CN200987070Y

CN200987070Y - Phase lacking protection circuit for Intermediate voltage frequency-changing speed regulator

Info

Publication number: CN200987070Y
Application number: CN 200620152067
Authority: CN
Inventors: 李淑香
Original assignee: TIANJIN HUAYUN AUTOMATION CONTROL CO Ltd
Current assignee: TIANJIN HUAYUN AUTOMATION CONTROL CO Ltd
Priority date: 2006-12-26
Filing date: 2006-12-26
Publication date: 2007-12-05
Anticipated expiration: 2016-12-26

Abstract

The utility model relates to an open-phase protection circuit of medium-voltage variable frequency speed control equipment. A primary side of the three-phase isolation transformer is connected to three phase of the three-phase power, the output terminal of the three-phase isolation transformer is connected to the circuit board, the current is rectified to direct current by the three-phase rectification via the rectifier bridge composed from diodes, then the direct current is transmitted to the trigger terminal of the optic coupler after the current limiting resistor and the stable voltage tube, photoelectric isolated signal trigs the triode to emit the failure signal for transmitting to the CPU. The stop signal is emitted from the signal-chip microprocessor and stops the operation of the open-phase equipment or breaks the failure power supply. The utility model utilize the photoelectric isolation and in favor of anti-interference, and avoid the power fluctuation at the direct introduction or the mistaken operation of the introduction of higher harmonic in the power supply. The utility model utilizes the high-speed digital signal processor (DSP) to treat the failure signal, so as to respond sensitively, protect rapidly and has good universality. The circuit can be used for detection and protection of various three-phase AC 380 Volts circuits.

Description

Medium voltage converter speed regulating device open-phase protection circuit

Technical field

The phase shortage that the utility model belongs to three phase mains detects and protective circuit, relates to a kind of medium voltage converter speed regulating device open-phase protection circuit, is applicable to that the phase shortage of the three-phase circuit that all use three phase mains detects and protection.

Background technology

Three phase mains in the daily life uses general, and threephase load such as phase-deficient operations such as blower fan, water pump will cause insulation damages and burn; Therefore the phase shortage of three phase mains detects and protects particularly important; generally be designed to get three-phase voltage and directly guide to circuit board; again through the detection method of three single-phase transformer transformations; it is bigger to introduce the creepage distance that requires behind the high pressure like this on the circuit board; circuit board increases, and does not have electrical isolation very dangerous between circuit board and the power supply.

Summary of the invention

Problem to be solved in the utility model is, overcome the deficiencies in the prior art, a kind of safe and reliable three phase mains lack detection circuit is provided, with three phase mains process three-phase isolation transformer step-down earlier, introduce circuit board after reducing to three-phase safe voltage, the voltage stabilizing value after the rectifier bridge rectification drives optocoupler, sends fault-signal by the optocoupler trigger triode, send CPU to, stop the running or the open failure power supply of phase shortage equipment.

The utility model solves its technical problem and takes following technical scheme to realize:

A kind of medium voltage converter speed regulating device open-phase protection circuit that provides according to the utility model, comprise three-phase isolation transformer, the former limit of described three-phase isolation transformer connects the three-phase of three phase mains, the three-phase isolation transformer output is received circuit board, behind the rectifier bridge that diode is formed, carry out three phase rectifier and become direct current; Behind current-limiting resistance and voltage-stabiliser tube, guide to the trigger end of optocoupler again, the signal triggering triode of being isolated by photoelectricity sends fault-signal, sends CPU to, sends stop signal by the CPU single-chip microcomputer, stops the running of phase shortage equipment, or the open failure power supply.

It is to take following technical scheme further to realize that the utility model solves its technical problem:

