To analyze the impact mechanism of valve flow characteristics on power oscillation

an electromechanical coupling simulation model considering the valve flow characteristics is developed. And simulation is carried out to learn about the impact of numerical deviation and slope deviation of flow characteristics on the step response of the unit power. The simulation results show that if the valve flow characteristics deviation is just a numerical deviation in the absence of any slope deviation from the flow characteristics

the unit power response characteristics will

in the main

remain unchanged. When the slope deviation exceeds the overall stability margin of the closed-loop system of a turbine-generator unit

the unit is prone to power oscillation in the presence of small signal disturbance. This work is supported by the Scientific Research Project of China Southern Power Grid (No. K-GD2013-0491).