Research And Application Of Photovoltaic Maximum Power Point Tracking Control Via Output Parameters

It is known that photovoltaic system is one of the cleanest, most practicable, most promising resource in all kinds of renewable energy resources nowadays. In order to promote the development of the solar power generation techniques in China, the research on the basal theory and the experiments on solar power generation should be carried out.In the paper, by analyzing photovoltaic array model and its output characteristics, A new approach for tracking the maximum power point of photovoltaic arrays is presented. The maximum power point tracker output voltage and current are used for control purposes, rather than for its input voltage and current. Based on the characteristic of photovoltaic array and further research on photovoltaic system and its control strategy, a control scheme based on DSP is designed. There are two stages in the control system that can realize maximum photovoltaic power tracking (MPPT).At the same time, the simulation result for the photovoltaic system and it's solving scheme is given in the paper.By deep analysis and research, the system is designed. Based on the scheme of the control system, the design thought of the system's main circuit and its parameters are introduced. This paper also includes the control circuits whose core cell is MOTOROLA'S digital signal processor DSP56F803. The design of drive and protection circuit are introduced in detail.The experiment results demonstrate that the system can implement the control scheme proposed in this paper perfectly. It has been proved that the control strategy presented in this paper can rapidly, accurately and efficiently track the maximum power point, restrain the diversions of the solar panel's working point, reduce the power fluctuations of control processing and get maximum power from the solar panel. It is shown that using the output parameters simplifies the maximum power point tracker controller for only one out of the two output parameters needs to be sensed by this approach. Moreover, this observation is general and applies regardless of the power stage or the realisation control algorithm. Contrary to what might have previously been assumed, it is theoretically shown that the MPPT control that uses a single output control parameter applies to nearly all practical load types, regardless of the load nature.