CN106385002A - Phase current difference eliminating zero sequence current Y-side compensation method for YNy6 transformer - Google Patents

Abstract

The invention discloses a phase current difference eliminating zero sequence current Y-side compensation method for a YNy6 transformer and is applicable to main transformers of various voltage levels of substations of various voltage levels of a power transmission and distribution network to complete current phase compensation of longitudinally differential protection phase current difference eliminating zero sequence current Y-side phase shift for a YNy6 transformer. A calculation method of phase current difference eliminating zero sequence current is employed both for Y-side and y-side differential protection of the YNy6 transformer to conduct current phase compensation, thereby preventing misoperation on the transformer for external faults due to zero sequence current. For differential protection of the YNy6 transformer, phase compensation employs a Y-side phase shift current phase compensation method with the y side as the reference.

Description

YNy6 transformer phase differential current eliminates zero-sequence current Y side compensation method

Technical field

The present invention relates to a kind of YNy6 transformer phase differential current eliminates zero-sequence current Y side compensation method, more particularly, to a kind of YNy6 transformer longitudinal linked differential protection phase differential current eliminates the current phase compensate method of zero-sequence current Y sidesway phase, belongs to electric power The relay protection and control technical field of transmission and distribution networkses.

Background technology

Because electric current possible phase place in transformer each side is inconsistent, therefore transformer longitudinal linked differential protection (hereinafter referred to as transformation Device differential protection) current phase compensate to be carried out.The method of transformer differential protection current phase compensate has two kinds：1st, traditional Analog shifter：Such as YNd11 transformer Y side current transformer (hereinafter referred to as TA) Secondary Winding adopts triangle d-11 wiring, d side TA Secondary Winding adopts star Y-12 wiring；2nd, digit shifter：I.e. using software program and computing formula carry out electric current phase shift Lai Complete phase compensation.At present, 220kV and above tranformer protection are generally main protection back-up protection integrated design, dual Configuration, main protection back-up protection integrated design is main protection and all of back-up protection all in a cabinet using same Individual hardware and software, the electric current of the every side of transformer main protection back-up protection, voltage are all using same group two of TA, voltage transformer Secondary winding.Because main protection back-up protection integrated transformer protective current loop is the same current loop adopting, therefore Current phase compensate can not be carried out using traditional analog shifter, the therefore TA of each side of transformer must adopt star connection, adopt Carry out phase compensation with electric current digit shifter.110kV and following microcomputer transformer differential protection do not adopt traditional hard at present yet Part phase shift carries out current phase compensate, and the TA of each side is typically also adopted by star connection, is also adopted by the electric current software phase of differential protection Position compensates, and progressively to main protection back-up protection integrated design, double set configuration transition.But each tranformer protection system at present Make manufacturer and only devise this several transformer connection group of YNd11, YNd1 and YNyn12 and its wiring combination differential protection electric current Software phase compensating method, does not design the transformer differential protection electric current software phase of other wiring groups and wiring combination mode Position compensation method.It is mutually electric that the present invention will propose a kind of YNy6 (wiring containing Yy6 and its wiring combination, similarly hereinafter) transformer differential protection Stream difference eliminates the electric current software Phase Compensation scheme of zero-sequence current y sidesway phase.

Content of the invention

It is an object of the invention to provide a kind of YNy6 transformer phase differential current eliminates zero-sequence current Y side compensation method, should For the various electric pressure main transformer of various electric pressure electric substations of transmission and distribution networkses, complete YNy6 transformer longitudinal differential Protection phase differential current eliminates the current phase compensate of zero-sequence current Y sidesway phase.

The purpose of the present invention is achieved by the following technical programs：

A kind of YNy6 transformer phase differential current eliminates zero-sequence current Y side compensation method, comprises the following steps：

Step 1：YNy6 high voltage side of transformer, low-pressure side TA Secondary Winding are all connected in star connection；

Step 2：For y side, carry out phase transition by following equation, that is, participate in each phase current of differential protection differential current computing For：

${\stackrel{\·}{I}}_{da}=({\stackrel{\·}{I}}_a-{\stackrel{\·}{I}}_b)/\sqrt{3}---\left(1\right)$

${\stackrel{\·}{I}}_{db}=({\stackrel{\·}{I}}_b-{\stackrel{\·}{I}}_c)/\sqrt{3}---\left(2\right)$

${\stackrel{\·}{I}}_{dc}=({\stackrel{\·}{I}}_c-{\stackrel{\·}{I}}_a)/\sqrt{3}---\left(3\right)$

