CN106680638A - Detection method for current loop of transformer of intelligent substation - Google Patents

Abstract

The invention discloses a detection method for a current loop of a transformer of an intelligent substation. The detection method comprises the following steps: arranging a transformer protection device, short-circuiting three sides of a to-be-detected transformer and calculating primary impedances on the three sides; injecting a current on one side with the minimal primary impedance and utilizing an outgoing line interval to short-circuit and ground the three phases on the other two sides; simultaneously injecting the current to the three phases and independently injecting the current to each phase, and meanwhile, acquiring the working parameters of primary side and secondary side of the to-be-detected transformer and an auxiliary device; judging the performance of the current loop of the to-be-detected transformer. According to the invention, the transformer is considered as a whole and the integral and one-time tests are performed on the primary and secondary current loops on the three sides of the transformer, so that the test efficiency is greatly increased; a large-scale boosting device or the unfastening for a transformer primary wire is not required, the test wiring is simple and the expansibility is excellent; one-point current injection for the whole station current loop can be performed, so that the efficiency of the whole station current-boosting test of the substation can be greatly increased.

Description

The detection method in intelligent substation transformer current loop

Technical field

The invention belongs to electric automatization field, and in particular to a kind of detection side in intelligent substation transformer current loop Method.

Background technology

With the development and the improvement of people's living standards of national economy technology, electric energy has become people's daily life In one of the most important energy.Transformer station is used as the important step in electrical energy transportation, and its importance is self-evident.Transformer is to become One of power station nucleus equipment, thus to the protection of transformer must quickly, it is accurate, reliable.

The current loop of the side of transformer three is influence transformer main protection (transformer differential protection) most important factor.Pass The electric current of the transformer that system transformer station is gathered due to fault wave recording device comes from the liter dais current transformer of transformer, therefore Three sides up-flow simultaneously cannot be carried out to transformer with flow device is once risen, its main cause is that the capacity of liter flow device cannot bear The impedance of Transformer Winding, if necessary to up-flow then must using many large scale equipments include Large Copacity rising current transformer, Fork truck, lift truck etc., the transformer station's inconvenience for 220kV and following voltage class are promoted.Current intelligent substation has turned into change The basic model in power station, the side electric current of transformer three of intelligent substation wall collection comes from the Current Mutual Inductance at three sides interval Device, power transformer enclosure current transformer is primarily as measurement winding temperature and the function of locking pressure regulation.

At present, it is for the mode that the current loop of transformer is detected：Field adjustable personnel or maintainer are branches pair Current loop checked, i.e., the no-load voltage ratio polarity of transformer current transformer tested by a personnel first, secondly by Secondary personnel check the secondary current loop of transformer, point side are finally carried out to transformer and is flowed up.This method of testing Really tested the current loop of the side of transformer three as a test object, without by the side of transformer three Current loop is tested as an entirety, but in actual motion, transformer differential protection is by the electricity of the side of transformer three Stream is calculated as an entirety, and especially for intelligent substation, the relatively conventional transformer station in transformer current loop increases The link of combining unit, generates many new problems, such as the latency issue of combining unit, polarity problems, jitter performance, Transient problems etc., these problems significantly increase the complexity in transformer current loop, and current method of testing is obvious It is no longer desirable for new-type intelligent substation.

The content of the invention

Can carry out that globality test, testing efficiency be high, test is accurate to transformer it is an object of the invention to provide one kind The detection method in exactness intelligent substation transformer current loop high.

The detection method in this intelligent substation transformer current loop that the present invention is provided, comprises the following steps：

S1. the protection device to transformer to be detected is configured, and three sides of transformer to be detected is carried out into short circuit, together When calculate an impedance value of the side of transformer three under this kind of state；

S2. minimum side is used as Current injection points in the impedance value that selecting step S1 is calculated, and utilizes Line is spaced the both sides three-phase shortcircuit ground connection of remaining non-Current injection points；

S3. in the decanting point side of transformer to be detected, Injection Current and split-phase are separately injected into electric current to three-phase simultaneously, while obtaining Take the running parameter of transformer primary side to be detected, secondary side and auxiliary equipment during Injection Current；

S4. the running parameter for being obtained according to step S3, the property in transformer current loop to be detected is judged according to judgment principle Energy.

