Proposal for Virtual Synchronous Machine with Control Voltage on the DC

Abstract

The Virtual Synchronous Machine (VSM) concept is emerging as a flexible approach for controlling power electronic converters in grid-connected as well as stand-alone or microgrid applications. Several implementation of VSM have been proposed with the emulation of inertia and damping of a traditional synchronous machine (SM) as their common feature, however it does not consider the DC bus. The goal of this paper is investigate a VSM implementation based on a Voltage Source Converter (VSC), where the voltage control utilize the dc-bus voltage for stabilize any eventual adversity in the system. In addition, the control system also includes a dq0 current reference control and a frequency droop controller those precedes the VSM. A linearized small-signal model of the VSM, including a converter and an LCL filter, the control system and an equivalent of AC grid, is developed and verified by time domain simulations