CN103248008A - Longitudinal differential protection current phase compensation method for YNd7 transformer - Google Patents

Abstract

The invention belongs to a relay protection controlling technology of power transmission and distribution network, and relates to a longitudinal differential protection current phase compensation method for an YNd7 transformer, which comprises the steps of enabling TA secondary windings of the high-voltage side and the low-voltage side of the YNd7 transformer to be in Y connection; b, connecting the A-phase current, B-phase current and the C-phase current of the Y-side TA secondary windings of the transformer to loops of the A-phase current, the B-phase current and the C-phase current of a YNd11 transformer differential protection device; connecting each phase current of the d-side TA secondary windings of the transformer into the YNd1 transformer differential protection device according to the reversed polarity of each d-side phase current of the YNd7 transformer; and d, utilizing the YNd1 transformer protection device to finally realize the differential protection phase compensation of the YNd7 transformer. The longitudinal differential protection current phase compensation method for the YNd7 transformer is simple in principle, convenient to implement and can adapt to the longitudinal differential protection current phase compensation of the YNd7 connecting transformer.

Description

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

Technical field

The invention belongs to the relaying protection control technology of power transmission and distribution network, relate to a kind of method of YNd7 serial transformer longitudinal differential protection current phase compensation.

Background technology

Because each side electric current possibility phase place of the transformer in the transmission and distribution networks is inconsistent, so transformer longitudinal linked differential protection (hereinafter to be referred as transformer differential protection) will carry out the current phase compensation.The method of transformer differential protection current phase compensation has two kinds: 1, traditional hardware phase shift: adopt triangle d-11 wiring, d side TA secondary winding to adopt star Y-12 wiring such as YNd11 transformer Y side current transformer (hereinafter to be referred as TA) secondary winding; 2, software phase shift: namely utilize software program and computing formula to carry out the electric current phase shift and finish phase compensation.At present; 220kV and above tranformer protection are generally main protection backup protection integrated design, dualization configuration; main protection backup protection integrated design is main protection and same hardware and software is all used in all backup protections in a cabinet, and the electric current of the every side of transformer main protection backup protection, voltage all are to adopt TA, same group of secondary winding of voltage transformer.Because the integrated tranformer protection current circuit of main protection backup protection is the same current circuit that adopts; therefore can not adopt traditional hardware phase shift to carry out the current phase compensation; therefore the TA of each side of transformer must adopt wye connection, adopts the phase shift of electric current software to carry out phase compensation.110kV and following microcomputer transformer differential protection do not adopt traditional hardware phase shift to carry out the current phase compensation at present yet, and the TA of each side generally also adopts wye connection, also adopts the electric current software phase compensation of differential protection.But each tranformer protection manufacturer differential protection electric current software phase compensating method can only adapt to YNd11, YNd1 and these several transformer connection groups of YNyn12 and wiring combination thereof at present; can not adapt to other wiring groups and wiring compound mode, also not have other documents to provide solution.

Summary of the invention

Problem to be solved by this invention is; provide a kind of principle simple, implement convenient; meet transformer differential protection current phase compensation principle fully, can adapt to the compensation method of the uncommon YNd7 wiring transformer of various electric pressure transformers longitudinal differential protection current phase.

Provide the technical scheme of the inventive method below.

Be applied to the various electric pressure YNd7 main transformers of the various electric pressure electric substation of transmission and distribution networks in YNd7 transformer longitudinal linked differential protection current phase of the present invention compensation method.The basic skills of YNd7 transformer differential protection current phase compensation proposed by the invention is:

YNd7 transformer high-voltage side, low-pressure side TA secondary winding are all connect be wye connection.

B. this transformer Y side TA secondary winding A phase current, B phase current, C phase current insert A phase current, B phase current, the C phase current loop of YNd1 transformer differential protection respectively;

C. each phase current of this transformer d side TA secondary winding is according to inserting the YNd1 transformer differential protection with each phase current reversed polarity of YNd7 transformer d side, that is:

1) with this transformer Y side reversed polarity TA secondary current

Insert YNd1 protection equipment for transformer d side a phase current loop;

2) with this transformer Y side reversed polarity TA secondary current

Insert YNd1 protection equipment for transformer d side b phase current loop;

3) with this transformer Y side reversed polarity TA secondary current

Insert YNd1 protection equipment for transformer d side c phase current loop;

D. by above-mentioned phase transition; the transformer differential protection of YNd7 wiring has been transformed into the transformer differential protection of YNd1 wiring; and then the software phase compensation that utilizes the YNd1 protection equipment for transformer finishes the phase compensation of the transformer differential protection of YNd1 wiring, finally realizes the phase compensation of YNd7 transformer differential protection.

