Новая централизованная топология фотоэлектрических преобразователей, работающих с сетью, оптимизированная для условий частичного затенения

Abstract

Grid-connected centralized inverters based on traditional topologies are one of the best solutions for medium and large-scale photovoltaic (PV) power plants due to their low cost and simplicity. However, the output power of these conventional topologies is drastically decreased because of partial shading effects or mismatch between PV panels. This paper proposes a new grid-connected centralized inverter topology based on a novel photovoltaic current collector optimizer (CCO) to enhance the power yield from PV array in case of partial shading or PV modules mismatch. The PV modules are stacked by CCOs and then interfaced to the grid through three phase-two level voltage source inverter (VSI). The CCOs are used to improve the power harvest from PV array instead of using bypass and blocking diodes which deforms the PV array characteristics and reduces its output power. The VSI is used to inject a high-quality AC current into the grid and perform maximum power point tracking (MPPT) together. Computer simulation is carried out using MATLAB/Simulink in order to test operation of the proposed topology. Simulation results show that the proposed topology offers an excellent steady-state response, fast dynamic response, perfect and robust tracking of maximum power point during partial shading condition.