一种特殊接线方式下的站变备自投装置故障原因分析

变电站站用变压器备用电源自动投入装置(简称站变备自投装置)给全站的交直流用电提供安全保障,对电力系统安全可靠运行具有非常重要的意义。文章以粤北某500 kV变电站许继CSL210B型站变备自投装置在特殊接线方式下运行中出现的误动作为例,进行了分析与探索,找出了误动作的根源,并针对许继CSL210B型站变备自投装置在该变电站特殊接线方式下运行的特点,充分考虑到与现有的设计相兼容,对现有备自投装置硬件的设计进行了重新设计,消除了误动作根源,保证了该500 kV变电站交直流站用电的安全稳定运行。     

一种特殊接线方式下的站变备自投故障分析与解决

站变备用电源自动投入装置(简称站变备自投)给全站的交直流用电提供安全的保障,对电力系统安全可靠运行具有非常重要的意义。该文以粤北某500kV变电站许继CSL210B型站变备自投装置在特殊接线方式下运行中出现的误动作为例,进行了分析与探索,找出了误动作的根源,并针对许继CSL210B型站变备自投装置在该站特殊接线方式下运行的特点,充分考虑到与现有的设计相兼容,对现有备自投装置硬件的设计进行了重新设计,消除了误动作根源,保证了该500kV变电站交直流站用电的安全稳定运行。     

站用变低压备自投装置故障的分析与解决

分析某220kV变电站站用变备自投装置运行中拒动的根源,并针对该型号站用变备自投装置在该站接线方式下运行的特点,提出改进建议,以方便该型号备自投装置后期运维,保证该变电站交直流站用电的安全稳定运行。     

一例站用电备自投运行方式的变更及建议

文章对南方电网1座500 kV枢纽变电站站用电的备自投改造进行了介绍,指出了原备自投设计上的不足,说明了改造的过程及步骤,重点介绍了改造中应注意的问题,包括工作母线电压的选取、工作母线母联开关位置以及工作母线电压二次空开跳闸对备自投的影响等因素,最后对改造大中型变电站备自投方式提出了建议.改造后,将之前不能满足实际运行需要的母线自投改为进线互投,满足了实际运行的需要.     

变电站站用电源低压备自投装置回路的改进

针对变电站站用电源低压备自投装置运行中存在的问题,对其回路接线进行分析,提出了相应的改进措施。改造结果表明:站用电源低压备自投回路接线完善后,确保了站用电低压备自投装置动作的正确性、可靠性。     

220kV变电站单主变运行的备自投实现方式

单主变220 kV变电站正常方式下,主变中压侧110 kV系统不和其它的220 kV变电站的110 kV系统环网运行,当主变110 kV侧失压时,将会造成本站110 kV母线及母线上所接的110 kV变电站全停。针对单主变220 kV变电站的运行特点,我们充分考虑与现有国产设备的兼容性,在对国产现有备自投装置硬件稍加改动的基础上,设计开发出了单主变备自投,并编制了相应备自投装置充电、动作及闭锁方案。目前,该备自投装置已经投产运行两年,运行状况良好。该方案设计在全国尚属首次,应用前景广阔,有普遍的推广意义。     

220 kV变电站单主变运行的备自投实现方式

单主变220 kV变电站正常方式下,主变中压侧110 kV系统不和其它的220 kV变电站的110 kV系统环网运行,当主变110 kV侧失压时,将会造成本站110 kV母线及母线上所接的110 kV变电站全停.针对单主变220 kV变电站的运行特点,我们充分考虑与现有国产设备的兼容性,在对国产现有备自投装置硬件稍加改动的基础上,设计开发出了单主变备自投,并编制了相应备自投装置充电、动作及闭锁方案.目前,该备自投装置已经投产运行两年,运行状况良好.该方案设计在全国尚属首次,应用前景广阔,有普遍的推广意义.     

罗家庄变电站110 kV断路器手动分闸后备自投动作原因分析

罗家庄变电站110 kV部分为内桥接线,备自投方式采用分段断路器自投与两条110 kV进线自投自适应方式,在对进线断路器进行手动分闸时备自投装置误动作.通过对备自投装置进行实地检查,认真分析,查找故障出现原因,针对该问题提出三种解决方案,采用最合适的方案进行整改,将汇控柜内断路器就地操作把手摘除,避免就地操作,从而使备自投装置能正确动作.     

