随着电网规模的不断扩大,无人机作为一种安全稳定高效的设备已逐步被应用于对输电线路的巡检中。同时,如何提升巡检作业的可靠性,保障无人机及线路的安全,成为重要的研究课题。首先利用Ansoft Maxwell电磁场仿真软件计算输电线路周围电...随着电网规模的不断扩大,无人机作为一种安全稳定高效的设备已逐步被应用于对输电线路的巡检中。同时,如何提升巡检作业的可靠性,保障无人机及线路的安全,成为重要的研究课题。首先利用Ansoft Maxwell电磁场仿真软件计算输电线路周围电磁场强度;进而以某中型电力巡线无人机为例,分析其可承受电磁场强度的范围;并在此基础上提出无人机巡检安全飞行距离确定方法,给出安全距离计算公式。利用该公式计算出某中型电力巡线无人机对500 k V交流输电线路巡检的安全距离。输电线路无人机巡检安全飞行区域的确定能够提高无人机电力巡线作业的可靠性和安全性,对保证人身、电网和设备的安全具有重要意义。展开更多
电容式电压互感器作为一次电压监测设备,其性能直接影响着二次电压的准确采集和继电保护的正常工作。首先介绍了电容式电压互感器的典型结构,并针对一起220 k V母线电容式电压互感器二次电压异常故障的处理过程进行了详细介绍,最终解体...电容式电压互感器作为一次电压监测设备,其性能直接影响着二次电压的准确采集和继电保护的正常工作。首先介绍了电容式电压互感器的典型结构,并针对一起220 k V母线电容式电压互感器二次电压异常故障的处理过程进行了详细介绍,最终解体发现由于电容式电压互感器电磁单元一次线圈的短路烧蚀造成了这起故障。最后对预防此类故障的发生提出了相关建议。展开更多
The stress on a test specimen during tensile testing is generally measured by a strain gauge. This method has some problems in that it would influence the measurement conditions of the tensile test and can evaluate on...The stress on a test specimen during tensile testing is generally measured by a strain gauge. This method has some problems in that it would influence the measurement conditions of the tensile test and can evaluate only the position at which the strain gauge is attached. The acoustoelastic method is proposed as a method replacing the strain gauge method. However, an ultrasonic sensor with a piezoelectric oscillator requires a coupling medium to inject an ultrasonic wave into a solid material. This condition, due to the error factor of the stress measurement, makes it difficult for the ultrasonic sensor to move on the specimen. We then tried to develop a non-contact stress measurement system during tensile testing using an electromagnetic acoustic transducer (EMAT) with an SH0-plate wave and S0-Lamb wave. The EMAT can measure the propagation time in which the ultrasonic wave travels between a receiver and a transmitter without a coupling medium during the tensile testing and can move easily. The interval between the transmitter and the receiver is 10mm and can be moved along the parallel direction or the vertical direction of the tensile load. The transit time was measured by a cross-correlation method and converted into the stress on the test specimen using the acoustoelastic method. We confirmed that the stress measurement using an SH0-plate wave was superior to that with an S0-Lamb wave.展开更多
文摘随着电网规模的不断扩大,无人机作为一种安全稳定高效的设备已逐步被应用于对输电线路的巡检中。同时,如何提升巡检作业的可靠性,保障无人机及线路的安全,成为重要的研究课题。首先利用Ansoft Maxwell电磁场仿真软件计算输电线路周围电磁场强度;进而以某中型电力巡线无人机为例,分析其可承受电磁场强度的范围;并在此基础上提出无人机巡检安全飞行距离确定方法,给出安全距离计算公式。利用该公式计算出某中型电力巡线无人机对500 k V交流输电线路巡检的安全距离。输电线路无人机巡检安全飞行区域的确定能够提高无人机电力巡线作业的可靠性和安全性,对保证人身、电网和设备的安全具有重要意义。
文摘电容式电压互感器作为一次电压监测设备,其性能直接影响着二次电压的准确采集和继电保护的正常工作。首先介绍了电容式电压互感器的典型结构,并针对一起220 k V母线电容式电压互感器二次电压异常故障的处理过程进行了详细介绍,最终解体发现由于电容式电压互感器电磁单元一次线圈的短路烧蚀造成了这起故障。最后对预防此类故障的发生提出了相关建议。
文摘The stress on a test specimen during tensile testing is generally measured by a strain gauge. This method has some problems in that it would influence the measurement conditions of the tensile test and can evaluate only the position at which the strain gauge is attached. The acoustoelastic method is proposed as a method replacing the strain gauge method. However, an ultrasonic sensor with a piezoelectric oscillator requires a coupling medium to inject an ultrasonic wave into a solid material. This condition, due to the error factor of the stress measurement, makes it difficult for the ultrasonic sensor to move on the specimen. We then tried to develop a non-contact stress measurement system during tensile testing using an electromagnetic acoustic transducer (EMAT) with an SH0-plate wave and S0-Lamb wave. The EMAT can measure the propagation time in which the ultrasonic wave travels between a receiver and a transmitter without a coupling medium during the tensile testing and can move easily. The interval between the transmitter and the receiver is 10mm and can be moved along the parallel direction or the vertical direction of the tensile load. The transit time was measured by a cross-correlation method and converted into the stress on the test specimen using the acoustoelastic method. We confirmed that the stress measurement using an SH0-plate wave was superior to that with an S0-Lamb wave.
