CN214124898U

CN214124898U - Pre-charging circuit suitable for high-voltage direct-current bus capacitor

Info

Publication number: CN214124898U
Application number: CN202023256156.6U
Authority: CN
Inventors: 温铁钝; 张宇; 蒋永杰; 李藩为; 徐中行; 刘启进
Original assignee: AECC Aero Engine Control System Institute
Current assignee: AECC Aero Engine Control System Institute
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-09-03
Anticipated expiration: 2030-12-29

Abstract

The utility model relates to a pre-charging circuit suitable for a high voltage direct current bus capacitor, which comprises a control switch, a current limiting circuit and a switching circuit; the control switch is composed of a first field effect transistor, the current limiting circuit is composed of a first resistor, a triode and a third resistor, and the switching circuit is composed of a second field effect transistor, a second resistor and a photoelectric coupler. The utility model discloses a work in the enlarged work area with control switch and simulate current-limiting resistance function, and possess the ability that the constant current charges, reduced the volume effectively, optimized the charging process for bus-bar capacitance's work is more reliable.

Description

Pre-charging circuit suitable for high-voltage direct-current bus capacitor

Technical Field

The utility model belongs to the technical field of the pre-charge circuit of high voltage direct current bus-bar capacitance, specifically speaking are pre-charge circuit suitable for high voltage direct current bus-bar capacitance.

Background

In a high-voltage high-power system, when the system is started, a high-voltage direct-current power supply charges a large-capacity capacitor in the system, and the capacitor in the system is damaged due to excessive charging current. The traditional pre-charging mode adopting the current-limiting resistor has the defects that the volume of the resistor is large, the volume of a product is influenced, and the utilization rate of the resistor in the whole life cycle is low. The utility model discloses a work in the enlarged work area with control switch and simulate current-limiting resistance function, and possess the ability that the constant current charges, reduced the volume effectively, optimized the charging process for bus-bar capacitance's work is more reliable.

Disclosure of Invention

The utility model aims at overcoming the not enough of existence among the prior art, provide one kind possess the constant current charging ability, can reduce the volume effectively, optimize the charging process and make bus capacitance's work more reliable be applicable to high voltage direct current bus capacitance's pre-charge circuit.

According to the technical scheme provided by the utility model, the pre-charging circuit suitable for high voltage direct current bus capacitor, it includes control switch, current-limiting circuit and switching circuit; the control switch consists of a first field effect transistor, the current limiting circuit consists of a first resistor, a triode and a third resistor, and the switching circuit consists of a second field effect transistor, a second resistor and a photoelectric coupler;

the high-voltage direct-current power supply is connected with a drain electrode of a first field effect transistor, a source electrode of the first field effect transistor is connected to a base electrode of the triode, and a grid electrode of the first field effect transistor is connected to a collector electrode of the triode;

the power supply is connected with one end of the first resistor, the other end of the first resistor is connected with the collector of the triode, the base of the triode is connected with one end of the third resistor and is connected to the drain of the second field effect transistor, the other end of the third resistor is connected with the emitter of the triode and is connected to the output end, and the negative end of the power supply is connected with the output end;

the positive pole and the negative pole of optoelectronic coupler input side link to each other with first control signal, second control signal respectively, and optoelectronic coupler's collecting electrode links to each other with power supply, and optoelectronic coupler's emitter links to each other with the grid of second field effect transistor and the one end of second resistance, and the source of second field effect transistor links to each other and is connected to the output with the other end of second resistance.

Preferably, the first field effect transistor and the second field effect transistor are both N-type transistors, and the triode is NPN-type transistor.

Preferably, the first field effect transistor and the second field effect transistor are both of a P type, and the triode is of a PNP type.

The utility model discloses a work in the enlarged work area with control switch and simulate current-limiting resistance function, and possess the ability that the constant current charges, reduced the volume effectively, optimized the charging process for bus-bar capacitance's work is more reliable.

Drawings

Fig. 1 is a schematic circuit diagram of the present invention.

Detailed Description

The present invention will be further described with reference to the following specific embodiments.

A pre-charging circuit suitable for a high-voltage direct-current bus capacitor is shown in figure 1 and comprises a control switch 1, a current limiting circuit 2 and a switching circuit 3; the control switch 1 consists of an N-type first field effect transistor V1, the current limiting circuit 2 consists of a first resistor R1, an NPN-type triode V3 and a third resistor Rs, and the switching circuit 3 consists of an N-type second field effect transistor V2, a second resistor R2 and a photoelectric coupler E1;

the high-voltage direct-current power supply Vin is connected with the drain electrode of a first field-effect transistor V1, the source electrode of the first field-effect transistor V1 is connected with the base electrode of a triode V3, and the grid electrode of the first field-effect transistor V1 is connected with the collector electrode of a triode V3;

the power supply Vcc is connected with one end of a first resistor R1, the other end of the first resistor R1 is connected with the collector of a triode V3, the base of the triode V3 is connected with one end of a third resistor Rs and is connected with the drain of a second field effect transistor V2, the other end of the third resistor Rs is connected with the emitter of a triode V3 and is connected with an output end Vbus, and the negative end of the power supply Vcc is connected with the output end Vbus;

an anode and a cathode of an input side of the photoelectric coupler E1 are respectively connected with the first control signal A and the second control signal B, a collector of the photoelectric coupler E1 is connected with a power supply Vcc, an emitter of the photoelectric coupler E1 is connected with a grid of the second field effect transistor V2 and one end of the second resistor R2, and a source of the second field effect transistor V2 is connected with the other end of the second resistor R2 and is connected with an output end Vbus.

