DSP Based Sliding Mode Control for Photovoltaic System

In this paper a new and simple DSP-based Sliding Mode Controller (SMC) has been developed for the Buck-Boost converter to get regulated DC power supply from solar PV. Firstly, all the control laws, such as reaching law, power rate reaching law, exponential reaching law, and sigmoid variable reaching law, are simulated for the efficient working of SMC. Then, these control laws have been programmed in DSP to make SMC controller for the Buck-Boost converter. Finally, a hardware model of buck-boost converter has been designed on PCB and programmed DSP has been utilized as SMC to get regulated DC supply from the solar panel to drive various industrial loads. The accuracy and performance of the proposed ‘DSP based SMC’ have been revealed by estimating various performance parameters, such as, chattering, load variation, controlled voltage, settling time, reaching time, and output voltage deviation. It is found that ‘DSP based SMC’ provides proficient performance with all of these reaching laws. Especially, with the exponential reaching law, the chattering magnitude and duration are found very small with minimum reaching time whereas sigmoid variable reaching law provides minimum settling time.