機場捷運廠商得標後執行供電系統設計時，首須進行各項系統模擬分析，以驗證並確認系統架構、供電模式、變電站位置、各項供電設備型式與容量等，以符合系統運轉需求，並作為後續設計依據。供電系統模擬分析項目，計有直流牽引動力負載分析、交流分析、諧波分析、短路電流分析、發電機容量及傅倫第效應（Ferranti Effect）分析、系統保護協調分析等。其中交流分析所模擬驗證範圍，包含從各主變電站（BSS）的AC 161kV電源側，經系統AC 22kV側，分至車站設施變電站（SSS）的AC 380V側及牽引動力變電站（TSS）的AC 589V側。
機場捷運系統交流模擬分析，係採用「ETAP 5.0」來進行，模擬模式計有7個情境，分為：正常營運（各BSS皆正常供電）、青埔BSS 161kV故障時之非正常營運、A8 BSS 161kV故障時之非正常營運、A3 BSS 161kV故障時之非正常營運、青埔BSS 22kV故障時之非正常營運、A8 BSS 22kV故障時之非正常營運及A3 BSS 22kV故障時之非正常營運等，所需資訊包含變壓器資料、電纜饋線資料、台電電源特性資料、匯流排資料等，進行交流分析首步驟是將欲模擬分析之供電系統架構及系統內各設備組成元件的資料輸入分析軟體資料庫中，依分析理論及模擬軟體之實際操作程序，分析結果必須滿足：正常營運時各主變壓器負載不得超過其自然風冷容量；非正常營運（任一BSS故障）由其他BSS轉供時，主變壓器負載不得超過其強迫風冷容量；正常營運狀態下，22kV匯流排的電壓降不得超過5%；非正常營運由其他BSS轉供時，22kV匯流排的電壓降不得超過7%；及各設備（如電纜饋線、變壓器等）之負載不得超過其額定承載容量。
Upon winning the TIAA MRT Project, the contractor must execute the design of power supply system. First, various system simulation analysis are required to verify and confirm the system architecture, power supply mode, location of substations, types and capacities of various power supply equipment, so as to meet system operation requirements and serve as a follow-up design basis. Simulation analysis of the power supply system included DC traction power load study, AC study, harmonic study, short circuit current analysis, generator capacity, Ferranti effect analysis and system protection coordination analysis. The simulation scope of AC study included from AC 161kV power supply end of each bulk supply substation (BSS) to the AC 380V end of the station substation (SSS) and AC 589V end of the traction substation (TSS) via the system AC 22kV route.
The AC study mainly simulates power failure of a BSS or one of the main transformers in the BSS fails. The system can still maintain normal operation power under such circumstances. Through this simulation, the setting capacity of BSS main transformers, SSS transformers, TSS transformers, switch devices and power cable can be determined. Simultaneously, the study can confirm whether the voltage drop of the system feeder complies with the terms of the contract and related regulations.
The TIAA MRT System AC simulation study adopted the “ETAP 5.0” which simulated 7 scenarios including: normal operation (normally powered by all BSSs), abnormal operation with Chingpu BSS powered at 161kV, abnormal operation with A8 BSS powered at 161kV, abnormal operation with A3 BSS powered at 161kV, abnormal operation with Chingpu BSS powered at 22kV, abnormal operation with A8 BSS powered at 22kV and abnormal operation with A3 BSS powered at 22kV. The required information includes transformer data, cable feeder data, Taipower source characteristics data, bus data, etc. The first step in conducting the AC study is to input the data of the power supply system architecture and the components of each equipment in the system into the analysis software database, and simulate actual operating procedures according to the analysis theory and the simulation software. The analysis results must satisfy: The load of each main transformer must not exceed its natural air-cooling capacity during normal operation; when the power (any BSS error) is transferred from another BSS during abnormal operation, the main transformer load must not exceed its forced air cooling capacity; under normal operating conditions, the voltage drop of 22kV bus must not exceed 5%; under abnormal operation conditions when the power is transferred from another BSS, the voltage drop of 22kV bus must not exceed 7%; The load of each equipment (such as cable feeders, transformers, etc.) must not exceed its rated load capacity.
The AC study is an important planning item for the design of the TIAA MRT power supply system. The analysis results will be of great help to the system architecture and equipment capacity selection, and can even serve as a reference for the future power-saving operations.