An Observer-Based Optimal Voltage Control Scheme for Three-Phase Three Level UPS Systems

Abstract

Uninterrupted Power Supply (UPS) system supplies required power in case of utility power failures. UPS system has got significant importance in the field of industrial electronics due to increase in technology of power electronic devices.This paper proposes a Neutral Point Clamped (NPC) inverter with simple Sinusoidal Pulse Width Modulation Technique (SPWM), which is well suitable for inverter control. The proposed system would be subjected to fast transient response, small steady state error and low harmonic distortion test under different load conditions. Finally, the comparative results for the proposed scheme and the observer based voltage control scheme are presented to show that the proposed scheme achieves better performance. The results are tested and verified through MATLAB/Simulink. The proposed methodology reduces the total cost, complexity and THD.