CN104701814A

CN104701814A - Phase compensating method for longitudinal differential protective current of YNd7 wired transformer

Info

Publication number: CN104701814A
Application number: CN201510110179.0A
Authority: CN
Inventors: 李静; 汤大海; 刘丛洲
Original assignee: State Grid Corp of China SGCC; State Grid Jiangsu Electric Power Co Ltd; Zhenjiang Power Supply Co of Jiangsu Electric Power Co
Current assignee: State Grid Corp of China SGCC; State Grid Jiangsu Electric Power Co Ltd; Zhenjiang Power Supply Co of Jiangsu Electric Power Co
Priority date: 2015-03-13
Filing date: 2015-03-13
Publication date: 2015-06-10

Abstract

The invention belongs to a protective relaying control technology of power transmission and distribution networks, and relates to microcomputer-controlled phase compensating method for a longitudinal differential protective current of an YNd7 wired transformer. A specific wiring method thereof is as follows: 1) remaining each current phase that connects each phase of current of a TA secondary winding on a Y side of the YNd7 transformer to a differential protection of a YNd11 wired transformer unchanged; 2) reversely connecting a b-phase current, a c-phase current and an a-phase current of a TA secondary current on a d side of the YNd7 transformer respectively to an a-phase current loop, a b-phase current loop and a c-phase current loop on a d side of a protective device of the YNd11 transformer; 3) using a software phase compensation of the protective device of the YNd11 transformer to finish the differential protective phase compensation of the YNd7 wired transformer. The phase compensating method for the longitudinal differential protective current of the YNd7 wired transformer is able to finish the differential protective current phase compensation of the YNd7 wired transformer; and the phase compensating method for the longitudinal differential protective current of the YNd7 wired transformer is simple in theories, and convenient in implementations.

Description

The compensation method of YNd7 wiring transformer longitudinal differential protection current phase

Technical field

The invention belongs to the relay protection and control technology of electrical power distribution electric network, relate to a kind of for the compensation method of micro-processor controlled YNd7 wiring transformer longitudinal differential protection current phase.

Background technology

Because transformer each side electric current possibility phase place is inconsistent, therefore transformer longitudinal linked differential protection (abbreviation transformer differential protection) will carry out current phase compensation.The method that transformer differential protection current phase compensates has two kinds: 1, traditional analog shifter: such as YNd11 transformer Y side current transformer (being called for short TA) secondary winding adopts triangle d-11 wiring, d side TA secondary winding adopts star Y-12 wiring; 2, digit shifter: namely utilize software program and computing formula to carry out electric current phase shift to complete phase compensation.At present; 220kV and above tranformer protection are generally main protection backup protection integrated design, duplicate system retrofit; main protection backup protection integrated design is main protection and all backup protections all use same hardware and software in a cabinet, and the electric current of the every side of transformer main protection backup protection, voltage are all adopt TA, voltage transformer same group of secondary winding.Because main protection backup protection integrated transformer protective current loop is the same current circuit adopted; therefore traditional analog shifter can not be adopted to carry out current phase compensation; therefore the TA of each side of transformer must adopt wye connection, adopts electric current digit shifter to carry out phase compensation.110kV and following microcomputer transformer differential protection do not adopt traditional analog shifter to carry out current phase compensation at present yet; the TA of each side generally also adopts wye connection; also the electric current software phase compensation of differential protection is adopted, and progressively to main protection backup protection integrated design, two coverization configuration transition.But current each tranformer protection manufacturer differential protection electric current software phase compensating method can only adapt to this several transformer connection group of YNd11, YNd1 and YNyn12 and wiring combination thereof, can not adapt to other wiring groups and wiring compound mode.Chinese patent application 201210452816.9 and 201310186018.0 proposes the compensation method of 2 kinds of YNd7 transformer longitudinal linked differential protection current phases; but still there is the limitation in the mode of connection in it, therefore needs more alternative plan in actual applications.