(1-3) in formulaFor a phase after device y side software phase compensation, b phase, c phase current； For access device y side a phase, b phase, c phase TA secondary current；

Step 3：For Y side, it is that Y side makes each phase current of participation differential protection differential current computing and y side participate in differential protection Each phase current phase place of differential current computing is identical, carries out phase transition by following equation, that is, participate in each of differential protection differential current computing Phase current is：

${\stackrel{\·}{I}}_{dA}=({\stackrel{\·}{I}}_B-{\stackrel{\·}{I}}_A)/\sqrt{3}---\left(4\right)$

${\stackrel{\·}{I}}_{dB}=({\stackrel{\·}{I}}_C-{\stackrel{\·}{I}}_B)/\sqrt{3}---\left(5\right)$

${\stackrel{\·}{I}}_{dC}=({\stackrel{\·}{I}}_A-{\stackrel{\·}{I}}_C)/\sqrt{3}---\left(6\right)$

(4-6) in formulaFor the A phase current of device Y side participation differential current computing, B phase current, C phase current；TA secondary current for access device Y side A phase, B phase, C phase.

The purpose of the present invention can also be realized further by following technical measures：

Aforementioned YNy6 transformer phase differential current eliminates zero-sequence current Y side compensation method, applies also for Yy6 wiring and its connects The transformer of line combination.

Aforementioned YNy6 transformer phase differential current eliminates zero-sequence current Y side compensation method, in based Transformer differential protection Application is run in device.

Aforementioned YNy6 transformer phase differential current eliminates zero-sequence current Y side compensation method, in PLC type transformer differential protection dress Put middle operation to apply.

Aforementioned YNy6 transformer phase differential current eliminates zero-sequence current Y side compensation method, described TA model LCZ series.

Compared with prior art, the invention has the beneficial effects as follows：Principle is simple, easy to implement, complies fully with transformer poor The method of dynamic protective current phase compensation principle, makes the transformer Y side of YNy6 wiring participate in each phase of differential protection differential current computing The each phase current phase place of electricity is consistent with each mutually electric each phase current phase place that y side participates in differential protection differential current computing.

Brief description

Fig. 1 is the YNy6 transformer connection figure of the inventive method；

Fig. 2 is the vectogram after the YNy6 wiring transformer both sides electric current software compensation of the inventive method.

Specific embodiment

Because computer-based transformer protection is generally main protection back-up protection integrated design, duplicate system retrofit, transformer is poor Dynamic protection requires YNy6 high voltage side of transformer, low-pressure side TA Secondary Winding to be all connected in star connection.Fig. 1 is that the YNy6 of the present invention becomes Depressor wiring diagram.The electric current software phase compensation scheme of YNy6 wiring transformer differential protection is：

A kind of YNy6 transformer phase differential current eliminates zero-sequence current Y side compensation method, comprises the following steps：

Step 1：YNy6 high voltage side of transformer, low-pressure side TA Secondary Winding are all connected in star connection；

Step 2：For y side, carry out phase transition by following equation, that is, participate in each phase current of differential protection differential current computing For：

${\stackrel{\·}{I}}_{da}=({\stackrel{\·}{I}}_a-{\stackrel{\·}{I}}_b)/\sqrt{3}---\left(1\right)$

${\stackrel{\·}{I}}_{db}=({\stackrel{\·}{I}}_b-{\stackrel{\·}{I}}_c)/\sqrt{3}---\left(2\right)$

${\stackrel{\·}{I}}_{dc}=({\stackrel{\·}{I}}_c-{\stackrel{\·}{I}}_a)/\sqrt{3}---\left(3\right)$

(1-3) in formulaFor a phase after device y side software phase compensation, b phase, c phase current； For access device y side a phase, b phase, c phase TA secondary current；

Step 3：For Y side, it is that Y side makes each phase current of participation differential protection differential current computing and y side participate in differential protection Each phase current phase place of differential current computing is identical, carries out phase transition by following equation, that is, participate in each of differential protection differential current computing Phase current is：

${\stackrel{\·}{I}}_{dA}=({\stackrel{\·}{I}}_B-{\stackrel{\·}{I}}_A)/\sqrt{3}---\left(4\right)$

${\stackrel{\·}{I}}_{dB}=({\stackrel{\·}{I}}_C-{\stackrel{\·}{I}}_B)/\sqrt{3}---\left(5\right)$

${\stackrel{\·}{I}}_{dC}=({\stackrel{\·}{I}}_A-{\stackrel{\·}{I}}_C)/\sqrt{3}---\left(6\right)$

(4-6) in formulaFor the A phase current of device Y side participation differential current computing, B phase current, C phase current；TA secondary current for access device Y side A phase, B phase, C phase.

