plate through the signal terminals.

2. The integrated brake device for a frequency converter according to claim 1, further comprising a support frame disposed on the printed circuit board and corresponding to the protruding position of each of the power terminals.

3. Integrated braking device applied to frequency converters, according to claim 1, characterized in that said power terminals comprise in particular:

the first power terminal is arranged on the first ceramic copper-clad plate and is positioned above the left side of the fast recovery diode, and the first power terminal is connected with the cathode of the fast recovery diode and is used as an output P end of the integrated brake device;

the second power terminal is arranged on the second copper-clad ceramic plate and is positioned at the upper right part of the insulated gate bipolar transistor, and the second power terminal is connected with an emitter of the insulated gate bipolar transistor and is used as an output N end of the integrated brake device;

and the third power terminal is arranged on the second copper-clad ceramic plate and is positioned at the right lower part of the insulated gate bipolar transistor, and the third power terminal is connected with a collector electrode of the insulated gate bipolar transistor and an anode of the fast recovery diode and is used as an output PB end of the integrated brake device.

4. The integrated braking device applied to a frequency converter according to claim 1, characterized in that the signal terminals comprise in particular:

the first signal terminal is arranged on the first ceramic copper-clad plate and is positioned above the left side of the fast recovery diode, and the first signal terminal is connected with the cathode of the fast recovery diode;

the second signal terminal is arranged on the second copper-clad ceramic plate and is positioned at the upper right part of the insulated gate bipolar transistor, and the second signal terminal is connected with an emitting electrode of the insulated gate bipolar transistor;

the third signal terminal is arranged on the second copper-clad ceramic plate and is positioned above the left side of the second signal terminal, and the third signal terminal is connected with the grid electrode of the insulated gate bipolar transistor;

and the at least two fourth signal terminals are arranged on the second copper-clad ceramic plate and positioned on the left side of the insulated gate bipolar transistor, and the two fourth signal terminals are respectively connected with two ends of the temperature resistor.

5. The integrated brake device applied to the frequency converter according to claim 4, wherein a plurality of circuits are integrated on the printed circuit board, and the circuits comprise:

the over-temperature protection circuit is arranged in the middle of the printed circuit board, and the input end of the over-temperature protection circuit is connected with the temperature resistor through the fourth signal terminal;

the voltage detection circuit is arranged at the upper left of the over-temperature protection circuit, and the input end of the voltage detection circuit is connected with the cathode of the fast recovery diode through the first signal terminal and is connected with the emitter of the insulated gate bipolar transistor through the second signal terminal;

the IGBT overcurrent protection circuit is arranged at the lower right side of the overtemperature protection circuit, and the input end of the IGBT overcurrent protection circuit is connected with the collector electrode of the insulated gate bipolar transistor;

the IGBT driving circuit is arranged at the lower right of the over-temperature protection circuit, the input end of the IGBT driving circuit is respectively connected with the output end of the over-temperature protection circuit, the output end of the IGBT over-current protection circuit and the output end of the voltage detection circuit, and the output end of the IGBT driving circuit is respectively connected with the grid electrode of the insulated gate bipolar transistor and the emitting electrode of the insulated gate bipolar transistor;

and the DC-DC circuit is arranged on the left side of the over-temperature protection circuit, is respectively connected with the power supply end of the over-temperature protection circuit, the power supply end of the voltage detection circuit, the power supply end of the IGBT over-current protection circuit and the power supply end of the IGBT driving circuit, and is connected with the cathode of the fast recovery diode and the emitter of the insulated gate bipolar transistor.

6. The integrated brake device applied to the frequency converter according to claim 5, wherein a signal leading-out terminal is further integrated on the printed circuit board, and the signal leading-out terminal is respectively connected with the output end of the over-temperature protection circuit and the output end of the IGBT over-current protection circuit.

7. The integrated braking device applied to a frequency converter according to claim 1, wherein the number of the fast recovery diodes is three, and each of the fast recovery diodes is connected in parallel.

