ZHANG Zhong-yuan, CHEN Yu-tong. A High Frequency Circuit Model for Potential Transformer in Gas Insulated Substation Based on the Black Box Method[J]. High voltageapparatus, 2008, (4): 295-297+300.
ZHANG Zhong-yuan, CHEN Yu-tong. A High Frequency Circuit Model for Potential Transformer in Gas Insulated Substation Based on the Black Box Method[J]. High voltageapparatus, 2008, (4): 295-297+300.DOI:
In order to study the interference caused by very fast transient overvoltage on the secondary circuit via potential/current transformers(PT/CT) in GIS
a method for building a high frequency terminal model of PT based on the black box technique was presented.An equivalent π circuit model of PT was set up based on the rational function approximation of admittance matrix Y(s) by means of vector fitting method
and a higher order RLC equivalent lumped circuit was constructed based on the Foster synthesis method.To guarantee the simulation stability of the circuit model
a correction of the real part of Y(s) was made
which enforces the positive-definite criterion(passivity) to be satisfied.The simulation and the measurement results of a real PT confirm the validity of the proposed method.