Marçal, RuiRodrigues, RicardoFortunato, CarlosMartins, L. SousaPires, V. Fernão2013-05-282013-05-282006http://hdl.handle.net/10400.26/4300This paper describes a power amplifier system for testing of distance relay operating characteristic. This power amplifier is based on two three phase inverters with a neutral wire. The output power currents and voltages are controlled by a sliding mode controller. A developed matlab/simulink digital simulator generates the test signals. This test signals are converted in current and voltage references using a microcontroller to connect the digital simulator to the power converter amplifier. Experimental results from a laboratory prototype are presented and discussed.engPower amplifier systemDigital relayDigital simulatorconference object