The method that transformer air-cooled full cut-off is judged using transformer cooler load current
Technical field
The present invention relates to a kind of method that employing transformer cooler load current judges transformer air-cooled full cut-off.
Background technology
To ensure that large-scale power transformer works at the allowed temperature, large-scale power transformer is configured with forced oil-circulation
Air-cooled (abbreviation forced-oil-air cooling).In the case where load and environment temperature are constant, forced-oil-air cooling Transformer once occurs
" cooler full cut-off ", oil temperature can steeply rise, and very big threat will be caused to inside transformer insulating materials, be likely to result in insulation old
Change, puncture.If processing not in time or dealing with improperly, transformer damage and more large power system accident can be caused, thus it is large-scale strong
Compel oil circulating air cooling transformer and configure the protection of cooler full cut-off.
Its protection philosophy is by the contactor auxiliary contact position of air-cooled electric power incoming line and all fan power auxiliary contact positions
Put parallel connection to be judged, the determination methods are primarily present problems with.1st, judge that contactor used is installed in Outdoor Terminal Case
In, work under bad environment easily causes contactor loose contact, easily causes transformer air-cooled full cut-off relay fail.2nd, contactor
Install near transformer, because vibrations are big in large-scale power transformer work, contactor and relay are auxiliary after being given a shock
Adjuvant grafting point easily by vibrations closure, causes transformer air-cooled full cut-off false protection.3rd, after transformer air-cooled power supply produces fluctuation,
Contactor produces therewith division, and mistake sends out full cut-off signal air-cooled.
The content of the invention
It is an object of the invention to provide a kind of employing transformer cooler load current judges the side of transformer air-cooled full cut-off
Method, can accurately judge transformer air-cooled full cut-off, so as to be prevented effectively from the mistake that the air-cooled full cut-off protection of large-scale power transformer is present
Dynamic and tripping.
A kind of method that employing transformer cooler load current judges transformer air-cooled full cut-off, it is particular in that,
Comprise the steps:
(1) transformer air-cooled electric power incoming line electric current is gathered, gathers the operating current of every group of blower fan and oil pump, particular by
The device of installing measurement electric current, will be gathered by the device on transformer air-cooled electric power incoming line, every group of blower fan and oil pump loop
To current value input transformer wind cooling controller in;
(2) when the transformer air-cooled electric power incoming line current value for collecting and each group blower fan and operation of oil pump current value sum phase
Deng when, air cooling control device of transformer judges transformer air-cooled normal work;When the transformer air-cooled electric power incoming line electricity for collecting
Flow valuve vanishing, and each group blower fan and the also vanishing simultaneously of operation of oil pump current value, then air cooling control device of transformer judgement
There is full cut-off in transformer air-cooled.
The inventive method be judging transformer air-cooled power supply in carry out air-cooled full cut-off judgement by way of analog quantity, solve
Using the single various disadvantages for judging air-cooled full cut-off of contactor, specifically by transformer air-cooled electric power incoming line electric current and each group wind
Machine and operation of oil pump electric current are acquired, under normal operation, air-cooled inlet wire current size and each group working fan and oil pump
Operating current is in the same size.Under the operating mode of air-cooled full cut-off, transformer air-cooled inlet wire current vanishing, each group working fan and oil
The also vanishing simultaneously of pump work electric current, by electric current from having to without this change procedure, can be accurately judged to transformer air-cooled
Whether full cut-off really there occurs.
Description of the drawings
Accompanying drawing 1 is current collector installation site of the present invention and transformer air-cooled control principle drawing;
The fundamental diagram of the present invention of accompanying drawing 2.
Specific embodiment
The invention provides one kind judges transformer air-cooled full cut-off guard method using transformer cooler load current, wrap
Include following steps:
(1) electric current, (transformer air-cooled) the every group of blower fan for gathering transformer air-cooled electric power incoming line is every with (transformer air-cooled)
The electric current of group oil pump.The cold electric power incoming line of the transportation work style of large-scale power transformer 2 for running on scene is selected behind wherein 1 tunnel by contactor
Supply the multigroup blower fan and oil pump for cooling down transformer.Air-cooled electric power incoming line and every group of blower fan are adopted with the operating current of oil pump
After collection in the intelligent air-cooled control device of input transformer.
(2) electric current of transformer air-cooled electric power incoming line and the electric current of every group of blower fan and oil pump by gathering enters line transformer
The judgement of air-cooled full cut-off.
