Uninterruptible power supply with fuzzy logic approach

A new control method for real time digital control of the single-phase PWM inverter for UPS applications is presented. An approach for combining the deadbeat control and the fuzzy logic compensator is proposed. Using the state variables measured at every sampling time, the controller calculates the inverter pulse width for the next sampling time. The fuzzy logic controller is used to compensate for the voltage drop due to nonlinear loads. The proposed control scheme is verified by simulations for nonlinear load conditions, sudden load changes, and system parameter variations. The control approach provides excellent transient response, low total harmonic distortion (THD) and robustness for parameter variation