Design And Experimental Research Of Residential Photovoltaic System

Solar photovoltaic power generation is an important aspect of solar energy utilization, it has advantages of safety, reliability, few moving parts, little noise, easy maintenance, long service life, non-consumption of fuel, power autonomy, high flexibility, etc. In the long term, solar photovoltaic power generation is an ideal choice to achieve sustainable development. The International Energy Agency (IEA) forecasts that the share of global cumulative installed PV capacity will reach 20% of total world electricity generation by 2040.The previous design in PV system usually only considered the latitude and longitude, radiation intensity, sunshine hours, etc., processed the total radiation data using the diffuse fraction correlations and finally converted them to the standard condition to estimate the daily, monthly and annual power generation capacity of the PV modules. While calculating the battery capacity, it is often designed to sustain the longest rainy days of years. It directly leads to deviation of the estimated capacity of PV modules as well as the battery capacity to match load poorly.In this paper, learn from the results of previous studies to improve the design of residential photovoltaic system and carry out experimental study. Based on energy balance to size the batteries and photovoltaic array for the required load. After a preliminary selection of PV modules and batteries, starting from the cell temperature, ambient temperature, radiation intensity, sunshine hours, wind speed and other factors which have impact on the performance of the photovoltaic modules, the PV system has been check to ensure the feasibility of the PV system in design. In order to test the designed PV system, experimental researches are carried out. The experimental results show that it achieved good performance, generating capacity of PV modules fully meet the load power consumption needs, In addition, compared curves of radiation intensity, charge current, ambient temperature, PV module temperature under different weather conditions, it can be found that PV module temperature is affected by solar radiation intensity, ambient temperature and other factors.Battery failure and shorter life-span are an important aspect to restrict the promotion of PV systems, In the basis of comprehensive comparison of various batteries used in PV system, lead-acid batteries widely used were studied. In this paper, a new charging method for VRLA batteries-a pressure-controlled charging method-is adopted. The pressure-controlled VRLA battery was proposed and patented by Zhejiang University (Patent No. CN97249861.3). A pressure-controlled charging method is different from other traditional charging control mode using an electrical parameter which can be called "voltage-controlled method". A pressure-controlled charging method is based on the internal oxygen cycle theory. For it mainly uses the internal pressure to control the battery charging, so it called "pressure-controlled method". Experimental results show that the "pressure-controlled method" can effectively improve the battery charging characteristics in high-temperature and low-temperature environments, and can effectively reduce overcharging and potential for thermal runaway of the VRLA. In addition, because the pressure-controlled point is before the point of valve regulated, thus it can minimized water loss. Control circuit of "pressure-controlled method" is relatively simple, but it achieved good performance. If the "pressure-controlled method " is adopted and promoted, it will play a positive role in promoting photovoltaic systems engineering applications.