Mixed Voltage Angle and Frequency Droop Control for Transient Stability of Interconnected Microgrids with Loss of PMU Measurements

TL;DR

This paper introduces a mixed voltage angle and frequency droop control framework to enhance the transient stability of interconnected microgrids, especially when PMU measurements are lost, using a dissipativity-based distributed control approach.

Contribution

It proposes a novel hybrid control scheme and stability analysis method for microgrids with measurement loss, improving reliability over traditional angle droop control.

Findings

The control framework maintains stability under measurement loss.

Simulation confirms improved transient stability.

The approach effectively switches between control modes.

Abstract

We consider the problem of guaranteeing transient stability of a network of interconnected angle droop controlled microgrids, where voltage phase angle measurements from phasor measurement units (PMUs) may be lost, leading to poor performance and instability. In this paper, we propose a novel mixed voltage angle and frequency droop control (MAFD) framework to improve the reliability of such angle droop controlled microgrid interconnections. In this framework, when the phase angle measurement is lost at a microgrid, conventional frequency droop control is temporarily used for primary control in place of angle droop control. We model the network of interconnected microgrids with the MAFD architecture as a nonlinear switched system. We then propose a dissipativity-based distributed secondary control design to guarantee transient stability of this network under arbitrary switching between angle droop and frequency droop controllers. We demonstrate the performance of this control framework by simulation on a test 123-feeder distribution network.