Main Transformer DC Bias Suppression Technology Research And Application

About two-thirds of China’s coal resources are concentrated in Inner Mongolia and Shanxi,the use of these energy sources to generate electricity economically developed areas,need long distance transmission.DC transmission technology for long-distance power transmission,power system operation can improve the economy,and has broad prospects for development.However,the HVDC system prone transformer DC bias,DC bias is outside imposed on the transformer,Guohua Hulunbeier process plant operation,the emergence of transformer DC bias,seriously affecting the security of the AC system and stable operation,so study DC bias suppression and elimination of the normal operation of the power system is of great practical significance.Due to the local power grid Hulunbeier architectural complexity,the presence of AC and DC hybrid power grid infrastructure,the main transformer DC bias,will directly affect the stable operation of equipment and safety systems.Firstly,it analyzes the DC bias mechanism transformer,causes and its impact on the transformer,but also analyzed the DC bias transformer hazards,provide a theoretical basis for this study.Then from the main principle of variable DC bias suppression technology,we analyze the main transformer DC bias supp ression technology,the series capacitance method,several methods series resistor method,analyzes the main transformer DC bias suppression technology.Finally Guohua Hulunbeier Power Plant,for example,analysis of transformer DC bias suppression application,analysis application,the main technical equipment,operation of the device,the operating mode Power Transformer neutral blocking device,etc.,and from on line protection,on the main transformer protection,generator protection on three aspects,analyzes the transformer DC bias suppression devices of.Through case studies,concluded that: the blocking capacitor method to actually take on the system operation mode,aspect of transmission lines,etc.,will not have a greater impact protection,based on the transformer neutral DC blocking capacitor method current suppression device can effectively inhibit the DC current transformer neutral point,in case of a grid failure,the device can protect the transformer security purposes,while the overvoltage condition can not be guaranteed capacitor breakdown.After Guohua Hulunbeier Power Plant and the blocking capacitor means to implement effectively improve the local security and stability of the main transformer.Blocking capacitor device embodiment can effectively avoid the elevated seat transformer current transformer,when the magnetic bias and system failures occur simultaneously,due to system saturation caused by differential,quick-break protection malfunction.Guohua Hulunbeier Power Plant Phase Main Transformer Neutral successful implementation of AC and DC isolated from the system to protect the DC system in a single stage operation mode is conducive to the safe and stable operation of the transformer.