一种计及损耗的变压器非线性模型

建立了一种计及损耗的变压器模型，用线性电阻、电感的串联模拟漏阻抗，用非线性电阻和非线性电感的并联模拟励磁支路，并提出建模算法，由变压器空载试验测得的电压、电流有效值和功率损耗，得到非线性电阻和非线性电感分段线性化的瞬时值特性曲线．应用该变压器模型和另两种模型，分别对330kV系统中的切除空载变压器过电压进行了仿真，对比计算表明，计及变压器铁损的非线性后，切除空载变压器过电压有明显的降低，过电压的幅值由忽略铁损的723．099kV和用线性电阻模拟铁损的582．036kV，降低到铁损的非线性模型的396．519kV．该变压器模型有助于准确地对电力系统中涉及变压器饱和特性的现象进行研究．

Nonlinear Transformer Model Considering Losses

A 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 subsection-linear characteristic curves of the nonlinear inductance and nonlinear resistance with the data of voltage, current and power loss that are measured in no-load test. The overvoltage due to switch off no-load 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.