Quantification and Regulation of Energy Reserves for Distributed Frequency and Voltage Control of Grid-Forming Inverters
A novel control scheme improves power sharing and stability in microgrids with 100% renewable energy sources.
A new research paper tackles a critical challenge in the transition to renewable energy: maintaining stability in decentralized power grids. Authored by Ahmed Saad Al-Karsani and Maryam Khanbaghi, the work proposes a novel framework for quantifying and regulating energy reserves in microgrids powered by Battery Energy Storage Systems (BESS). As Renewable Energy Sources (RES) and Distributed Energy Resources (DERs) proliferate, forming isolated Microgrids (MGs) and Networks of MGs (NMGs), traditional centralized grid control fails. This paper addresses a gap in linking secondary control (frequency/voltage) with tertiary control (managing energy reserves for service and adequacy).
The core innovation is a modified Distributed-Averaging Proportional-Integral (DAPI) controller that incorporates a consensus mechanism for regulating the proposed energy reserves. This allows multiple grid-forming inverters—which act as the voltage and frequency backbone for a microgrid—to coordinate not just on immediate power balance but also on their available stored energy for future disturbances. The team validated their scheme using Controller Hardware-In-the-Loop (CHIL) simulations on a microgrid modeled after the standard IEEE 13 bus test system in MATLAB/Simulink.
The results demonstrated that the proposed control strategy successfully maintains stable frequency and voltage while enabling more equitable and efficient power and energy sharing. It worked effectively across different inverter control philosophies, including traditional droop-controlled inverters and more advanced Virtual Synchronous Machine (VSM)-controlled inverters. This unified approach is a significant step toward creating resilient, self-regulating islanded grids that can rely entirely on variable renewables and storage, moving beyond theoretical studies to a practical control framework validated in a high-fidelity simulation environment.
- Proposes a novel BESS energy reserves framework to bridge secondary and tertiary control levels in microgrids.
- Introduces a modified DAPI controller with regulation energy reserve consensus for distributed coordination.
- Validated via CHIL simulation on an IEEE 13 bus system, showing improved stability and power sharing across inverter types.
Why It Matters
Enables more reliable, 100% renewable microgrids, crucial for energy resilience and decarbonization.