Development Of A Novel Excitation System Based On Voltage Source Converter

With China’s growing commitment to the development of the grid area interconnectedcause, the scale the power system is growing day by day, the capacity of huge synchronousgenerator using rapid excitation system is expending. But great risks have threatened thesecurity of power grid in the form of a wide range of inter-regional power low-frequencyoscillation, causing damping decreasing of the entire grid continuously. One of mosteffective and economical measures to solve low-frequency oscillation is excitation control.In this paper, combined with high-power power electronics technology and its wideapplication in power system, a novel self shunt excitation system based onfull-controlled-devices rectifier is presented. Relying on existing theories, the controlstrategy for a novel excitation system based on voltage source converter is proposed, andthe excitation system is designed and developed. Through dynamic experiment, the systemis not only able to complete the basic functions of the traditional excitation system, but alsohas the ability to enhance power system damping.This paper refers excitation system based on voltage source converter to excitationsystem based on current source converter as the research object. The basic workingprinciple of the main circuit is introduced; The excitation system control strategy isanalyzed in details; The power unit of the excitation system is designed and establishedmatching to the parameters of synchronous generator set designed for dynamic simulationexperiments; The excitation controller hardware system is designed and developed; Thesoftware system for excitation control system appointed DSP as the core is developed; Thedynamic experiment is accomplished in a single machine infinite bus system.The experimental results show that the novel excitation system can realize of the basicfunctions of the traditional excitation system, its reactive-power-injection unit has theability to improve power system damping, while reducing low-frequency oscillationeffectively, the grid’s stability enhanced.