CN104345223A - 6KV voltage transformer and secondary loop power supply monitoring method thereof - Google Patents
6KV voltage transformer and secondary loop power supply monitoring method thereof Download PDFInfo
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- CN104345223A CN104345223A CN201310322027.8A CN201310322027A CN104345223A CN 104345223 A CN104345223 A CN 104345223A CN 201310322027 A CN201310322027 A CN 201310322027A CN 104345223 A CN104345223 A CN 104345223A
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Abstract
The invention belongs to the technical field of an electrical test, and particularly relates to a 6KV voltage transformer and a secondary loop power supply monitoring method thereof. The method successively comprises the following steps that one PT (8) is respectively connected on a 6KV safe I-section bus (5) and 380V safe I-section and II-section buses, voltage of the three PTs (8) is monitored respectively, and when abnormally low voltage is not displayed by the three PTs (8), power supply of the 6KV safe I-section bus (5) is normal through judgment; when abnormally low voltage is displayed by any one of the PTs (8), the risk of power loss is judged, a number one EDG (2) is started, alarm is issued and processing is performed; and when abnormally low voltage is displayed by any two or all the PTs (8), power loss is judged, an external power supply (1) connected with the PTs (8) is cut off, the number one EDG (2) is started and alarm is issued. The beneficial effects of the technical scheme are that system reliability can be greatly enhanced according to logic rule judgment of the aforementioned method.
Description
Technical field
The invention belongs to electrical testing technical field, be specifically related to a kind of 6KV voltage transformer (VT) and secondary circuit thereof and power monitoring method.
Background technology
Up for Qinshan Nuclear Power Plant 300,000 kilowatts of nuclear power generating sets be China's Mainland First paddle one's own canoe strength research, design, construction and management nuclear power station, research and design works in and starts the seventies in last century.Wherein nuclear island 6KV nuclear safe level Medium voltage power supply system adopts binary channels to power, be respectively 6KV safe I, II section bus, respectively corresponding physically-isolated A, channel B, opening heap, Power operation, shutdown, to reload and under the operating mode such as to meet an urgent need, for the security system of nuclear island and visual plant provide power supply.Above-mentioned two sections of buses are also configured with three diesel emergency generating set (hereinafter referred to as " EDG ") as emergency power pack.No. 1 EDG is as A channel emergency power pack; No. 3 EDG are as channel B emergency power pack; No. 2 EDG, as the substitute of No. 1 EDG and No. 3 EDG, both can replace No. 1 EDG to meet an urgent need at A channel, No. 3 EDG can be replaced again to meet an urgent need in channel B.At A channel, 6KV safe I section bus by step-down transformer to 380V safe I, II section bussed supply; In channel B, 6KV safe II section bus by step-down transformer to 380V safety III, IV section of bussed supply.
In prior art, every bar 6KV and 380V bus are connected to a voltage transformer (VT) (hereinafter referred to as " PT ") for detecting busbar voltage, to judge that whether bussed supply is normal.When the PT that 6KV safe I, II section bus connects shows electric voltage exception, be 6KV safe I, II section bussed supply by corresponding for startup EDG; When the PT that certain section of 380V essential supplies bus connects shows electric voltage exception, power adopting another section of 380V essential supplies bus of same passage.
The PT that existing 6KV safe I, II section bus adopts is pressed by three single-phase potential transformers
connection forms, and no-load voltage ratio is
high-pressure side is often connected in series 0.5A high-tension fuse mutually, neutral-point solid ground; Low-pressure side by Y shape winding and
shape winding form, the B phase ground connection of Y shape winding, neutral point through breakdown fuse ground connection,
the direct ground connection in shape winding one end.In use, the two-phase in the three-phase of PT judges 6KV safe I, II section bus dead electricity when there is abnormal low-voltage.But, in actual motion repeatedly due to external factor cause voltage transformer (VT) resonance thus fusing high-tension fuse, the two-phase of a PT is caused to occur abnormal low-voltage, send out bus dead electricity signal when safe I, II section bus normal power supply of 6KV by mistake, thus cause extremely serious run case.
Summary of the invention
The present invention is directed to prior art and easily cause voltage transformer (VT) resonance fusing high-tension fuse, thus cause the technical matters by mistake sending out bus dead electricity signal, provide a kind of new 6KV voltage transformer (VT) and secondary circuit thereof to power monitoring method, by introducing the monitoring result of 380V bus PT, form the compound detection of three PT, thus judge 6KV bus whether dead electricity, improve monitoring accuracy.
