Study On Main DC Circuit For The HVDC Transmission Project With Double DC Line On The Same Tower

In order to implement the"West-East power transmission project", the long-distance high-power high-voltage direct current transmission technology has been widely used in the domestic grid construction in recent years. In order to reduce the construction costs, the transmission line must be shorten and the reasonable use of the grounding site and the resources of converter station site must be taken into consideration. The power transmission project of the Xiluodu Right Bank Power Station to Guangdong is the first time to apply the dual DC (±500kV) project in the world. There are two±500kV converter station sites and double circuit DC transition built in the same place at the same time. This is a project with the advanced technology. As one of the key issues, it is necessary for us to study the DC circuit in the DC converter stations with the double DC Line on the Same Tower。This thesis mainly studies the power transmission project of the Xiluodu Right Bank Power Station to Guangdong Province. Based on the commonly used DC circuit configurations which is widely used in the current high-voltage direct current transmission project, this thesis combined with the double-circuit HVDC transmission tower construction site with the characteristics of the same period and sharing the common ground. As for the DC DC circuit in the neutral converter station, the thesis put forward several alternative suggestions to the lines between the high-voltage lines. Besides this, this thesis also analyzed the operating performance of all the connection schemes, including the transmission power, line losses, the comparison of the ground current in both the technical and economic perspectives, together with the control and protection of the various programs and other factors. This thesis proposed the DC circuit scheme for the Double DC Line on the Same Tower project in the converter station and determined a reasonable operation mode for the connection of DC circuit. Then, with the help of the computer program HAP developed by ABB, this thesis verified and compared the filter performances of the two DC filters in a variety of connection schemes and recommend some related solutions. After the steady-state calculations, the thesis finally made recommendations to the DC filter wiring components a corresponding fixed value.The results of this study provide the technical support to the power transmission project of the Xiluodu Right Bank Power Station to Guangdong Province which is under construction now. Besides this, it also provides some guidance and reference to the subsequent design of similar projects in the future.