8. The integrated brake device applied to the frequency converter according to claim 1, wherein the number of the insulated gate bipolar transistors is three, and each of the insulated gate bipolar transistors is connected in parallel.

9. The integrated brake device applied to the frequency converter according to claim 1, wherein the substrate is a copper base plate, the copper base plate is made of T2 red copper material, and is plated with solderable nickel on the surface and is subjected to radian pre-bending treatment.

10. The integrated brake device applied to the frequency converter according to claim 1, wherein the housing is made of PBT material.

Technical Field

The invention relates to the technical field of frequency converters, in particular to an integrated brake device applied to a frequency converter.

Background

The frequency converter is an electric control device which applies a frequency conversion technology and a microelectronic technology and controls an alternating current motor by changing the frequency mode of a working power supply of the motor. The motor is suitable for motor driving and is widely applied to various industries.

The braking unit is called as a 'special energy consumption braking unit for a frequency converter' or a 'special energy feedback unit for a frequency converter', and is mainly used for controlling occasions with heavy mechanical loads and high braking speed requirements, and the regenerative electric energy generated by the motor is consumed through a braking resistor so as to keep the stability of a frequency converter system in the braking process.

At present, all low-power frequency converters on the market adopt built-in brake units, all high-power frequency converters adopt external brake units, and the external brake units are large in appearance and high in cost. With the development of power electronic technology, the requirement of the industry on the reliability of the module is higher and higher, the integration level of devices is higher and higher, and a brake unit module product with higher integration level and more stability is urgently needed.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides an integrated brake device applied to a frequency converter, which specifically comprises the following components:

a substrate, on which:

the first ceramic copper-clad plate is welded on the substrate, and at least one fast recovery diode is welded on the first ceramic copper-clad plate;

the second ceramic copper-clad plate is welded on the substrate, the second ceramic copper-clad plate is positioned on the right side of the first ceramic copper-clad plate, and at least one insulated gate bipolar transistor and at least one temperature resistor positioned on the left side of the insulated gate bipolar transistor are welded on the second ceramic copper-clad plate;

the power terminals are respectively arranged on the first ceramic copper-clad plate and the second ceramic copper-clad plate;

the signal terminals are respectively arranged on the first ceramic copper-clad plate and the second ceramic copper-clad plate;

the shell covers the substrate, and holes extending out of the power terminals and the signal terminals are formed in the shell;

the printed circuit board is placed in a first groove on one side of the shell, which is far away from the substrate, and the printed circuit board is connected with the first ceramic copper-clad plate and the second ceramic copper-clad plate through the signal terminals.

Preferably, the power module further comprises a support frame, which is arranged on the printed circuit board and corresponds to the extending position of each power terminal.

Preferably, the power terminal specifically includes:

the first power terminal is arranged on the first ceramic copper-clad plate and is positioned above the left side of the fast recovery diode, and the first power terminal is connected with the cathode of the fast recovery diode and is used as an output P end of the integrated brake device;

the second power terminal is arranged on the second copper-clad ceramic plate and is positioned at the upper right part of the insulated gate bipolar transistor, and the second power terminal is connected with an emitter of the insulated gate bipolar transistor and is used as an output N end of the integrated brake device;

and the third power terminal is arranged on the second copper-clad ceramic plate and is positioned at the right lower part of the insulated gate bipolar transistor, and the third power terminal is connected with a collector electrode of the insulated gate bipolar transistor and an anode of the fast recovery diode and is used as an output PB end of the integrated brake device.

Preferably, the signal terminal specifically includes:

the first signal terminal is arranged on the first ceramic copper-clad plate and is positioned above the left side of the fast recovery diode, and the first signal terminal is connected with the cathode of the fast recovery diode;

the second signal terminal is arranged on the second copper-clad ceramic plate and is positioned at the upper right part of the insulated gate bipolar transistor, and the second signal terminal is connected with an emitting electrode of the insulated gate bipolar transistor;

the third signal terminal is arranged on the second copper-clad ceramic plate and is positioned above the left side of the second signal terminal, and the third signal terminal is connected with the grid electrode of the insulated gate bipolar transistor;

and the at least two fourth signal terminals are arranged on the second copper-clad ceramic plate and positioned on the left side of the insulated gate bipolar transistor, and the two fourth signal terminals are respectively connected with two ends of the temperature resistor.

