Evaluate the Effect of Hydro Turbine Governor Decentralized Control by Transient Energy

The power fluctuation (ΔP_e) between generator and electric power system is the main measurable disturbance for destroying generator stability. In order to improve the ability of generator for restraining disturbance, a governor additional decentralized control (HGADC) used on hydro-turbine generator is proposed in the paper based on H_∞ robust control theory. When the ΔP_e is used as a feedback in HGADC, the couple and nonlinear problem of generator equation will be avoided, and the control equation will be simplified. At the same time, in order to quantitatively evaluate the control effect of HGADC by transient energy (TE), the TE curve is shown in the paper comparing with the curve of rotor speed under different conditions. The results of theoretical analysis and simulating tests show that TE is reduced more quickly by HGADC and HGADC is helpful to improve the stability of synchronous hydro-turbine generator. TE can be used as a quantitative index to evaluate and compare the effect of different stability control laws.