Research On Fast Dynamic Performance And Control Strategy Of Magnetically Controllable Reactor With Multi-Configuration FACTS Technology

With the developing of flexible AC transmission system(FACTS),many reactive power compensation devices,such as Static Synchronous Compensator(STATCOM),Static Var Compensator(SVC)and Fixed Capacitor(FC)are used to improve the flexibility,economy,reliability as well as the stability of the power system whose voltage profile ranging from 110KV-500 KV.However,there are some factors that limiting the wide installation of the FACTS devices:with the use of power electronic element in the main compensating circuit,large quantities of harmonics would be bring in the system;furthermore,power electronic element need to be designed to sustain high voltage,current and power,as a result the cost will be very high.Magnetically controllable reactor(MCR)is becoming more important among the aforementioned FACTS devices: 1)As the power electronics used in the MCR are not directly attached to the power system,a wide range of voltages below 110 k V and over 500 k V can be operated by MCR.2)Furthermore,it can compensate the reactive power without introducing a lot of harmonic contents.In this way,the MCR can not only improve transmission power but also improve power quality and voltage regulation in HV and UHV with simple control,low cost,and low harmonics and a wide range of applications.However,although the benefits of using MCR,as a magnetic-controlled device,MCR suffers from a slow dynamic response to meet the desired voltage regulation due to the inherent hysteresis effect.Moreover,only relying on a single MCR can only perform inductive reactive power compensation for the system and cannot perform capacitive reactive power compensation.Therefore,a single MCR does not have the full range of inductive to capacitive reactive power compensation capability that mainstream FACTS devices can provide.In order to fill the mentioned technological gap,firstly,the working principle,hysteresis characteristics of MCR,physical as well as the mathematical model and the equivalent electromagnetic model is presented in this dissertation.Secondly,the fast reactive power compensation strategy by using dual parameters based Voltage Current Control(VCC)system is proposed to improve the dynamic response of the traditional MCR.Thirdly,the factors affecting the dynamic performance of typical MCR,the principle to improve the dynamic performance of typical MCR and the fast exciting MCR with rapid magnetization and demagnetization strategy is further proposed by theoretical analysis as well as simulation studies;Fourthly,a novel multiFACTS configuration,considering the combination of the MCR and other existing FACTS,and the corresponding multi-FACTS coordination control strategy is proposed to realize the full range of smooth compensation from inductive reactive power to capacitive reactive power.And finally,a modified IEEE 30 bus radial simulation system is built in PSCAD/EMTDC for the validation of the proposed coordination control strategy.The research achievements of this dissertation can be used to solve the reactive power compensation problem in the developing power system,which can provide voltage regulation quickly,reliably and flexibly in an economical way.