Fixed Point Arithmetic Implementation of Digital Proportional - Resonant Single-Phase Current Controllers

The main objective of this paper is to present practical digital implementation of Proportional Resonant-based-single phase current controller for low-cost Digital Signal Controllers (DSCs). In this work, the PR controller was developed by using a 16-bit fixed-point arithmetic with Q15 data format, and the codes were embedded in a low-cost 16-bit DSC to control 50 Hz AC current of single-phase inverter systems. Although the PR controller is implemented digitally, the designed processes of the PR current controller in this paper are served in continuous model. The discreet model than derived by using a simple backward difference approximation. To be easily adopted in different size of single-phase inverter systems, all the state variables and its parameters of the PR controller are represented in Q15 number format and manipulated in the same data format. Experimental and testing results show the effectiveness of the proposed digital implementation technique of the PR current controller.