Preferably, the printed circuit board has a plurality of circuits integrated thereon, and the circuits include:

the over-temperature protection circuit is arranged in the middle of the printed circuit board, and the input end of the over-temperature protection circuit is connected with the temperature resistor through the fourth signal terminal;

the voltage detection circuit is arranged at the upper left of the over-temperature protection circuit, and the input end of the voltage detection circuit is connected with the cathode of the fast recovery diode through the first signal terminal and is connected with the emitter of the insulated gate bipolar transistor through the second signal terminal;

the IGBT overcurrent protection circuit is arranged at the lower right side of the overtemperature protection circuit, and the input end of the IGBT overcurrent protection circuit is connected with the collector electrode of the insulated gate bipolar transistor;

the IGBT driving circuit is arranged at the lower right of the over-temperature protection circuit, the input end of the IGBT driving circuit is connected with the output end of the over-temperature protection circuit, the output end of the IGBT over-current protection circuit and the output end of the voltage detection circuit, and the output end of the IGBT driving circuit is connected with the grid electrode of the insulated gate bipolar transistor and the emitting electrode of the insulated gate bipolar transistor;

and the DC-DC circuit is arranged on the left side of the over-temperature protection circuit, is respectively connected with the power supply end of the over-temperature protection circuit, the power supply end of the voltage detection circuit, the power supply end of the IGBT over-current protection circuit and the power supply end of the IGBT driving circuit, and is connected with the cathode of the fast recovery diode and the emitter of the insulated gate bipolar transistor.

Preferably, a signal leading-out terminal is further integrated on the printed circuit board, and the signal leading-out terminal is respectively connected with the output end of the over-temperature protection circuit and the output end of the IGBT over-current protection circuit.

Preferably, the number of the fast recovery diodes is three, and each of the fast recovery diodes is connected in parallel.

Preferably, there are three insulated gate bipolar transistors, and each of the insulated gate bipolar transistors is connected in parallel.

Preferably, the substrate is a copper base plate, the copper base plate is made of T2 red copper material, weldable nickel is electroplated on the surface of the copper base plate, and radian pre-bending treatment is performed.

Preferably, the shell is made of PBT material.

The technical scheme has the following advantages or beneficial effects: the integrated brake device has the advantages of higher integration level, small volume, low cost, higher reliability and convenience in use.

Drawings

FIG. 1 is a schematic structural diagram of an integrated braking device applied to a frequency converter according to a preferred embodiment of the present invention;

FIG. 2 is a schematic view of an integrated brake device filled with epoxy in accordance with a preferred embodiment of the present invention;

FIG. 3 is a schematic diagram of a substrate structure of an integrated braking device according to a preferred embodiment of the present invention;

FIG. 4 is a schematic circuit diagram of an integrated braking device according to a preferred embodiment of the present invention.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present invention is not limited to the embodiment, and other embodiments may be included in the scope of the present invention as long as the gist of the present invention is satisfied.

In a preferred embodiment of the present invention, based on the above problems in the prior art, there is provided an integrated braking device for a frequency converter, as shown in fig. 1 to 4, specifically including:

a substrate 1, on the substrate 1:

the first ceramic copper-clad plate 11 is welded on the substrate 1, and at least one fast recovery diode D is welded on the first ceramic copper-clad plate 11;

the second ceramic copper-clad plate 12 is welded on the substrate 1, the second ceramic copper-clad plate 12 is positioned on the right side of the first ceramic copper-clad plate 11, and the second ceramic copper-clad plate 12 is welded with at least one insulated gate bipolar transistor T and at least one temperature resistor R positioned on the left side of the insulated gate bipolar transistor T;

the power terminals are respectively arranged on the first ceramic copper-clad plate 11 and the second ceramic copper-clad plate 12;

the signal terminals are respectively arranged on the first ceramic copper-clad plate 11 and the second ceramic copper-clad plate 12;

the shell 2 covers the substrate 1, and the shell 2 is provided with holes for extending the power terminals and the signal terminals;

the printed circuit board 3 is placed in a first groove 21 on one side of the shell 2, which is far away from the substrate 1, and the printed circuit board 3 is connected with the first ceramic copper clad laminate 11 and the second ceramic copper clad laminate 12 through signal terminals.

