CN106451355A - Y-side phase-shifting current phase compensation method for YNy10 transformer differential protection - Google Patents

Abstract

The invention discloses a Y-side phase-shifting current phase compensation method for YNy10 transformer differential protection. At a Y side and a y side of a YNy10 transformer, zero-sequence currents are eliminated in phase currents, so that the misoperation by transformer differential protection due to the influence of the zero-sequence currents can be prevented. For the YNy10 transformer differential protection, phase compensation is carried out by using a Y-side phase shifting method based on a y side as a benchmark. At the y side, current phase compensation is carried out by using a calculation method of zero-sequence current elimination in phase currents in sequence by using an a-phase current as a benchmark; and at the Y side of the YNy10 transformer, current phase compensation is carried out by using a calculation method of zero-sequence current elimination in phase currents in sequence based on a principle of having the identical phase with the corresponding current of the y side. The provided method is suitable for a technical scheme for current software phase compensation for transformer longitudinal differential protection devices with various voltage levels in a YNy10 wiring mode in a transmission and distribution network substation. Moreover, the method having simple and clear characteristics is easy to implement.

Description

YNy10 transformer differential protection Y sidesway phase current phase compensating method

Technical field

The present invention relates to a kind of YNy10 transformer longitudinal linked differential protection eliminates zero-sequence current Y sidesway phase current phase compensation Method, belongs to the relay protection and control equipment technical field of electrical power distribution electric network.

Background technology

Due to each side electric current of transformator may phase place inconsistent, therefore transformer longitudinal linked differential protection (hereinafter referred to as transformation Device differential protection) current phase compensate will be carried out.The method of transformer differential protection current phase compensate has two kinds：1. traditional Analog shifter：Such as current transformer TA Secondary Winding in YNd11 transformator Y side adopts triangle d-11 wiring, d side TA Secondary Winding Using star Y-12 wiring；2. digit shifter：Carry out electric current phase shift using software program and computing formula to complete phase place benefit Repay.At present, 220kV and above tranformer protection are generally main protection, back-up protection integrated design, duplicate system retrofit, main guarantor Shield, back-up protection integrated design be main protection and all of back-up protection all in a cabinet, filled using same hardware Put and software, transformator main protection, back-up protection are per the electric current of side, voltage be all using current transformer TA, voltage transformer Same group of Secondary Winding.As the tranformer protection current loop of main protection, back-up protection integration is the same electricity of employing Road is flowed back to, so current phase compensate can not be carried out using traditional analog shifter.Therefore the current transformer of each side of transformator TA must adopt star connection, carry out phase compensation using digit shifter.110kV and following microcomputer transformer differential protection are current Also current phase compensate is not carried out using traditional analog shifter, the TA of each side is typically also adopted by star connection, is also adopted by differential The electric current software of protection carries out phase compensation, and progressively to main protection back-up protection integrated design, double set configuration transition.But Be, at present each tranformer protection manufacturer only devise this several transformer connection group of YNd11, YNd1 and YNyn12 and its The differential protection current phase compensate method of wiring combination, does not design the transformator of other wiring groups and wiring combination mode Differential protection electric current software phase compensating method.The present invention will propose a kind of YNy10 transformer differential protection and eliminate zero-sequence current Y Sidesway phase current Phase Compensation scheme.

Content of the invention

It is an object of the invention to provide a kind of YNy10 transformer differential protection Y sidesway phase current phase compensating method, should For the various electric pressure main transformers of the various electric pressure electric substations of transmission and distribution networkses, YNy10 transformer longitudinal connection is completed Differential protection eliminates the phase compensation of zero-sequence current Y sidesway phase current.

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

A kind of YNy10 transformer differential protection Y sidesway phase current phase compensating method, comprises the following steps：

Step 1：YNy10 high voltage side of transformer, low-pressure side current transformer TA Secondary Winding are all connected in star connection；

Step 2：On the basis of y side, for y side, because zero-sequence current will be eliminatedImpact to differential protection, so ginseng A phase current with differential protection differential current computingB phase flowsWith c phase currentFor：

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

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, with y side a phase, b phase, c phase the synchronous Y side TA secondary current of TA secondary current Respectively-B phase ,-C phase ,-A phase, because zero-sequence current will be eliminatedImpact to differential protection, so it is poor to participate in differential protection The A phase current of stream calculationB phase currentC phase currentRespectively：

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

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

Aforementioned YNy10 transformer differential protection Y sidesway phase current phase compensating method, apply also for Yy10 wiring and its The transformator of wiring combination.

Aforementioned YNy10 transformer differential protection Y sidesway phase current phase compensating method, in based Transformer differential protection Operation application in device.

Aforementioned YNy10 transformer differential protection Y sidesway phase current phase compensating method, in PLC type transformer differential protection Operation application in device.

Aforementioned YNy10 transformer differential protection Y sidesway phase current phase compensating method, the current transformer TA model LJZ series.

Compared with prior art, the invention has the beneficial effects as follows：YNy10 transformator Y side and y side are all using in phase current Zero-sequence current is eliminated, the misoperation for preventing transformer differential protection from producing as zero-sequence current affects.For YNy10 transformator Differential protection, phase compensation is the method on the basis of y side using Y sidesway phase, and wherein y side is employed on the basis of a phase current Order phase current eliminates the computational methods of zero-sequence current and carries out current phase compensate, employs order for YNy10 transformator Y side Phase current eliminates the computational methods of zero-sequence current and current in phase corresponding to y side ground principle carries out current phase compensate.

