In order to assess the validity of power system dynamic equivalent model accurately

a quantitative credibility evaluation method based on power sensitivity is proposed in this paper. First

the basic concept of power sensitivity of power system is introduced and the power sensitivity matrix for power system with consideration of induction motors is derived. It is pointed out that the dynamical responses of power system are essentially determined by the transmitting power sensitivities between dynamical components. Then

the relationship between power sensitivity matrices of the original and equivalent system is analyzed according to the characteristics of the equivalent system. Power sensitivity errors in the study system and the external system are given and the credibility of the equivalent model is defined. Finally

this credibility evaluation method is tested in the IEEE 10-machine and 39-bus system. The credibilities of different equivalent models are calculated respectively. Simulation results show that the depicted credibility index reflects the validity of the equivalent model precisely and quantitatively. It can distinguish different equivalent models goodly. This method can be effectively applied in equivalent model validation due to a very small amount of calculation.