Specifically, in this embodiment, the integrated brake device of the present invention includes a printed circuit board portion and a power portion disposed in an upper layer and a lower layer, and further includes a housing 2, the power portion and the printed circuit board 3 are respectively disposed at two sides of the housing 2, the power portion includes a substrate 1 and two ceramic copper clad laminates welded on the substrate 1, and a plurality of signal terminals are disposed on the two ceramic copper clad laminates for connecting the power portion and the printed circuit board 3. The two ceramic copper-clad plates are also provided with a plurality of power terminals which extend out of the holes on the shell 2, and the corresponding positions of the holes are respectively provided with a support frame 4 for supporting the bending parts of the power terminals when the power terminals are bent, so that the power terminals can be conveniently installed and used by users. In this embodiment, the hole is disposed at the bottom of the first groove 21, and is shielded by the printed circuit board 3 corresponding to the positions of the power terminal and the signal terminal on the substrate 1, which are not specifically shown in the figure.

Preferably, the substrate 1 is a copper base plate, a T2 red copper material is adopted, weldable nickel is electroplated on the surface of the substrate, radian pre-bending treatment is carried out, and the two ceramic copper-clad plates and the copper base plate are connected by adopting a vacuum welding technology; the power terminal and the signal terminal are made of pure copper materials, weldable nickel is electroplated on the surfaces of the power terminal and the signal terminal, and a bend is designed above a welding point to buffer the installation stress; the housing 2 is made of PBT material, and a structure for preventing the terminal from falling off is designed in the housing 2.

In this embodiment, the manufacturing process of the integrated brake device is as follows;

firstly, a copper base plate is taken as a substrate, two ceramic copper clad plates with front etched circuits are welded on the substrate 1, and at least one insulated gate bipolar transistor T, at least one fast recovery diode D and at least one temperature resistor R are placed on the ceramic copper clad plates in a vacuum welding mode. In this embodiment, the fast recovery diode D and the first ceramic copper-clad plate 11 are connected by aluminum wire bonding, and the insulated gate bipolar transistor T and the second ceramic copper-clad plate 12 are connected by aluminum wire bonding, so that the insulated gate bipolar transistor T and the fast recovery diode D are connected in series.

The specific numbers of the insulated gate bipolar transistors T and the fast recovery diodes D are different according to different current specifications, and power can be adjusted by adjusting the numbers of the insulated gate bipolar transistors T and the fast recovery diodes D. In this embodiment, at most three fast recovery diodes D can be placed on the first ceramic copper-clad plate 11, at most three insulated gate bipolar transistors T can be placed on the second ceramic copper-clad plate 12, and the maximum current of the power part is 300 amperes in a full-scale configuration state. In this embodiment, when a plurality of fast recovery diodes D and a plurality of insulated gate bipolar transistors T are provided, the fast recovery diodes D are connected in parallel and then connected in series with the insulated gate bipolar transistors T connected in parallel.

Preferably, the back surface of the fast recovery diode D is connected with the first ceramic copper-clad plate 11 by adopting a vacuum welding technology, and the back surface of the insulated gate bipolar transistor T is connected with the second ceramic copper-clad plate 12 by adopting the vacuum welding technology, so that the thermal resistance of the integrated brake device is effectively reduced, and the heat dissipation capacity of the integrated brake device is effectively improved. Furthermore, the front materials of the fast recovery diode D and the insulated gate bipolar transistor T are aluminum, and the back materials are silver; and the front surface of the integrated brake device is connected with the ceramic copper-clad plate by adopting a pure aluminum wire, the aluminum wire connection mode is preferably an ultrasonic bonding mode, and an aluminum wire bonding process is adopted, so that the production efficiency and the product consistency of the integrated brake device are effectively improved.

