- 學位論文
以EMTP做一次變電所主變壓器激磁特性模擬分析
Analysis of Main Transformer Excitation Characteristics in the Primary Substation Based on EMTP Simulations
摘要
摘 要 本文以電磁暫態程式EMTP來模擬分析台電一次變電所主變壓器之激磁特性。建構EMTP模擬用變壓器模型，此模型考慮到鐵心之殘餘磁通、磁滯迴線環和變壓器其它參數。以EMTP開關模型之切換模式來模擬斷路器各種投入情況之激磁電流和電壓。此開關切換模擬包括三相同步操作、和三相不同步操作(一相延遲動作)等情況。可詳細解析激磁電流和電壓之大小波形和諧波成分。此解析結果顯示不同之開關切換模式將產生不同之激磁突入電流。其中影響激磁特性最大因素為鐵心之殘餘磁通及激磁電壓投入角度。 當開關投入情況為正極性殘餘磁通和激磁電壓波形為非負的且朝正峰值上昇時，及投入情況為負極性殘餘磁通和激磁電壓波形為 非正的，且朝負峰值下降時，將產生大的激磁電流。
關鍵字
無並列摘要
Abstract In this thesis the excitation characteristics of main transformer in the primary substation are analyzed based on the electromagnetic transient program (EMTP) simulations. The transformer model for EMTP simulation is first constructed where the residual flux, hysteresis loop and other parameters of transformer are considered. The excitation inrush currents and voltages with respects to various switching modes of transformer to be energized are simulated. The switching modes including three-pole operation, single-pole operation and three-pole operation with time delay are involved into the simulation. The magnitudes, wave shape and harmonic components of excitation currents and voltage, are analyzed in detail. The simulation results have shown that the different switching modes will have different excitation inrush currents but the dominated factors are associated with the residual flux and switching angle. Large excitation inrush currents will be developed when the switching conditions are such that positive residual flux with non-negative excitation voltage with upward tendency, and negative residual flux with non-positive excitation voltages with downward tendency.