Full-Time-Scale Power Management Strategy for Hybrid AC/DC/DS Microgrid with Dynamic Concatenation and Autonomous Frequency / Voltage Restorations

TL;DR

This paper presents a comprehensive power management strategy for hybrid AC/DC microgrids that unifies transient and steady-state control, ensuring stable frequency and voltage with autonomous restoration capabilities.

Contribution

It introduces a novel dynamic concatenator for unified control and a global equivalent circuit model for simplified analysis, addressing both transient and steady-state power sharing.

Findings

Maintains nominal frequency and voltage in steady state.

Enables seamless transition between transient inertia support and power sharing.

Achieves stable operation across all time scales.

Abstract

Hybrid AC/DC microgrids with distributed energy storage (DS) improve power reliability in remote areas. Existing power management methods either focus on steady-state power sharing or transient inertia support, but rarely combine both. They also often ignore frequency and voltage deviations caused by droop control, which can harm sensitive loads. To overcome these issues, this paper proposes a full-time-scale (FTS) power management strategy that unifies transient inertia sharing and steady-state power allocation through a novel dynamic concatenator. It also introduces autonomous frequency/voltage restoration to eliminate steady-state deviations in each subgrid. Additionally, a global equivalent circuit model (GECM) is developed to simplify system analysis and design. Experiments confirm that the approach maintains nominal frequency and voltage in steady state while enabling seamless transition between transient inertia support and proportional power sharing across all time scales.