Research And Design Of The Stand-alone Photovoltaic Power Generation System Controller

The current situation of photovoltaic systems (PV systems) is introduced at first, and then basic concepts, theories, and components of PV systems are discussed in this paper. Key technology of PV system is checked, especially methods of battery monitoring are explored. Three monitoring methods of charging state are presented: the method based on battery on-line voltage monitoring, the method based on battery off-line voltage monitoring and the method based on formulas. The functions which PV system controllers need to have are discussed in theory too, such as controlling of charging and discharging, adaptation of orientation and position of solar cell, maximum power point tracking(MPPT). On the basis of the above discussed methods, three PV system controllers are developed. Two of the three are orientated towards simple and low-cost applications, but the third one based on ARM core processors and uC/OS-Ⅱ embedded operating system is more complex and advanced. The complex control has communication function, which can transfer data with remote controller. To transfer data reliably, a wireless protocol is developed. Finally operation data of the three controllers are given and the development of PV industry in future is predicted.