Simulation and Study on Cascaded Nineteen-Level Dynamic Voltage Restorer

Cascaded multi-level dynamic voltage restorer (DVR) is considered to be the most economical and effective compensation device to restrain the problem of voltage sag. This paper studies a cascaded nineteen-level DVR on its operating principle, topology, sinusoidal pulse width modulation (SPWM) strategy based on carrier phase shifting technology, and Control algorithm. The simulation result shows that the output voltage of cascaded nineteen-level DVR has less harmonic content and the waveform of output voltage is good, it also increases the switching frequency of inverter.