Research On Control System Of Back-to-Back HVDC Power Station

At present HVDC transmission technology has become mature gradually, its advantage in long distance power transmission and interconnection between power grids has been applied worldwidely as a powerful supplement to the technology of AC power transmission. Especially in the power grids interconnection, the Back-to-Back HVDC transmission system has become a hot research of the interconnection between different power network system since the first Back-to-Back transmission engineering of our country–The Lingbao Back-to-Back transmission project put into operation. Along with more and more back to back HVDC transmission project construction and operation, it is necessary to do deeper research and the development in its control system.The present paper takes the Hunan University test platform of new technology in power transmission which based on the key science & technology project 05GK1001-2 of the Tenth Five Year Plan of Hunan Province–research & manufacture of new-style converter transformer in HVDC power transmitting system as depend, has made a series of research work on the back to back convertor station control system. First it briefly introduced the application domain and the present situation of research of HVDC transmission project. Then it elaborated the back to back direct current transmission system and its control system, simultaneously introduced the new-type converter transformer which the test platform uses, mainly about its design feature and its new-type filtering way. System cascade control of the test platform and the way to realize were mentioned, also. Then it expounded the theory of the HVDC pole control system, and established a system simulation model of the new HVDC transmission control system in MATLAB, and carried on the simulation analysis under the situation which adopted VAPID controler to its stable state operating characteristic, and then picked up its deficiency. Afterward a HVDC transmission control system simulation model which based on BP neural networks PID controler through the S function was designed, and carried on the simulation analysis for the characteristics of its stable state operating. Finally, a hardware platform based on DSP/CPLD which can be used in the Back-to-Back HVDC transmission control system has been designed.