The method of the phase compensation of YNd7 wiring transformer longitudinal differential protection electric current of the present invention meets transformer longitudinal linked differential protection basic principle fully, compares with employed method in the existing microcomputer type transformer differential protection device, has following advantage:

1, is applicable to the current phase compensation technique scheme of the various electric pressure transformer longitudinal of the YNd7 of transmission and distribution networks electric substation wiring linked differential protection device; And existing microcomputer type transformer longitudinal linked differential protection device can only be applicable to YNd11, YNd1, three kinds of wiring groups of YNy12 and combination thereof.

2, by inserting the conversion of each phase current of transformer longitudinal linked differential protection device, YNd7 wiring transformer differential protection is converted to YNd1 wiring transformer differential protection, the current phase compensation scheme of the existing YNd1 microcomputer transformer differential protection device of recycling, realized the current phase compensation scheme of all YNd7 wiring transformer longitudinal differential protection devices, simple and practical, secondary circuit is changed little, realizes easily;

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

Description of drawings

Fig. 1 is YNd1 serial transformer winding diagram and both sides current vector figure;

Fig. 2 is YNd7 serial transformer winding diagram and both sides current vector figure;

Fig. 3 is that the inventive method embodiment is used for YNd7 transformer differential protection current phase compensation principle figure;

Specific embodiments

1, YNd1 transformer both sides current phase relation

As Fig. 1 be YNd1 transformer connection figure and and both sides current vector figure, a) be YNd1 transformer connection figure, b) be YNd1 transformer current vectogram.By Fig. 1 b) as seen, Y side current phase is than leading 30 degree of d side current phase.

2, YNd7 transformer both sides current phase relation

As Fig. 2 be YNd7 transformer connection figure and and both sides current vector figure, a) YNd7 is transformer connection figure, b) is YNd7 transformer both sides current vector figure.By Fig. 2 b) visible Y side current phase is than d side current phase 150 degree that lag behind.

3, YNd7 and YNd1 transformer d side current phase relation

Because YNd1 transformer Y side current phase is than leading 30 degree of d side current phase, YNd7 transformer Y side current phase is than d side current phase hysteresis 150 degree.If think identical with each phase current phase place of YNd1 transformer Y side the YNd7 transformer, comparison diagram 1 b) with Fig. 2 b), be not difficult then to find that YNd7 transformer and each phase current phase relation of YNd1 transformer d side are each phase current 180 degree of the leading YNd7 transformer of YNd1 transformer d each phase current of side d side.

4, YNd7 transformer differential protection phase compensation specific embodiments

YNd7 transformer differential protection phase compensation specific embodiments is:

YNd7 transformer high-voltage side, low-pressure side TA secondary winding all connect and are wye connection.This transformer Y side TA secondary winding A phase current, B phase current, C phase current insert A phase current, B phase current, the C phase current loop of YNd1 transformer differential protection respectively; Since each phase current 180 degree of the leading YNd7 transformer of YNd1 transformer d each phase current of side d side could insert the YNd1 transformer differential protection with each phase current reversed polarity of YNd7 transformer d side, that is: so

1) with YNd7 transformer reversed polarity TA secondary current

Insert YNd1 protection equipment for transformer d side a phase current loop;

2) with YNd7 transformer reversed polarity TA secondary current

Insert YNd1 protection equipment for transformer d side b phase current loop;

3) with YNd7 transformer reversed polarity TA secondary current

Insert YNd1 protection equipment for transformer d side c phase current loop;

Fig. 3 is seen in concrete wiring.According to this phase transition; just be equivalent to the transformer differential protection of YNd7 wiring has been transformed into the transformer differential protection of YNd1 wiring; and then the software phase compensation that utilizes the YNd1 protection equipment for transformer finishes the phase compensation of the transformer differential protection of YNd1 wiring, thereby reaches the phase compensation of YNd7 transformer differential protection at last.Obviously this scheme ratio is easier to realize, as long as change on-the-spot d side secondary current circuit connection, and the wiring of changing is also few.

Claims (1)

1. YN7 transformer differential protection current phase compensation method is characterized in that:

YNd7 transformer high-voltage side, low-pressure side TA secondary winding are all connect be wye connection;

B. this transformer Y side TA secondary winding A phase current, B phase current, C phase current insert A phase current, B phase current, the C phase current loop of YNd1 transformer differential protection device respectively;

C. each phase current of this transformer d side TA secondary winding is according to each phase current reversed polarity of YNd7 transformer d side is inserted in the YNd11 transformer differential protection device;

D. by above-mentioned phase transition; the transformer differential protection of YNd7 wiring has been transformed into the transformer differential protection of YNd1 wiring; and then the software phase compensation that utilizes the YNd1 protection equipment for transformer finishes the phase compensation of the transformer differential protection of YNd1 wiring, finally realizes the phase compensation of YNd7 transformer differential protection.

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