In order to reduce the frequency of real-time data transmission between (WAMS) and phasor measurement unit (PMU)

without affecting the advanced applications of WAMS

this paper presents a “three-segment variable rate transmission” method of the PMU data. The status of the WAMS/PMU application is introduced

and application scenarios for PMU data are summarized. And then “three-segment variable rate transmission” of PMU real-time data that divides PMU data transmission into 3 segments is proposed. During steady state

PMUs will transmit real-time data at rate FL. When disturbance occurs

firstly PMU will send out A-segment data in buffer immediately. Then B-segment data during disturbance will be transmitted at rate FH

and finally reporting rate will be lowered to FL to transmit C-segment data after disturbance. By extending the existing PMU

a “three-step variable rate transmission” method compatible with the existing PMU communication protocol is achieved. Finally

the feasibility and effectiveness of the method is verified via simulation. This work is supported by National Natural Science Foundation of China （No. 61233007）

State Grid Corporation of China and Electronics and Information Industry Development Foundation of China.