A grid-forming energy storage damping strategy based on bidirectional proportional regulation

Abstract

To address the challenge faced by grid-connected energy storage systems using the typical Virtual Synchronous Generator (TVSG) control strategy in balancing both steady-state and dynamic performance during active power reference changes and grid frequency disturbances, this paper proposes a bidirectional proportional damping control (BPDC) strategy. This strategy introduces a proportional component to replace the traditional damping source, resolving the conflict between steady-state performance and dynamic response. The proportional component acts as both a frequency feedback controller and a power feedforward compensator, allowing significant improvement in dynamic performance during active power reference and grid frequency disturbances by adjusting only one proportional coefficient without altering the original inertia characteristics or introducing steady-state error. This paper first establishes small-signal transfer function models for the TVSG and the BPDC-based VSG (BPDC-VSG), conducts a detailed theoretical analysis, and compares the results with existing damping strategies. The results indicate that BPDC-VSG offers higher efficiency and simplified design in performance optimization, parameter tuning, and control structure complexity. Finally, simulations are conducted to compare the performance of BPDC-VSG with other damping strategies under power and grid frequency disturbances. The results validate the effectiveness and superiority of the proposed method in enhancing both steady-state and dynamic performance.© 2017 Elsevier Inc. All rights reserved.

Keywords

• Grid-Forming energy storage
• Bidirectional proportional
• Small-signal closed-loop model
• Virtual Synchronous Generator