Stabilizing Transient Disturbances With Utility-Scale Inverter-Based Resources

TL;DR

This paper introduces a control strategy for inverter-based resources that stabilizes transient disturbances in power systems by tracking the center-of-inertia angle, thereby enhancing system stability and transmission capacity.

Contribution

It proposes a novel trajectory tracking control method for inverter resources that supports transient stability using real-time wide-area measurements and a linearized system model.

Findings

Improves transient stability and system reliability.

Increases power transfer capacity on key transmission paths.

Validated on a model of the North American Western Interconnection.

Abstract

This paper presents a trajectory tracking control strategy that modulates the active power injected by geographically distributed inverter-based resources to support transient stability. Each resource is independently controlled, and its response drives the local bus voltage angle toward a trajectory that tracks the angle of the center of inertia. The center-of-inertia angle is estimated in real time from wide-area measurements. The main objectives are to stabilize transient disturbances and increase the amount of power that can be safely transferred over key transmission paths without loss of synchronism. Here we envision the actuators as utility-scale energy storage systems; however, equivalent examples could be developed for partially-curtailed photovoltaic generation and/or Type 4 wind turbine generators. The strategy stems from a time-varying linearization of the equations of motion for a synchronous machine. The control action produces synchronizing torque in a special reference frame that accounts for the motion of the center of inertia. This drives the system states toward the desired trajectory and promotes rotor angle stability. For testing we employ a reduced-order dynamic model of the North American Western Interconnection. The results show that this approach improves system reliability and can increase capacity utilization on stability-limited transmission corridors.