- 學位論文
台灣高速鐵路主變電站之三相電壓不平衡率計算
Numerical Evaluation on the Main Substation Three –phase Voltage Unbalance of Taiwan High Speed Rail
摘要
台灣高速鐵路長約345公里，沿線設置七個主變電站，採2×30 kV AT饋電方式，將三相電源經由史考特變壓器轉變為二個單相電源（M相與T相）送電至電車線及負饋線，而引發三相不平衡問題，列車經由集電弓擷取列車牽引動力所需電力，當列車速度逐漸增加時所需負載功率也逐漸增加，造成高鐵主變電站於責任分界點之三相不平衡問題顯著。 本文針對台灣高速鐵路七個主變電站進行負載模擬及三相電壓不平衡率計算，採用台電系統之短路電流值，依據對稱成分分量法，引述高鐵三相不平衡率速算公式，模擬七個模擬區間內容及十種模擬狀況，以MATLAB程式計算高速鐵路主變電站負載，計算上、下行之南北側負載差及三相電壓不平衡率。 由模擬結果可知，在短路容量較少之楊梅、苗栗、雲林及新營等高鐵主變電站的三相電壓不平衡率可能高達1.125%、1.1724%、1.5529%及1.1305%，超過台電公司的三相電壓不平衡率1.0%的限制，其中以高鐵雲林主變電站的三相電壓不平衡率可能高達1.5529%最為嚴重；若採降低總負載量及降低主變電站負載差異量可以有效地降低電壓不平衡率，高鐵主變電站應避免發生故障或單側負載異常增加，及適當調整班距運轉，以減少對電力系統的衝擊，或加裝適當的補償器（例如SVC）以改善三相電壓不平衡現象。
並列摘要
Seven bulk supply stations erected along the 345 km long HSR. In principle, the stations are designed to be operative even if any one of then fails. To meet the requirement of dual-circuit and three-phase input, each circuit adopts one set of transformers with the primary connected to Scott wire. Each bulk supply station uses 4 sets of autotransformers. The traction power required for trains is supplied by feeding a 2x30kV voltage from these seven stations to the overhead catenary system, the traction car then picks up with its pantograph the 30kV power between the catenary and tracks for use in train. Two sets of same phased power on the secondary end of transformer be fed to the overhead catenary in parallel. The feeder adopts the type of 2x30 kV +AT that is more consistent with the trend of application at this time. With increase of speed, high-speed trains requires more current, and with the development of electronic control circuits, their advantage is that the problem of the phase unbalance coming from power stations. This paper presents methodologies and results of numerical evaluation on the three-phase voltage unbalance, which accounts for unbalanced load from 7 main substations of Taiwan High Speed Railway.