The influencing factors of photovoltaic solar irradiation have?

Photovoltaic modules is nominal power under the condition of standard test, is it possible that the actual power more than nominal power, everyone's different versions, this is don't focus on one of the problems of photovoltaic power station design, affects the power of inverter type selection and system

the nominal power of the pv module in standard conditions for testing. If there's any possibility of actual power over rated power, this is a widely discussed problem. This is also didn't notice that one of the problems in the design of photovoltaic power station, and will affect the choice of the inverter and the system of power generation. Solar irradiance: solar radiation to the radiation power per unit area known as the solar irradiance. The unit is watts per square metre. Photovoltaic modules of nominal power under the condition of standard test, standard test conditions as follows: 1. Irradiance: 1000 watts per square metre, 2. Temperature: 25 amperes. Plusmn。 1) ℃，3。 Spectral characteristics: AM1. 5 standard spectrum. Therefore, factors that affect component big output power is the solar irradiance and temperature, has nothing to do with inverter devices such as factors. The sun irradiance limit value is constant, and a value of 1368 watts per square metre. After reaching the earth's surface, photovoltaic power generation is affected by the weather and other factors, high of about 1200 watts per square metre. The power of the module temperature is about - system 0. 39%/℃。 When the module temperature drop, module power will increase. Whatever equipment loss, 250 - watt module at minus 30 degrees of large power output Pmax = 1. 2 * ( ( 25 + 30) ( - 0. 0039). * 250 = 1. 2 * 1. 1755 * 250 = 352. 65 watts. In fact, in the sunny areas in China, such as northern northern ningxia, gansu, southern xinjiang and other regions, a 250 - watt module can have 300 watts of power output. 。 Factors that affect the solar irradiance include: 1. Angle of the sun or latitude: the greater the Angle of the sun, the shorter the path through the atmosphere, the smaller the weakening effect of solar radiation, atmosphere on the ground of the stronger the solar radiation; The greater the Angle of the sun, the sun radiation amount of diffusion area is smaller, the stronger the solar radiation. For example, at noon the sun radiation is better than in the morning and evening. 2. Elevation: the higher the altitude air, the air is thinner, the atmosphere of the reduction in solar radiation effect is smaller, to reach the more solar radiation on the ground. For example, the qinghai-tibet plateau is a strong solar radiation area. 3. Weather condition: sunny few cloud, the less impact on the solar radiation is very small, on the ground of the solar radiation is very strong. Sichuan basin, for example, there are many rainy days, solar radiation, solar radiation in our country has become a base area. 4. Atmospheric transparency: high atmospheric transparency to abate solar radiation have little impact, to reach the ground solar radiation is very strong. 5, the length of a day. 6. Air pollution: if pollution is serious, will weaken the sun radiation, reduce the solar radiation on the ground.