Close loop compensation technique for high performance MPPT using ripple correlation control

Abstract

Conventional RCC uses Type-I compensator or Integrator which cannot track the Maximum Power Point (MPP) for all the operating condition without Adaptive Gain Tuning. The Type-II compensator based closed loop control scheme of the proposed MPPT makes it robust against all types of disturbances, panel and plant parameter variations. The RCC technique is very simple to implement and the total MPPT controller can be easily implemented using analog circuitry only. However, the challenge lies in designing the compensator as the RCC technique, along with PV panel, exhibits highly non-linear dynamics. Conventional Bode plot technique is used for designing the compensator where the plant parameters (Gain and Phase) are obtained by perturbing the panel operation around the MPP at crossover frequency. This paper proposes a compensator based implementation of Dynamic Maximum Power Point Tracking (MPPT) for rapidly changing irradiation and load variation using Ripple Correlation Control (RCC) technique. The proposed control scheme has a very fast convergence and is very prompt in tracking irradiance variation and load disturbance rejection. The efficacy of the proposed MPPT and the compensator are verified by simulation.