The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
A worst-case model of spurious resonances which can occur in electromagnetic system consisting of an antenna, cable and transmitter output filter (or receiver input filter) is proposed. These resonances may cause significant increase in power of spurious emissions for transmitting equipment and the decrease in out-of-band radiated susceptibility levels for receiving equipment. Three amplitude-frequency...
This work suggests some new solutions to TDR-based liquid level detectors. A 3D-printed waveguide cylinder has been designed in order to increase the sensitivity of the level measurement. By wrapping the probing waveguide-pair around a cylinder, an inclination angle ϕ is introduced which increases the time-of-flight by a factor of 1/sinϕ and hence the level resolution is increased (by the same factor)...
A Time Domain Reflectometer (TDR) level measurement device capable of generating and receiving electromagnetic waves for the measurement of waste water is presented. The primary objective is to measure the height of waste water in a tank and design an efficient measuring device. The TDR is based on the reflection mechanism, in which the time delay between the transmitted and reflected signals helps...
Monitoring on the power off cables is relatively difficult and they are in a high risk of being stolen. This seriously affects the safe operation of power system, so anti-theft of power-off cables can't be ignored. An anti-theft and location method based on pulse transmission attribute for power cables is presented in the paper. Firstly, low voltage pulse transmission attribute in cables with common...
In many industrial applications, Pulse Width Modulated (PWM) inverter-fed induction motors needs long cables. The PWM inverter output voltage pulses behave like travelling waves on these cables. This phenomenon causes voltage reflection that results in over voltage at the motor terminals. Over voltage at the terminals of the motor is attributed by the rise time of the inverter pulses, length of the...
Three-phase coupling transmission line equation is derived from the distributed-parameter circuit model and telegraph equation in this paper. According to the theoretical analysis, a novel shunt filter design approach is proposed to mitigate motor terminal overvoltage caused by voltage reflection in pulse width modulation (PWM) inverter-fed AC motor drive systems with long three-phase coupling cable...
A solid-state high voltage pulse generator developed as part of the Advanced Radiographic Capability (ARC) mission for the National Ignition Facility (NIF) has been deployed. This paper will provide details of the pulser design and the upgrades required to achieve reliable operation for multi-pulse bursts for an ever-increasing mission space. The pulser design has been demonstrated to be robust, reliable...
Polymeric-insulated power cables are often subjected to multiple sources of degradation. Generally, the main cause for electrical breakdown in this type of cable insulation is usually due to the microscopic impurities and defects located in the bulk, or even at the interfaces of the material. When the dielectric is subjected to a high electrical stress, imperfections such as protrusions, contaminants...
Spread Spectrum Time Domain Reflectometry for cable fault detection and location on-line is analyzed and studied deep in this paper. On that basis, the simulation model of cable fault detection and location on-line technology is built, the results of the simulation verify the feasibility of cable fault detection and location on-line. On the basis of that, the regular pattern of effects of the measured...
Time Domain Reflectometry (TDR) has been commonly used for testing and diagnosis of faults along a transmission line. It involves the sending of an electrical pulse along a cable and using an oscilloscope to observe the reflected pulses. In this paper, the experimental set up based on Time Domain Reflectometry technique is developed using PSpice circuit simulation software. From the PSpice circuit...
Time domain reflection is a method which detects a cable's fault position and reason by analyzing the relationship between transmitted pulse and reflected pulse. Aimed at the blind spot in the domain reflection with narrow transmitted pulse, a method which used wide differential transmitted pulse was put forward in this paper. Network cable length and type of fault can be located by the method and...
In this paper, the studies of finding the failure location on a sample cable by using the pulse reflection method and the effects of parameters resulting from the fault on the results of the measurement have been examined. A pulse generator with amplitude of 5 V and pulse width between 40 ns and 2000 ns has been designed as a novel pulse reflection meter. The images of reflection seen on the oscilloscope...
As techniques for locating the fault position of the power feeding line of the optical submarine cable, the electric time domain reflector, and the AC resistance measurement are discussed. Authors measured the fault position of the cable that was subject to fault using these two methods. The actual fault point was directly located by divers using AC magnetic field detection method. Comparison of both...
Recently different models have been proposed for analyzing the BPLC systems based on transmission line (TL) theory. In this paper one such BPLC model is validated using laboratory experiments by comparing the channel transfer functions. A good agreement between the BPLC model based on TL theory and experiments is found for channel frequencies up to about 100 MHz.
A study is presented of the validity of some general suppositions of traveling waves on power cables. It is generally accepted that the load voltage during a switching transient will rise to not more than twice the input surge voltage magnitude, and that this can only be associated with relatively fast rise times. It is also generally held that the period of the oscillating load voltage is only dependent...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.