The Virtual Synchronous Generator control for transient stability support in power systems with large-scale renewable plants

Abstract

The dynamic security assessment of power systems is a critical activity to ensure a safe energy delivery to consumers and the study of transient stability is a fundamental part of this process. The power systems are experiencing a growth of large-scale renewable energy plants connected to the system, which in turn are connected to the grid by power converters that are not capable of contributing to the system inertial stabilization and, therefore, could compromise its transient stability. One way to mitigate this problem is to make these plants contribute to the system stabilization by adopting specific control strategies, such as the virtual synchronous generator (VSG), for their interface power converters. In this paper, a quantitative evaluation of the transient stability support of a VSG is proposed in large-scale applications. For this purpose, the stability assessment of a single-machine infinite-bus (SMIB) system with the VSG is done using transient stability metrics such as the critical clearing time (CCT) and the transient stability index (TSI). In addition, the same analysis is made for a conventional synchronous machine (SM) and the results are compared and discussed. Furthermore, the VSG parameters adaptability is presented as an alternative to optimizing the system stability.

Keywords

• transient stability
• critical clearing time
• power systems
• virtual synchronous generator