A methodology for simulation of power generation characteristics and enhancement of MPPT performance of offshore floating photovoltaic arrays

Abstract

The irradiance distribution conditions and power generation characteristics of offshore floating photovoltaic (PV) arrays on multiple types of floating body structures are complex due to the influence of spatially and temporally variable wave environments, which greatly increases the difficulty of maximum power point tracking and hinders the efficient and economic operation of offshore floating PV power plants. Considering the influence of different scales of floating body structures, PV module arrangements and wiring methods on the irradiance distribution conditions and power generation characteristics of offshore floating PV arrays, this paper proposes a simulation method for power generation characteristics of offshore floating PV systems adapted to multiple types of floating body structures. The proposed method is validated in laboratory and actual operation scenarios using the six-degree-of-freedom motion experimental platform and the actual sea-measured irradiance data of the floating PV power generation unit. Based on two types of floating structure power generation units of offshore floating PV power plant in Bohai Bay, the multimodal uniform and non-uniform irradiance conditions and power generation characteristics of offshore PV arrays are generated, and the performance test of the proposed hybrid improved MPPT technique is carried out. The results show that by using a large hexagonal floating structure unit and centralizing the modules so that the PV arrays connected to the same MPPT control are spread out over as few floating structures as possible, fast and efficient MPPT can be achieved using the classical MPPT technique. The number of local maximal power points in the PV curves is larger in number and speed of change with the small rectangular floating structure, but better MPPT performance can be ensured by adopting the proposed MPPT technique. The proposed MPPT technique has a tracking time of no more than 20 ms and a tracking efficiency of no less than 99.85 % under uniform and non-uniform irradiance conditions.