A time delay model of the wide area monitoring and control system

Abstract

A phasor measurement unit (PMU)-based wide area monitoring and control (WAMC) system is an essential part of the next-generation smart power grid. The performance of a WAMC system largely depends on the time delay of transmitting data through the communication network used by the WAMC system. This paper proposes a time delay model of the WAMC system. The model considers the time delays caused by data sampling of PMUs, data propagation in the communication network, and data processing in the control center. An algorithm is proposed to determine the shortest-time route and calculate the corresponding shortest routing time between each PMU and the control center, from which the components of the proposed time delay model can be calculated. According to the time delay calculated by the proposed model and a marginal processing time in the control center defined in this paper, the possibility of the appearance of a hidden cascading failure of a power grid can be evaluated. The proposed time delay model is demonstrated by case studies of a WAMC system communication network in a normal and a fault conditions.