Communication delay in the wide area measurement system (WAMS) is a not-to-be-neglected factor during controller design yet lacking an effective model for its description. A method based on a probabilistic model for describing the communication delay in WAMS is proposed. Under the actual operation condition of WAMS of Zhejiang Power Grid

the communication delay between phasor measurement units (PMUs) substation and the main station of WAMS is measured and the statistical characteristics of the delay are analyzed based on the characteristics of the data packets and structure of WAMS. It is shown that: the average communication delays of all substations are less than 100 ms; in most substations

the measured data that are over 100 ms accounts for less than 1% of the total measurements. Finally

a model of communication delay is built based on the probabilistic model and the large amount of actual operation data measured in the WAMS of Zhenjiang Power Grid. The result indicates that Rice distribution is able to effectively show the probability distribution characteristics of communication delay in WAMS during different periods of time and in different PMU substations. This work is supported by National Natural Science Foundation of China (No. 51137003

No. 51407160)

Ph.D. Programs Foundation of Ministry of Education of China (No. 20120101110081) and State Grid Corporation of China (No. 5211011400B8).