CN201345548Y

CN201345548Y - Dynamic reactive power compensation intelligent composite switch

Info

Publication number: CN201345548Y
Application number: CNU2008202162231U
Authority: CN
Inventors: 沈金荣; 李书旗
Original assignee: Changzhou Campus of Hohai University
Current assignee: Changzhou Campus of Hohai University
Priority date: 2008-11-20
Filing date: 2008-11-20
Publication date: 2009-11-11
Anticipated expiration: 2018-11-20

Abstract

The utility model relates to a low-voltage dynamic reactive power compensation capacitor switching device in power transmission and distribution technology. The device comprises a power supply circuit, a single-chip microcomputer, a detecting circuit, a control circuit, a protecting circuit and a three-phase main circuit, wherein the detecting circuit comprises the zero-crossing detection, the switching signal detection, and the contact state detection of all phase contacts; the control circuit comprises a silicon-controlled trigger circuit, a relay trigger circuit, and a state indicating circuit; the three-phase main circuit comprises three large-power relays and controlled silicon respectively connected with the static contacts of the three large-power relays parallelly. The dynamic reactive power compensation intelligent composite switch has the advantages of sensitive zero-crossing detection, zero-crossing switching, no surge, quick action response, small capacitor impact, long service, closed-loop control, self-diagnosis and correction functions, high reliability, a double-coil magnetic latching relay, simplified control circuit, further reduction of power consumption, large contact capacity, and strong anti-harmonic and overload capacity.

Description

A kind of intelligent compound switch of dynamic passive compensation

One, technical field

The utility model belongs to the power transmission and distribution technical field, relates to a kind of capacitor switching device of low pressure dynamic passive compensation.

Two, background technology

In order to improve grid power factor, reduce grid loss, power transformation in one's power enterprises and institutions' power distribution station all to carry out reactive power compensation, the general mode that adopts electrical network and connect capacitor, and according to the variation of load number and character, need in time to change the capacity of compensation condenser, could guarantee the stabilization of power grids.The switching of capacitor generally adopts different contactors, the pre-special-purpose contactor of resistance, the pure controllable silicon etc. thrown of band, and mainly there are shortcomings such as big, the contact easy-sintering of shoving, life-span weak point, fragile capacitor in preceding two kinds of methods; A kind of method major defect in back is that big, the anti-harmonic wave ability of power consumption is weak etc.Recent study goes out can be in conjunction with the advantage of said method, avoid the combination switch of its shortcoming, is applied within the specific limits.But there are problems such as dynamic response is unhappy, volume is big, cost is high, reliability is not high.

Three, summary of the invention

The utility model is pin the problems referred to above, around improve dynamic responding speed, further reduce volume, improve reliability and the intelligent compound switch of a kind of dynamic passive compensation of proposing.The occasion that can be widely used in low-pressure reactive compensation.

The technical solution of the utility model: device comprises power circuit, single-chip microcomputer, testing circuit, control circuit, protective circuit and three-phase main circuit.Wherein testing circuit comprises that zero passage detection, switching input, the contacts status of each phase contact detect; Control circuit comprises thyristor gating circuit, relay circuits for triggering, condition indication circuit; The every one-way SCR that comprises two reverse parallel connections mutually of three-phase main circuit, in parallel with the normally opened contact of a power magnetic force keeping relay again, relay coil is centre tapped twin coil, centre cap is a common port, only need by the other two ends of two-way triggering signal difference wiring circle, can realize the disconnection or the closure of contact by trigger impulse, contacts status keeps by magnet steel, need not to keep by coil current.

The Single-chip Controlling software programming adopts closed-loop control in conjunction with the characteristics and the operating process of reactive power compensation.After detecting the switching signal, at first carry out state and judge that next carries out corresponding operating, detect contacts status then, judge state once more, withdraw from or carry out error-correction operation, as error correction repeatedly can not successfully then wrong indication and etc. pending fault manually get rid of just and can resume work.Realize two closed-loop controls, guarantee the reliability of operating to improve program running efficient.

