Solar Powered DC Motor Speed Control by MPPT and Discrete Controller

In this paper modeling and simulation of solar powered DC motor speed control by Maximum Power Point Technique (MPPT) and Discrete Sliding Mode Controller (DSMC) is presented. The DC motors are having non-linear characteristics like friction, backlash and the voltage produced from PV array is highly fluctuating because of variation of irradiance. These non-linearity properties are affecting the performance of the system in low speed applications like chemical processing. So there is a requirement of an efficient non-linear controller under load side uncertainties and source side voltage fluctuations; DSMC can overcome these problems. The Boost converter powered by solar array is tuned with Perturb and Observe (P & O) MPPT algorithm to obtain maximum power from the PV array. The boosted voltage is supplied to the DC motor through chopper circuit and the speed of DC motor is controlled by armature voltage control method using DSMC technique. The gate pulse of the chopper is tuned by the discrete controller by comparing actual speed with the reference speed. The non-linearity problem faced by the system is overcome by DSMC and its robustness is proved by introducing variation in irradiance as well. The proposed controlled make the system robust, efficient, simple and cost effective by the utilization of solar energy.