CN2458799Y

CN2458799Y - Current locking type bus protector

Info

Publication number: CN2458799Y
Application number: CN 00253481
Authority: CN
Inventors: 王英男; 李安平; 陈春华; 赵庆杞
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-12-18
Filing date: 2000-12-18
Publication date: 2001-11-07
Anticipated expiration: 2010-12-18

Abstract

The utility model relates to a current blocking type bus protector which is composed of a line switch current blocking element I1, a bus voltage starting element U, a transformer current actuating device I2, a relay PLC, a logic circuit and an executive element. The utility model does not need a secondary coil of a special current transformer and solves the problem of no protection of 66KV buses in a transformer station; the utility model has the advantages of less investment, obvious effect, simple wiring connection, high actuating speed and strong anti-interference performance.

Description

Current interlock formula protection equipment for busbar

The utility model relates to the current interlock formula protection equipment for busbar that a kind of transformer station that is used for 66 kilovolts of buses of electric power system uses.

The power system transformer substation bus fault that is short-circuited can produce serious consequence.As electric equipments such as scaling loss transformer, high-voltage switch gear or buses, may cause large-area power-cuts.National economy is brought about great losses.So, in order to guarantee the safe operation of electric power system, must the installing protection equipment for busbar.

At present, the Current Transformer Secondary coil of 66 kilovolts of elements that bus connects of domestic many transformer stations and circuit all adopts two rollings, does not have special-purpose mother's difference coil, and can't realize bus differential protection.If carry out improvement project and updating the equipment, invest many, waste greatly.

The purpose of this utility model provides a kind of current interlock formula protection equipment for busbar, and this product need not special-purpose Current Transformer Secondary coil, and small investment, instant effect have solved 66 kilovolts of unshielded problems of bus of transformer station.

For achieving the above object; the technical solution of the utility model is: a kind of current interlock formula protection equipment for busbar; by line switching current interlock element I1; busbar voltage starting component U; transformer current action element I2; relay PLC; logical circuit and executive component are formed; current interlock element I1 and line switching DL1 are in series; after being in series, transformer current action element I2 and line switching DL2 connect with busbar voltage starting component U; circuit with current interlock element I1 and DL1 composition is in series again; link to each other with the exit relay Y of PCL inside through time relay T; link to each other with tripping relay again, connect transformer switch trip(ping) circuit T at last _DL

The utility model is owing to adopt said structure, need not special-purpose Current Transformer Secondary coil, and small investment, instant effect have solved 66 kilovolts of unshielded problems of bus of transformer station.This device wiring is simple, quick action, and antijamming capability is strong.

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

Fig. 2 is the electrical block diagram of current interlock element I1.

Fig. 3 is a transformer current action element electrical block diagram.

Fig. 4 is a busbar voltage starting component electrical block diagram.

Fig. 5 is a line switching auxiliary contact DL1 electrical block diagram.

Fig. 6 is a line switching auxiliary contact DL2 electrical block diagram.

