This paper describes the useful experiences about dynamic performance improvement of synchronous generators in the Tong-Shiao Generation Station of the Taiwan Power System. This work includes the dynamic performance test, parameter identification, and parameter retuning of static excitation systems (SESs). Since the hardware circuits of SESs had been modified, it caused the detuning of parameters so that the generators did not have enough ability to sustain large voltage fluctuation disturbances. Those SESs were temporarily retuned according to the results from simple field tests. However, step responses of field tests were different from those-of computer simulations. Thus, the least-squared-error algorithm has been employed to estimate the parameters of inner-loop regulators in SESs. Finally, the hybrid differential evolution method was used to get suitable parameter values. The SESs of six gas-turbine generators have been retuned again and these have worked well till now. The experiences and results provide useful references.