Summary of the invention

Problem to be solved by this invention is; propose one and can utilize YNd1 transformer differential protection electric current software Phase Compensation System; complete the current phase compensation that various electric pressure transformer is YNd7 wiring (containing Yd7 wiring) transformer differential protection; and principle is simple, enforcement is convenient, meets the YNd7 wiring transformer longitudinal differential protection current phase compensation method of transformer differential protection current phase compensation principle.

Provide the technical scheme of the inventive method below:

YNd7 high voltage side of transformer, low-pressure side TA secondary winding are all connect as wye connection, by each for YNd7 transformer side electric current access YNd11 computer-based transformer protection device, concrete mode of connection as follows:

1) by mutually constant for each phase current of YNd7 transformer Y side TA secondary winding each phase current access YNd11 wiring transformer differential protection, namely YNd7 transformer Y side TA secondary winding A phase current, B phase current, C phase current connect A phase current, B phase current, the C phase current of YNd11 transformer differential protection respectively;

2) YNd7 transformer d side TA secondary current a phase current, b phase current, c phase current difference anti-phase (i.e. reversed polarity side electric current) are accessed a phase current loop, YNd11 protection equipment for transformer d side, b phase current loop, c phase current loop;

3) the software phase compensation of YNd11 computer-based transformer protection device is utilized to complete the phase compensation of the transformer differential protection of YNd7 wiring.

According to above-mentioned transformer differential protection phase transition; just be equivalent to the transformer differential protection transformer differential protection of YNd7 wiring being transformed to YNd11 wiring; and then utilize the software phase compensation of YNd11 protection equipment for transformer to complete the phase compensation of the transformer differential protection of YNd7 wiring, thus finally reach the phase compensation of YNd7 transformer differential protection.

The transformer longitudinal linked differential protection general principle that the method for the phase compensation of this YNd7 wiring transformer longitudinal differential protection electric current meets completely, compared with the method used in existing based Transformer differential protection, tool has the following advantages:

1, the current phase compensation technique scheme of transmission and distribution networks electric substation YNd7 wiring various electric pressure transformer longitudinal linked differential protection device is applicable to.

2, by the conversion of each phase current of access transformer longitudinal linked differential protection device, YNd7 wiring transformer differential protection is converted to YNd11 wiring transformer differential protection, recycle the current phase compensation scheme of existing YNd11 microcomputer transformer differential protection, achieve the current phase compensation scheme of all YNd7 wiring transformer longitudinal differential protection devices, simple and practical, secondary circuit is changed little, easily realizes;

3, the current phase compensation scheme of YNd7 wiring transformer longitudinal differential protection device does not need the current phase compensation scheme changing existing microcomputer transformer longitudinal differential protection device inside.

Accompanying drawing explanation

Fig. 1 is YNd7 transformer and YNd1 transformer connection figure in the conversion of the inventive method embodiment, and wherein (a) is YNd7 transformer connection figure, and (b) is YNd1 transformer connection figure;

Fig. 2 is YNd11 transformer and YNd1 transformer connection figure in the conversion of the inventive method embodiment, and wherein (a) is YNd11 transformer connection figure, and (b) is YNd1 transformer connection figure; ;

Fig. 3 is the YNd7 transformer differential protection current phase compensation principle figure of the inventive method embodiment.

Embodiment

1, the phase relation of YNd7 wiring transformer and YNd1 series wiring transformer

YNd7 wiring transformer winding diagram is shown in Fig. 1 a).Because YNd7 high voltage side of transformer, low-pressure side three-phase voltage are all symmetrical, as long as therefore take out 1 line voltage compare, so have in advance 210 degree.Fig. 1 b is shown in by YNd1 wiring transformer winding diagram), in like manner YNd1 transformer in advance 30 degree.We are YNd7 transformer with YNd1 transformer think and compare YNd7 transformer and YNd1 step down side by homophase between relation, then have YNd7 step down side delayed YNd1 step down side 180 degree, i.e. YNd7 transformer difference 180 degree corresponding to each phase current of YNd1 step down side.

