Research On Reliability Of PV Power Generation System Considering Weather Factors

Photovoltaic power generation system could use photovoltaic cells based on photovoltaic effect to convert solar energy into electricity directly. Characteristics of Photovoltaic power generation system are high reliability, long service life, no pollution, independent power generation and grid connected operation. PV array is generation equipment in the photovoltaic power generation system, which has a greater impact on itself and weather factors. Reliability of Photovoltaic power generation system is analyzed deeply based on analysis of reliability of PV array.According to the principle of photovoltaic power generation and PV cell equivalent circuit, the characteristics of PV module and the factors that affect reliability of PV module are analyzed. Using state space analysis method, it obtains the reliability state space of PV modules to analyze the reliability state space of photovoltaic array.Output power of PV array is closely related to local real-time weather conditions and shadow shielding. PV array could be covered to cause failure of PV module which could affect output power of PV array. Through statistical analysis of cloud cover by historical data, probability of different cloud is got and solar irradiance in the cloud weather is calculated by cloud cover coefficient method. Fault types of PV module are divided into two. One is itself factor failure simulated by fault rate curve. The other is external factors lead failure simulated by mathematical model.Considering time, weather, temperature, solar radiation, cloud environment factors and based on sunshine time model, solar irradiance model, the probability model of cloud and photovoltaic component failure model, it establishes the reliability model of PV array. PV array reliability model is simulated to record operation of the PV array, output power situation, cumulative situation of different state and other state indicators in a certain period of time.It uses two different clustering methods to evaluate reliability of photovoltaic array. Solar irradiance clustering method is to cluster data based on solar irradiance and fault conditions. PV array operation is divided into several states to get equivalent output power, state cumulative time and other data which can evaluate reliability of photovoltaic array. Output power clustering method is to cluster data based on output power. PV array operation is divided into several states to get state index of every state and state transition matrix, which can evaluate reliability of photovoltaic array.