Small-signal Stability Analysis and Performance Evaluation of Microgrids under Distributed Control

TL;DR

This paper develops a theoretical framework for analyzing the small-signal stability and performance of microgrids with distributed control, considering communication latency and system parameters.

Contribution

It introduces a generalized frequency-domain framework that integrates generator/load dynamics, control loops, and latency for stability analysis.

Findings

The framework effectively predicts microgrid stability under various conditions.

Communication latency significantly affects system stability and performance.

Design guidelines are provided for optimizing microgrid stability.

Abstract

Distributed control, as a potential solution to decreasing communication demands in microgrids, has drawn much attention in recent years. Advantages of distributed control have been extensively discussed, while its impacts on microgrid performance and stability, especially in the case of communication latency, have not been explicitly studied or fully understood yet. This paper addresses this gap by proposing a generalized theoretical framework for small-signal stability analysis and performance evaluation for microgrids using distributed control. The proposed framework synthesizes generator and load frequency-domain characteristics, primary and secondary control loops, as well as the communication latency into a frequency-domain representation which is further evaluated by the generalized Nyquist theorem. In addition, various parameters and their impacts on microgrid dynamic performance are investigated and summarized into guidelines to help better design the system. Case studies demonstrate the effectiveness of the proposed approach.