DSP based proportional integral sliding mode controller for photo-voltaic system

Abstract

Abstract The buck–boost converter is controlled using different algorithms like voltage mode control, current mode control, V2 control, enhanced V2 control, Sliding Mode Control (SMC), and Proportional Integral (PI) control. In all these algorithms the steady state error is more. On combining PI control and sliding mode control the steady error can be minimized. In industry and commercial applications involving Photo-Voltaic (PV) systems, uses buck–boost converter. In this converter above control algorithms are implemented using hardware circuitry or microcontroller. In industry and commercial applications Digital Signal Processor (DSP) is used for automation purposes and the same DSP can be used to implement control algorithms so as to get maximum electrical energy from solar energy. The efficient utilization of resources such as DSP is achieved as we are using the same DSP for implementing control algorithm. In the proposed study, PI control method and sliding mode control methods are combined to obtain a Proportional Integral Sliding Mode Control (PISMC) and it is used to control the buck–boost converter which is used to drive the electrical loads from solar energy. The buck–boost converter is designed, simulated and implemented. The algorithms PI, SMC and PISMC are simulated in using MATLAB simulink and then implemented in DSP TMS 320 2808. In the proposed study PISMC, a stable and efficient output voltage is obtained in which the steady state error and maximum overshoot are minimum. The PISMC is better in terms of transient and steady state performances as validated by our experiments. The proposed study will work in real-time since DSP is used for implementing the control algorithms and found to be better in terms of speed and regulation. The proposed DSP based PISMC can also be used to control other types of DC–DC converters.