School of Electrical and Electronic Engineering North China Electric Power University Beijing 102206 P.R.China;
School of Electrical and Electronic Engineering North China Electric Power University Beijing 102206 P.R.China;
School of Electrical and Electronic Engineering North China Electric Power University Beijing 102206 P.R.China;
School of Electrical and Electronic Engineering North China Electric Power University Beijing 102206 P.R.China;
Frequency equivalent model; Generation expansion planning; Inertia; Primary frequency response;