Employing Virtual Synchronous Generator with a New Control Technique for Grid Frequency Stabilization

Abstract

This paper aims to develop a control technique for grid-interfaced voltage source converters in distributed power generation systems. The proposed method is composed of two control loops, i.e., inner and outer controllers. The former one is based on a fast current control technique, with the capability of handling active and reactive power. The inertial characteristic of conventional synchronous generators is mimicked by means of the outer control loop, with the aim of providing required inertia for the main grid. This developed control strategy results in mitigation of frequency nadir and rate of change of frequency level in the system frequency response, and thereby, frequency stability during disturbances. Herein, the dynamics of the suggested control scheme is first presented in the $dq$ rotating frame for the design of current control loops. Virtual inertia emulation using the frequency-power response based topology is then discussed in detail. Finally, a 200 kVA virtual synchronous generator is simulated in MATLAB to support theoretical analyses and demonstrate the appropriate performance of the suggested technique in control of interfaced voltage source converters between distributed energy sources and power grids.