Patent
Dual channel dynamic line isolation monitor
Reads0
Chats0
TLDR
In this article, a line isolation monitor for indicating the maximum hazard current in an ungrounded power distribution system with conductor lines having leakage impedances is proposed, where the impedance voltage response to the measurement current is separated from the line voltage signal, phase shifted and compared to the reference voltage signal to produce a difference signal which is used to control the magnitude of both the capacitive component signal and the resistive component signal.Abstract:
A line isolation monitor for indicating the maximum hazard current in an ungrounded power distribution system with conductor lines having leakage impedances. A signal proportional to the maximum voltage to ground of any of the conductor lines in the system is determined and used as a reference voltage for the monitor. Separate circuits each responsive to the reference voltage generate respectively a capacitive component signal and a resistive component signal which are combined and applied as a measurement signal across the system leakage impedances in parallel. The impedance voltage response to the measurement current is separated from the line voltage signal, phase shifted and compared to the reference voltage signal to produce a difference signal which is used to control the magnitude of both the capacitive component signal and the resistive component signal. The magnitude of the combined capacitive component signal and the resistive component signal represents the maximum hazard current.read more
Citations
More filters
Patent
Catheter with multiple ultrasound radiating members
Richard R. Wilson,Robert L. Wilcox,Curtis Genstler,Tim Abrahamson,Wm. Gerrit Barrere,Amy Cohen,George Keilman,Leonard R. Oliver,Natalya Peskin +8 more
TL;DR: In this paper, a catheter for delivering ultrasonic energy and therapeutic compounds to a treatment site within a patient's vasculature comprises a tubular body with a proximal region and a distal region opposite the proximal regions.
Patent
System for calibrating a line isolation monitor
Donald R. Janke,James A. Rodrian +1 more
TL;DR: The Line isolation monitor (LIM) as mentioned in this paper is a microcontroller-based line isolation monitor that continuously monitors a fault impedance for each phase of the distribution system and calculates the hazard current based on the maximum line to ground voltage of the ungrounded system.
Patent
Method of and apparatus for detecting ground faults in isolated power supply systems
TL;DR: In this paper, a line isolation monitor for detecting ground faults in isolated power systems by determining the potential personnel hazard current due to the complex ground fault impedances and a method for accomplishing the same.
Patent
Energy saving system and method for devices with rotating or reciprocating masses
TL;DR: In this paper, a closed loop controller in electrical connection with the motor computes the necessary information from the observed phase angle between the voltage and current supplied to the motor, which is used in the closed-loop control system as an indication of the load condition, to which the closed loop motor controller may react, supplying power when needed, such as in the energy consumption mode.
Patent
System for measuring line to ground impedance
Donald R. Janke,James A. Rodrian +1 more
TL;DR: In this article, a line isolation monitor (LIM) is used to estimate the maximum hazard current of an ungrounded polyphase power distribution system by injecting a continuous sine wave measurement current into a ground terminal to generate a measurement voltage across the fault impedance.
References
More filters
Patent
Ground fault detector and method of ground fault detection
TL;DR: A ground fault detector for detecting both balanced and unbalanced faults, eg. leakages to ground or other faults in a floating direct current system, comprises, first and second resistances connectible respectively to the positive and negative buses of the system, a two-way switching device operable to connect to the first and to the second resistance alternately, a fault condition being detected by voltage level detecting means connected between the switching device and ground, and a method of detecting ground faults in such a system by continuously alternately checking positive or negative sides of such system against predetermined known reference
Patent
Dynamic ground detector
TL;DR: In this paper, a dynamic ground detector for monitoring a two-wire power distribution system, where both sides are nominally isolated from ground, is proposed, where a sampling bridge is connected between the lines, each shunt section of the bridge comprising a resistor and a capacitor having impedances in quadriture at the line frequency; and the junctions of the shunt sections of the sampling bridge are alternatively sampled by a switching network.
Patent
Isolated power ground fault detector system
TL;DR: In this paper, a ground fault detector system for isolated power lines, especially those for use with operating room and intensive care monitoring equipment including an isolated test circuit arrangement for checking the operation of the system, is described.
Patent
Ground fault detection system with sequential line testing
Joo C Lee,Charles S Tak +1 more
TL;DR: In this article, an a-c line, isolated from ground by a transformer, is continuously tested for ground faults through a switching network which sequentially completes a circuit between the a -c conductors, an apparent active power source, and a ground fault detection network.
Patent
Monitoring circuit for detecting leakage currents
TL;DR: In this article, the leakage currents to ground from the power input conductors connected to a load are detected by means of a diode connected to each input conductor, the latter carrying an ac voltage, which diodes are connected in common to ground through a load resistor to provide paths for purely resistive leakage currents in phase with the ac voltage.