A new fast peak current controller for transient voltage faults for power converters

Power converters are the basic unit for transient voltage fault ride through capability for most renewable distributed generators. When a transient fault happens, the grid voltage will drop suddenly, and probably, will also suffer a phase-jump event also. State of the art voltage fault control techniques regulate the current injected during the grid fault. However, the beginning of the fault could be too fast for the inner currents control loops of the inverter, and transient over-current would be expected. In order to avoid excessive peak current of methods presented in the literature, a new fast peak current control technique is proposed. Controlling the peak current magnitude avoids undesirable disconnection of the distributed generator in a fault state and improves the life-expectancy of the converter. Experimental and simulation tests with high power converters provide detailed behaviour of the method with excellent results.