The protection device to transformer to be detected described in step S1 is configured, specially by three sides in protection device The mode of connection be all revised as the Y/Y/Y modes of connection；Three side magnitudes of voltage of protection device are revised as same magnitude of voltage；Will protection The actual current mutual inductor ratio value of the side of change ratio transformer three of each side current transformer of transformer is configured in device.

Electric current injection is carried out in decanting point side described in step S3, the value of described Injection Current is to be flowed back to according to once liter The impedance on road and once rise flow device calculation of capacity obtain.

After described injected value of current will ensure injection transformer, the primary current of transformer is more than 100A, so as to transformation The value and current waveform figure that show secondary current that the secondary device of device can be stablized.

The work ginseng of transformer primary side to be detected, secondary side and auxiliary equipment when obtaining Injection Current described in step S3 Number, specially obtains show value, the protection equipment for transformer difference stream display of protection equipment for transformer primary current and secondary current Value, the electric current show value of other secondary devices, the primary current of line segregation secondary device and secondary current show value, Yi Jibian The current value of each standby winding of side current transformer of depressor.

The performance for judging transformer current loop to be detected described in step S4, specially according to following rule to be detected The performance in transformer current loop is judged：

The detected rule of current loop under the monophase current injection way of table 1

The detected rule of current loop under the three-phase current injection way of table 2

The detection method in this intelligent substation transformer current loop that the present invention is provided, by using transformer as Individual entirety is accounted for, while realizing in the side primary side injection high current of transformer three, so as to the electric current to the side of transformer three is mutual The no-load voltage ratio of sensor, polarity, the time delay of combining unit and jitter performance, the parameter setting of protection equipment for transformer, the side of transformer three Secondary current loop carry out globality and disposable test, greatly improve testing efficiency, can be complete by the method Ensure the correctness of the side current loop of transformer three, for transformer put into operation and later stable operation provides most strong technology Support；Meanwhile, the method need not use large-scale booster apparatus, and need not untie wire of transformer, and test connection is simple, Therefore possess very strong operability, can be promoted in transformer station's new construction or reconstruction and extension project；Last the method is also Some beams of whole station current loop can be carried out, the efficiency of transformer station's whole station rising test project can be greatly improved, Under equal conditions, more than 50 percent test period can be saved, and substantially reduce the work physical strength of personnel.

Brief description of the drawings

Fig. 1 is flow chart of the method for the present invention.

Fig. 2 is test principle figure of the invention.

Fig. 3 be the present invention implement when by three side short circuit of transformer when the first operating diagram.

Fig. 4 be the present invention implement when by three side short circuit of transformer when the second operating diagram

Specific embodiment

It is as shown in Figure 1 the flow chart of the inventive method：This intelligent substation transformer current that the present invention is provided is returned The detection method on road, comprises the following steps：

S1. the protection device to transformer to be detected is configured, and three sides of transformer to be detected are carried out into short circuit (such as Shown in Fig. 3 and Fig. 4), while calculating an impedance value of the side of transformer three under this kind of state；

Connect, it is necessary to the mode of connection of three sides in protection device is all revised as into Y/Y/Y when the setting of protection device is carried out Line mode；Three side magnitudes of voltage of protection device are revised as same magnitude of voltage；By each side Current Mutual Inductance of transformer in protection device The actual current mutual inductor ratio value of the side of change ratio transformer three of device is configured；

S2. minimum side is used as Current injection points in the impedance value that selecting step S1 is calculated, and utilizes Line is spaced the both sides three-phase shortcircuit ground connection of remaining non-Current injection points；

S3. in the decanting point side of transformer to be detected, Injection Current and split-phase are separately injected into electric current to three-phase simultaneously, while obtaining Take the running parameter of transformer primary side to be detected, secondary side and auxiliary equipment during Injection Current；

In concrete operations, the value of Injection Current needs according to the once impedance in up-flow loop and once rises the appearance of flow device Amount is calculated；By substantial amounts of field test, it is found that after injected value of current will ensure injection transformer, the once electricity of transformer Stream is more than 100A, so as to the value and current waveform figure that show secondary current that the secondary device of transformer can be stablized；

