固態變壓器於我國配電網之應用與資源配置

Abstract

本研究針對固態變壓器（Solid-State Transformer, SST）在我國配電網的應用進行探討。SST是一種新型電力電子設備，具備多種功能，包括電壓調節、虛功補償、電力品質改善以及能源管理。SST能夠有效結合再生能源及儲能系統，實現靈活的能源轉換和控制，從而提升電壓穩定性和電力品質。然而，由於SST的高成本，需合理設置以達到經濟效益。 隨著科技不斷發展，全球各國逐漸重視環保議題並朝向運具電氣化的方向邁進，電動車(Electric Vehicle, EV)數量持續上升，充電需求的增加對電網造成了顯著壓力，導致線路損失增加及電壓不穩定。此外，再生能源發電的間歇性和不確定性，也對電網穩定性構成了挑戰。 本研究的目標是透過固態變壓器的合理設置，來應對未來大量再生能源併網及電動車普及所帶來的電壓問題。本文設計了三種SST放置方案，分別為單點集中補償法、均勻分散補償法及適應性選擇補償法，並通過模擬和實驗驗證其效果。結果顯示，且三種方法皆顯示SST在提高電力品質、減少線路損失和提升電網穩定性方面具有顯著效果，在一天線路損失最高的18:00，損失大約可以降低5%。另外三種方法都套用本研究提出的補償因子算法，在12:00三相不平衡率相對高，加入SST之前為1.85%，而加入SST後三相不平衡率下降至0.39%。而三種方法比較中以適應性選擇補償可以使用最少的裝置容量，相較其他方法節省了10%總裝置容量。

This study explores the application of SST in the distribution network of our country. SST is an innovative power electronic device that offers multiple functionalities, including voltage regulation, reactive power compensation, power quality improvement, and energy management. SST can effectively integrate renewable energy sources and energy storage systems, achieving flexible energy conversion and control, thereby enhancing voltage stability and power quality. However, due to the high cost of SSTs, their deployment needs to be optimized to achieve economic efficiency. With continuous technological advancement, countries worldwide are increasingly focusing on environmental issues and moving towards the electrification of transportation. The rising number of EVs and the corresponding increase in charging demands have placed significant pressure on power grids, resulting in increased line losses and voltage instability. Additionally, the intermittent and unpredictable nature of renewable energy generation poses further challenges to grid stability. The objective of this study is to address voltage issues arising from the large-scale integration of renewable energy and the widespread adoption of EVs by optimally deploying SSTs. Three SST placement strategies were designed in this study: the single-point centralized compensation method, the evenly distributed compensation method, and the adaptive selective compensation method. The effectiveness of these strategies was validated through simulations and experiments. The results demonstrated that all three methods significantly improve power quality, reduce line losses, and enhance grid stability. At 18:00, when line losses peak, the losses can be reduced by approximately 5%. Furthermore, the compensation factor algorithm proposed in this study was applied to all three methods, reducing the three phase unbalance rate from 1.85% to 0.39% at 12:00 when the unbalance rate is relatively high before the implementation of SSTs. Among the three methods, the adaptive selective compensation method was found to use the least device capacity, saving 10% of the total device capacity compared to the other methods.