Keywords: uninterrupted power supply, UPS inverters, regenerative snubber, soft-switching inverters, PWM inverters, energy recovery, power electronics, total harmonic distortion, sinusoidal PWM, pulse width modulation, SPWM, multiple pulse width modulation, MPWM, simulation
Regenerative snubber for UPS inverter
An uninterrupted power supply (UPS) is used to provide electrical power to a load during an emergency situation in which the main utility power is not available. UPS topologies are well known. The inverter plays the most important role as an element in the UPS system. Usually, pulse width modulated inverters with voltage control and waveform shaping are used in UPS. This paper proposes an inverter with regenerative snubber for high frequency UPS applications, because regenerative snubber is superior to dissipative snubber due to the reduced losses and increased reliability. The Simulink model for a single phase UPS system with regenerative snubber is developed and the same is used for simulation studies. Also, FFT analysis has been done to study the total harmonic distortion (THD) of the inverter output using sinusoidal pulse width modulation (SPWM) and multiple pulse width modulation (MPWM) techniques. The measured performance proves that the efficiency of the developed UPS is improved by employing energy recovery snubber. The experimental results are compared with simulation results.