Technical scheme of the present invention is as described below:
A kind of 6KV essential supplies bus voltage transformer (VT) and secondary circuit thereof are powered monitoring method, in turn include the following steps:
Step 1,6KV safe I section bus connects a PT;
Step 2, respectively connect a PT at 380V safe I, II section bus;
The voltage of step 3, respectively monitoring three PT, carries out Logic judgment and operation according to the following rules by monitoring result:
3.1 work as 3 PT does not all show abnormal low-voltage, judges to break as 6KV safe I section bussed supply is normal;
3.2, when there being any 1 abnormal low-voltage of display in 3 PT, being namely judged as that 6KV safe I section bus has dead electricity risk, not starting No. 1 EDG, but alert row relax of going forward side by side of transmitting messages;
3.3, when having any 2 or the abnormal low-voltage of whole display in 3 PT, are namely judged as 6KV safe I section bus dead electricity, cut off the external power that it connects, start No. 1 EDG and give the alarm;
Step 4, judged result is fed back to reactor protection system (hereinafter referred to as " RPS ").
Further, a non-linear harmonic elimination resistance is connected in series at PT high-pressure side neutral point with increasing between ground.The non-linear harmonic elimination resistance of described serial connection is carbofrax material, can limit primary current, fuse is not easily fused when normal operation and single-phase earthing.
Further, the 0.5A high-tension fuse that the high-pressure side of PT is often connected in series mutually adopts the high voltage fuse of band fusing flip flop equipment.During such fuse failure, PT locking dead electricity signal, can improve accuracy and the reliability of system.
In order to improve test accuracy, the basis of above-mentioned steps increasing two-stage under-voltage protection and arranges, above-mentioned steps 3 is replaced with following steps:
The voltage of step 3, respectively monitoring three PT, carries out monitoring result judging and operating according to the following rules:
3.1 work as 3 PT does not all show abnormal low-voltage, judges to break as 6KV safe I section bussed supply is normal;
3.2, when there being any 1 abnormal low-voltage of display in 3 PT, being namely judged as that 6KV essential supplies bus has dead electricity risk, not starting No. 1 EDG, but alert row relax of going forward side by side of transmitting messages;
3.3 work as whole in 3 PT or have any 2 display voltages all lower than 70% of ratings,
3.3.1 to continue lower than 70% through time delay in 0.5 second, signal to No. 1 EDG and start;
3.3.2 continue lower than 70% through time delay in 4 seconds, send out dead electricity signal to reactor protection system, RPS sends out immediately and sweeps load signal, cuts off the external power that it connects;
3.3.3 when No. 1 EDG starts successfully for after 6KV essential supplies bus powers, PT has sent out electric signal and has started a band program of carrying immediately to RPS, RPS and reload by the equipment cleared away;
3.4 work as whole in 3 PT or have any 2 display voltages all lower than 90% of ratings,
3.4.1 continue lower than 90% through time delay in 60.5 seconds, repeat step 3.3.1;
3.4.2 continue lower than 90% through time delay in 64 seconds, repeat step 3.3.2;
3.4.3 repeat step 3.3.3;
The situation of step 3.3 is defined as dead electricity by design, and the situation of step 3.4 is defined as brown, and namely voltage is defective.
The beneficial effect of technical solution of the present invention is: the fiduciary level probability that during employing prior art, 6KV safe I, II section bussed supply detects is 0.99.And adopting the technical scheme of the present embodiment, logic rules according to the method described above judge, greatly can improve system dependability.
Accompanying drawing explanation
Fig. 1 is 6KV voltage transformer (VT) and secondary circuit schematic diagram thereof in the present invention.
In figure, 1-external power, 2-1 EDG, 3-2 EDG, the safe I section of 4-3 EDG, 5-6KV, the safe I section of 6-380V, the safe II section of 7-380V, 8-PT.
Embodiment
Below in conjunction with drawings and Examples to a kind of 6KV voltage transformer (VT) of the present invention and secondary circuit thereof power monitoring method do explain explanation.Because 6KV safe I, II section bus adopts identical power supply monitoring method, be only described in detail for 6KV safe I section bus therefore, the method is equally applicable to 6KV safe II section bus.Applicant believes that those of ordinary skill in the art can realize 6KV safe II section bussed supply by the following explanation to 6KV safe I section bussed supply monitoring method completely and detect.