And after Injection Current, obtaining the running parameter of transformer then includes that transformer to be detected is once during Injection Current The running parameter of side, secondary side and auxiliary equipment, specially obtains the aobvious of protection equipment for transformer primary current and secondary current Indicating value, protection equipment for transformer difference stream show value, the electric current show value of other secondary devices, line segregation secondary device are once The current value of electric current and each standby winding of side current transformer of secondary current show value, transformer；

S4. the running parameter for being obtained according to step S3, the property in transformer current loop to be detected is judged according to judgment principle Energy；The performance in transformer current loop to be detected is judged according to following rule specially：

The detected rule of current loop under the monophase current injection way of table 1

The detected rule of current loop under the three-phase current injection way of table 2

Theoretical foundation of the invention is：By the direct short circuit in the side of transformer three, from the side input current that impedance value is minimum, so It is grounded simultaneously in circuit outlet by mother in other both sides afterwards, it is possible to use reference interval releases the size of both sides shunting, According to kirchhoff node current equilibrium theorem I1=I2+I3；The poor stream of transformer should be zero, simultaneously because inside transformer Impedance opposite outer short circuit loop is much bigger, therefore I1 ", I2 " and I3 ' will be very small；If in experiments it is found that I1 ", I2 " and I3 ' electric currents are larger or inside transformer shunting is larger, then inside transformer winding there may be in sleeve pipe outgoing line side near-end The alternate direct short-circuit in portion or the phenomenon of relatively direct short-circuit.

Claims (7)

1. a kind of detection method in intelligent substation transformer current loop, comprises the following steps：

S1. the protection device to transformer to be detected is configured, and three sides of transformer to be detected are carried out into short circuit, while meter Calculate an impedance value of the side of transformer three under this kind of state；

S2. minimum side is used as between Current injection points, and utilization outlet in the impedance value that selecting step S1 is calculated It is grounded every by the both sides three-phase shortcircuit of remaining non-Current injection points；

S3. in the decanting point side of transformer to be detected, Injection Current and split-phase are separately injected into electric current to three-phase simultaneously, while obtaining note Enter the running parameter of transformer primary side to be detected, secondary side and auxiliary equipment during electric current；

S4. the running parameter for being obtained according to step S3, the performance in transformer current loop to be detected is judged according to judgment principle.

2. the detection method in intelligent substation transformer current loop according to claim 1, it is characterised in that step S1 The described protection device to transformer to be detected is configured, and specially all repaiies the mode of connection of three sides in protection device It is changed to the Y/Y/Y modes of connection；Three side magnitudes of voltage of protection device are revised as same magnitude of voltage；Transformer in protection device is each The actual current mutual inductor ratio value of the side of change ratio transformer three of side current transformer is configured.

3. the detection method in intelligent substation transformer current loop according to claim 1, it is characterised in that step S3 Described to carry out electric current injection in decanting point side, the value of described Injection Current is according to the once impedance in up-flow loop and once The calculation of capacity for rising flow device is obtained.

4. the detection method in intelligent substation transformer current loop according to claim 2, it is characterised in that step S3 Described to carry out electric current injection in decanting point side, the value of described Injection Current is according to the once impedance in up-flow loop and once The calculation of capacity for rising flow device is obtained.

5. the detection method in the intelligent substation transformer current loop according to claim 3 or 4, it is characterised in that described Injected value of current to ensure injection transformer after, the primary current of transformer is more than 100A, so as to the secondary device of transformer The value and current waveform figure that show secondary current that can stablize.

6. according to the detection method in the described intelligent substation transformer current loop of one of Claims 1 to 4, it is characterised in that The running parameter of transformer primary side to be detected, secondary side and auxiliary equipment when obtaining Injection Current described in step S3, specifically For obtain the show value of protection equipment for transformer primary current and secondary current, protection equipment for transformer difference stream show value, other The electric current show value of secondary device, the primary current of line segregation secondary device and secondary current show value, and transformer are each The current value of the standby winding of side current transformer.

7. according to the detection method in the described intelligent substation transformer current loop of one of Claims 1 to 4, it is characterised in that The performance for judging transformer current loop to be detected described in step S4, specially according to following rule to transformer to be detected electricity The performance for flowing back to road is judged：

The detected rule of current loop under the monophase current injection way of table 1

The detected rule of current loop under the three-phase current injection way of table 2