A DSP-based variable AC power source

This paper presents the development of a single-phase AC power source. The power source described is capable of providing a stable AC voltage with variable amplitude and variable frequency over a wide range. Moreover, it can generate various high-quality low-frequency arbitrary waveforms. This is achieved by applying advanced digital control techniques to perform closed-loop control of the single-phase inverter used in the circuit. In this system, a high-performance digital signal processor has been used to realize the discrete-time sliding-mode control strategy. This leads to a system that is robust with respect to system parameter variations and external disturbances. Consequently, high-quality output waveforms can be maintained despite dynamic loading conditions. Some experimental results are demonstrated.