On the failure of power system automatic generation control due to measurement noise

Abstract

This paper discusses a class of measurement noise that has the potential to destabilize power systems with automatic generation control (AGC). AGC is responsible for maintaining nominal frequency and interchange power between balancing areas as scheduled. The results in this paper show that AGC is robust to measurement white noise. However, when the intensity of the measurement noise depends on the system state, the AGC system fails to meet its performance requirements. The measurement noise is modeled as a stochastic process, while the overall power system dynamic behavior is described by a stochastic differential equation (SDE) model. The impact of measurement noise is evaluated through a set of differential equations describing the evolution of the statistics of the system states, which are derived from the SDE model. Mitigation strategies to address this problem are also discussed.