| 引用本文: | 陈 俊,司红建,周荣斌,徐 金,严 伟,沈全荣.抽水蓄能机组SFC系统保护关键技术[J].电力自动化设备,2013,33(8): |
| CHEN Jun,SI Hongjian,ZHOU Rongbin,XU Jin,YAN Wei,SHEN Quanrong.Key technologies of SFC system protection for pumped storage hydro unit[J].Electric Power Automation Equipment,2013,33(8): |
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| 摘要: |
| 介绍了抽水蓄能机组静止变频器（SFC）系统保护的配置方案。针对SFC系统保护的关键技术中的难点，提出了相应的解决方法。SFC变流桥本体差动保护：将机桥侧变频电流转换成工频校正电流，再与网桥侧电流构成差动电流和制动电流，采用全周傅氏算法计算，并提出了提高保护可靠性的比率制动特性。输出变压器变频差动保护：采用了启停机保护算法，实现了低频启动过程中的准确测量；采用变斜率比率制动特性，防止区外故障导致的误动；脉冲换相阶段，经旁路开关位置接点将该保护退出。电流变化率保护：为了提高其可靠性，连续、多次判断是否满足动作条件，并增加采样值过流辅助判据，其与电流变化率判据均满足动作条件时，保护才出口。设计了数字低通滤波器，保证脉冲换相阶段机桥侧频率的准确测量。上述措施已经在抽水蓄能机组上得到应用，应用效果良好。 |
| 关键词: 抽水蓄能机组 SFC 变压器 继电保护 电流变化率保护 |
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| Key technologies of SFC system protection for pumped storage hydro unit |
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CHEN Jun1, SI Hongjian2, ZHOU Rongbin1, XU Jin1, YAN Wei1, SHEN Quanrong1
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1.NR Electric Co.，Ltd.，Nanjing 211102，China;2.Jiangsu Shahe Pumped-Storage Power Generation Co.，Ltd.，Liyang 213333，China
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| Abstract: |
| The configuration scheme of SFC（Static Frequency Converter） system protection for pumped storage hydro unit is introduced and solutions are proposed for its key technologies. Differential protection of SFC converter bridge：the variable-frequency current at generator side is converted to power-frequency current，which is used together with the current at grid side to form the differential current and braking current； full-period Fourier algorithm is adopted and the proportional breaking characteristic is applied to enhance its reliability. Variable-frequency differential protection of output transformer：the protection algorithm of generator startup／shutdown is applied to realize the accurate measuring during the low-frequency startup；the variable-slope braking characteristic is applied to avoid the misoperation due to out-zone fault；it is disabled by the position contact of bypass switch during the pulse commutation. Current changing rate protection：the repeated and continuous detection of action conditions and the additional auxiliary criterion of sampling value over-current are applied to enhance its reliability；the digital low-pass filter is designed to guarantee the accurate measuring of frequency at generator side during pulse commutation. All measures mentioned above are applied in the pumped storage hydro unit with excellent effect. |
| Key words: pumped storage hydro unit SFC power transformers relay protection current changing rate protection |