Cause transformer air-cooled full cut-off misoperation to prevent current sample from exception occur, using transformer air-cooled inlet wire current
Verified mutually with the electric current of every group of working fan and oil pump, specifically in normal course of operation, air-cooled inlet wire current with
The electric current sum of all each group blower fans and oil pump is equal, in two electric currents simultaneously all from having to nothing, and variable condition always when, i.e.,
Air-cooled full cut-off is can determine whether, the corresponding signal of full cut-off is sent immediately.
Embodiment 1:
By taking the air-cooled full cut-off protection of certain substation transformer as an example as shown in Figure 1, the air-cooled full cut-off of conventional transformer is using figure
In, contactor K1, contactor K2, the normally closed contact of contactor are judged, i.e., when the cold power supply of 2 transportation work styles is lost, contactor K1,
Contactor K2, contactor can lose excitation due to non-transformer, so normally closed contact closure, transformer air-cooled full cut-off protection act.
The method is primarily present problems with
1st, judge that contactor used is installed in Outdoor Terminal Case, work under bad environment easily causes contactor to contact
It is bad, transformer air-cooled full cut-off relay fail is easily caused, cause transformer to damage.
2nd, contactor is installed near transformer, because vibrations are big in large-scale power transformer work, contactor and relay
After being given a shock, auxiliary contact easily by vibrations closure, causes transformer air-cooled full cut-off false protection to device, has a strong impact on power supply
Reliability.
3rd, after transformer air-cooled power supply produces fluctuation, contactor produces therewith division, and mistake sends out full cut-off signal air-cooled, adjoint
Produce transformer air-cooled full cut-off protection misoperation.
For the problems referred to above, after the inventive method, continue to be analyzed by taking the protection of above-mentioned transformer air-cooled full cut-off as an example.Such as
Shown in accompanying drawing 1,2, the inventive method is adopted by installing electric current at transformer air-cooled electric power incoming line and every group of blower fan oil pump power supply
Acquisition means, so as to obtain transformer air-cooled incoming power electric current (LHA, LHB) and every group of blower fan and oil pump electric current (LH1,
LH11, LH2, LH21, LH3, LH31, LHN, LHN1) value, by the intelligent air-cooled control device of value input transformer, passing through
Judge transformer air-cooled incoming power electric current from having to nothing and every group of blower fan oil pump current value sum from there is the mode to nothing to sentence
Read the accident that transformer air-cooled occurs full cut-off.
Specifically as shown in figure 1, contactor K1, contactor K2 are respectively the road inlet wire contactor of transformer air-cooled power supply 2;Adopt
Storage LHA, collector LHB are respectively the tunnel inlet wire current collector of transformer air-cooled power supply 2;Collector LH1, collector LH11 point
It is not the 1st group of oil pump fan power operating current collector;Collector LH2, collector LH21 are the 2nd group of oil pump and blower fan electricity
Source operating current collector;Collector LH3, collector LH31 are the 3rd group of oil pump and fan power operating current collector;Collection
Device LHN, collector LHN1 are N groups oil pump and fan power operating current collector;Contactor K11, contactor K12, contact
Device K13, contactor K1N are respectively first group, second group, the 3rd group, N group oil pump fan power contactors.Judge wind at present
The condition of cold full cut-off be contactor K1, contactor K2 normally closed contacts closure or contactor K11, contactor K12, contactor K13,
Contactor K1N normally closed contacts are closed, and are judged as transformer air-cooled full cut-off.
As shown in Fig. 2 contactor K1, contactor K2 are respectively the road inlet wire contactor of transformer air-cooled power supply 2;Collector
LHA, collector LHB are respectively the tunnel inlet wire current collector of transformer air-cooled power supply 2;Collector LH1, collector LH11 are respectively
For the 1st group of oil pump fan power operating current collector;Collector LH2, collector LH21 are the 2nd group of oil pump and fan power work
Make current collector;Collector LH3, collector LH31 are the 3rd group of oil pump and fan power operating current collector;Collector
LHN, collector LHN1 are N groups oil pump and fan power operating current collector.
To guarantee that current collecting device breaks down erroneous judgement, introducing transformer air-cooled power supply carries out contactor normally closed contact work
For additional criteria.The method is simple and reliable, can prevent malfunction and the generation of tripping accident caused due to transformer air-cooled full cut-off.