CN202503295U

CN202503295U - Controllable silicon controlled triggering circuit with zero-voltage input

Info

Publication number: CN202503295U
Application number: CN 201220094526
Authority: CN
Inventors: 沈雷明; 陈东华; 张凤雏
Original assignee: JIANGYIN SFERE ELECTRIC CO Ltd
Current assignee: JIANGYIN SFERE ELECTRIC CO Ltd
Priority date: 2012-03-14
Filing date: 2012-03-14
Publication date: 2012-10-24
Anticipated expiration: 2022-03-14

Abstract

The utility model discloses a controllable silicon controlled triggering circuit with zero-voltage input, comprising a pulse width modulation (PWM) pulse triggering source circuit, a current zero-crossing detection circuit, a logic control circuit and a pulse transformer, wherein a control signal is connected to the input end of the logic control circuit; the output end of an electric signal on the controllable silicon is connected to the input end of the current zero-crossing detection circuit of which the output end is connected to the input end of the logic control circuit; the output end of the logic control circuit is connected to the input end of the PWM pulse triggering source circuit of which the output end is connected to the input end of the pulse transformer; and the output end of the pulse transformer is connected to the input end of the controllable silicon. The triggering circuit disclosed by the utility model is high in reliability, wide in application and applicable to low-voltage reactive compensation of controllable silicon switching, has the advantages of no current in switching and no impact on a system and has the capability of protecting a capacitor effectively.

Description

The SCR control circuits for triggering that a kind of no-voltage drops into

Technical field

The utility model relates to a kind of power electronics application circuit, specifically relates to a kind of SCR control circuits for triggering that are used for switching low-voltage reactive power compensation loop.

Background technology

In the low-pressure reactive compensation field; Tradition silicon controlled switching mode is contactor control, and mainly there are following defectives in it: or response speed is slow, or produces very big shoving during switching; Or can produce system during switching and impact, or can not protect the reactive power compensation power capacitor.

The utility model content

The utility model purpose: the purpose of the utility model is in order to solve the problems of the prior art, a kind of SCR control circuits for triggering that are used for switching low-voltage reactive power compensation loop mainly to be provided, having realized the switching no-flashy-flow, and whole system is not had impact.

Technical scheme: in order to realize above purpose, the SCR control circuits for triggering that the utility model provides a kind of no-voltage to drop into comprise: pwm pulse triggers source circuit, current over-zero testing circuit, logic control circuit and pulse transformer; Said pwm pulse triggers the pwm signal that source circuit is used to provide fixed frequency, and said current over-zero testing circuit is used to detect the silicon controlled current zero-crossing point, and said pulse transformer is used for the driving of pulse and amplifies; Said logic control circuit is used for the control signal and the crossover point signal of input are carried out logic determines; Promptly working as controllable silicon voltage difference is zero, and control signal is effective, through logic and the output of back control pwm signal; Pulse transformer, thus reach the function of controlling the controllable silicon switching.

The operation principle of above-mentioned each parts is following in the utility model: control signal links to each other with the logic control circuit input; The output of controllable silicon power on signal links to each other with the input of current over-zero testing circuit; The output of current over-zero testing circuit links to each other with the input of logic control circuit; The output of logic control circuit links to each other with the input that pwm pulse triggers source circuit; Pwm pulse triggers the source circuit output and links to each other with the input of pulse transformer, and the pulse transformer output links to each other with the controllable silicon input.

Control signal described in the utility model links to each other with the logic control circuit input through the output of isolating optocoupler, uses the isolation optocoupler to separate control loop and driving loop effectively, avoids two loops to influence each other, and has further improved reliability.

The testing circuit of current over-zero described in the utility model comprises: high-power resistance, integrated optocoupler and on draw power supply; The input of said integrated optocoupler is connected with said silicon controlled output; The power access end of integrated optocoupler through high-power resistance with on draw power supply to be connected, the output of said integrated optocoupler is connected with the input of said logic control circuit; Said integrated optocoupler detects controllable silicon two ends pressure reduction, according to integrated optocoupler characteristic, and when no zero passage, integrated optocoupler conducting, the output of said current over-zero testing circuit is output as low level; When zero passage, integrated optocoupler ends, and the output of said current over-zero testing circuit is output as high level.

Pulse transformer comprises described in the utility model: triode, resistance and high frequency transformer; Said pwm pulse trigger pwm signal that source circuit sends and enable signal with, through controlling and driving triode after the resistance current limliting, amplify drive current, and then the driving high frequency transformer through triode, export to said controllable silicon through the high frequency transformer isolation.

Pwm pulse described in the utility model triggers source circuit, comprises the RC oscillating circuit, and the RC oscillating circuit is used for confirming that pwm pulse triggers the frequency of the PWM of source circuit output.

Beneficial effect: the advantage of the utility model is following: all functions module all adopts pure hardware circuit in the utility model; Reliability is high; Be applicable to the reactive power compensation of controllable silicon switching low-voltage, be widely used that switching has no-flashy-flow, system do not had impact and electric capacity had an advantage such as protection.

Description of drawings

Fig. 1 is the schematic diagram of the utility model.

Fig. 2 is the circuit diagram of current over-zero testing circuit among the embodiment in the utility model.

Fig. 3 is the circuit diagram of pulse transformer among the embodiment in the utility model.

Fig. 4 is a circuit diagram of controlling power supply in the utility model among the embodiment.

Fig. 5 be in the utility model among the embodiment pwm pulse trigger the circuit diagram of source circuit.

