CN100477047C

CN100477047C - Intelligent compound switch

Info

Publication number: CN100477047C
Application number: CNB200710111270XA
Authority: CN
Inventors: 赵世红; 乔云庭; 高有生; 郑会权
Original assignee: ZHAO SHIHONG QIAO YUNTING
Current assignee: ZHAO SHIHONG QIAO YUNTING
Priority date: 2007-06-20
Filing date: 2007-06-20
Publication date: 2009-04-08
Anticipated expiration: 2027-06-20
Also published as: CN101086925A

Abstract

The invention provides an intelligent multiplex switch, it belongs to switch executing element of low voltage electric power system, it circuit includes silicon control trigger circuit, said silicon control trigger circuit includes two similar zero detecting circuits. Aiming at defects of current technique, the intelligent multiplex switch of the invention can realize accurate zero detecting, it can ensure that relay (or contactor) switches after the silicon control is conducted, polarity of capacitor is the same when switch is cut, over voltage can not be generated, switch can closed within short time.

Description

Intelligent compound switch

Technical field

Invention provides a kind of intelligent compound switch, belongs to the switch executing element in the low-voltage power system, is mainly used in quick, the big electric current switching of capacitor in the reactive power compensator.

Background technology

At present, the switch executing element in the reactive power compensator generally adopts switch-capacitor contactor, controllable silicon, combination switch.Generally use the switch-capacitor contactor, characteristics are to adopt mechanical system to add current-limiting resistance, and when dropping into capacitor, it is bigger to shove, and influences the useful life of switch and capacitor; Though controllable silicon can be accomplished no-flashy-flow and drop into capacitor that silicon controlled power loss, reliability, price and heating problem make to use and be restricted; Combination switch can be avoided switch-capacitor contactor and silicon controlled deficiency, and still, general combination switch switching is grown (being not less than 1S) at interval, and through-current capacity little (being not more than 60A) often has phenomenons such as adhesion damage in the use.

The problem that three aspects need solve below the combination switch ubiquity under the prior art:

1, switch fracture two ends zero passage detection accurately: the voltage at general combination switch zero passage detection chip commonly used (such as MOC3083 etc.) sense switch fracture two ends, this chip uses in resistive load, it is more accurate to detect, in capacitive or inductive load, the accuracy that detects will descend, incorrect zero passage detection will cause great rush of current (normal current tens times), will damage controllable silicon and shortening capatcitor useful life.

2, relay (or contactor) just closes a floodgate after guaranteeing the controllable silicon conducting: general combination switch is after sending switching signal to the zero passage detection chip, time-delay certain hour (about 300ms) send switching signal for relay (or contactor) again, because differing of three-phase electricity is that discharge needed tens seconds after 120 degree and capacitor disconnected, often give behind the zero passage detection chip switching signal and all can not find zero crossing in several seconds, make that controllable silicon can not triggering and conducting, and at this moment relay (or contactor) will close a floodgate through after the certain time-delay, because controllable silicon does not have conducting, relay (or contactor) directly closes a floodgate on capacitor, cause bigger rush of current, will shorten the useful life of relay (or contactor).

3, switch disconnects in the short time of back and closing a floodgate once more: in the capacitor that triangle connects, after controllable silicon in the combination switch disconnects, there is the peak value working voltage at the electric capacity two ends, because the uncertainty of alternating current polarity when disconnecting, may make a certain group of capacitance voltage surpass maximum permissible voltage, with shortening capatcitor useful life and discharge time of prolonging this group capacitor.Switch disconnects when closing a floodgate once more, prolongs the zero passage detection time, makes switch not close a floodgate once more at short notice, must wait the voltage of capacitor to be put into when hanging down and could to close a floodgate.

Summary of the invention

The present invention be directed to above deficiency, a kind of intelligent compound switch is provided, can realize accurately zero passage detection, guarantee that relay (or contactor) just closes a floodgate after the controllable silicon conducting, switch disconnects back capacitor charging polarity unanimity, not produce overvoltage, can close a floodgate once more in the short time.

The technical solution adopted for the present invention to solve the technical problems is:

A kind of intelligent compound switch comprises thyristor gating circuit, and described thyristor gating circuit is made of two identical zero cross detection circuit reverse parallel connections.

