Nonlinear Transformer Model Considering Losses
Ruan Quanrong1£¬Wang Liang1£¬2£¬Shi Wei1
£¨1£®School of Electrical Engineering£¬Xi'an¡¡Jiaotong¡¡University£¬Xi'an 710049£¬China£»
2£®Power System Division£¬Hebei Electric Power Design £¦ Research Institute£¬Shijiazhuang
050031£¬China£©
Abstract£ºA nonlinear transformer model considering losses is presented£¬ where the
leakage impedance is simulated by an inductance and a resistance in series£¬ and the
exciting branch by nonlinear inductance and resistance in parallel£® The corresponding
algorithm is proposed to demonstrate the subsectionª²linear characteristic curves of the
nonlinear inductance and nonlinear resistance with the data of voltage£¬ current and
power loss that are measured in noª²load test£® The overvoltage due to switch off noª²load
transformer in 330 kV system is evaluated comparatively£® The core losses of transformer
exert a remarkable effect on this kind of overvoltage£¬ whose magnitude approaches to
396.519 kV in this nonlinear model and obviously lower than 723.099 kV for core lossless
and 582.036 kV in linear model£®
Keywords£ºtransformer model£» core loss£» nonlinear£» overvoltage