A Reference-Feedforward-Based Damping Method for Virtual Synchronous Generator Control

Abstract

The virtual synchronous generator (VSG) control has been extensively applied for realizing grid-friendly interconnections of power converters. Nevertheless, due to the direct shaft dynamics emulation, low-frequency power oscillations may be introduced in the case of limited damping effects. To solve this issue, power control law modifications have been proposed based on the feedback control theory. Although power oscillations can be suppressed to an acceptable level, the original inertial response of VSG will be significantly degraded. This paper proposes a new damping method based on the reference feed forward (RFF) control. The proposed method is able to effectively attenuate poorly-damped power oscillations in VSG-controlled converters without affecting the original inertial response. Theoretical analysis and effectiveness of the proposed damping method have been validated by both EMT simulations and experiments.

Fuzzy model predictive control for frequency regulation of temporary microgrids during load restoration

“…After the first-order Euler discretization, the continuous state space function is converted to the discrete state space function, as shown in (15).…”

“…However, in contrast to daily small power disturbances which are random and unpredictable, the huge load selected to be restored at the next time step for temporary microgrids can be optimized and obtained in advance, which can be regarded as the feedforward information and play an important role in frequency control. Feedforward control strategies are usually derived by precise calculations based on system dynamics [15, 16], and have already been utilized in the field of frequency regulation during the restoration process. In [17], the network configuration during load restoration is calculated as an already‐known disturbance, to provide guidance for better frequency control performance.…”

Fractional-Order Virtual Synchronous Generator

“…4 and 5, respectively. In accordance with [11]- [13], the pole-zero map and the step response of ∆P/∆P * = G(s)/[1 + G(s)] are used for assessing the active power control in the grid-tied case, and the frequency response and the step response of ∆ω m /∆P = F (s) are used to assess the frequency dynamic in the islanded case.…”

“…To avoid the inertial effect degradation, control schemes simultaneously considering the damping and the inertial effect were developed in [11]- [13]. Specifically, Meng et al gave a solution using the active power derivative in [11].…”

Phase Angle Feed-Forward Control for Improving the Power Reference Tracking of Virtual Synchronous Machines

“…A feed-forward path from the power reference to the frequency of the VSM swing equation, based on a transfer function with two terms, was also proposed in [24]. However, the purpose of this approach was mainly to damp oscillations, and one of the transfer function terms included a limited derivative action to avoid influencing the steady-state characteristics.…”