A novel transmission line pilot protection principle based on current model recognition

作者：Jiale Suonan^*; Ma Chao; Kang Xiaoning; Wang Chenqing; Liu Xin; Li Zongpeng

来源：Proceedings of the CSEE, 2012, 32(19): 109-116.

• Capacitive currents
• Current data
• Current differential
• Distributed capacitance
• Distributed capacitive current
• Distributed parameter
• External fault
• Fast operation
• Fault component
• Fault data
• High sensitivity
• High voltage
• Internal faults
• Long transmission lines
• Matrix pencil
• Model errors
• Model recognition
• On currents
• Pilot protection
• The standard model
• Theoretical expression
• Transient current

Due to the distributed capacitance, the performance of current differential pilot protection will deteriorate when applied to ultra/extra high voltage long transmission lines. Considering matrix pencil algorithm can analyze the composition of transient currents, a novel pilot protection principle using only current data was proposed which can be applied to distributed parameter transmission lines. This principle adopted model recognition concept. Firstly, the theoretical expression was derived which described the ratio between the sum and difference of two terminal fault component currents, and the expression was treated as the standard model. Then the model error function was defined while the function measured the extent to which actual fault data accorded with the standard model. When an external fault occurs, fault data correspond with the standard model and model error equals zero. When an internal fault occurs, fault data do not correspond with the standard model and model error does not equal zero. Therefore, external fault and internal fault are distinguished. This principle is immune to the distributed capacitance and it is unnecessary to compensate the capacitive current. Besides, fault current data are fully used and filter becomes unnecessary. Moreover, fast operation speed and high sensitivity can be attained. Both ATP simulation results and dynamic simulation results show that the proposed principle is effective and reliable.

• 出版日期2012