Engineering Application Research And Parameter Setting Of 220kV Double-circuit Fixed Series Compensation Device

This paper takes the 220 k V series compensation project of somewhere as the research background.The 60% high compensation fixed series compensation is the first in China.Therefore,its overvoltage protection strategy,string compensation original parameter design and electromagnetic transient characteristic test Both have important research implications.By studying the principle and technical scheme of the series compensation device,the MOV-parallel gap combination protection is determined as the main protection of the series compensation station.On this basis,the overvoltage protection parameters of the series compensation component are simulated and calculated.The field test results of the operating overvoltage and manual single phase ground fault test in the middle verify the correctness of the parameter setting of the series compensation component.Firstly,the technical principle and technical scheme of the series compensation device are deeply studied.The applicability of different overvoltage protection strategies is analyzed.The MOV-parallel gap combination protection is selected as the main protection mode of the series compensation station,and the out-of-zone and zone are described in detail.Performance requirements for series-compensated protection systems under internal,single-phase and multi-phase faults are demonstrated.Besides,the control strategies for MOV,spark gap,and bypass breakers during fault conditions are proposed.On the basis of over-voltage protection strategy,the parameters such as MOV,damping circuit,bypass switch,spark gap energy consumption level under different working conditions and over-voltage protection level are simulated.Through the electromagnetic transient simulation software EMTPE,the system equivalent calculation model is established,and various series compensation components under various working conditions,fault locations(intra-zone,out-of-zone),fault mode(single-phase grounding,multi-phase grounding)are simulated.The maximum discharge current and maximum energy consumption determine the relevant technical parameters of the MOV,the damping circuit,the overvoltage protection level of the bypass switch,and the energy consumption level.At the same time,the spark gap parameters are calculated by the spark gap tolerance test,trigger test,etc.,and the minimum voltage level that can be broken down with the trigger signal is determined.The overvoltage parameters calculated in this chapter can be used as the basis for component selection in series compensation engineering.In the process of debugging the series compensation station system,tests such as air charging and opening and closing are carried out to verify the protection level of the series compensation components in response to the operating overvoltage.Taking the A?B line as an example,in another working mode of inputting and exiting the platform of the A?C line,the line compensation device is separately charged at both ends of the line of the A?B line,and is separately made at both ends of the line.The single-phase split-and-close operation of the switch analyzes the overvoltage condition on both sides of the platform,the line side,and the breaker break through the fault recording.The test results show that the maximum value of the overvoltage of the series compensation platform in the charging test is small,and the operating overvoltage in the split no-load line test is within the corresponding allowable range.In the single-phase instantaneous short-circuit grounding test on the line side of A series,the statistical analysis method is used first,when the single-phase grounding short circuit occurs on the A side line,the short-circuit current,MOV current and energy absorption,and the voltage of the series-compensated capacitor are The discharge gap current condition was subjected to 202 statistical short-circuit simulation calculations,and the parameters of the series-compensated components were checked.Secondly,the artificial short-circuit grounding test is carried out on the line side of the series compensation near the line,and the faulty waveform is analyzed to analyze the action of the spark gap,the damping circuit,the MOV action behavior and the absorbed energy.The test results show that the series compensation component has withstood the single The short-circuit current and over-voltage surge generated by the phase-to-earth fault,and the over-voltage parameters meet the system operation requirements.