关键词:

虚拟同步发电机, 转动惯量, 阻尼系数, 自适应控制

Abstract:

 [Objectives] Traditional power grids rely on the inertial response of synchronous generators to maintain frequency stability. However, the volatility, low inertia, and frequency regulation delay of photovoltaic (PV) generation exacerbate frequency fluctuations and lead to insufficient dynamic response under sudden changes in illumination or load disturbances. Moreover, the fixed parameters of conventional virtual synchronous generators (VSG) struggle to adapt to multiple operating conditions. To address these issues and enhance the frequency stability and dynamic regulation performance of PV-integrated power systems, this study focuses on adaptive optimization of the VSG moment of inertia and damping parameters. [Methods] First, a theoretical analysis was conducted to reveal the coupling influence of moment of inertia and damping coefficients on system stability. Based on this, a cooperative adaptive algorithm for inertia and damping was proposed. This algorithm dynamically adjusts the moment of inertia and damping values by real-time monitoring of frequency deviation and its rate of change: increasing inertia during the initial stage of frequency fluctuations to suppress overshoot, and reducing inertia during the recovery phase to accelerate regulation. Additionally, a band-pass damping power feedback loop was introduced to effectively suppress steady-state error. [Results] Simulation results demonstrate that, compared to conventional fixed-parameter control, the proposed strategy effectively reduces frequency overshoot, shortens regulation time, and achieves a smoother dynamic response. System stability under various operating conditions, such as sudden changes in illumination and load disturbances, is significantly improved. [Conclusions] The proposed cooperative adaptive control strategy for inertia and damping optimizes VSG parameters in real time based on system frequency dynamics, effectively mitigating frequency fluctuations in PV-integrated power systems. This provides a feasible technical approach for ensuring the stable operation of power systems with high penetration of renewable energy.

Key words: virtual synchronous generato, moment of inertia, damping coefficient, adaptive control