Unified Control of Voltage, Frequency and Angle in Electrical Power Systems: A Passivity and Negative-Imaginary based Approach

TL;DR

This paper introduces a unified control framework for voltage, frequency, and rotor angle regulation in power systems using passivity and negative-imaginary system theories, validated through simulations.

Contribution

It develops a novel passivity and NI-based control approach for simultaneous regulation of multiple power system variables, integrating battery storage with real-time measurements.

Findings

Successful control of voltage, frequency, and angle in simulations

Robustness demonstrated in a four-area transmission network

Effective coordination of batteries and generators

Abstract

This paper proposes a unified methodology for voltage regulation, frequency synchronization, and rotor angle control in power transmission systems considering a one-axis generator model with time-varying voltages. First, we formulate an output consensus problem with a passivity and negative-imaginary (NI) based control framework. We establish output consensus results for both networked passive systems and networked NI systems. Next, we apply the output consensus problem by controlling large-scale batteries co-located with synchronous generators -- using real-time voltage phasor measurements. By controlling the battery storage systems so as to dispatch real and reactive power, we enable simultaneous control of voltage, frequency, and power angle differences across a transmission network. Validation through numerical simulations on a four-area transmission network confirms the robustness of our unified control framework.