考慮自備電源之特高壓供電科技廠接地故障及諧波特性分析

Analysis of Ground Fault and Harmonic Characteristics in the High-Tech Industrial Plants Supplied by VHV System Considering the Backup Power Supply System

陳璟漢(Ching-Han Chen)

指導教授 ： 周至如

國立臺北科技大學/電資學院/電機工程系所/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00072

摘要

本研究主要分析特高壓(161kV)供電科技廠內供電系統及接地系統於高壓接地故障時之暫態與穩態特性，以及平時運轉之諧波特性並評估其影響，首先應用電磁暫態分析軟體(EMTP/ATP)建構電路模型，模型涵蓋特高壓變電站等效模型、主變壓器、高壓電纜、高壓變壓器、下游系統負載以及各種設備接地線等。並且使用所建構之模型進行分析單相接地故障之暫態與穩態特性，其中故障位置分別為主變壓器二次側之高壓匯流排(22.8kV)匯流排、下游高壓(22.8kV)馬達匯流排及自備電源昇壓變壓器一次側(4.16kV)等三種情況，並考慮市電與自備電源併聯供電及單獨供電，且下游負載含有諧波電流。此外，藉由前述分析所得注入接地網之電流，再應用接地系統分析軟體(CDEGS)來模擬地網電磁暫態及穩態特性包括地電位昇(GPR)、地表電位、接觸電壓、步間電壓、導體電流及地表電磁場之分佈狀況，其中各地網間互連之情形亦加以比較差異，藉由上述分析結果，最後將評估可能發生之風險包括對於人員與設備所受的影響。

關鍵字

接地故障 ； 諧波電流 ； 地電位昇 ； 步間電壓 ； 接觸電壓 ； 地表電磁場

並列摘要

The thesis is to study the characteristics of transient state and steady state of power supply system and grounding system with respect to high voltage grounding faults in the high-tech plaints supplied by 161kV power, and to analyze the harmonic characteristics during normal operation and assess their affections. The circuit model is first constructed by using the electromagnetic transient program/ alternative transient program (EMTP/ATP), in which the very high voltage (VHV) substations, main transformers, high voltage cables, down-stream system loads and each equipment grounding lines are considered. The model is used to analyze the characteristics of transient state and steady state of single-phase ground fault. Three fault points, namely, the second of main transformer, down-stream high voltage bus, and the primary of a step-up transformer of back-up power system are analyzed, besides, the conditions of with and without back-up power system interconnected, down-stream load included harmonic current sources are also considered. Based on the simulation results, the fault currents injected into grounding system at fault points are obtained and the electromagnetic characteristics values of ground grids are further analysis. Finally, a software package for grounding system analysis, namely, CDEGS(Current Distribution Electromagnetic Grounding and Soil Structure Analysis) are used, from which we can find the distribution of ground potential rise (GPR), potential on the ground surface, touch voltage, step voltage, conductor current and electromagnetic field (EMF) on the ground surface. All the electromagnetic characteristics of grounding system for both case of with and without interconnection between main ground grid and down-stream ground grid are analyzed and compared. Then based on the above analysis results, the affections on personnel, equipments and systems are evaluated.

並列關鍵字

Ground Fault ； Harmonic Current ； Ground Potential Rise (GPR) ； Step Voltage ； Touch Voltage ； Electromagnetic Field (EMF) on the Ground Surface

參考文獻

[1] 林南瑞，「大型科技廠接地系統之接地故障特性研究」，中原大學碩士論文，民國九十二年六月。

[24] 邱森福，「大型科技廠特高壓及高壓配電系統之地電流特性分析」，中原大學碩士論文，民國九十三年六月。

[26] 胡開泰，「多地網大型接地系統接地故障之電磁特性研究」，中原大學碩士論文，民國九十年六月。

[27] 吳基福，「考慮人孔接地條件探討特高壓地下環路接地系統之接地故障特性」，中原大學碩士論文，民國九十四年七月。

[43] 溫茂廷，「特高壓地下環路接地系統開關突波特性研究」，中原大學碩士論文，民國九十五年六月。