Adaptive control of protective-relay-testing inverter

An inverter designed for protective relay testing (PRT) purpose is modeled and analyzed in frequency domain, which is named as PRT inverter. By introducing the concepts of ldquobiased on-timerdquo and ldquotime-voltage transfer coefficientrdquo, a modified model is proposed, which realizes the linear transition from duty cycle to output voltage and breaks the frequency limitation of the linearized models. Quasi-PID controller that is able to eliminate the inherent tracking error of the PI controller was assigned to control the modified model. To deal with the impacts of parameters drifting on the controller, a single neuron adaptive quasi-PID controller based on perceptron supervised Hebb learning rule (PSHLR) is put forward, which ameliorates the control performance excellently and makes the strategy fulfill the accuracy requirements of PRT, especially electrical fault waveform regeneration (EFWR).