Power System Stabilization Using Virtual Synchronous Generator With Alternating Moment of Inertia

TLDR

The virtual synchronous generator (VSG) is a control scheme applied to the inverter of a distributed generating unit to support power system stability by imitating the behavior of a synchronous machine. The paper elaborates a VSG with alternating moment of inertia to enhance system stability. The VSG is modeled with a swing equation whose parameters are controllable in real time, allowing a virtual inertia that can be alternated to improve fast frequency response and damping, as investigated through transient energy analysis and evaluated for its effect on neighboring machines. Simulations and experiments confirm that the alternating inertia VSG markedly improves fast damping of oscillations.

Abstract

The virtual synchronous generator (VSG) is a control scheme applied to the inverter of a distributed generating unit to support power system stability by imitating the behavior of a synchronous machine. The VSG design of our research incorporates the swing equation of a synchronous machine to express a virtual inertia property. Unlike a real synchronous machine, the parameters of the swing equation of the VSG can be controlled in real time to enhance the fast response of the virtual machine in tracking the steady-state frequency. Based on this concept, the VSG with alternating moment of inertia is elaborated in this paper. The damping effect of the alternating inertia scheme is investigated by transient energy analysis. In addition, the performance of the proposed inertia control in stability of nearby machines in power system is addressed. The idea is supported by simulation and experimental results, which indicates remarkable performance in the fast damping of oscillations.