| 引用本文: | 王晓宇,张 涛,操丰梅,刘 树,文 晶,刘 全,杨奇逊.用于抑制SSR的高压大容量低频电流发生器的研究与实现[J].电力自动化设备,2014,34(3): |
| WANG Xiaoyu,ZHANG Tao,CAO Fengmei,LIU Shu,WEN Jing,LIU Quan,YANG Qixun.High-voltage high-power low-frequency current generator for SSR damping[J].Electric Power Automation Equipment,2014,34(3): |
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| 摘要: |
| 针对火电厂用于提高机组抑制次同步谐振（SSR）能力的机端阻尼控制器向机组定子注入与扭振模态互补频率的次同步和超同步补偿电流的问题，提出一种应用级联式H桥多电平逆变器实现高压大容量低频电流发生器（HHLCG）的控制系统设计方法。HHLCG存在低频电流与输出的工频电压矢量非同速旋转、解耦困难、直流电压波动较大、电容电压平衡等突出问题，对HHLCG的电压内、外环和电流内环的三环控制方法进行了研究，重点研究了电压环的控制，提出电压闭环控制中对采样直流电压经过平滑处理的方法和占空比微调电容电压平衡控制方法。搭建了基于RTDS的数／模混合仿真平台。仿真及现场试验结果表明所提方法能够准确跟踪低频次同步目标电流的同时，实现直流电压的稳定与均衡控制，且稳态特性好，动态响应快。 |
| 关键词: 级联式低频电流发生器 直流电容电压 占空比微调 实时数字仿真 数／模混合仿真 |
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| High-voltage high-power low-frequency current generator for SSR damping |
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WANG Xiaoyu1, ZHANG Tao2, CAO Fengmei2, LIU Shu2, WEN Jing2, LIU Quan2, YANG Qixun1
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1.State Key Lab of New Energy Power System，North China Electric Power University，Beijing 102206，China;2.Beijing Sifang Automation Co.，Ltd.，Beijing 100085，China
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| Abstract: |
| The generator terminal damping controller is used in thermal power plants to inject the controllable sub-／super-synchronous compensating currents into generator stators for damping the ＳＳＲ（Ｓub-Ｓynchronous Ｒesonance），for which，a control system of HHLCG（High-voltage High-power Low-frequency Current Generator） is designed based on the cascaded H-bridge multi-level inverters. Aiming at the asynchronous rotation of low-frequency current and output voltage vector，the difficult decoupling，the large fluctuation of DC voltage and the difficult balancing of capacitor voltage，a tri-loop control scheme is developed for the voltage and current control. The voltage control loop is emphasized by smoothing the DC voltage samples and fine tuning the duty cycle for capacitor voltage balance. A digital／physical hybrid simulation platform of HHLCG is constructed based on RTDS. Simulative and experimental results demonstrate that，the low-frequency sub-synchronous reference current is completely traced and the stable and balanced control of DC voltage is realized with excellent steady-state and dynamic performance. |
| Key words: cascade low-frequency current generator DC capacitor voltage fine duty tuning real-time digital simulation digital／physical hybrid simulation |
