Intelligent Damping Control of Long-Distance Transmission in Large-Scale Energy Base

摘要

Series Compensated Transmission Systems and AC/DC Hybrid Transmission systems are commonlyrnused to transport electricity from generating units in the large energy base to a long distance. Theserntransmission systems increase the risk of sub-synchronous oscillation while improving transmissionrncapacity at the same time. So how to improve the damping level of the sub-synchronous oscillationrnand ensure the safety and stability of regional power grid and generating units is one of the key issuesrnneeded to be urgently addressed in the construction of large power grids. In this paper, dampingrncontrol measures used in long-distance electricity transmission are deeply researched, and methods forrnmitigation of sub-synchronous oscillation by improving damping are detailed introduced.rnFirst of all, the mechanism of sub-synchronous oscillation in Series Compensated TransmissionrnSystems and AC/DC Hybrid Transmission systems has been studied in this paper. We use damping tornmeasure the harm degree of sub-synchronous oscillation. Different solutions aimed to improve therndamping were proposed and the characteristics of different methods were analyzed and compared.rnSecond, in order to solve the sub-synchronous problem in Compensated Transmission Systems andrnAC/DC Hybrid Transmission systems, we proposed three damping control methods in this paper, thernSupplementary Excitation Damping Control (SEDC), Generator Terminal Sub-synchronous DampingrnControl (GTSDC) and Sub-synchronous Damping Control method used in DC Transmission Systemrn(SSDC). In addition, we studied the principle of controller parameters design, the process of subsynchronousrnoscillation signal including signal extracting and filtering, the relationship and interactionrnof different sub-synchronous damping control methods. Above all, we put forward the fieldrnapplication solution which can be briefly described as follows, the combination of SEDC and GTSDCrnbe used in AC Compensated Transmission Systems, and the combination of SEDC and SSDC be usedrnin DC Transmission Systems to achieve the aim of improving damping of system in sub-synchronousrnoscillation.rnFinally, the function of damping control in sub-synchronous oscillation is verified by Real-timerndynamic simulation based on the RTDS platform. The simulation results show that the subsynchronousrndamping controller can effectively improve the sub-synchronous damping level and canrnbe used in field applications. It is an effective and economical way to solve the sub-synchronousrnoscillation problem in the long-distance transmission of large-scale energy base.