罗家庄变电站110 kV断路器手动分闸后备自投动作原因分析

罗家庄变电站110 kV部分为内桥接线,备自投方式采用分段断路器自投与两条110 kV进线自投自适应方式,在对进线断路器进行手动分闸时备自投装置误动作。通过对备自投装置进行实地检查,认真分析,查找故障出现原因,针对该问题提出三种解决方案,采用最合适的方案进行整改,将汇控柜内断路器就地操作把手摘除,避免就地操作,从而使备自投装置能正确动作。     

双电源自动切换装置在500kV东坡变电站站用电系统中的应用分析

在介绍500 kV变电站站用电系统的基础上,通过分析两种常用站用电系统备自投方案及各自的优缺点,阐明500 kV东坡站所采用方案的经济性、简易性。通过比较两种常用备自投装置——微机型备自投装置和双电源自动切换装置,阐明采用双电源自动切换装置的可靠性、简便性。站用电系统投产前,按照相关验收规范,对双电源自动切换装置进行调试验收,确认双电源自动切换装置是合格的、可靠的。投产后,双电源自动切换装置进行数次正确、可靠的自动切换,运行状态良好。     

Optimization of a door seal structure of a microwave oven using a FDTD method

The optimum door seal configuration to prevent radiation leakage from a microwave oven is still a manufacturing concern. Here, we propose a numerical algorithm to simulate the radiation propagation along a door seal structure using the finite‐difference time domain method, which is used for a priori shielding efficiency tests. The results agree with experimental data. The critical dimensions of the choke structure were found and high shielding is anticipated for a simpler choke structure. Copyright © 2008 John Wiley & Sons, Ltd.     

一起箱变着火事故分析

介绍一起光伏电站箱变着火事故,分析着火原因,并从产品制造和运行维护方面提出针对性建议,对箱变安全运行具有一定的实际意义.     

Simulation of a generator for a wind-power unit

Analysis of excitation systems of generators for wind-power units is carried out, a software package for generator simulation is presented, and the sequence of the generator design is presented.     

Electric potential near a tip of a local discharge on a conductive film

To develop a propagation model of a local discharge on a wet polluted insulator, the authors have examined characteristics of the local discharge on an electrolytic solution simulating the wet polluted insulator surface. The local discharge was propagated on the solution under the impulse voltage. A shape of a contacting surface between the local discharge and the solution has been already obtained by the authors. By using the contacting surface, an electric potential near a tip of the local discharge on a conductive film of 1 mm in thickness was calculated. Furthermore, the potential was measured with a probe. The calculated values and the measured values of the electric potential agreed well regardless of the propagation length of the local discharge, the width of the conductive film, the resistivity of the conductive film, the peak value of the applied voltage and the applied voltage waveform.     

飞机座舱空气调节系统检查仪

文中分析飞机座舱空气调节系统的功能,研制以单片机为核心的检查仪,实现对飞机空调系统工作性能的检测.实际应用表明,该检测设备性能稳定、操作便捷、可靠性高,提高了维修工作的质量和效率,而且该设备对于相关机型具有一定的通用性.     

On the development of a core for a low-power transformer on a basic of wasteless technology

Innovations in critical technology for the production of magnetic materials is considered. On the basis of these innovations, a new design of a low-power transformer is proposed. The operating characteristics of transformers of the pilot and analog design are studied.     

Development of a deceleration control system for a winding machine based on a microcontroller

The development of an automatic deceleration system for a winding machine in a siderurgy factory is presented in this paper. The proposed system controls the speed of a winding machine in order to obtain the optimum stop point in terms of security and fast production. The system is based on a microcontroller and an extremely simple hardware. The system has been tested for two years and results evince a very good mean time between failures.     

Extension of a driving-point and a transfer function to a positive real two-port matrix

A solution is presented to the problem, which arises in two-port modelling, of determining a second driving-point function from a given driving-point function and a transfer function. the given functions must have a common denominator and satisfy the necessary positive real (PR) matrix conditions: the driving-point function must be PR and on the imaginary axis the real part of the transfer function must be zero whenever the real part of the driving-point function is zero. By using a partial fraction expansion and determining a required first-order polynomial, a unique second (minimum) driving-point function is obtained. Examples to illustrate the method are worked out.     

Development of a fault locator for a branch line

Formerly, only pulse radar and the Murray loop bridge could be utilized in a cable fault location method that is applicable to branch lines. Those methods need a terminal connection at the far end. Therefore, it is difficult in fault location involving branch lines. Pulse radar is applicable only for high‐resistance ground faults and the Murray loop bridge is applicable only for low‐resistance ground faults. We have developed current‐detection pulse radar and tested it. In high‐resistance ground fault location, the measured result includes discharge delay error. Therefore, we have proposed an error correction method and confirmed it. In addition, we have designed a new cable fault location method of pulse radar and tested it. © 2000 Scripta Technica, Electr Eng Jpn, 134(2): 19–28, 2001