Embodiment

Below in conjunction with accompanying drawing and specific embodiment; Further illustrate the utility model; Should understand these embodiment only be used to the utility model is described and be not used in the restriction the utility model scope; After reading the utility model, those skilled in the art all fall within the application's accompanying claims institute restricted portion to the modification of the various equivalent form of values of the utility model.

Embodiment

The SCR control circuits for triggering that a kind of no-voltage as shown in Figure 1 drops into comprise: pwm pulse triggers source circuit, current over-zero testing circuit, logic control circuit and pulse transformer; Said pwm pulse triggers the pwm signal that source circuit provides fixed frequency, and said current over-zero testing circuit is used to detect the silicon controlled current zero-crossing point, and said pulse transformer is used for the driving of pulse transformer and amplifies; Said logic control circuit is used for the control signal and the crossover point signal of input are carried out logic determines; Promptly working as switching capacitance voltage difference is zero, and control signal is effective, through logic and the output of back control pwm signal; Pulse transformer, thus reach thyristor controlled function.

The operation principle of above-mentioned each parts is following: the level controling signal that is sent by idle compensating control links to each other with the logic control circuit input; The output of controllable silicon power on signal links to each other with the input of current over-zero testing circuit; The output of current over-zero testing circuit links to each other with the input of logic control circuit; The output of logic control circuit links to each other with the input that pwm pulse triggers source circuit; Pwm pulse triggers the source circuit output and links to each other with the input of pulse transformer circuit, pulse transformer circuit output end link to each other with the controllable silicon input (as shown in Figure 1).

During work; Said logic control circuit carries out logic determines with the control signal of input and the crossover point signal of current over-zero testing circuit output; Promptly working as controllable silicon voltage difference is zero, and control signal is effective, through logic and the output of back control pwm signal; Pulse transformer, thus reach control silicon controlled function.

In the present embodiment, as shown in Figure 3, said pulse transformer comprises: triode Q3, resistance R 50 and high frequency transformer T3; Said pwm pulse trigger pwm signal that source circuit sends and enable signal EN4 with; Through controlling and driving triode Q3 after resistance R 50 current limlitings; Amplify drive current through triode Q3, and then drive high frequency transformer T3, isolate through high frequency transformer T3 and export to said controllable silicon K1D and K2D.

In the present embodiment, as shown in Figure 2, said current over-zero testing circuit comprises: high-power resistance R30, integrated optocoupler U10 and on draw power supply+15V; The input of said integrated optocoupler U1 is connected with the output of said controllable silicon K1D, K2D, and said controllable silicon K1D and K2D are through resistance R 35, and R36 is parallelly connected or pass through R37, inserts integrated optocoupler U10 after the R38 parallel connection; The power access end of integrated optocoupler through high-power resistance R30 with on draw power supply to be connected, the output ZC2 of integrated optocoupler is connected with the input of said logic control circuit; Said integrated optocoupler U10 detects controllable silicon two ends pressure reduction, according to integrated optocoupler characteristic, and when no zero passage, the optocoupler conducting, output ZC2 is output as low level; When zero passage, optocoupler ends, and output ZC2 is output as high level.

In the present embodiment, as shown in Figure 5, said pwm pulse triggers source circuit and comprises: integrated circuit U8, resistance R 15～R18, and capacitor C 4, C5 and diode D3 constitute.D3, R15, R16 and C5 have formed a RC oscillating circuit, and this oscillating circuit has determined the frequency of the output PWM of integrated circuit U8.

VCC in the present embodiment among Fig. 2, Fig. 3, Fig. 5 and+two groups of D.C. regulated power supplies of 15V provide by circuit shown in Figure 4, do as one likes can constitute by integrated Voltage stabilizing module LM2576S-ADJ good, that reliability is high.

Claims

1. the SCR control circuits for triggering that no-voltage drops into is characterized in that: comprising: pwm pulse triggering source circuit, current over-zero testing circuit, logic control circuit and pulse transformer; Control signal links to each other with the logic control circuit input; The output of controllable silicon power on signal links to each other with the input of current over-zero testing circuit; The output of current over-zero testing circuit links to each other with the input of logic control circuit; The output of logic control circuit links to each other with the input that pwm pulse triggers source circuit, and pwm pulse triggers the source circuit output and links to each other with the input of pulse transformer circuit, and the pulse transformer circuit output end links to each other with the controllable silicon input.

2. the SCR control circuits for triggering that a kind of no-voltage according to claim 1 drops into is characterized in that: said control signal links to each other with the logic control circuit input through the output of isolating optocoupler.

3. the SCR control circuits for triggering that a kind of no-voltage according to claim 1 drops into, it is characterized in that: said current over-zero testing circuit comprises: high-power resistance, integrated optocoupler and on draw power supply; The input of said integrated optocoupler is connected with said silicon controlled output; The power access end of integrated optocoupler through high-power resistance with on draw power supply to be connected, the output of integrated optocoupler is connected with the input of said logic control circuit; Said integrated optocoupler detects controllable silicon two ends pressure reduction, according to integrated optocoupler characteristic, and when no zero passage, integrated optocoupler conducting, said current over-zero testing circuit output is output as low level; When zero passage, integrated optocoupler ends, and said current over-zero testing circuit output is output as high level.

4. the SCR control circuits for triggering that a kind of no-voltage according to claim 1 drops into, it is characterized in that: said pulse transformer comprises: triode, resistance and high frequency transformer; Said pwm pulse trigger pwm signal that source circuit sends and enable signal with, through controlling and driving triode after the resistance current limliting, amplify drive current, and then the driving high frequency transformer through triode, export to said controllable silicon through the high frequency transformer isolation again.