The former limit of aforesaid three-phase isolation transformer connects three-phase A, B, the C of three phase mains, the output of transformer is received on pin R1, S1, the T1 of the binding post X1 of circuit board, receives then on the interstage exchange input contact of the little rectifier bridge of being made up of IN4007 diode V1～V6 of three-phase; The output cathode of three-phase commutation bridge connects the end of current-limiting resistance R1, current-limiting resistance R1 and the positive pole of receiving voltage-stabiliser tube VZ1 after current-limiting resistance R2 connects, the negative pole of voltage-stabiliser tube VZ1 connects the light-emitting diode input of optocoupler U1 TLP521, and the negative electrode of light-emitting diode is connected to the negative terminal of rectifier bridge; Penetrating of optocoupler U1 output triode collects the ground GND1 that receives 5V, the collector electrode of triode is received 5V (+V1) positive source through pull-up resistor R3, receive the base stage of triode VT2 simultaneously through current limliting input resistance R4, the base stage of triode VT2 is through pull down resistor R5 ground connection simultaneously; The collector electrode of triode VT2 through pull-up resistor R6 receive 5V (+V1) positive source, the signal LP of triode VT2 collector electrode transmits CPU simultaneously; Simultaneously, the collector electrode of optocoupler U1 output triode is guided to base one end of short-circuited conducting sleeve S1, the base other end of short-circuited conducting sleeve S1 is received ground GND1; Judge by the height of current potential whether three phase mains is phase-deficient operation, open failure power supply during fault, thus equipment is played a protective role.

The utility model compared with prior art has significant advantage and beneficial effect.

The utility model is owing to use isolating transformer, accomplishes that the high and low pressure circuit isolates, and introduces circuit board after reducing to three-phase safe voltage, making and introducing the whole of circuit board is light current, compares safety, and requires lower to the rectifier diode of rear end, therefore circuit board is less, and cost is lower; It is anti-interference to adopt the photoelectricity isolation to help, the misoperation when high order harmonic component is introduced in power-supply fluctuation or the power supply when avoiding directly introducing; Utilize high speed digital signal processor DSP to come the handling failure signal, can accomplish to be quick on the draw, protection fast, and also this circuit versatility is good, and the detection and the protection of all three-phase AC380V circuit all can be adopted this circuit.

Embodiment of the present utility model is provided in detail by following examples and accompanying drawing thereof.

Description of drawings

Fig. 1 is a schematic block circuit diagram of the present utility model;

Fig. 2 is the circuit interconnect pattern of three-phase isolation transformer of the present utility model;

Fig. 3 is circuit theory diagrams of the present utility model.

Embodiment

Below in conjunction with accompanying drawing, embodiment, structure, feature and effect thereof that foundation the utility model is provided, describe in detail as after.

See Fig. 1～3, a kind of medium voltage converter speed regulating device open-phase protection circuit, comprise three-phase isolation transformer, the former limit of described three-phase isolation transformer connects the three-phase of three phase mains, the three-phase isolation transformer output is received circuit board, and three phase mains A, B, C are passed through the three-phase transformer step-down mutually earlier, is about to line voltage and reduces to safe voltage AC30V by AC380V, behind the rectifier bridge that 6 diodes are formed, carry out three phase rectifier and become direct current; Behind current-limiting resistance and voltage-stabiliser tube, guide to the trigger end of optocoupler again, the signal triggering triode of being isolated by photoelectricity sends fault-signal, sends CPU to, sends stop signal by the CPU single-chip microcomputer, stops the running of phase shortage equipment, or the open failure power supply.

The former limit of three-phase isolation transformer connects three-phase A, B, the C of three phase mains, the output of transformer is received on pin R1, S1, the T1 of the binding post X1 of circuit board, receives then on the interstage exchange input contact of the little rectifier bridge of being made up of IN4007 diode V1～V6 of three-phase; The output cathode of three-phase commutation bridge connects the end of current-limiting resistance R1, current-limiting resistance R1 and the positive pole of receiving voltage-stabiliser tube VZ1 after current-limiting resistance R2 connects, the negative pole of voltage-stabiliser tube VZ1 connects the light-emitting diode input of optocoupler U1 TLP521, and the negative electrode of light-emitting diode is connected to the negative terminal of rectifier bridge; Penetrating of optocoupler U1 output triode collects the ground GND1 that receives 5V, the collector electrode of triode is received 5V (+V1) positive source through pull-up resistor R3, receive the base stage of triode VT2 simultaneously through current limliting input resistance R4, the base stage of triode VT2 is through pull down resistor R5 ground connection simultaneously; The collector electrode of triode VT2 through pull-up resistor R6 receive 5V (+V1) positive source, the signal LP of triode VT2 collector electrode transmits CPU simultaneously; Simultaneously, the collector electrode of optocoupler U1 output triode is guided to base one end of short-circuited conducting sleeve S 1, the base other end of short-circuited conducting sleeve S1 is received ground GND1; Judge by the height of current potential whether three phase mains is phase-deficient operation, open failure power supply during fault, thus equipment is played a protective role.