Below in conjunction with accompanying drawing embodiment of the present utility model is described further: a kind of current interlock formula protection equipment for busbar; by line switching current interlock element I1; busbar voltage starting component U; transformer current action element I2; relay PLC; logical circuit and executive component are formed; current interlock element I1 and line switching DL1 are in series; after being in series, transformer current action element I2 and line switching DL2 connect with busbar voltage starting component U; circuit with current interlock element 11 and DL1 composition is in series again; link to each other with the exit relay Y of PCL inside through time relay T; link to each other with tripping relay again, connect transformer switch trip(ping) circuit T at last _DLI1 is a line switching current interlock element, the effect of Lock bus protection.DL1 is the line switching auxiliary contact, plays a part to select this switch to move on certain bar bus.When the DL1 contact is connected, represent that this line switching moves on certain bar bus.I1 and DL1 mutually " with ".U is the busbar voltage starting component.Voltage reduces during busbar fault, the action of busbar voltage starting component.I2 is the transformer current action element.DL2 plays a part the same with DL1.I1 current element action when line fault is the bus external fault, locking bus protection are that T and Y and CKJ all are failure to actuate.When busbar fault, I2 and U action, I2 and DL2 mutually " with " back forms " with door " with U, and then with I1 mutually " with ".Receive after the time component, Y removes tripping relay CKJ through the outlet element, connects transformer switch TDL trip(ping) circuit by tripping relay CKJ contact at last.The inner AND circuit of symbol " ∝ " expression PLC, " T " expression PLC internal time relay, the inner exit relay of " Y " expression PLC.CKJ represents to protect tripping relay.TDL indication transformer switch trip loop.Fig. 2 is identical with transformer current element I2 circuit with Fig. 3 line current blocking element I1.BL is a current transformer, and Z1, Z2 are that amplitude limiter, R1 to R9, Z3, Z4, C1 to C3 and LM747 are for amplifying rectification circuit.C4, C10, R10 to R12, LM747 are filter circuit.R13, R14, C11, LM747 form the electric current operating value circuit of adjusting.R15 to R20, Z5, Z6, LM747 form threshold and trigger and the resetting ratio circuit.D1 is a driver.R21 to R23, GO1 are the level output conversion circuit.Q1 is line current element output termination PLC input (X1).Q2 is transformer current element output termination PLC input (X3).Fig. 4 is the busbar voltage element.YB is a transformer, and Z6, Z7 are that amplitude limiter, R24 to R26, C12, LM747 are formed the voltage operating value circuit of adjusting, C13 to C15, R27 to R33, LM747 for amplify rectification circuit C16 to C22, R34 to R36, LM747 are filter circuit.R37 to R42, C23, Z10, Z11, LM747 form threshold and trigger and the resetting ratio circuit.D2 is a driver.R43 to R45, GO2 are the level output conversion circuit.Q5 voltage component output termination PLC input (X5).Accompanying drawing 5,6 is for isolating and auxiliary contact switch input variable loop, pass.R46, R47, R50, R51 are dividing potential drop and current limliting loop.C24, C25, Z12, Z13 are anti-interference and the earial drainage device.GO3, GO4, R48, R49, R52, R53 are the level output conversion circuit.Q2 switch input variable element output termination PLC input (X2).Q4 switch input variable element output termination PLC input (X4).CKJ is the protection tripping relay.Start by PLC exit relay output " Y " end.The CKJ contact connects the transformer switch trip(ping) circuit.Z11 is an anti-interference device.Line current element output Q1 meets PLC input X1.Transformer current element output Q2 meets PLC input X2.Busbar voltage element output Q5 meets PLC input X5.Line switching auxiliary contact DL1 output Q2 meets PLC input X2.Transformer switch auxiliary contact DL2 output Q4 meets PLC input X4.Wherein, the line current blocking element is identical with the circuit theory of transformer current action element, as accompanying drawing 2, shown in Figure 3.Transmitter BL in the fault current inflow device of transformer or line switching current transformer, current conversion is become the small voltage signal, connect behind diode ZL amplitude limit that high precision operating amplifier LM747 amplifies, rectification, filtering, adjust and compare with threshold value Uk for standard signal, if its value is greater than threshold value, then isolate the switching value input of output high level, carry out analysis and judgement as actuating quantity or locking amount for the PLC relay logic circuit whether busbar fault takes place to PLC through photoelectrical coupler GO.

The operating principle of the busbar voltage starting component circuit in the device as shown in Figure 4, when busbar fault, the voltage transmitter YB of residual voltage in the voltage transformer access device is transformed into the small voltage signal, connect behind the ZL amplitude limit that high precision operating amplifier LM747 adjusts, amplification, rectification, be filtered into standard signal and compare with threshold value, if its value is greater than threshold value, then isolate the switching value input of output high level, carry out the criterion whether analysis and judgement busbar fault takes place for the PLC relay logic circuit as the startup amount to PLC through photoelectrical coupler GO.

DL is the auxiliary contact of transformer or circuit high-voltage switch gear, can switch by physical cabling in double-bus as the selection element of its connection bus.The DL contact is connected through photoelectrical coupler GO and is converted the switching value input that high level inserts PLC to.

PLC programmable controller (MicroLogix ^TM1500) input carries out logic analysis and judgement with the switching value signal that receives with relay trapezoidal pattern software.If busbar fault, then the internal time relay starts exit relay Y after delaying time.The junction closure of Y starts tripping relay CKJ.The contact of CKJ is connected transformer switch trip(ping) circuit T _DLCut off the electricity supply the protection fault bus.

Claims

1, a kind of current interlock formula protection equipment for busbar is characterized in that this device is by line current blocking element I ₁, busbar voltage starting component U, transformer current action element I ₂, relay PLC, and executive component form current interlock element I ₁With line switching DL1 series connection, transformer current action element I ₂Connect the back with line switching DL2 with busbar voltage starting component U series connection, again with current interlock element I ₂After after the time relay T time-delay, exit relay Y links to each other with relay PLC inside, relay Y outlet connects tripping relay CKJ, connects transformer switch trip(ping) circuit TDL by tripping relay CKJ contact at last with the series connection of line switching DL1 circuit.