Power calibrator using switched mode voltage source

The paper is focused on a sophisticated switched mode power supply with a pure sinusoidal output voltage waveform with frequency (40-65 Hz) and voltage range (30-500 V). In order to cope with stringent voltage (10.2%) and distortion constraint (THD<0.7%) in a modern calibration system, traditional inverter design with an output LC filter is upgraded with a feedback-feedforward control principle. The paper presents the voltage source topology, analyzes its steady-state response and gives its comprehensive evaluation. Using a simple sensor that is capable to detect a small voltage asymmetry at the presence of a high AC component (500 VRMS), the parasitic DC component is limited below 5 mV. Experimental results demonstrate exceptional voltage accuracy (<0.2%) and low total harmonic distortion (THD).