An Improved WAMS Framework for Multi-modal Oscillation Detection in a Power Electronics Dominated Power System

In power electronics dominated power systems, the multi-modal oscillation becomes one of the culprits that threaten the system stability. However, the existing wide-area measurement system (WAMS) focusing on single-modal oscillation such as low-frequency oscillation. It fails in meeting the requirements of multi-modal oscillation monitoring due to the adoption of conventional phasor measurement units (PMUs). Therefore, in this paper, an improved WAMS framework is proposed. The modifications include the deployment of wide-band phasor monitoring units (WPMUs) at several vital nodes to detect oscillation dynamically and trigger the wave-recording function of traditional PMUs simultaneously when oscillation is detected. The synchronized multi-modal phasor data captured by WPMUs, together with the recorded wave data, will be transmitted to the master station for real-time oscillation analyzing. While meeting the requirements of wide-band oscillation monitoring, the proposed framework can be compatible with the existing hardware and communication architecture to the greatest extent without affecting the operation of the present WAMS system. The practice of the proposed WAMS framework on a realistic regional power grid has validated the feasibility, the backward compatibility, and the multi-modal oscillation detection capability.