Selective Wave-Front Based Protection Algorithm for MTDC Systems
... (Zeq) which is a combination of all equipment connected at that point (e.g. inductance, converter, neighbouring cables AC network etc). Since the voltage and current at the relaying point must fulfil the circuit laws according to Zeq and the incident waves are determined at the fault location, some ...
... (Zeq) which is a combination of all equipment connected at that point (e.g. inductance, converter, neighbouring cables AC network etc). Since the voltage and current at the relaying point must fulfil the circuit laws according to Zeq and the incident waves are determined at the fault location, some ...
Superconducting Fault Current Limiter for Energy Storage Protection
... for a stable operation of the distribution system has been recognized as one of the promising solutions for fault current problems, because of its fast fault current limiting and automatic characteristics of recovery. The devices in electronics and electrical circuits are sensitive to disturbance an ...
... for a stable operation of the distribution system has been recognized as one of the promising solutions for fault current problems, because of its fast fault current limiting and automatic characteristics of recovery. The devices in electronics and electrical circuits are sensitive to disturbance an ...
more information and higher functionality introduced by modern
... minimum, thereby shortening repair times and minimising repair costs. In isolated supply systems, a first ground/earth fault could be allowed to merely trigger an alarm, while the plant continues to operate until it is convenient to shut down, such as the end of a shift, day, or week. During the sch ...
... minimum, thereby shortening repair times and minimising repair costs. In isolated supply systems, a first ground/earth fault could be allowed to merely trigger an alarm, while the plant continues to operate until it is convenient to shut down, such as the end of a shift, day, or week. During the sch ...
VRDC-Hz - Atkinson Electronics Inc
... frequency applications. The VRDC-Hz can be used in applications where a varying frequency is used to switch an adjustable relay such as in generator control or a frequency Hydro Power Plant load disconnect. The “cut-in” frequency, “cut-out” frequency, and the time delay value are adjusted on multi-t ...
... frequency applications. The VRDC-Hz can be used in applications where a varying frequency is used to switch an adjustable relay such as in generator control or a frequency Hydro Power Plant load disconnect. The “cut-in” frequency, “cut-out” frequency, and the time delay value are adjusted on multi-t ...
Tutorial on Single-Pole Tripping and Reclosing
... automatic generation-shedding (AGS) and automatic loadshedding (ALS) systems in the peninsular grid to prevent a system collapse upon the loss of both 400 kV lines. With both lines in service, the loss of one line requires no AGS or ALS system operation. However, with one line in service and high po ...
... automatic generation-shedding (AGS) and automatic loadshedding (ALS) systems in the peninsular grid to prevent a system collapse upon the loss of both 400 kV lines. With both lines in service, the loss of one line requires no AGS or ALS system operation. However, with one line in service and high po ...
fault location on distribution systems - Working Group
... With this simple equation, we can estimate answers with voltage and current magnitudes. For a ground fault, Zl=ZS is about one ohm per mile. If the line-to-ground voltage, V=5000 V, and the fault current, I=1500 A, the fault is at about 3.3 miles (5000/1500). Remember to use the phaseto-phase volta ...
... With this simple equation, we can estimate answers with voltage and current magnitudes. For a ground fault, Zl=ZS is about one ohm per mile. If the line-to-ground voltage, V=5000 V, and the fault current, I=1500 A, the fault is at about 3.3 miles (5000/1500). Remember to use the phaseto-phase volta ...
Generator Third-Harmonic Stator Ground Fault Detection Element
... limited to the generator and grounding system. These conditions impact both the magnitude of the third harmonic voltage produced by the generator and the distribution of that voltage across the ground zone impedances. To maintain element security, it may be necessary to disable the 64G element while ...
... limited to the generator and grounding system. These conditions impact both the magnitude of the third harmonic voltage produced by the generator and the distribution of that voltage across the ground zone impedances. To maintain element security, it may be necessary to disable the 64G element while ...
Megger PULSAR Equipment Specifications
... LINE SYNCHRONIZATION: PULSAR was designed to be completely independent of the line voltage and frequency. However, there may be applications where synchronizing to the line frequency may be desirable. With Line Synchronization activated, the output voltages and currents will be in phase with the inp ...
... LINE SYNCHRONIZATION: PULSAR was designed to be completely independent of the line voltage and frequency. However, there may be applications where synchronizing to the line frequency may be desirable. With Line Synchronization activated, the output voltages and currents will be in phase with the inp ...
Lighting Control System Guideform
... fiberglass circuit boards. based on micro processor technology they control simultaneously up to relays. 2.1.5.1.3.7. An auxiliary output on a connector shall also be available to cascade modules in order to control more than 12 relays. Each slave module added will control an additional 12 relays. T ...
... fiberglass circuit boards. based on micro processor technology they control simultaneously up to relays. 2.1.5.1.3.7. An auxiliary output on a connector shall also be available to cascade modules in order to control more than 12 relays. Each slave module added will control an additional 12 relays. T ...
Reliable Protection for systems, generators and motors up to 1600 A
... Even under load conditions the Eaton switch-disconnector operates safely. The reason: the 3- or 4-pole snap-action closing mechanism which is also applied with circuit-breakers. That’s why the rated short time withstand current is so high and can handle currents up to 150 000 A. The long lifetime wi ...
... Even under load conditions the Eaton switch-disconnector operates safely. The reason: the 3- or 4-pole snap-action closing mechanism which is also applied with circuit-breakers. That’s why the rated short time withstand current is so high and can handle currents up to 150 000 A. The long lifetime wi ...
Snímek 1
... Protection in case of a malfunction: the separation from other circuits; Protection construction elements: powered by the source of low voltage by the SELV or PELV source separating the appliance from the network; Type of protection sign: picture no. 3 on the label Powering winding: two-vein ...
... Protection in case of a malfunction: the separation from other circuits; Protection construction elements: powered by the source of low voltage by the SELV or PELV source separating the appliance from the network; Type of protection sign: picture no. 3 on the label Powering winding: two-vein ...
RM17TG00 Datasheet - Mouser Electronics
... 35 mm symmetrical DIN rail conforming to EN/IEC 60715 ...
... 35 mm symmetrical DIN rail conforming to EN/IEC 60715 ...
NERC Synchronizing Islands
... The frequencies of two islands will likely be different because the generation for each island being independently controlled. Before the circuit breaker can be closed the frequencies must be very close together and “in phase”. Think of a mechanical transmission that is about to lock two large machi ...
... The frequencies of two islands will likely be different because the generation for each island being independently controlled. Before the circuit breaker can be closed the frequencies must be very close together and “in phase”. Think of a mechanical transmission that is about to lock two large machi ...
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.