Title Experiment using variable reactor of rectifier type
... Abstract—A rectifier type superconducting fault current limiter using an additional shot-circuited trigger coil has been studied. Such reactor consists of two well-coupled superconducting coils; the main coil and trigger coil. The main coil is connected to the DC link of the bridge circuit while the ...
... Abstract—A rectifier type superconducting fault current limiter using an additional shot-circuited trigger coil has been studied. Such reactor consists of two well-coupled superconducting coils; the main coil and trigger coil. The main coil is connected to the DC link of the bridge circuit while the ...
Extending the MFJ-927 to 160-Meters
... discussed in that review only the SG-230 had enough internal inductance to tune the 43foot vertical on 160 meters, so I described an external inductor (in the “Articles” section of this website) that could be strapped in to permit the MFJ-927 to tune a 43-footer on top band. I’ve also recently added ...
... discussed in that review only the SG-230 had enough internal inductance to tune the 43foot vertical on 160 meters, so I described an external inductor (in the “Articles” section of this website) that could be strapped in to permit the MFJ-927 to tune a 43-footer on top band. I’ve also recently added ...
Negative-Sequence Impedance Directional Element
... gives a negative-sequence impedance which is positive and a forward fault gives a negativesequence impedance which is negative, Z2R is always set more positive than Z2F. For practically every application, Z2F can be set for ½ the positive-sequence impedance of the line and Z2R can be set equal to Z2 ...
... gives a negative-sequence impedance which is positive and a forward fault gives a negativesequence impedance which is negative, Z2R is always set more positive than Z2F. For practically every application, Z2F can be set for ½ the positive-sequence impedance of the line and Z2R can be set equal to Z2 ...
Generator specification - Schneider Electric België
... logic discrimination in order to discriminate correctly when used in a cascade scheme. Overload protection will be based on RMS current value (up to a minimum 17th harmonic) and will take into account the ambient temperature. The protection and control unit shall include learnt cooling time constant ...
... logic discrimination in order to discriminate correctly when used in a cascade scheme. Overload protection will be based on RMS current value (up to a minimum 17th harmonic) and will take into account the ambient temperature. The protection and control unit shall include learnt cooling time constant ...
Power Electronic Device Protection (VFD, Drive Protection)
... components very difficult. For external faults, drives using IGBTs incorporate electronic protection that shut off the switching components when fault currents are detected. However, over time, transient voltage surges can lead to the electronics’ inability to shut off the IGBT switching. This can l ...
... components very difficult. For external faults, drives using IGBTs incorporate electronic protection that shut off the switching components when fault currents are detected. However, over time, transient voltage surges can lead to the electronics’ inability to shut off the IGBT switching. This can l ...
Capacitor Self
... turns on, if it turns on at all. 2. The bending of the leads can cause stress on the end of the glass vial, and a minute crack can develop that will eventually cause failure of the glass or oxidation of the contacts. ...
... turns on, if it turns on at all. 2. The bending of the leads can cause stress on the end of the glass vial, and a minute crack can develop that will eventually cause failure of the glass or oxidation of the contacts. ...
15P0161B1 - DCREG for Applications to Electromagnets
... series-connected to contact NO of button PE. When the time set in par. P177 is over, contact MDO 2 opens, and the reference becomes the magnet rated voltage set in potentiometer PV, whose full-scale value is set in par. P122. Switching from the max. voltage reference to the rated reference of the ma ...
... series-connected to contact NO of button PE. When the time set in par. P177 is over, contact MDO 2 opens, and the reference becomes the magnet rated voltage set in potentiometer PV, whose full-scale value is set in par. P122. Switching from the max. voltage reference to the rated reference of the ma ...
0943p ERICO CRITEC in switchboard components
... Closing operation: Provide independent manual operation with trip free closing mechanisms and positive mechanically operated ON and OFF indication. Opening operation: Provide independent manually operated release for opening. Auxiliary switch contacts: Provide contacts with minimum rated operational ...
... Closing operation: Provide independent manual operation with trip free closing mechanisms and positive mechanically operated ON and OFF indication. Opening operation: Provide independent manually operated release for opening. Auxiliary switch contacts: Provide contacts with minimum rated operational ...
Document
... each winding assigned to the REF protection element and compares this calculated quantity to the measured zero-sequence current on the transformer neutral (3I0). ...
... each winding assigned to the REF protection element and compares this calculated quantity to the measured zero-sequence current on the transformer neutral (3I0). ...
Protective relay
In electrical engineering, a protective relay is a device designed to trip a circuit breaker when a fault is detected. The first protective relays were electromagnetic devices, relying on coils operating on moving parts to provide detection of abnormal operating conditions such as over-current, over-voltage, reverse power flow, over- and under- frequency. Microprocessor-based digital protection relays now emulate the original devices, as well as providing types of protection and supervision impractical with electromechanical relays. In many cases a single microprocessor relay provides functions that would take two or more electromechanical devices. By combining several functions in one case, numerical relays also save capital cost and maintenance cost over electromechanical relays. However, due to their very long life span, tens of thousands of these ""silent sentinels"" are still protecting transmission lines and electrical apparatus all over the world. An important transmission line or generator unit will have cubicles dedicated to protection, with many individual electromechanical devices, or one or two microprocessor relays.The theory and application of these protective devices is an important part of the education of an electrical engineer who specializes in power systems. The need to act quickly to protect circuits and equipment as well as the general public often requires protective relays to respond and trip a breaker within a few thousandths of a second. In these cases it is critical that the protective relays are properly maintained and regularly tested.