Microprocessor-based modified discrete integral variable-structure controlfor UPS

This paper presents a digital signal processor microprocessor-based high-pe rformance uninterruptible power system (UPS). It also modifies the integral variable-structure control (IVSC) approach to be more suitable for the UPS , which is tracking a sinusoidal ac voltage with specified frequency and am plitude. Since the implementation of the control laws has tended to the dig ital microprocessor, the paper extends the modified IVSC to the discrete ti me domain, Procedures are developed for determining the control function, t he switching plane, and the integral control gain, so that the system has d esired properties. Simulation and experimental results show that the propos ed scheme can supply a high-quality voltage power source in the presence of load disturbance and parameter variation.