Research On The Participation Of Photovoltaic Power Generation In Frequency Regulation Of Power Grid

The full utilization of solar energy plays an important role in mitigating carbon emissions and alleviating environmental problems.Photovoltaic power generation is the most commonly used kind of solar power generation.With the continuous increase of the scale of grid-connected photovoltaic power generation system,the output of its active power is decoupled from the grid frequency,and the photovoltaic output will change with the change of weather,cloud movement and other factors,which will bring a certain impact on the safe and stable operation of the power grid.Therefore,it is of great significance to explore the participation of photovoltaic power generation in the regulation of power grid frequency to enhance the safe and stable operation of power grid.The main work of this paper includes the following parts.First,the mathematical model of photovoltaic cells is given,and the output characteristic curve of photovoltaic array is analyzed.Secondly,the overall structure of grid-connected photovoltaic power generation system is analyzed,the model of DC/DC conversion circuit and DC/AC inverter circuit are analyzed and established.On this basis,the maximum power point tracking control strategy and the grid voltage control strategy are studied.And then,in view of the fact photovoltaic can not provide additional power support to cope with the change of frequency at the maximum power point,the droop control and virtual inertia control strategies are studied under the de-loading control.Through the analysis of the inverter side capacitor,the virtual inertia control strategy based on the inverter side capacitor is studied.These methods can make photovoltaic power generation participate in the regulation of grid frequency.Finally,considering that the droop control coefficient of traditional droop control is fixed and the solar irradiation intensity has certain randomness and volatility,an adaptive droop control strategy based on the improved gravitational search algorithm of quantized minimum error entropy is proposed,which makes the droop control coefficient of photovoltaic system change adaptively according to the frequency deviation,It improves the ability of photovoltaic frequency regulation.