风电场箱式变压器高压侧短路电磁暂态过程研究

Research on Short Circuit Electromagnetic Transient Progress of the Wind Farm Box-type Transformer High Voltage Side

能够接纳以风力发电为代表的清洁能源发电是智能电网的重要特征。风力发电机组一般通过箱式变压器将风电机组出口较低电压等级变换到较高的电压等级后接入电网。箱式变压器作为风电机组能够并网运行的重要环节,其暂态运行特性对风电机组和电网的安全稳定运行具有重要作用。为了研究风电场箱式变压器高压侧短路时的电磁暂态过程,以单相变压器的等效电路为基础,从电路分析的角度研究了变压器二次侧突然短路时的暂态过程,建立了变压器二次短路时的数学模型,并对模型进行了求解和讨论。基于PSCAD/EMTDC电力系统仿真平台,搭建了风电机组通过箱式变压器接入电网的仿真模型,仿真分析了变压器二次侧短路时短路电流的变化规律,验证了模型的有效性。

Acceptance of clean energy is one of the features in smart grid. Wind power has become an important part of the sustainabledevelopment strategy. Wind turbines convert low voltage into high voltage by box-type transformer, electromagnetic transient characteris-tics of which plays the important role to the safety of wind turbines and integration. It is based on the equivalent circuit of single-phasetransformer to analyses the short circuit transient characteristics of its high voltage side. Math method on secondary short circuit currenthas been set, calculated and discussed. With the help of PSCAD/ EMTDC, the model that wind turbines integrate to the grid by box-type transformer has been simulated. The variation characteristics of transformer secondary short circuit current have been analyzed andthis model has been validated by the simulation result.