Described zero cross detection circuit comprises the controllable silicon S1 that is connected to contactor J two ends, be serially connected with current transformer CT between described controllable silicon S1 and the contactor J, described controllable silicon S1 connects the base stage of triode T1 by diode D1, the collector electrode of described triode T1 connects the collector electrode of triode T2, controllable silicon S1 also connects the collector electrode of triode T2 by diode S2, the base stage of described triode T2 connects optocoupler O1, is serially connected with capacitor C 1 between the emitter of described triode T2 and the base stage.

Capacitor C 1 in the zero cross detection circuit of two reverse parallel connections is selected different specifications for use.

A kind of intelligent compound switch of the present invention has the no-flashy-flow switching, and reliability height, the fast characteristics of response speed are finished a switching and only needed 0.2 second at interval, and through-current capacity can reach more than the 1000A.

Description of drawings

Fig. 1 is the circuit theory diagrams of the zero cross detection circuit of intelligent compound switch of the present invention;

Fig. 2 is the circuit theory diagrams of intelligent compound switch of the present invention.

Embodiment

The present invention is further described below in conjunction with drawings and Examples.

Provide a specific embodiment with reference to accompanying drawing 2:

Be serially connected with resistance R 1 between current transformer CT and the diode D1, be serially connected with resistance R 2 between the base stage of triode T1 and the emitter, and the resistance R 3 that connects and R4 be connected between the collector electrode of diode S2 and triode T2, is serially connected with resistance R 5 between the base stage of triode T2 and the capacitor C 1.

As shown in Figure 1, during A, B end input triggering signal, optocoupler O1 conducting, triode T2 conducting, M, N both end voltage when zero passage, triode T1 by, at this moment, the S2 triggering and conducting, simultaneously, S1 is conducting also, realizes the zero cross fired of controllable silicon S1.

Half of 1 thyristor gating circuit that draws of accompanying drawing, second half is symmetry therewith, inverse parallel, triggering mode is identical therewith.

As shown in Figure 2: between contactor J and controllable silicon S1, be in series with a current transformer CT, have only that the CT loop just has electric current to flow through after controllable silicon is connected, at this moment, just give relay (or contactor) switching signal, can before the controllable silicon conducting, not close a floodgate to guarantee relay (or contactor).

As shown in Figure 2: after A, B end signal are removed, optocoupler turn-offs, because capacitor C 1 is arranged, triode T2 can not turn-off at once, and certain time-delay (delay time can be set to as requested 20ms or more than) is arranged, select the C1 difference in antiparallel two groups of controllable silicons, can guarantee after A, B end signal are removed have one group of controllable silicon to disconnect earlier, like this, after control signal disconnected, the charging polarity of capacitor C was consistent at every turn.

Since adopted zero cross detection circuit, when having only M, N terminal voltage zero passage, just conducting of controllable silicon; And be added with current transformer CT and detect whether conducting of controllable silicon, to guarantee relay (or contactor) combined floodgate just after the controllable silicon conducting; Signal is added with delay capacitor after disconnecting, and makes two antiparallel controllable silicons have only one to disconnect earlier, and the another time-delay disconnects, and guarantees that the charging polarity on the capacitor C is consistent.

In addition, diode S2 can be the triode the same with T1.

Above-described embodiment, the utility model embodiment a kind of more preferably just, the common variation that those skilled in the art carries out in the technical solutions of the utility model scope and replacing all should be included in the protection range of the present utility model.

Claims

1, a kind of intelligent compound switch, comprise thyristor gating circuit, it is characterized in that, described thyristor gating circuit is made of two identical zero cross detection circuit reverse parallel connections, described zero cross detection circuit comprises the controllable silicon S1 that is connected to contactor J two ends, be serially connected with current transformer CT between described controllable silicon S1 and the contactor J, described controllable silicon S1 connects the base stage of triode T1 by diode D1, the collector electrode of described triode T1 connects the collector electrode of triode T2, controllable silicon S1 also connects the collector electrode of triode T2 by diode S2, the base stage of described triode T2 connects optocoupler O1, is serially connected with capacitor C 1 between the emitter of described triode T2 and the base stage.

2, a kind of intelligent compound switch according to claim 1 is characterized in that, the capacitor C 1 in the zero cross detection circuit of two reverse parallel connections is selected different specifications for use.