New Virtual Synchronous Generator Control Technique of Distributed Generator Unit to Improve Transient Response of the Microgrid

Abstract

To allow a high penetration of the renewable energy into the grid, Distributed Generator (DG) based Virtual Synchronous Generator (VSG) control technique has been proposed. DG units are often connected to low and medium line voltage, where the impedance line is not purely inductive. The active and reactive powers are nonlinear functions, which makes the control of active and reactive power more complicated. Thus, dramatic oscillations of the delivered power and frequency of the DG based VSG may occurred in dynamic steady state. The oscillation of frequency and power could be suppressed by increasing the VSG damping coefficient. However, the response time of the system is increased. The main contribution of this work is to propose a new VSG control technique to improve the dynamic performances of the conventional one. With the proposed VSG technique the damping coefficient is auto-adjustaed to eliminate the power and frequency oscillation without scarifying the response time of the system. The effectiveness of the proposed VSG control strategy is verified and compared with basic VSG control technique by simulation, the results demonstrate the superior performances of the proposed VSG control strategy.