Research On Control System Of Single Phase Photovoltaic Generation

With the increasingly serious energy depletion and environmental pollution,the development and utilization of solar energyConcern.Photovoltaic power generation is an important form of solar energy utilization,which has broad application prospects and research significance.In this paper,the photovoltaic grid connected power generation system is studied,and its control technology is studied deeply.The research object of this paper is the photovoltaic power generation control system,including photovoltaic module,inverter module and grid connected module.the first part mainly introduces the background and significance of the research;The first is to study the photovoltaic cells convert sunlight into electrical energy efficiency,which requires the maximum power point of the solar tracking the maximum power point tracking algorithm which can quickly achieve stability,but in the light intensity change is not very good for the sun to track,and to be stable fluctuations,so this paper proposes a variable step incremental conductance method,this method can make the illumination intensity change is also to achieve the maximum tracking of the sun;The second is the inverter,there are a lot of the current of the inverter tracking method,but there are many problems such as the control of current proportional integral with nonlinear disturbance effect is not obvious,not on the outside of the repetitive control of uncertain interference reasonable control,error if the control of the whole system are higher,so this paper uses improved SPWM with voltage feedforward compensation control method to achieve good results;finally,the research of detecting islanding,current methods for islanding detection are blind islanding detection,detection efficiency and detection of instability and other shortcomings,so this paper adopts active frequency drift method for islanding detection of.The beginning can quickly achieve stable and small fluctuations,by using the method of feedforward compensation in current tracking which reduce or eliminate the effect of grid voltage and current,frequency shift method for islanding detection in this paper can soon to detect islanding.