Resreach And Design Of400V/200kA Synthesis Test System

Aiming at the research and development of400V/200kA low synthetic circuit test system.Domestic and foreign application synthesis loop of high voltage breaker for breakingcapacity test has been quite mature. In recent years, low voltage breaker capacity increasesceaselessly, in low pressure power supply system which is becoming more and moreimportant, in order to ensure that the low voltage breaker at the site of the safe and reliableoperation, the research and development of carrying out low voltage circuit breakerinterrupting capacity of synthetic test system has high academic significance and practicalvalue.Synthetic circuit test system is the basic principle of which, low voltage and highcurrent source circuit will produce short circuit current to make the arc burn when thebreaker open, that is used to simulate the actual short-circuit current; high voltage sourcewith small power, which will generate high voltage is used to simulate the arc isextinguished when the transient recovery voltage (TRV) and in the proper time before arccurrent zero,as a result,which can help analyze the interrupting capacity of the lowvoltage breaker, the breaking capacity of the circuit breaker. According to thecharacteristics and requirements of low pressure synthetic circuit test, The paper developsand designs the voltage source circuit and the current source circuit about single-phasesynthesis test, and calculated the parameters; First, according to the national standard GB998-1982verify of low-voltage circuit breaker which provide breaking capacity testrequirements for low voltage circuit breaker, when the low-voltage circuit breaker open,the transient recovery voltage simulation is carried out, According to its waveform, thepaper analyses its characteristic; Secondly, according to the oscillation frequency andamplitude coefficient of the load circuit, using standard formulas for the design, with twoparameters to determine the voltage source circuit parameters and carrying on thesimulation analysis, the paper gets the peak value and frequency of the of TRV waveform,contrast analysis of the load circuit on the fracture generated TRV waveform and voltagesource circuit is provided by the TRV, which takes account of the circuit components,circuit parameters and the effect of error, at last,the paper draw the conclusion: voltagesource circuit provides TRV is consistent with the low pressure synthesis test requirements. According to procedures about the synthetic circuit test, paper design control systemwith a single chip microcomputer (PIC16F877) control center. The system mainlycomprises charging process automatic control about a voltage source and a current sourcecircuit, sampling the capacitor charging current and voltage about the voltage source andcurrent source loop, driving relay switch to make timing control, zero-crossing detection ofthe short circuit current, and the trigger control before0.2ms of zero point current. In studydesign, the author fully consider the every link of the system’s coordination, should ensurethat the synthetic test system of reliable operation and opening ability assessment for lowvoltage breaker.