Adaptive Virtual Synchronous Generator Based on Model Predictive Control with Improved Frequency Stability

Abstract

With the massive integration of renewable energy into the grid, grid inertia and its stability continue to decrease. To improve inertia and facilitate grid restoration, a control strategy for radial basis function virtual synchronous generators based on model predictive control (MPC-VSG-RBF) is proposed in this paper. In this method, virtual synchronous generator (VSG) control strategy is introduced into the model predictive control (MPC), so that the reference value of the inner loop current can vary with the grid voltage and frequency. Using the radial basis function (RBF) neural network to adjust the VSG virtual inertia online can solve the large fluctuation of frequency and power caused by excessive load fluctuation. The simulation model was built based on MATLAB and compared and analyzed with the MPC control method. The simulation results show that: when the output power of the inverter changes, the model predictive control of the adaptive virtual synchronous generator can increase the inertia and stability of the power grid; by adjusting the moment of inertia, the system damping ratio is improved to effectively suppress the transient process overshoot and oscillation in medium power.

VSG‐controlled parallel‐connected voltage‐source converters in low‐voltage microgrid with dominant resistive impedance

“…In [27], a damping term produced from a state feedback control is added to a VSG control and applies a low pass filter to the measured active power to improve its ripple attenuation ability at the cost of increased design complexity. In [28], a VSG control strategy based on improved damping and angular frequency deviation feedforward is proposed to address the problems of oscillation and steady‐state errors. A relatively large virtual inertia in a VSG may result in power oscillation, and consequently in [29] a control scheme is suggested to mitigate the power oscillation by adjusting virtual synchronous reactance, damping and load frequency coefficients.…”

An Adaptive Inertia and Damping Control Strategy Based on Enhanced Virtual Synchronous Generator Model

“…There is always a need to find a trade-off between reliability and efficiency of regulation, e.g., during changes in grid strength [15]. Thus, given the continuously changing total inertia in modern power systems, the virtual inertia formed by VSG must be adaptive to changing grid conditions to provide permissible ranges in RoCoF and magnitude of frequency deviation [16,17].…”