The utility model discloses in, high voltage dc power source Vin's voltage is 270V, power supply Vcc's voltage is 15V (negative terminal connects output Vbus), third resistance Rs equals 5.1 omega, first resistance R1 equals 1k omega, second resistance R2 equals 20k omega, NPN's triode V3 adopts MMBT5551, optoelectronic coupler E1 adopts MCT62, N's first field effect transistor V1 adopts IXFN110N60P3, N's second field effect transistor V2 adopts IPT004N 03L.

The working principle of the utility model is as follows:

after the high voltage direct current power Vin is powered on, the voltage value between the first control signal a and the second control signal B is zero at this time, the secondary side of the photoelectric coupler E1 is in an off state, the N-type second field effect transistor V2 is in an off state, when the voltage of the power supply Vcc is gradually established, the power supply Vcc charges the junction capacitor of the N-type first field effect transistor V1 through the first resistor R1, so that the N-type first field effect transistor V1 is changed from an off working area to an amplification working area, at this time, the current charges the load capacitor of the output terminal Vbus through the N-type first field effect transistor V1 and the third resistor Rs, the current gradually increases through the third resistor Rs, when the voltage of the third resistor Rs reaches the on voltage of the NPN-type triode V3, the NPN-type triode V3 enters the amplification working area, and the N-type first field effect transistor V1 is maintained in the amplification working area, the current passing through the third resistor Rs is not increased any more, a circuit between the high-voltage direct-current power supply Vin and the output end Vbus is equivalent to a gradually reduced resistor, and the load capacitor of the output end Vbus is charged with constant current. After the pre-charging is finished, the voltage value between the first control signal A and the second control signal B is controlled to be larger than the starting voltage of the primary side of a photoelectric coupler E1, a power supply Vcc enables an N-type second field effect transistor V2 to be conducted in a saturated mode through the secondary side of the photoelectric coupler, the voltage between the base electrode and the emitter electrode of an NPN-type triode V3 is reduced, the NPN-type triode V3 enters a cut-off working area, the voltage between the grid electrode and the source electrode of the N-type first field effect transistor V1 is the voltage value of the Vcc minus the conducting voltage of the N-type second field effect transistor V2, the N-type first field effect transistor V1 enters the saturated working area, a circuit between a high-voltage direct-current power supply Vin and an output end Vbus is equivalent to a resistor with a negligible resistance value, and the high-voltage direct current power supply Vin can provide large current for the output end Vbus. In the circuit, the drain-source withstand voltage of the N-type second field effect transistor V2 does not exceed the conduction voltage of the NPN-type triode V3 in the working state, a low-voltage low-conduction-impedance field effect transistor can be selected, and the equivalent impedance between the high-voltage direct-current power supply Vin and the output end Vbus when the N-type second field effect transistor V2 is conducted is effectively reduced.

Claims

1. The utility model provides a precharge circuit suitable for high voltage direct current bus capacitance which characterized in that: the circuit comprises a control switch (1), a current limiting circuit (2) and a switching circuit (3); the control switch (1) is composed of a first field effect transistor (V1), the current limiting circuit (2) is composed of a first resistor (R1), a triode (V3) and a third resistor (Rs), and the switching circuit (3) is composed of a second field effect transistor (V2), a second resistor (R2) and a photoelectric coupler (E1);

the high-voltage direct current power supply (Vin) is connected with the drain electrode of the first field effect transistor (V1), the source electrode of the first field effect transistor (V1) is connected to the base electrode of the triode (V3), and the grid electrode of the first field effect transistor (V1) is connected to the collector electrode of the triode (V3);

the power supply (Vcc) is connected with one end of a first resistor (R1), the other end of the first resistor (R1) is connected with a collector of a triode (V3), a base of the triode (V3) is connected with one end of a third resistor (Rs) and is connected to a drain electrode of a second field effect transistor (V2), the other end of the third resistor (Rs) is connected with an emitter of a triode (V3) and is connected to an output end (Vbus), and a negative end of the power supply (Vcc) is connected with the output end (Vbus);

the anode and the cathode of the input side of the photoelectric coupler (E1) are respectively connected with a first control signal A and a second control signal B, the collector of the photoelectric coupler (E1) is connected with a power supply (Vcc), the emitter of the photoelectric coupler (E1) is connected with the grid of a second field effect transistor (V2) and one end of a second resistor (R2), and the source of the second field effect transistor (V2) is connected with the other end of the second resistor (R2) and is connected to the output end (Vbus).

2. The pre-charging circuit suitable for the high-voltage direct-current bus capacitor as claimed in claim 1, wherein: the first field effect transistor (V1) and the second field effect transistor (V2) are both N-type, and the triode (V3) is NPN-type.

3. The pre-charging circuit suitable for the high-voltage direct-current bus capacitor as claimed in claim 1, wherein: the first field effect transistor (V1) and the second field effect transistor (V2) are both of a P type, and the triode (V3) is of a PNP type.