Operation principle: the power supply+V1 among the figure, GND1 are the 5V power supply, are the working power of DSP, are provided by the Switching Power Supply on the power panel, as the working power of circuit board; Three phase mains is just often: three-phase AC380V power supply becomes AC30V and introduces circuit board after step-down, after the diode rectifier bridge rectification that V1～V6 forms, becomes about direct current 42V, is higher than the voltage stabilizing value DC30V of voltage-stabiliser tube VZ1; So voltage-stabiliser tube work, burning voltage is at 30V, commutating voltage exceeds pressure pipe 12V, the input light-emitting diodes pipe end of electric current by the U1 optocoupler about 2MA arranged behind current-limiting resistance R1, R2, led lighting, the trigger triode conducting, because the tube voltage drop of triode own is about 0.3V, so optocoupler is output as the base stage that low-voltage is given triode VT2, so VT2 ends, thereby test point LP is+the 5V high potential to export to DSP through the current potential of pull-up resistor R6, high potential is that power supply is normal, so equipment runs well.

When the power supply phase shortage, then be lower than DC30V, so voltage-stabiliser tube VZ1 ends by the voltage after the rectifier bridge rectification, the triode of optocoupler U1 is in cut-off state, the voltage of+5V is added to the base stage of triode VT2 through base stage current-limiting resistance R4, is higher than the conducting voltage 0.7V of triode emitter junction, so triode VT2 saturation conduction, collector electrode is about 0V, export to DSP, electronegative potential is thought the power supply phase shortage, so the control signal of sending, the power supply of disengagement failure power supply, the safety of guarantee electricity consumption three-phase equipment.

And also increased the debugging short-circuiting terminal in the design, when the debug circuit plate or when the non-at-scene debugging of three phase mains is not arranged, when both terminal X1 does not introduce at the place AC30V voltage, short-circuiting terminal S1 can be used the short-circuited conducting sleeve short circuit, the base stage that makes triode VT2 is an electronegative potential, the current collection that guarantees VT2 very high potential (+5V), make circuit board or the equipment can good debug under non-at-scene situation, relatively flexibly, convenient.

Claims

1. medium voltage converter speed regulating device open-phase protection circuit, comprise three-phase isolation transformer, it is characterized in that: the former limit of described three-phase isolation transformer connects the three-phase of three phase mains, the three-phase isolation transformer output is received circuit board, behind the rectifier bridge that diode is formed, carry out three phase rectifier and become direct current; Behind current-limiting resistance and voltage-stabiliser tube, guide to the trigger end of optocoupler again, the signal triggering triode of being isolated by photoelectricity sends fault-signal, sends CPU to, sends stop signal by the CPU single-chip microcomputer, stops the running of phase shortage equipment, or the open failure power supply.

2. medium voltage converter speed regulating device open-phase protection circuit according to claim 1 is characterized in that:

The former limit of described three-phase isolation transformer connects three-phase A, B, the C of three phase mains, the output of transformer is received on the pin of the binding post of circuit board (X1) (R1, S1, T1), receives then that (interstage exchange of the little rectifier bridge of three-phase of V1～V6) forms is imported on the contact by the IN4007 diode; The output cathode of three-phase commutation bridge connects an end of current-limiting resistance (R1), current-limiting resistance (R1) and the positive pole of receiving voltage-stabiliser tube (VZ1) after current-limiting resistance (R2) is connected, the negative pole of voltage-stabiliser tube (VZ1) connects the input of the light-emitting diode of U1 optocoupler TLP521, and the negative electrode of light-emitting diode is connected to the negative terminal of rectifier bridge; Penetrating of optocoupler (U1) output triode collects the ground (GND1) of receiving 5V, the collector electrode of triode is received 5V (+V1) positive source through pull-up resistor (R3), receive the base stage of triode (VT2) simultaneously through current limliting input resistance (R4), the base stage of triode (VT2) is through pull down resistor (R5) ground connection simultaneously; The collector electrode of triode (VT2) through pull-up resistor (R6) receive 5V (+V1) positive source, the signal LP of triode (VT2) collector electrode transmits CPU simultaneously; Simultaneously, the collector electrode of optocoupler (U1) output triode is guided to base one end of short-circuited conducting sleeve (S1), the base other end is received ground (GND1); Judge by the height of current potential whether three phase mains is phase-deficient operation, open failure power supply during fault, thus equipment is played a protective role.