Preferably, the ceramic copper-clad plate is of a three-layer structure, wherein the upper layer and the lower layer are made of pure copper materials, the middle layer is made of aluminum oxide ceramics, and non-welding and bonding areas on the upper copper layer are coated with solder resist ink.

And secondly, welding a plurality of power terminals and a plurality of signal terminals on the two ceramic copper-clad plates, covering the shell on the substrate after welding is finished, and packaging the shell and the substrate into a whole through sealant.

Finally, the printed circuit board 3 is placed in the first groove 21 of the shell 2, the printed circuit board 3 is provided with a DC-DC circuit 35, an over-temperature protection circuit 31, an IGBT driving circuit 34, a voltage detection circuit 32 and an IGBT over-current protection circuit 33, the output ends of the over-temperature protection circuit 31 and the IGBT over-current protection circuit 33 are led out through a signal leading-out terminal 36, and the signal leading-out terminal 36 is connected with an external host, so that the external host can receive corresponding over-temperature alarm information and over-current alarm information in real time. After the printed circuit board 3 is installed, the support frame 4 is placed at the corresponding position of the hole of the printed circuit board 3, then the epoxy resin is filled into the groove of the shell until the groove is filled, and the power terminal is bent after high-temperature curing, so that the power terminal can be installed by a user conveniently.

Preferably, after the housing 2 is installed, silica gel is used for internal filling to achieve sufficient pressure resistance; after the printed circuit board 3 and the support frame 4 are mounted, epoxy resin is used for internal filling so as to achieve sufficient pressure resistance and heat dissipation effects.

In the preferred embodiment of the present invention, a support frame 4 is further included, which is disposed on the printed circuit board 3 and corresponds to the protruding position of each power terminal.

In a preferred embodiment of the present invention, the power terminal specifically includes:

the first power terminal 51 is arranged on the first ceramic copper-clad plate 11 and is positioned above the left side of the fast recovery diode D, and the first power terminal 51 is connected with the cathode of the fast recovery diode D to be used as an output P end of the integrated brake device;

the second power terminal 52 is arranged on the second copper-clad ceramic plate 12 and is positioned at the upper right side of the insulated gate bipolar transistor T, and the second power terminal 52 is connected with an emitter of the insulated gate bipolar transistor T to be used as an output N end of the integrated brake device;

and the third power terminal 53 is arranged on the second copper-clad ceramic plate 12 and is positioned at the lower right side of the insulated gate bipolar transistor T, and the third power terminal 53 is connected with the collector of the insulated gate bipolar transistor T and the anode of the fast recovery diode D to serve as an output PB end of the integrated brake device.

In a preferred embodiment of the present invention, the signal terminal specifically includes:

the first signal terminal 61 is arranged on the first ceramic copper-clad plate 11 and is positioned above the left side of the fast recovery diode D, and the first signal terminal 61 is connected with the cathode of the fast recovery diode D;

the second signal terminal 62 is arranged on the second copper-clad ceramic plate 12 and is positioned at the upper right of the insulated gate bipolar transistor T, and the second signal terminal 62 is connected with an emitter of the insulated gate bipolar transistor T;

the third signal terminal 63 is arranged on the second copper-clad ceramic plate 12 and positioned above the second signal terminal 62, and the third signal terminal 63 is connected with the gate of the insulated gate bipolar transistor T;

and the at least two fourth signal terminals 64 are arranged on the second copper-clad ceramic plate 12 and located on the left side of the insulated gate bipolar transistor T, and the two fourth signal terminals 64 are respectively connected with two ends of the temperature resistor R.

