Virtual Synchronous Generator Adaptive Control of Energy Storage Power Station Based on Physical Constraints

Abstract

The virtual synchronous generator (VSG) can simulate synchronous machine’s operation mechanism in the control link of an energy storage converter, so that an electrochemical energy storage power station has the ability to actively support the power grid, from passive regulation to active support. Since energy storage is an important physical basis for realizing the inertia and damping characteristics in VSG control, energy storage constraints of the physical characteristics on the system control parameters are analyzed to provide a basis for the system parameter tuning. In a classic VSG control, its virtual inertia and damping coefficient remain unchanged. When the grid load changes greatly, the constant control strategy most likely result in the grid frequency deviation beyond the stable operation standard limitations. To solve this problem, a comprehensive control strategy considering electrified wire netting demand and energy storage unit state of charge (SOC) is proposed, and an adaptive optimization method of VSG parameters under different SOC is given. The energy storage battery can maintain a safe working state at any time and be smoothly disconnected, which can effectively improve the output frequency performance of energy storage system. Simulation results further demonstrated the effectiveness of the VSG control theoretical analysis.