A new cost-effective analog maximum power point tracker for PV systems

Analog circuitry based maximum power point (MPP) tracker is attractive due to its low cost and capability of easy integration with a normal DC/DC controller such that “plug and play” can be expected for many photovoltaic (PV) applications. However, the challenge for analog MPPT controller is how to implement an algorithm and store necessary information (i.e., PV panel voltage V_PV and output power P_PV) to find MPP. In this paper, a new cost-effective analog MPPT controller is proposed. By creating a truth table from the perturbation and observation (P&O) algorithm, the algorithm can be implemented with only several logic gates. Thanks to the capacitor based storage cell, information like V_PV and P_PV in last perturbation cycle can be stored easily. Compared with existing analog MPPT solutions, the proposed controller can find the real MPP dynamically and its operation is independent of converter topologies or its control. The operation principle of the new controller is explained and the cost of proposed solution is evaluated. The tracking performance of the proposed controller has been validated by both of the simulation and experimental results using a single phase PV inverter prototype with 200 W PV panels under different sun irradiation level and temperature.