As for the applic ation of compensation modular multi-level converter in the reactive power compensation of distribution network

in this paper the control strategy of reactive power compensationof modular multi-level converter is studied and the reactive power compensation and voltage balance control of power grid are achieved.On the basis of basic working principle of MMC

the equivalent mathematical model is set up.The reactive power compensation control strategy of current inner loop and power outer loop as well as active and reactive decoupling control method of current inner loop are proposed so to achieve the decoupling control of positive sequence and negative sequence components in case of fault.Based on the traditional constant voltage PI control

a voltage feedback controller is added to the power outer loo panel a k-parameter control strategy is proposed to further improve the linear working area of MMC.Finally

the control strategy proposed in this paper is simulated by Simulink.It is shown by the resultthat the control strategy

in case of symmetric and asymmetric operation mode of power network

can achieve reactive compensation and voltage stability control of the system.Moreover

the content of the study this paper provides reference for the application of modular multilevel converter in reactive power compensation of power system.