Real-time digital simulation of power electronic apparatusinterfaced with digital controllers

摘要

This paper presents a new approach for the real-time digitalnsimulation of power electronic controllers in power systems. Digitalncontrollers for power electronic systems present a problem when testingnin real-time using a digital simulator due to the discrete nature ofntheir outputs which are not necessarily in synchronism with the timenstep of the simulator. The proposed algorithm combines the variablenstep-size numerical integration method with linear interpolation for thensynchronization of a real-time digital simulator and a digitalncontroller. It is shown that lack of such synchronization leads toninaccurate simulation results, specifically with regard to thenfundamental and harmonics of the voltage and current signals. Samplingntheory is used to model the interaction between a digital simulator andna digital controller. A pulse width modulated (PWM) voltage sourcenconverter (VSC) based reactive power compensator system is used as annillustrative example for the simulation