雙饋式感應發電機之穩態運轉點解析法與故障保護策略

Steady-State Operating Point Analysis Method and Faulted Protection Scheme for Doubly-Fed Induction Generators

錢一丰(I-Feng Chien)

指導教授 ： 許源浴

國立臺灣大學/電機資訊學院/電機工程學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.01411

摘要

本論文之主要目的在於提出一種利用串聯補償電阻之保護策略，以改善併網之雙饋式感應發電機遭遇低電壓故障時的穿越能力，希望在故障期間仍可持續維持運轉，以提供系統更多能量，並評估電力系統故障時發電機之穩態運轉工作點，藉此做為所需補償電阻之依據。
利用穩態運轉點解析法預估系統端發生低電壓故障時對雙饋式感應發電機之影響，並提出故障保護策略使雙饋式感應發電機在故障期間仍可維持最大功率輸出且穩定運轉。所提出之補償策略除了在定子端裝上一個動態串聯電阻之外，在轉子側除了使用過去熟知的切離轉子側變流器之Crowbar電阻之應用，還能將Crowbar電阻串聯轉子側變流器以達到更好響應。
本文以MATLAB®/SIMULINK/SimPowerSystems進行分析模擬與驗證。理論分析與模擬結果顯示，本文所提出之串聯電阻補償策略能夠大幅提高雙饋式感應風力發電機的低電壓穿越能力，對於改善系統較弱的偏遠地區之風力發電機是相當可行的補償方式，也可直接應用於其他現有之風力發電廠。

關鍵字

雙饋式感應發電機 ； 保護策略 ； 動態串聯電阻 ； 轉子電流 ； 穩態運轉點解析法 ； 故障穿越能力

並列摘要

A new protection scheme for enhancing fault ride through capability of a doubly fed induction generator (DFIG) is proposed. The new protection scheme comprises a series dynamic braking resistor (SDBR) connected to the stator side and a Crowbar resistor connected to the rotor side. The SDBR is employed to boost stator voltage while the crowbar resistor is used to reduce the rotor overcurrent. To determine proper values for the SDBR under different fault voltage, an analytical approach is proposed to compute the post-fault steady-state operating point.
Various low voltage fault conditions are analyzed and used to design the protection scheme, including the switching strategy and the coordination of crowbar resistor and SDBR, and resistance value calculations. MATLAB®/SIMULINK/SimPowerSystems simulation results show that the proposed method is very effective for fault overcurrent protection and fault ride through capability enhancement.

並列關鍵字

Doubly fed induction generator (DFIG) ； protection schemes ； series dynamic braking resistor (SDBR) ； Crowbar resistor ； steady-state operating point analysis ； fault ride through capability

參考文獻

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