Research On FACTS Control Device Of Distributed Photovoltaic Power Supply

With the continuous development of China’s power industry,the stability of the power system has been put forward higher requirements in the transmission network construction.The new energy power generation has a lot of uncertainty,for example distributed photovoltaic power generation capacity changes due to the change of light intensity,when such a power system takes up a large proportion of the power grid,it can bring big fluctuations to the power grid.Therefore,flexible AC transmission technology using modern power electronic technology and the traditional flow control technology combined to compensate for new energy exists in the process of grid problems,in order to reduce the power loss and the cost of the whole power grid,improve the stability and reliability of power grid.The paper makes a simple analysis of the flexible AC transmission system,using STATCOM/BESS device for compensating system,STATCOM/BESS device can operate under four conditions of discharging / charging reactive power in the developed / absorbing mode,problems of new energy in the presence of more control in the process of grid.Direct power control strategy using hysteresis comparator,through the look-up table selection of voltage vector,which has the simple control,fast response advantages,but this method is not a constant switching frequency,will produce harmonic current frequency is not fixed.In order to overcome these shortcomings,the thesis puts forward a control strategy of direct power control based on SVPWM prediction technology,which improves the problems of direct power control,make the system more stable,higher reliability.Based on the MATLAB/SIMULINK simulation tools,namely to build traditional direct power control strategy based on STATCOM/BESS and device simulation model predictive direct power control strategy of SVPWM technology,and two kinds of control strategy were analyzed in system running effect.