Research On The Optimization Of SVG Control Strategy Of Transient Over-Repression In The New Energy Convergence Area

In the current era of striving for "carbon peak" and "carbon neutrality",a very important factor restricting the ability of new energy transmission is the transient overvoltage problem,and the analysis shows that the control characteristics of the dynamic reactive power compensation device are not ideal is one of the important reasons,of which the static reactive power generator(SVG)is widely used in the field of reactive power compensation with its advantages of fast response speed and wide adjustment range,so it is urgent to solve this problem.Therefore,in this paper,the control strategy of SVG is optimized for suppressing transient overvoltage,and the main work is as follows:Firstly,the mathematical model of SVG was derived and its control block diagram was derived.On the basis of analyzing the structure and working principle of SVG system,the mathematical model under the d-q rotating coordinate system is derived,and the control block diagram is obtained on this basis,which lays a good theoretical foundation for the optimization of control strategy and simulation model construction of SVG.Secondly,an optimization scheme for SVG control strategy based on transient overvoltage suppression is proposed.By comparing with the actual controller simulation of CLP Puri,on the basis of verifying that the existing simulation model is correct,an optimal control strategy of SVG is proposed: the feed-forward voltage in the current inner loop is obtained by the grid voltage through the first-order inertia link,and certain voltage source characteristics are introduced;the q-axis voltage outer loop adopts the advanced lag link to suppress the integral desaturation phenomenon.In addition,the selection principle of primary system inductance and capacitance parameters is also given.After that,the electromechanical transient model before and after the SVG optimization control strategy is built and verified to be correct.Ignoring the dynamic characteristics of the phase-locked loop and the dynamic characteristics of svg DC voltage,only the q-axis control link is retained,and the SVG electromechanical transient model before and after optimization is built in the PSASP simulation software.In the simple test system,the simulation curve of the electromagnetic transient model is compared to verify the correctness of the electromechanical transient model.Finally,the SVG electromechanical transient model is integrated into the actual power system to verify the effectiveness of the optimized control strategy in suppressing the transient overvoltage.The small system and the actual power system model of region A are built in the PSASP simulation software,and the SVG electromechanical transient model before and after optimization is connected,and the effectiveness of the optimization control strategy proposed in this paper is verified by comparing the size of the instantaneous transient overvoltage of fault clearance and the simulation curves of output current and reactive power.The optimized control strategy of SVG proposed in this paper is of great significance for suppressing transient overvoltage and improving the ability of new energy transmission.