摘要:
A capacitor status monitor that attaches across the bushings on the exterior of a capacitor container (commonly referred to as a “can”). The capacitor status monitor, which draws operating power from the power line, detects the internal impedance of the capacitor can to detect internal failures down to the level of a single capacitor pack. The monitor may include a radio transmitter and/or a visual status indicator, such as an electronic flag, indicating the detection of an internal capacitor failure. The monitor may also include a power supply current transformer providing power to the monitor from the power line. Capacitor status monitors throughout the capacitor bank may communicate with a remote transmission unit (RTU), which communicates with a central control station that schedules capacitor maintenance based on the data received from the status monitors.
摘要:
A blade closing detector for an electric power switch includes a blade closing detector and an electronic or visual indicator. A first type of detector uses a gravity switch and a magnetic pickup to detect proper engagement between the blade and the switch. A second type of detector uses a sliding latch with a visual indicator rod to provide a visual indication of proper engagement of the blade within the jaws. A third type of detector uses a magnetic switch with a pivot arm and a dome shaped visual indicator. These detectors may be deployed individually or in combination and may be augmented with communication equipment to transmit switch status to a remote location. It will be understood that specific embodiments may include a variety of features in different combinations, as desired by different users.
摘要:
A high impedance fault isolation system for a radially connected three phase electric power line that utilizes three phase current measurements to determine the presence of a fault without the need for any voltage measurements or a battery powered controller. This eliminates the need for costly phase voltage measuring devices conventionally required to detect high impedance faults, which makes it economical to install fault isolation system at a greater number of locations throughout the power system. The system detects faults using current measurements by computing the negative and zero sequence current components and comparing the amplitudes of the negative and zero sequence components. A fault is detected when the ratio of the amplitudes of the negative and zero sequence components falls within a predefined fault detection range, such as the range from 0.5 to 1.5.
摘要:
A limited flash-over electric power switch uses a dielectric gas regulator and a flash-over arrestor to greatly diminish the occurrences of high voltage flash-over during operation of a circuit interrupter. The dielectric gas regulator prevents the flow of the dielectric gas into the arc gap during an initial portion of the opening stroke of the interrupter contacts. Once the arc gap is sufficiently wide to greatly diminish the likelihood of a high voltage flash-over, the dielectric gas regulator allows the dielectric gas to flow into the arc gap to extinguish the arc. The flash-over arrestor snubs out incipient flash-over that may occur as the arc attempts to reform across the arc gap. The flash-over arrestor may be a conductive ring located on the interior surface of the nozzle in the region of the orifice.
摘要:
A current monitoring device (CMD) with a set of electromagnetic field sensors located within one or more grounded housings positioned within the combined electromagnetic fields generated by one or more electric power lines. The CMD includes electronics, typically located within the grounded housings, defining impedance networks that combine the measurements received from the field sensors to create output signal indicative of electric current values for the phase conductors. The housings can be conveniently attached and to transmission line towers, distribution line poles, and high voltage power line supports in transmission and distribution substations. The CMD controls response equipment, such as a circuit interrupter that responds to current disturbances detected by the CMD. The CMD may also include communication for sending the current values to a remote controller, such as a central control station, that implements a wide range of response equipment.
摘要:
A VAR generator compensation system wherein the voltage of the capacitor or reactor bank is changed as a means of adjusting the phase angle is taught. Briefly stated a reactive bank such as a capacitor bank is connected to the secondary of an autotransformer such that the voltage of the reactive bank is controlled by the autotransformer. The line and load are connected to the primary of the autotransformer, such that changing the voltage of the autotransformer and hence the secondary voltage connected to the reactive bank, thus changes the VARS generated on the grid or system.
摘要:
A circuit breaker utilizes a plurality of vacuum interrupters immersed in oil. A cross-bar with electrically conductive sections completes a series electrical circuit through the circuit breaker and actuates operating mechanisms, to close the contacts of the vacuum interrupters when in the raised position as the cross-bar is lowered, the contacts of the vacuum interrupters are opened by impact forces before isolation gaps which fill with oil are created in the series electrical circuit. Various arrangements of the vacuum interrupters are disclosed for uprating existing oil circuit breakers.
摘要:
A current transformer characterized by a terminal bushing extending from a tank with a pair of spaced conductors extending through the bushing and into the tank and with the portions of the conductors in the tank being enclosed within tubular means. The assembly of the conductors, bushing, and tubular means being clamped together by resilient (spring) means for holding the conductors in tension and the bushing and tubular means in compression. The transformer also embodies two separate oil systems.
摘要:
An instrumented electric power voltage arrester includes a temperature sensor, wireless transmitter, and a visual over-temperature indicator. A disk shaped module, a replacement varister block, or a dummy block containing the sensor/transmitter is placed between varister blocks inside the arrester housing. A strap-on module is attached to the outside of the arrester housing. The sensor/transmitter utilizes a harvesting power supply that draws electric power for the electronics from the power line protected by the arrester. An ambient temperature sensor may be utilized to enhance accuracy. The temperature sensor/transmitter typically sends arrester monitoring data wirelessly to an RTU or handheld unit located outside the arrester, which relays the monitoring data to an operations control center that scheduled replacement of the arrester based on the monitoring data. A surge counter keeps track of the number of equipment and lightning related temperature surges experienced by the arrester.
摘要:
A directional fault sectionalizing system that utilizes one phase voltage measurement and three phase current measurements to determine the directionality of high impedance faults on a three phase electric power circuit. This eliminates the need for two of the three voltage measuring devices at each monitoring station conventionally required to determine fault directionality, which makes it economical to install at a greater number of distribution tap points. The system is particularly useful for commonly used three-way tap points along distribution lines where three phase voltage measurement is not readily available. The system is capable of identifying faults under challenging circumstances, such faults occurring on unbalanced three phase power lines and faults occurring on tapped line segments where the currents are relatively small compared to the currents flowing in the main line segments.