Complex Torque Coefficient Scanning Analysis Method And Damping Characteristics Research

In recent years, the rapid development of series compensation and HVDC technology in our country, give a certain risks of sub-synchronous oscillation to our power grid. With the complicated structure of the grid, the study on SSO issue will be important. Complex torque coefficient method is a frequency-domain analysis,which can give more precise and quantitative research systems SSO detailed characteristics, Complex torque coefficient method based on time-domain simulation can combine with each’s advantage, which will be helpful for a further research on SSO.In this paper, complex torque coefficient and its realization based on time-domain simulation is depth studied, the main contents are:(1) This paper describes the principles of complex torque coefficient and describes the use of the Nyquist criterion to prove complex torque coefficient method and its criterion. The applicability of complex torque coefficient method in multi-machine system is analyzed, summarized the previous application of the principle of complex torque coefficient method in multi-machine system.(2) Complex torque coefficient method based on time-domain simulation is studied, prepared complex torque coefficient scanning modules are realized on the the electromagnetic transient software PSCAD, including mechanical complex torque coefficient scanning module, electrical complex torque coefficient scanning module and3D complex torque coefficient scanning module, the principle of the three modules are described and validated on the first IEEE SSO standard model. the factors affecting the accuracy of the scanning module are studied.(3) The damping characteristics of Hubei plant is analyzed with the complex torque coefficient method. The impact of HVDC and SSDC on the damping characteristics of the HuBei plant are analyzed using complex torque coefficient method and time-domain simulation method.