By above-mentioned phase transition, the transformator Y side of YNy10 wiring and y side is made to participate in each phase differential current computing of differential protection A phase currentWith a phase currentPhase place is consistent, B phase currentFlow with b phasePhase place is consistent, C phase currentElectric with c phase StreamPhase place is consistent.

Compared with the method used in existing based Transformer differential protection, the present invention is applied to power transmission and distribution The YNy10 wiring of network electric substation, the electric current software phase place of the various electric pressure transformer longitudinal linked differential protection devices of Yy10 wiring Compensation technique scheme, and simple clear, easily realize.

Description of the drawings

Fig. 1 is the YNy10 transformer connection figure of the present invention；

Fig. 2 is the vector diagram after the YNy10 wiring transformer both sides electric current software compensation of the present invention.

Specific embodiment

The invention will be further described with specific embodiment below in conjunction with the accompanying drawings.

As shown in figure 1, being YNy10 transformer connection figure according to the present invention.

As computer-based transformer protection is generally main protection back-up protection integrated design, duplicate system retrofit, transformator is poor Dynamic protection requires that YNy10 high voltage side of transformer, low-pressure side TA Secondary Winding are all connected in wye connection.YNy10 wiring transformer is poor The electric current software phase compensation scheme of dynamic protection device is：

Step 1：YNy10 high voltage side of transformer, low-pressure side current transformer TA Secondary Winding are all connected in star connection；

Step 2：On the basis of y side, for y side, because zero-sequence current will be eliminatedImpact to differential protection, so ginseng A phase current with differential protection differential current computingB phase flowsWith c phase currentFor：

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

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, with y side a phase, b phase, c phase the synchronous Y side TA secondary current of TA secondary current Respectively-B phase ,-C phase ,-A phase, because zero-sequence current will be eliminatedImpact to differential protection, so it is poor to participate in differential protection The A phase current of stream calculationB phase currentC phase currentRespectively：

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

Step 4：By above-mentioned phase transition, make the transformator Y side of YNy10 wiring and y side participate in differential protection and respectively differ The A phase current of stream calculationWith a phase currentPhase place is consistent, B phase currentFlow with b phasePhase place is consistent, C phase currentWith C phase currentPhase place is consistent.

Zero-sequence current is all eliminated using phase differential current using the transformator Y side and y side of YNy10 wiring, prevents transformator poor The misoperation that dynamic protection is produced as zero-sequence current affects；The current phase compensate of transformer differential protection adopts Y side phase place Compensation method.

Fig. 2 is seen with vector diagram after the current compensation of y side in Y side.Fig. 2 (a) is the vector after the current compensation of Y side Figure, Fig. 2 (b) is the vector diagram after the current compensation of y side.In Fig. 2

For small current neutral grounding system, due to there is no zero-sequence current, when step 2,3 conversion is carried out, formula (1- 3), in formula (4-5), zero-sequence current need not be eliminated.

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

Claims (5)

1. a kind of YNy10 transformer differential protection Y sidesway phase current phase compensating method, it is characterised in that comprise the following steps：

Step 1：YNy10 high voltage side of transformer, low-pressure side current transformer TA Secondary Winding are all connected in star connection；

Step 2：On the basis of y side, for y side, because zero-sequence current will be eliminatedImpact to differential protection, so participation is poor The a phase current of dynamic protection differential current computingB phase flowsWith c phase currentFor：

${\stackrel{\·}{I}}_{da}={\stackrel{\·}{I}}_a-{\stackrel{\·}{I}}_{y0}---\left(1\right)$

${\stackrel{\·}{I}}_{db}={\stackrel{\·}{I}}_b-{\stackrel{\·}{I}}_{y0}---\left(2\right)$

${\stackrel{\·}{I}}_{dc}={\stackrel{\·}{I}}_c-{\stackrel{\·}{I}}_{y0}---\left(3\right)$

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

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 the poor stream of differential protection The each phase current phase place for calculating is identical, with y side a phase, b phase, c phase the synchronous Y side TA secondary current of TA secondary current respectively For-B phase ,-C phase ,-A phase, because zero-sequence current will be eliminatedImpact to differential protection, so participate in differential protection difference flowmeter The A phase current of calculationB phase currentC phase currentRespectively：

${\stackrel{\·}{I}}_{dA}=-({\stackrel{\·}{I}}_B-{\stackrel{\·}{I}}_0)---\left(4\right)$

${\stackrel{\·}{I}}_{dB}=-({\stackrel{\·}{I}}_C-{\stackrel{\·}{I}}_0)---\left(5\right)$

${\stackrel{\·}{I}}_{dC}=-({\stackrel{\·}{I}}_A-{\stackrel{\·}{I}}_0)---\left(6\right)$

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

2. YNy10 transformer differential protection Y sidesway phase current phase compensating method as claimed in claim 1, it is characterised in that Can be applicable to the transformator of Yy10 wiring and its wiring combination.

3. YNy10 transformer differential protection Y sidesway phase current phase compensating method as claimed in claim 1, it is characterised in that Operation application in based Transformer differential protection.

4. YNy10 transformer differential protection Y sidesway phase current phase compensating method as claimed in claim 1, it is characterised in that Operation application in PLC type differential protective device of transformer.

5. YNy10 transformer differential protection Y sidesway phase current phase compensating method as claimed in claim 1, it is characterised in that The current transformer TA model LJZ series.