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Multi-Objective Optimal Design of Excitation Systems of Synchronous Condensers for HVDC Systems Based on MOEA/D

In order to optimize the reactive power characteristics of synchronous condensers and improve the capability of condensers to support the voltage of AC systems, in this paper, the outer loop control of the reactive power of condensers and the outer loop control of the voltage of AC systems are introduced into the design of the main excitation systems of condensers in high voltage direct current (HVDC) systems. Meanwhile, taking the integral values, peak values and steady-state values of voltage deviations of AC systems as objective functions, the multi-objective optimization design of the proportional adjustment coefficients in the outer loop control of the reactive power of condensers and the voltage of AC systems is carried out via utilizing a multi-objective evolutionary algorithm based on decomposition (MOEA/D) combining with fuzzy control method. Its purpose is to alleviate the overvoltage problems of power grids caused by the feedback of the reactive power of condensers and the voltage of AC systems. Lastly, the simulation model of ±100 kV HVDC system with a synchronous condenser is established. The simulation results show that the optimal design method of excitation systems of synchronous condensers proposed in this paper can optimize the reactive power characteristics of the condenser, ensure the rapid regulation of the voltage of the AC system by the condenser, and solve the overvoltage problem in the AC system caused by the reactive power regulation of the condenser which can not change suddenly and the feedback links of the reactive power of the condenser and the voltage of the AC system in the excitation system.