Transient stability analysis of high frequency AC microgrids

Abstract

Running megawatt-range ac microgrids at frequencies higher than the usual 50 or 60 Hz is feasible with readiness and maturation of advanced power system equipment, such as high speed generators and fast-response protection devices. Applications where weight and foot-print savings are vital would find it favorable and attractive. This paper examines the transient stability of such megawatt-range high frequency ac microgrids, as a function of system frequency, following severe faults. Fundamental analysis based on swing equation explains the underlying cause for the shortening of critical clearing time as frequency increases. Numerical simulation studies which consider a wide range of inertia constants prove that, despite the requirement for faster fault clearing, advanced circuit breaker technology is capable of maintaining rotor angle stability of up-to-800 Hz high frequency ac microgrids, even under severe faults.