变频器低电压穿越引起的压缩机喘振及改进措施

国家管网集团西部管道有限责任公司

压缩机;低电压穿越;喘振;裕度;出口压力

Analysis of compressor surge induced by converter low-voltage ride through and improvement measures
PU Bin,LI Xingxing,YANG Fuchao,SUN Yiwei

PipeChina West Pipeline Company

compressor, low-voltage ride through (LVRT), surge, margin, outlet pressure

DOI: 10.6047/j.issn.1000-8241.2024.04.009

备注

【目的】变频器低电压穿越功能是供电波动时保持变频器连续运行的一种方式,但电驱离心式压缩机在变频器低电压穿越过程中会造成压缩机喘振。喘振对离心式压缩机的平稳运行有较大危害,需分析低电压穿越引起喘振的原因、制定改进措施,以防止压缩机再次发生喘振。【方法】选取西气东输二线吐鲁番联络压气站电驱离心式压缩机为例,对变频器低电压穿越过程中压缩机转速、压力、流量、防喘振工作裕度等参数的变化情况进行分析。由于变频器低电压穿越过程中压缩机转速快速下降造成防喘振控制响应不及时,从而导致压缩机发生喘振;压缩机喘振后压力、流量剧烈波动使防喘振裕度控制失效,引起压缩机持续喘振。制定防喘振控制改进措施:增加低电压穿越时预防喘振控制措施及低电压穿越的状态判断,根据变频器低电压穿越过程中压缩机工作裕度、出口压力变化情况制定预防性打开防喘阀到指定开度的条件;增加压缩机喘振检测及保护措施,通过压缩机喘振后明显变化的出口压力、振动变化检测压缩机是否发生喘振,喘振后快速打开防喘阀摆脱喘振状态。【结果】通过改进措施的应用,解决了低电压穿越过程中的喘振问题;通过设定工作点裕度、出口压力变化阈值的方式,减少了提前打开防喘阀干预的频次,较短时间内恢复了压缩机正常运行。【结论】研究成果可有效减轻喘振危害,提升电驱离心式压缩机的运行平稳性,为电驱离心式压缩机优化防喘振控制、增加喘振检测提供参考。(图9表1,参[23]
[Objective] Centrifugal compressors encounter challenges in maintaining stable operation due to the occurrence of harmful surges, and the low-voltage ride through (LVRT) function of converters has been utilized to sustain continuous operation against power supply fluctuations. However, electric-driven centrifugal compressors frequently experience compressor surges during the converter LVRT process. Therefore, it is essential to analyze the surge causes and develop improvement measures for problem prevention. [Methods] This study focuses on electric-driven centrifugal compressors at the Turpan Interconnection Compressor Station of the West-East Gas Pipeline II. An investigation was carried out to analyze parameter changes, including compressor speed, pressure, flow, and anti-surge operating margin during the LVRT process. It was observed that the anti-surge control response was delayed as a result of rapid compressor speed drop during the converter LVRT process, leading to compressor surges. Subsequently, the sharp pressure and flow fluctuations following the surges rendered the anti-surge margin control ineffective, resulting in persistent compressor surges. Based on these findings, the following measures were devised to enhance anti-surge control: (1) incorporating additional measures for surge prevention during LVRT and LVRT state judgment, presetting trigger conditions for preemptively opening the anti-surge valve until a specified opening based on the compressor’s operating margins and outlet pressure changes during the LVRT process; (2) implementing supplementary measures for compressor surge detection and protection, specifically by detecting noticeable changes in outlet pressure and variations in vibration that occur following compressor surges, and in response to any detected surge, promptly opening the anti-surge valve to eliminate the surge state. [Results] The implementation of the improvement measures effectively resolved surge-related issues during the LVRT process. By setting operating point margins and outlet pressure change thresholds, the frequency of preemptively opening the anti-surge valve was reduced, resulting in a swift restoration of normal compressor operation. [Conclusion] The research findings provide valuable approaches for effectively mitigating surge hazards and improving the operational stability of electric-driven centrifugal compressors. Therefore, they can serve as a reference for optimizing anti-surge control and improving surge detection in electric-driven centrifugal compressors. (9 Figures, 1 Table, 23 References)
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