Design And Realization Of Power Amplification Subsystem For Relay Protection Test

Since relay protection equipment is very important to ensure reliable operation of thepower system, its reliability and stability are particularly important. In practicalapplication, we must carry on the overhaul regularly, so as to ensure the reliable and stableoperation of the entire power system. However, because the large volume, low accuracyand poor thermal stability lie in the present domestic relay protection test system whichcauses its inconvenient carrying and vulnerability, it is very important to improve theperformance and reduce the volume of the test system.Power amplification subsystem, as the final output of relay protection test system,largely determines the performance of the entire test system. Through the analysis of thecharacteristics of the current domestic and foreign products, this paper designs asymmetrical power amplification subsystem with switching power supply module whichcan reduce the volume and improve the stability of the system.According to the characteristics of the switching power supply, this paper designs thepower supply circuit of the power amplification subsystem and completes the designs ofthe front filter, automatic rectification and DC-DC module; Combined with the Pspicesimulation tools, this paper designs the voltage amplification and current amplificationmodule of the power amplification subsystem which includes the adjustment, input stage,intermediate stage, power output stage, protection circuit and so on. In order to meet theneed of the switch signal test, the system also provides eight digital inputs circuit and fourdigital outputs circuit.Finally, after adjusting the system parameters based on the previous testing data, allthe system performances meet the actual overhaul need through testing.