Decentralized robust governor additional control for improving stability of turbogenerator

The key reason for destroying generator stability is the coupled active power fluctuation (/spl Delta/P/sub e/) between generator and electric power system. When the power fluctuation is stimulated by fault in electric power system, the unbalanced torque on rotor will be increased greatly. From this aspect, the power fluctuation (/spl Delta/P/sub e/) can be looked as a main disturbance for destroying generator stability. A decentralized robust governor additional control (DRGAC) used on turbo-generator is proposed in the paper based on H/sub /spl infin// robust control theory. DRGAC is designed for restraining the disturbance (/spl utri/P/sub e/) by using it as a measurable input. When the /spl utri/P/sub e/ is used as a feedback in DRGAC, the problem of couple and nonlinear will be avoided, and the control equation will be simplified. Because the purpose of DRGAC is to reduce the power fluctuation and not to optimize the performance of one local generator, the problem of coordination in multi-machine system does not exist in DRGAC. The results of simulating tests on turbine-generator show that the stability of generator is improved through restraining the disturbance by adopting DRGAC. DRGAC can be adopted at every generator without coordination with the other controller. DRGAC will be an easy and feasible stability controller for the real power system.