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串联补偿法用于电流互感器高压介损测量 总被引:1,自引:0,他引:1
《防止电力生产重大事故的 2 5项重点要求》中 ,要求进行电流互感器的高压介损测量。传统方法是采用笨重的高压试验变压器作为升压电源。在现场试验时 ,需要运输及起重车辆进入升压站 ,由于停电范围的限制 ,试验设备的装卸及就位都给电网安全运行造成很大的威胁。为此 ,本文提出用便携式电抗器串联补偿法 ,解决电流互感器现场高压介损测量电源的问题。1 串联补偿法原理在进行高压介损测量时 ,电流互感器主要表现为容性负载 ,利用电抗与容抗的不同性质 ,串联补偿法可以大大减小试验电源的容量。其原理接线如图1所示。L—补偿电抗器 (补偿电… 相似文献
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1前言500kV变电站中,电容式电压互感器担负着进、出线的电压测量、电能的计量、继电保护的高频通道、电力载波通讯等各项综合任务。为了在现场进行交接验收试验,我们首次利用800kV串联谐振装置中的“谐振电抗器、谐振电容器、分压电容器”,并对其进行优化组合,采用并联补偿方法圆满地解决了高压试验电源问题,为现场试验大电容,高电压试品提供了手段。正电容式电压互感器参数及结构1.1铭牌参数参见表1。表回电容式电压百感器铭牌1.2结构原理TYD3500-0.005H型电容式电压互感器结构原理见图1。互感器由电容分压器单元及电磁单元(… 相似文献
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简要介绍了串联谐振升压装置的原理,阐述了CVT误差测试前电抗器的调整方法以及现场实际问题的处理方法,为现场实际操作提供了重要的参考数据。 相似文献
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简介唐山安各庄500kV变电站,电容式电压互感器误差的现场检验实例。采用串联谐振原理产生高压试验电源,使用电容式电压比例标准器外推法。实现500kV电容式电压互感器误差的现场检验,测量结果的不确定度符合电压互感器检定规程的要求。实践证明,检验方法正确,其结果经反复验证具有一定的准确度。这套检验装置完全适用于220kV及以上电容式电压互感器误差的现场检验。 相似文献
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详细分析了用变频串联谐振进行GIS现场耐压试验的方法。对变频串联谐振的参数选择,具体试验接线和试验装置在现场试验时,应该注意的问题也做了详细的论述。 相似文献
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通过描述山西铝厂自备电厂6号机-4号变压器组产生的谐振现象,分析了铁磁谐振产生的原因,介绍了系统对地容抗Xc0和电压互感器励磁电抗Xm与谐振的关系,最后提出了解决问题的办法。 相似文献
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新型可控电抗的潮流调节方法 总被引:18,自引:0,他引:18
提出了一种新型控制电抗方法-交耦电抗法,能独立快速地调节线路电抗,无高次谐波。文章阐明了调节原理、可控电抗特性、分析了线路功率调节特性,调节装置电流、电压和所需容量随调节参数的变化规律。通过实际系统计算,所需设备容量不大,技术实现容易,是一种简单经济潮流调节方法。 相似文献
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在35 kV及以下小电流接地系统中,大量采用电磁式电压互感器,由于铁芯的非线性特点,电压互感器在饱和时,随着激磁电流的增加励磁电抗急剧下降,存在着与系统对地容抗产生铁磁谐振的可能性。通过分析产生铁磁谐振的条件,提出了加装消谐电压互感器防止铁磁谐振的方法,并分析了相应的接线形式。 相似文献
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目前在中低压电网中使用比较多的消弧线圈是自动调谐调匝式消弧线圈,这种消弧线圈采取的是预调节方案,即在电网正常运行时调节消弧线圈档位使消弧线圈的电抗等于电网的容抗,为抑制全调谐状态下的串联谐振过电压,一般采取并联或串联阻尼电阻的方法,但如何选取阻尼电阻是比较困难的,该文详细分析了自动调谐调匝式消弧线圈阻尼电阻的选取原则,具有一定的实用价值。 相似文献
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The mutual leakage reactance between D‐axis damper and field windings is ignored in conventional D‐axis equivalent circuits. It has been pointed out, however, that the calculated value of the field current differs considerably from the measured value if this reactance is not taken into account. This is due to the difficulty of determining the physically correct damper winding impedance value. A method of determining the equivalent circuit constants using the mutual leakage reactance has been reported previously, where the D‐axis damper winding time constant is measured from the upper and lower envelopes of field current at sudden three‐phase short‐circuit. Yet there are machines for which the upper and lower envelopes of field current are not readily established, and in this case the method is unsatisfactory. The authors describe a method to accurately identify the equivalent circuit constants taking into account the mutual leakage reactance, using a standstill test with a small‐capacity DC power supply (DC decay testing method). The field current at sudden short‐circuit can be simulated accurately using these equivalent circuit constants. The validity of the proposed method is demonstrated by implementation results on two salient‐pole synchronous machines at the same specifications (one with damper winding, the other without). Furthermore, the dependent relation between the armature leakage reactance and mutual leakage reactance, as well as its influence on the calculation of field transient currents, are made clear. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(3): 61–70, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20113 相似文献
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IEC推荐的石英晶体电参数的(网络零相位测试方法依赖于对测试环境的严格限制来保证其测试精度。在实际应用中,生产现场的测试环境将引入杂散电抗并严重影响其测试精度.为提高测量精度,根据石英晶体的电参模型和理想网络与实际网络模型的差异,理论和实验分析了分布电感对石英晶体谐振频率测试精度的影响,采用电容补偿的方法可以显著减小这一影响。实验结果表明,经过补偿后的石英晶体串联谐振频率的测量精度可达到±2×10~(-6)。 相似文献
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无功补偿电容器组串联电抗器的参数匹配 总被引:2,自引:0,他引:2
串联电抗器是无功补偿电容器中重要的组成部分,串抗率选择不当,可能会使电容器组与系统发生谐振,影响设备的安全和系统的稳定。通过对某一变电站进行电力电容器投切试验和现场测试,得出无功补偿电容器组串联电抗器的参数不匹配是引起该案例中电容器熔丝群爆的直接原因。提出在有限流电抗器的情况下,电容器的设计除了选择合适的串抗率外,还应考虑电容器组等效串抗率,并结合现场实际情况,给出了相应的解决措施。同时分析了电容器组在不同串抗率的情况下,并联补偿支路各次谐波的情况。 相似文献
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Takashi Kano Hiroki Nakayama Takahiro Ara Toshihiro Matsumura 《Electrical Engineering in Japan》2009,167(2):71-78
The mutual leakage reactance between the d‐axis damper and field windings is ignored in the conventional d‐axis equivalent circuit. It has been pointed out that the calculated value of the field transient current differs considerably from the measured value when this reactance is not taken into account. A method to determine this reactance has been reported previously, but this method has problems concerning measurement precision. The authors have previously presented a calculation method for equivalent circuits, adapting a DC decay testing method, using two synchronous machines of the same specifications (one with damper winding, the other without). Yet, this method is not practical because of the use of two machines. This paper presents a calculation method for equivalent circuit constants taking into account the mutual leakage reactance to accurately represent the field transient current using a single machine. The proposed method determines equivalent circuit constants by calculating the physically correct d‐axis transient reactance from the operational impedances when the field winding is shorted and when the field winding is shorted with an external resistance. The validity of the proposed method is demonstrated by comparing the measured values with the calculated values of field and armature currents at sudden three‐phase short‐circuit. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(2): 71–78, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20891 相似文献