By above-mentioned phase transition, the transformer Y side of YNy6 wiring is made to participate in each mutually electric each of differential protection differential current computing Each mutually electric each phase current phase place that phase current phase place participates in differential protection differential current computing with y side is consistent.

In above-mentioned steps 2, step 3, YNy6 transformer differential protection Y side and y side all eliminate zero sequence electricity using phase differential current The computational methods of stream carry out current phase compensate, prevent external area error due to zero-sequence current, cause transformer misoperation.

Above-mentioned steps 2, step 3 are to be thought with y side for Yny6 transformer differential protection differential protection phase compensation Benchmark employs the current phase compensate method of Y sidesway phase.

Above-mentioned YNy6 transformer differential protection software current phase compensating method be applied to microcomputer transformer differential protection, In PLC type differential protective device of transformer.

Above-mentioned YNy6 transformer phase differential current eliminates zero-sequence current Y side compensation method, applies also for Yy6 wiring and its connects The transformer of line combination.

Fig. 2 is seen with the vectogram after the current compensation of y side in Y side, and Fig. 2 (a) is the vectogram after the current compensation of Y side, Fig. 2 (b) For the vectogram after the current compensation of y side.

In addition to the implementation, the present invention can also have other embodiment, all employing equivalents or equivalent transformation shape The technical scheme becoming, all falls within the protection domain of application claims.

Claims (5)

1. a kind of YNy6 transformer phase differential current eliminates zero-sequence current Y side compensation method it is characterised in that comprising the following steps：

Step 1：YNy6 high voltage side of transformer, low-pressure side TA Secondary Winding are all connected in star connection；

Step 2：For y side, carry out phase transition by following equation, that is, each phase current participating in differential protection differential current computing is：

${\stackrel{\·}{I}}_{da}=({\stackrel{\·}{I}}_a-{\stackrel{\·}{I}}_b)/\sqrt{3}---\left(1\right)$

${\stackrel{\·}{I}}_{db}=({\stackrel{\·}{I}}_b-{\stackrel{\·}{I}}_c)/\sqrt{3}---\left(2\right)$

${\stackrel{\·}{I}}_{dc}=({\stackrel{\·}{I}}_c-{\stackrel{\·}{I}}_a)/\sqrt{3}---\left(3\right)$

(1-3) in formulaFor a phase after device y side software phase compensation, b phase, c phase current； For access device y side a phase, b phase, c phase TA secondary current；

Step 3：For Y side, it is that Y side makes each phase current of participation differential protection differential current computing and y side participate in differential protection difference stream The each phase current phase place calculating is identical, carries out phase transition by following equation, that is, participate in each mutually electricity of differential protection differential current computing Flow and be：

${\stackrel{\·}{I}}_{dA}=({\stackrel{\·}{I}}_B-{\stackrel{\·}{I}}_A)/\sqrt{3}---\left(4\right)$

${\stackrel{\·}{I}}_{dB}=({\stackrel{\·}{I}}_C-{\stackrel{\·}{I}}_B)/\sqrt{3}---\left(5\right)$

${\stackrel{\·}{I}}_{dC}=({\stackrel{\·}{I}}_A-{\stackrel{\·}{I}}_C)/\sqrt{3}---\left(6\right)$

(4-6) in formulaFor the A phase current of device Y side participation differential current computing, B phase current, C phase current；TA secondary current for access device Y side A phase, B phase, C phase.

2. YNy6 transformer phase differential current as claimed in claim 1 eliminate zero-sequence current Y side compensation method it is characterised in that Apply also for the transformer of Yy6 wiring and its wiring combination.

3. YNy6 transformer phase differential current as claimed in claim 1 eliminate zero-sequence current Y side compensation method it is characterised in that Application is run in based Transformer differential protection.

4. YNy6 transformer phase differential current as claimed in claim 1 eliminate zero-sequence current Y side compensation method it is characterised in that Application is run in PLC type differential protective device of transformer.

5. YNy6 transformer phase differential current as claimed in claim 1 eliminate zero-sequence current Y side compensation method it is characterised in that Described TA model LCZ series.