Solar Energy, Vol.185, 516-524, 2019
Optical isolation mechanism based MPPT for PV array under partial shading condition
The status of each photovoltaic (PV) module, whether bypass or not, can play a vital role in the designing of an efficient MPPT, especially for partial shading conditions. In this paper, an optocoupler integrated circuit (optoIC) sensing based MPPT is presented. Initially, an electronic circuit of opto-IC is proposed for each module. Compared to analog sensing, this circuit is low power, less complex, inexpensive, fast and one package solution. Thereafter, a matrix network is devised, which uses the data of opto-IC to perform the following two tasks: (1) if partial shading is identified, only critical regions of I-V curve are examined to detect the global maximum (GM), and (2) if uniform condition is identified, the PV array is set at 0.8 of array's open-circuit voltage. Finally, P&O is used to reach the MPP precisely. Another important aspect of proposed MPPT is the smart estimation of opencircuit voltage of array through opto-IC data. A comparative analysis between multiple MPPTs is presented, according to which the proposed method outperforms other MPPTs in the context of convergence speed and dynamic efficiency.
Keywords:Maximum power point tracker (MPPT);Partial shading condition;Photovoltaic system;Optical isolation mechanism