For improving the reliability of system, the product that the existing equipment that the present embodiment adopts is identified preferably through core level, to solve the weak link and problem that find in probabilistic safety analysis.On home market, existing Duo Jia switchgear plant has carried out the qualification of core level to its product, and seismic spectrum selected during qualification can cover the most domestic nuclear power plant site comprising Up for Qinshan Nuclear Power Plant.
Embodiment 1
Technical scheme of the present invention is as described below:
A kind of 6KV essential supplies bus voltage transformer (VT) and secondary circuit thereof are powered monitoring method, in turn include the following steps:
Step 1,6KV safe I section bus 5 connects a PT8;
Step 2, respectively connect a PT8 at 380V safe I, II section bus;
The voltage of step 3, respectively monitoring three PT8, carries out Logic judgment and operation according to the following rules by monitoring result:
3.1 work as 3 PT8 does not all show abnormal low-voltage, judges to break as 6KV safe I section bus 5 is powered normally;
3.2, when there being any 1 abnormal low-voltage of display in 3 PT8, being namely judged as that 6KV safe I section bus 5 has dead electricity risk, not starting No. 1 EDG, but alert row relax of going forward side by side of transmitting messages;
3.3, when having any 2 or the abnormal low-voltage of whole display in 3 PT8, are namely judged as 6KV safe I section bus 5 dead electricity, cut off the external power 1 that it connects, start No. 1 EDG2 and give the alarm;
Step 4, judged result is fed back to reactor protection system (hereinafter referred to as " RPS ").
In the present embodiment, the 0.5A high-tension fuse that the high-pressure side of PT8 is often connected in series mutually adopts the high voltage fuse being with fusing flip flop equipment.During such fuse failure, PT8 locking dead electricity signal, can improve accuracy and the reliability of system.
PT8 can select with prior art in by three single-phase potential transformers by
the identical equipment of PT8 of connection composition or other can meet the existing equipment of technical solution of the present invention urban d evelopment.Further, can PT8 the connected mode of three single-phase potential transformers be improved.A non-linear harmonic elimination resistance is connected in series with increasing between ground at PT8 high-pressure side neutral point.The non-linear harmonic elimination resistance of described serial connection is carbofrax material, can limit primary current, fuse is not easily fused when normal operation and single-phase earthing.
The existing 6KV of Qinshan nuclear power plant safe I, II section bus and load equipment thereof, recent two decades since nineteen ninety puts into operation, there is not large accident in overall operation, but because of bus PT fault, and PT design is unreasonable, there occurs repeatedly run case.Adopt the technical scheme of the present embodiment, logic rules according to the method described above judge, the fiduciary level probability that can realize after " three get two " improves greatly, can realize by fiduciary level from " hundred have a mistake " before " three get two " to " three get two " after " perfectly safe ", embody technical solution of the present invention and there is outstanding substantive distinguishing features and technical progress significantly really.According to technique scheme, Up for Qinshan Nuclear Power Plant is carried out design and equipment buying and is manufactured after State Bureau of Nuclear Safety (NNSA) approval, and during 2009 the 11st time refueling outage, implement 6KV safe II section switch cubicle Overall Reconstruction, during 2010 the 12nd time refueling outage, implement 6KV safe I section switch cubicle Overall Reconstruction.Retrofit work implements under the supervision of NNSA, carried out comprehensive checking through perfect debugging and test to the function of reforming equipment and performance, confirms all to meet designing requirement.Technical scheme of the present invention embodies vital role and huge economic value in China's npp safety operational process.
Embodiment 2
In order to improve test accuracy, the basis of embodiment 1 increasing two-stage under-voltage protection and arranges.
