A Method Of Power Allocation For Small-scale Photovoltaic Electricity Complementary System

Solar energy development rapidly all over the world due to the advantages of rich energy and wide distribution. As a typical application of photovoltaic power generation, complementary system of photovoltaic and grid has caused more and more people’s attentionPhotovoltaic power generation is the primary application in various ways of using solar energy. However, photovoltaic power generation output is not stable and discontinuous because it restricted by light intensity and environmental temperature, In order to make sure that the system works stable and efficiency, we make the grid as a backup power supply, at the same time excess energy stored in the battery. Combining solar cell and grid, proposing a complementary power supply system of photovoltaic and grid, It is composed of a solar cell, grid, battery, DC/DC converter and DC/AC inverter.Take account of power supply capacity and load priority of solar cell, a power allocation method based on Small-scale photovoltaic electricity complementary system is proposed in the thesis, When the power of the solar cell is larger than the load power, solar cell supply power for the load; When the power of the solar cell is lower than the load power, solar cell and grid supply power for the load together; At night or the rainy weather, the solar cell can’s operate, the load power is supplied by grid. Charging the battery supply for the load in case of output power of photovoltaic cells is insufficient. To sum up, the system has a variety of different working conditions, through the switch control rules, ensure uninterruptible power supply of high priority load and implement energy optimization of the system.In order to verify proposed system structure and power allocation method, this thesis designed a photovoltaic electricity complementary system for small household, and design main circuit parameters of the system, then set up a simulation model to verify. The simulation results show that the proposed system structure and power allocation method is effective and practical.