Study On Simulation Of Extra High Voltage Transmission Line Protective Relay And Development Of Transmission Line Longitudinal Protective Relay

Modern extra high voltage (EHV) and ultra high voltage (UHV) networks require faults to be cleared rapidly and selectively as an effective method to increase power transfer and improve transient stability. This has motivated research on ultra high-speed (UHS) protection. The UHS directional protection has been widely used in EHV and UHV power systems as it can quickly isolate the fault and needs only limited data communication. The dissertation is focused on the development and simulation of new generation transmission line protection. At first, the summary of development of EHV transmission line protection is presented here. The history, nowadays and future of developing direction is given. The dissertation is based on these surveys.Utilized variety rule of superimposed component of compensation voltage and busbar voltage when forward and backward fault occurred, this dissertation put forward the fault directional discriminating criteria based on superimposed component of compensation voltage. Based on particular analysis of characteristic of presented scheme on different working condition, the setting rule is given. And the simulation and analysis of presented scheme is introduction. The software architure based on logic variables has been created. This architure reinvent software development of traditional digital protective relay. This developing model is decrease the requirement of programming skill of developer. At same time, this architure can help the analysis of the characteristic of protective relay. The prototype of new generation protection was passed the examination of experts on power system dynamic simulation lab. And nowadays it has been installed on industry field.Aim to develop the EHV transmission line protective relay, the general simulation platform aim for protection developing was established. This platform decreased depending of hardware test device in some extent and improved efficiency of protective relay development.At last, in this dissertation, a novel wavelet-based ultra high speed directional transmission line protection scheme is presented. It has been verified by the electromagnetic transient simulation program. And the amelioration of scheme is pointed.