Chinese Journal of Ship Research
基于晶闸管的自动调压变压器故障诊断技术
范磊,李维波*,徐聪,李巍,李齐武汉理工大学自动化学院,湖北武汉 430070
摘 要:[目的]船用设备的供电电压经常发生波动,现有的稳压方案经济效益和可靠性低,亟待研发适用于恶劣工作环境的自动配电设备。[方法]设计基于双向晶闸管与调压变压器的三相串联调压装置,通过控制双向晶闸管组件的投切方式,即可调节电压的幅值及方向。针对该调压装置的3种故障模态,分析其故障诊断方法和处理方案,并开展仿真验证实验。[结果]结果表明:该设计可以仅参考输入电压进行双向晶闸管组件投切,从而实现输出电压的调节、稳定功能。当晶闸管组件的H桥发生断路故障时,仅对装置的调压效果产生影响;当变压器高压侧的短路晶闸管发生断路故障时,将可能在变压器高压侧感应出大电压或在低压侧产生冲击大电流,进而对装置造成损害;当晶闸管组件发生短路故障时,若等效为变压器不补偿工作,对装置没有影响;而若等效为变压器短路运行,将可能在整个回路中产生冲击大电流,进而危害装置和用电设备。[结论]该设计方案将调压变压器直接串入供电回路之中,故其调压反馈效果较为显著;采用性价比更高的双向晶闸管作为交流开关,并采用所提出的故障诊断技术,可有效提升调压变压器的可靠性和使用寿命。关键词:双向晶闸管;变压器;调压;故障诊断中图分类号: U665.12 文献标志码:A DOI:10.19693/j.issn.1673-3185.01532
Fault diagnosis technology of automatic voltage regulating transformer based on thyristor
FAN Lei, LI Weibo*, XU Cong, LI Wei, LI Qi School of Automation, Wuhan University of Technology, Wuhan 430070, China Abstract: [Objectives]The voltage of marine electrical equipment often fluctuates, but the existing stabilization schemes have low reliability and high cost. As such, distribution equipment that can operate in harsh environments is required to stabilize the voltage.[Methods ] This paper puts forward the design for a threephase series voltage regulator based on a bidirectional thyristor and voltage regulator. It functions by controlling the magnitude and direction of voltage regulation through switching the bidirectional thyristor. Furthermore, the fault modes of the thyristor are analyzed and its fault diagnosis scheme obtained.[Results] The results show that this design can realize the stabilization of only the output voltage by switching the bidirectional thyristor only according to the input voltage. when the H-bridge of the thyristor assembly breaks, it only affects the voltage regulation effects of the device. When the short-circuit thyristor of the high-voltage side of the transformer has an open-circuit fault, a large voltage or a large impact current is generated on its low voltage side, causing damage to the device. When the thyristor component has a short-circuit fault, if the equivalent is that the transformer does not compensate for the work, it has no effect on the device. If the equivalent is the short-circuit operation of the transformer, a large impact current may be generated in the entire circuit, causing damage to the device and electrical equipment.[Conclusions ] The voltage-regulating effects of this design are significant because it directly integrates the voltage-regulating transformer into the power supply circuit. With the more cost-effective bidirectional thyristor as an AC switch and the designed fault diagnosis technology, the reliability and service life of voltage regulating transformers can be improved. Key words: bidirectional thyristor;transformer;voltage adjustment;fault diagnosis
0 引 言
对于船舶的大功率负载而言,若频繁切换操作,有可能引发负载侧电压的大幅波动,进而影响船用设备的工作状态,甚至导致用电设备故障并损坏。同时,恶劣的工作环境也极易诱发船用设备故障。因此,为了提高船用设备的可靠性,应对其健康运行情况进行监控[1-3]。对于船舶电力系统的电压波动问题,目前主要有3种解决办法:第一,增加船舶电站的容量,提高其带载能力,从而降低负载变化带来的影响,但该方法的成本极高,且不易付诸实践;第二,当系统电压波动时,采用大容量储能单元进行调压,但该方法易产生谐波,进而对电网造成污染;第三,采用稳压电源为船舶设备供电,较为精准地将电源电压稳定在一定范围之内,该方法的成本较低,也是目前应对此类问题的主流措施。根据是否采用隔离措施,可以将稳压电源分为隔离型和非隔离型2类。隔离型稳压电源又可以分为高频隔离稳压电源和工频隔离稳压电源2类。其工作原理是:首先,对电网交流电进行整流处理;然后,对整流输出的直流电进行特定频率的逆变处理;最后,通过隔离变压器输出,从而为后续设备供电。隔离型稳压电源对电网的影响较小且精度较高,但其结构复杂、成本偏高、输出效率偏低;同时,其配置了大功率隔离变压器,故设备体积偏大,由此可见,隔离型稳压电源无法满足船舶设备小型化和高效率的设计要求。非隔离型稳压电源的工作原理与前者基本一致,仅仅取消了隔离变压器,所以仍然存在成本偏高、效率偏低、体积偏大等问题[4-7]。与其他全控型器件相比,在同等级容量工况下,晶闸管(含触发)具备舰用环境适应度高、可靠性高、成本低等优点,为此,本文拟提出一种基于晶闸管的自动调压变压器( 220 V交流电压等级),其初级将配置3个晶闸管组件(每个组件由5个双向晶闸管组成),次级则将串入电源与负载之间,通过改变双向晶闸管组件的开断状态,即可完成三相电压的正负调压工作,从而解决电压波动问题。同时,本文将针对双向晶闸管的实时故障模式开展仿真分析,并设计相应的故障诊断方案,以及时反馈装置的健康状况,从而避免重大故障。
1 自动调压原理
基于晶闸管的自动调压变压器可以进行三相自动调压,其拓扑结构如图1所示。三相调压装置分别为EA ,EB ,EC ,其中每相均由大、中、小3个不同变比的调压变压器 T1,T2,T3 及其晶闸管组件 THSCR1 ,THSCR2 ,THSCR3 ,装置总开关KS、旁路开关 KBP、调压变压器高压侧熔断器FU 及装置监控系统组成。图1中,每个晶闸管组件均由晶闸管H 桥(包含晶闸管TH1 ,TH2 ,TH3 ,TH4 )、高压侧短路晶闸管THS 及短路功率电阻RS组成。