The technical scheme that the present embodiment adopts in turn includes the following steps:
Step 1,6KV safe I section bus 5 connects a PT8;
Step 2, connect a PT8 respectively at 380V safe I, II section bus;
The voltage of step 3, respectively monitoring three PT8, carries out monitoring result judging and operating according to the following rules:
3.1 work as 3 PT8 does not all show abnormal low-voltage, judges to break as 6KV safe I section bus 5 is powered normally;
3.2, when there being any 1 abnormal low-voltage of display in 3 PT8, being namely judged as that 6KV essential supplies bus 5 has dead electricity risk, not starting No. 1 EDG2, but alert row relax of going forward side by side of transmitting messages;
3.3 work as whole in 3 PT8 or have any 2 display voltages all lower than 70% of ratings,
3.3.1 to continue lower than 70% through time delay in 0.5 second, signal to No. 1 EDG2 and start;
3.3.2 continue lower than 70% through time delay in 4 seconds, send out dead electricity signal to reactor protection system, RPS sends out immediately and sweeps load signal, cuts off the external power 1 that it connects;
3.3.3 when No. 1 EDG start 2 be successfully the power supply of 6KV safe I section bus 5 after, PT8 has sent out electric signal and has started a band year program immediately to RPS, RPS and reload by the equipment cleared away;
3.4 work as whole in 3 PT8 or have any 2 display voltages all lower than 90% of ratings,
3.4.1 continue lower than 90% through time delay in 60.5 seconds, repeat step 3.3.1;
3.4.2 continue lower than 90% through time delay in 64 seconds, repeat step 3.3.2;
3.4.3 repeat step 3.3.3;
Step 4, judged result is fed back to reactor protection system.
The situation of step 3.3 is defined as dead electricity by design, and the situation of step 3.4 is defined as brown, and namely voltage is defective.
Obviously, those skilled in the art can carry out various change and modification to the present invention and not depart from the spirit and scope of the present invention.If these amendments and modification belong within the scope of the claims in the present invention and equivalent technologies thereof, then the present invention is also intended to comprise these change and modification.
Claims (5)
1. 6KV essential supplies bus voltage transformer (VT) and secondary circuit thereof are powered a monitoring method, in turn include the following steps:
Upper connection PT(8 of step 1,6KV safe I section bus (5));
Step 2, be respectively connected a PT the safe II section (7) of 380V safe I section (6) and 380V;
Step 3, respectively monitor three PT(8) voltage, monitoring result is carried out Logic judgment and operation according to the following rules:
Step 3.1 is as 3 PT(8) all do not show abnormal low-voltage, judge to break as 6KV safe I section bus (5) power supply is normal;
Step 3.2 is as 3 PT(8) in have any 1 abnormal low-voltage of display, be namely judged as that 6KV safe I section bus (5) has dead electricity risk, do not start No. 1 EDG(2), but alert row relax of going forward side by side of transmitting messages;
Step 3.3 is as 3 PT(8) in have any 2 or whole abnormal low-voltages of display, be namely judged as 6KV safe I section bus (5) dead electricity, cut off the external power (1) that it connects, start No. 1 EDG(2) and to give the alarm;
Step 4, judged result is fed back to reactor protection system.
2. as a kind of 6KV essential supplies bus voltage transformer (VT) in claim 1 and secondary circuit thereof are powered monitoring method, it is characterized in that: described step 3.3 adopts following rule judge monitoring result and operate:
3.3 as 3 PT(8) in all or have any 2 display voltages all lower than ratings 70% time, carry out following operation:
3.3.1 continue lower than 70% through time delay in 0.5 second, signal to No. 1 EDG(2) start;
3.3.2 continue lower than 70% through time delay in 4 seconds, send out dead electricity signal to reactor protection system, RPS sends out immediately and sweeps load signal, cuts off the external power (1) that it connects;
3.3.3 as No. 1 EDG(2) start successfully for after 6KV essential supplies bus powers, PT(8) send out and have electric signal to start a band program of carrying immediately to RPS, RPS to reload by the equipment cleared away;
3.4 as 3 PT(8) in all or have any 2 display voltages all lower than 90% of ratings,
3.4.1 continue lower than 90% through time delay in 60.5 seconds, repeat step 3.3.1;
3.4.2 continue lower than 90% through time delay in 64 seconds, repeat step 3.3.2;
3.4.3 repeat step 3.3.3.
3., as a kind of 6KV essential supplies bus voltage transformer (VT) in claim 1 or 2 and secondary circuit thereof are powered monitoring method, it is characterized in that: described PT(8) high-pressure side neutral point with increase a non-linear harmonic elimination resistance of connecting between ground.
4., as a kind of 6KV essential supplies bus voltage transformer (VT) in claim 3 and secondary circuit thereof are powered monitoring method, it is characterized in that: the non-linear harmonic elimination resistance of described serial connection is carbofrax material.
5., as a kind of 6KV essential supplies bus voltage transformer (VT) in claim 3 and secondary circuit thereof are powered monitoring method, it is characterized in that: described PT(8) the 0.5A high-tension fuse that is often connected in series mutually of high-pressure side adopt the high voltage fuse of band fusing flip flop equipment.
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