Parameter Optimization Of PI Controllers In Multi-HVDC Emergency Power Support

Our country’s energy needs and resource are distributed in contrary, so it is urgent and necessary to build HVDC to realize the long distance and high capacity power transmission. The state Grid of China has paid great attention to the development of HVDC technology, and construction of HVDC project. China has become the leading countries both on thelengthof transmission line and the commutation capacity in the world.HVDC system can not only realize the interconnection of different AC systems,the long-distance and large capacity transmission of power, but also can achieve the emergency control of AC system. Using the HVDC’S modulation function to improve the performance and security of AC system has been paid more and more attention in the world, and there have been numerous successful use of HVDC modulation function in project now.This paper describes the four main type of HVDC modulation include:additional frequency modulation, additional damping modulation,emergency power support,and the big single of DC power modulation.And this paper also discuss their different control principle and implementation process. At last the paperproposes the problem of parameter optimization.For parameter optimization problem, this paper introduces the research status of parameter optimization, the optimization methods in general, as well as optimizing object, different indicators to measure the effect of optimizing, the choice of optimization software and so on. After a comprehensive comparative study, this paper proposed a new program of parameter optimization progress,that is time domain simulation combined with optimization algorithm. By using multiple run in PSCAD and PSO algorithm written in C program,we can realize the optimization progress.The key problem is how to design the objective function and how to interface the different software program. Finally the paper prove the effective of the program by simulation of AC-DC project in PSCAD.