The utility model beneficial effect compared with the prior art is: the zero passage detection sensitivity, realize operating passing zero, and no-flashy-flow, and dynamic response improves; Closed-loop control has self diagnosis and error correction, the reliability height; Adopt the twin coil magnetic latching relay, simplified control circuit further reduces device power consumption, and contact capacity is big, and anti-harmonic wave and overload capacity are strong.

Four, description of drawings

The circuit structure diagram of the intelligent compound switch of a kind of dynamic passive compensation of Fig. 1.

The switching subroutine flow chart of the intelligent compound switch of a kind of dynamic passive compensation of Fig. 2.

Five, embodiment

As shown in Figure 1, device comprises that power circuit (1), single-chip microprocessor MCU (2), signal deteching circuit (3), zero cross detection circuit (4), state detection circuit (5), state indication (6), controllable silicon trigger (7), relay triggers (8), protective circuit (10) and three-phase main circuit (9).Each circuit links to each other by wiring board, and wherein single-chip microprocessor MCU (2) is the control core; Testing circuit comprises zero passage detection (4), the switching input (3) of each phase contact, the state-detection (5) of contact; Control circuit comprises thyristor gating circuit (7), relay circuits for triggering (8), condition indication circuit (6); Three-phase main circuit (9) is every to comprise two antiparallel one-way SCRs mutually, in parallel with the normally opened contact of a high power relay again, high power relay adopts magnetic latching relay, and coil is a twin coil, complicated insecure commutating circuit when having save the switching driving.The control core obtains input information by testing circuit, handles through software analysis, draws control decision, carries out opening or closing of main circuit by control circuit.

This device adopts closed-loop control, switching subprogram flow process as shown in Figure 2, after detecting the switching signal, at first carry out state and judge, if state is consistent with control signal then directly to be withdrawed from, if inconsistent, then carry out corresponding operating, the property confirmed contacts status detects once more; State is judged inerrancy, if correctly then withdraw from, judges if mistake is then carried out the error correction number of times; If the error correction number of times does not reach set point, then carry out error-correction operation, and get back to the control signal detection and proofread once more, if the error correction number of times reaches and withdraws from after set point is then sent error indication signal, wait pending fault manually to get rid of just and can resume work.Software flow is realized two closed-loop controls, guarantees the reliability of operating to improve program running efficient.

When catering to operation, earlier this phase contact voltage is detected, send triggering signal to controllable silicon during zero passage, and then send tens of milliseconds magnetic latching relay and cater to signal, remove silicon controlled trigger signal again, when realizing voltage zero-cross capacitor is catered to, and realize that electric current is by the transfer of controllable silicon to relay contact, no-flashy-flow.When cutting out operation, only need to give earlier the controllable silicon program to send triggering signal, send the signal that relay disconnects again, postpone to remove silicon controlled trigger signal behind tens of milliseconds, utilize the controllable silicon self-characteristic when current over-zero, to cut off voluntarily.As seen, this circuit is realized the functions such as intellectual monitoring, control, error correction, state indication to main circuit.

Claims

1, a kind of intelligent compound switch of dynamic passive compensation; described device is the actuator that is used for the low-voltage reactive power compensation capacitor switching of the electronic monitoring control of a kind of mcu of having; it is characterized in that: device comprises power circuit, single-chip microcomputer, testing circuit, control circuit, protective circuit, main circuit; each circuit links to each other by wiring board; single-chip microcomputer links to each other with testing circuit, control circuit respectively, and control circuit, protective circuit link to each other with main circuit respectively.

2, according to the intelligent compound switch of the described a kind of dynamic passive compensation of claim 1, it is characterized in that: described three-phase main circuit is every to be two one-way SCR reverse parallel connections mutually, in parallel with the normally opened contact of magnetic latching relay again, the magnetic latching relay coil is centre tapped twin coil.

3, according to the intelligent compound switch of the described a kind of dynamic passive compensation of claim 1, it is characterized in that: described testing circuit comprises the voltage zero-crossing detection circuit, switching signal deteching circuit of each phase contact, the contacts status testing circuit that is used to feed back.