The Decentralized Coordinated Control For AC/DC Hybrid Interconnected Power Systems

The prominent characteristic of modern power system is to form large-scale AC / DC interconnected power networks. Due to its distinct advantages, HVDC plays an important role in remote power transmission and large-scale interconnected power systems. Consequently HVDC has been being adopted in more and more power systems. The interconnection of power systems is to make power's generating and transmitting more economical and reliable, but at the same time it brings many new dynamic problems which increase the possibility of power systems' losing stability. In interconnected power systems, the spinning reserve of each area should be greatly reduced and the operating condition should increasingly be close to the stability limitation, which causes the stability problem more crucial. The primary means to improve power systems' stability is to develop their control systems. Moreover, the reliability of an interconnected power network needs to be guaranteed by developing advanced control system. With new-style devices such as HVDC and FACTS present in power systems, on the one side the controllable degree of power systems is increased, and on the other side, the stability and control characteristic of power systems become more complex. Because each of the controllers uses local and uncoordinated control strategy, there may be unstable interactions between controllers. So it is necessary to integrate and coordinate all kinds of controllers.This dissertation aims to study the decentralized coordinated control for AC / DC hybrid interconnected power systems, especially the system characteristic analysis and coordinated control for HVDC links. The main objects of this thesis is to design decentralized coordinated schemes, by utilizing the quick response ability of HVDC links, to improve the global stability and to damp the oscillation of AC / DC hybrid interconnected power systems. In this field, some innovative work has been made: (1) Based on correlative measured vector, a correlative measured decentralized coordinated control strategy is firstly presented for AC / DC hybrid interconnected power systems, which only require local information and is a simple...