In a preferred embodiment of the present invention, the printed circuit board 3 has integrated thereon a plurality of circuits, including:

the over-temperature protection circuit 31 is arranged in the middle of the printed circuit board 3, and the input end of the over-temperature protection circuit 31 is connected with the temperature resistor R through a fourth signal terminal 64;

a voltage detection circuit 32, which is disposed at the upper left of the over-temperature protection circuit 31, and the input end of the voltage detection circuit 32 is connected to the cathode of the fast recovery diode D through a first signal terminal 61, and is connected to the emitter of the insulated gate bipolar transistor T through a second signal terminal 62;

the IGBT overcurrent protection circuit 33 is arranged at the lower right side of the overtemperature protection circuit 31, and the input end of the IGBT overcurrent protection circuit 33 is connected with the collector electrode of the insulated gate bipolar transistor T;

the IGBT driving circuit 34 is arranged at the lower right of the over-temperature protection circuit 31, the input end of the IGBT driving circuit 34 is respectively connected with the output end of the over-temperature protection circuit 31, the output end of the IGBT over-current protection circuit 33 and the output end of the voltage detection circuit 32, and the output end of the IGBT driving circuit 34 is respectively connected with the grid electrode of the insulated gate bipolar transistor T and the emitting electrode of the insulated gate bipolar transistor T;

and the DC-DC circuit 35 is arranged on the left side of the over-temperature protection circuit 31, and the DC-DC circuit 35 is respectively connected with the power supply end of the over-temperature protection circuit 31, the power supply end of the voltage detection circuit 32, the power supply end of the IGBT over-current protection circuit 33 and the power supply end of the IGBT driving circuit 34, and is connected with the cathode of the fast recovery diode D and the emitter of the insulated gate bipolar transistor T.

Specifically, in this embodiment, the voltage detection circuit 32 preferably detects a resistance voltage division between the output P terminal and the output N terminal, and sets a corresponding comparator to determine whether the voltage between the output P terminal and the output N terminal is overvoltage, and transmits an overvoltage result to the input terminal of the IGBT drive circuit 34 through the output terminal of the voltage detection circuit 32 when overvoltage occurs, so as to turn off the IGBT T through the IGBT drive circuit 34;

the temperature resistor R is arranged on the left side of the insulated gate bipolar transistor T and used for detecting the working temperature of the insulated gate bipolar transistor T, the input end of the over-temperature protection circuit 31 is connected with the temperature resistor R, and when the working temperature detected by the temperature resistor R is higher than a preset prefabricated temperature, an over-temperature result is transmitted to the input end of the IGBT drive circuit 34 through the output end of the over-temperature protection circuit 31 so as to turn off the insulated gate bipolar transistor T through the IGBT drive circuit 34, and meanwhile, an over-temperature alarm signal is sent to an external host through a signal leading-out terminal 36 connected with the output end of the over-temperature protection circuit 31;

the IGBT overcurrent protection circuit 33 preferably detects a voltage drop between the output PB terminal and the output N terminal, and as a current flowing through the IGBT T increases, a conduction voltage drop of the IGBT T also gradually increases, that is, the voltage drop between the output PB terminal and the output N terminal gradually increases, and when the voltage drop increases to a voltage drop threshold, an overcurrent result is transmitted to an input terminal of the IGBT drive circuit 34 through an output terminal of the IGBT overcurrent protection circuit 33, so that the IGBT T is turned off through the IGBT drive circuit 34, and simultaneously, an overcurrent alarm signal is transmitted to an external host through a signal leading terminal 36 connected to an output terminal of the IGBT overcurrent protection circuit 33.

In the preferred embodiment of the present invention, a signal leading terminal 36 is further integrated on the printed circuit board 3, and the signal leading terminal 36 is respectively connected to the output terminal of the over-temperature protection circuit 31 and the output terminal of the IGBT over-current protection circuit 33.

In the preferred embodiment of the present invention, there are three fast recovery diodes D, and each fast recovery diode D is connected in parallel.

In the preferred embodiment of the present invention, there are three igbts T1, and each igbts T1 are connected in parallel.

In the preferred embodiment of the present invention, the substrate 1 is a copper substrate, and the copper substrate is made of T2 red copper material, and the surface is plated with solderable nickel and is subjected to arc pre-bending treatment.

In the preferred embodiment of the present invention, the housing 2 is made of PBT.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.