The Analysis Of 20MWp Grid-connected PV Station And Solar Cell Module’s Dust Elimination Device’s Design

Due to the consumption and excessive exploitation of energy, the world faces a serious energy crisis. Solar energy is safe, non-pollution, renewable and inexhaustible. Thus, it becomes the first choice to replace the non-renewable energy and alleviate energy crisis.At present, solar photovoltaic technology aims at low cost and high efficiency. The key to improving generation efficiency of PV station and reducing the economic loss is how to use the solar cell array energy mostly. And the generation efficiency of PV station associates with solar cell array parameters, such as azimuth angle, obliquity, distances between the arrays etc. Besides, the generation efficiency of PV station sill depends on photoelectric conversion efficiency of solar cell module. And the photoelectric conversion efficiency is greatly influenced by the surrounding environment. The dust accumulates on the surface of solar cell module, and becomes the dirt retention. On the one hand, the dust’s occlusion can reduce the photoelectric conversion efficiency of solar cell module. On the other hand, it has a hot spot effect and damages module. Choosing the related parameters of PV power generation system reasonably is very important. Removing the surface dust of solar cell module to improve the photoelectric conversion efficiency of solar cell module and the generation efficiency of PV station is very relevant.In this paper, the PV power generation system and electrical system of plateau 20MWp grid-connected PV station are analyzed. And based on the dust’s impact on the solar cell module, a new automatic device is proposed. In this paper, the main research results as follows:(1) This paper analyses the related parameter of PV power generation system. The model of polysilicon solar cell module is JKM300P-72. The inverter model is YLSSL-500U. The solar cell array’s azimuth angle is 0°. And the solar cell array’s optimum obliquity is 27°. This paper also determines the access way of electric power system, current collecting methods, connection of power lines, line-out mode, junction box’s number etc.(2) This paper analyzes the actual operation data of PV station. The PV station’s generation energy depends on intensity of solar radiation. And the intensity of solar radiation is closely related to weather condition. The actual day generation energy is higher than the day on-grid energy in PV station. Furthermore, the generation energy has a lot of loss in the process of transmission lines. And about 1.40%～2.03% generation energy is lost daily.(3) This paper proposes a solar cell module’s automatic dust elimination device. The device can work automatically, timely and circularly through circulatory working circuit, motor control circuit and the limit switch. In this way, the surface of solar cell module can be clean, and this device can improve its photoelectric conversion efficiency and generation efficiency of PV station.