2, the phase relation of YNd1 wiring transformer and YNd11 series wiring transformer

Fig. 2 b is shown in by YNd1 wiring transformer winding diagram).Because YNd1 high voltage side of transformer, low-pressure side three-phase voltage are all symmetrical, as long as therefore take out 1 line voltage compare, so have in advance 30 degree.YNd11 wiring transformer winding diagram is shown in Fig. 2 a), in like manner YNd1 transformer delayed 30 degree.We are YNd1 transformer with YNd11 transformer think and compare the relation between YNd1 transformer with each phase of YNd11 step down side by homophase.YNd1 transformer in comparison diagram 2 and the wiring of YNd11 transformer, obtain the d side phase relation of YNd1 wiring transformer and YNd11 wiring transformer as table 1.

The d side phase relation contrast table of table 1, YNd1 wiring transformer and YNd11 wiring transformer

3, the phase relation of YNd11 wiring transformer and YNd7 wiring transformer

Due to YNd1 step down side delayed YNd7 step down side 180 degree, i.e. YNd1 transformer difference 180 degree corresponding to each phase current of YNd7 step down side.Contrast table 1 again, so we obtain the d side phase relation of YNd11 wiring transformer and YNd7 wiring transformer: namely a phase negative-phase sequence curent of YNd7 wiring transformer d side winding, c phase negative-phase sequence curent, b phase negative-phase sequence curent respectively with a phase current, b phase current, the c phase current homophase of YNd11 wiring transformer d side winding, in table 2.

The d side phase relation contrast table of table 2, YNd11 wiring transformer and YNd7 wiring transformer

3, YNd7 transformer current phase compensating method

YNd11 wiring transformer differential protection, manufactory has achieved transformer differential protection electric current software compensation in protection equipment for transformer.Requirement YNd7 high voltage side of transformer, low-pressure side TA secondary winding all connect as wye connection.

Suppose each phase current homophase of YNd11 and YNd7 wiring transformer Y side winding, by table 2 item have a phase negative-phase sequence curent of YNd7 wiring transformer d side winding, c phase negative-phase sequence curent, b phase negative-phase sequence curent respectively with a phase current, b phase current, the c phase current homophase of YNd11 wiring transformer d side winding.Therefore, the compensation method of YNd7 wiring transformer differential protection current phase is drawn:

(1) each phase current of this YNd7 transformer Y side TA secondary winding each phase current access YNd11 wiring transformer differential protection is constant, and namely YNd7 transformer Y side TA secondary winding A phase current, B phase current, C phase current connect A phase current, B phase current, the C phase current of YNd11 transformer differential protection respectively.

(2) YNd7 transformer d side TA secondary current a phase current, c phase current, b phase current difference anti-phase (i.e. reversed polarity side electric current) are accessed a phase current loop, YNd11 protection equipment for transformer d side, b phase current loop, c phase current loop;

(3) according to above-mentioned transformer differential protection phase transition; just be equivalent to the transformer differential protection transformer differential protection of YNd7 wiring being transformed to YNd11 wiring; and then utilize the software phase compensation of YNd11 protection equipment for transformer to complete the phase compensation of the transformer differential protection of YNd7 wiring, thus finally reach the phase compensation of YNd7 transformer differential protection.Fig. 3 is shown in concrete wiring.

Claims

1. YNd7 wiring transformer longitudinal differential protection current phase compensation method; it is characterized in that: YNd7 high voltage side of transformer, low-pressure side TA secondary winding are all connect as wye connection; by each for YNd7 transformer side electric current access YNd11 microcomputer transformer differential protection, concrete mode of connection is as follows:

2) by YNd7 transformer d side TA secondary current a phase current, b phase current, c phase current a phase current loop, anti-phase access YNd11 protection equipment for transformer d side, b phase current loop, c phase current loop respectively;

3) the software phase compensation of YNd11 microcomputer transformer differential protection is utilized to complete the phase compensation of the transformer differential protection of YNd7 wiring.