Voltage transformers would have primaries that are either connected directly to the power system (VTs) or across a section of a capacitor string connected between phase and ground (coupling capacitor… Read more
Nov 28, 2018 | Edvard
The main purpose of an unbalance detection scheme is to remove a capacitor bank from the system in the event of a failure and fuse operation. This will prevent damaging… Read more
Nov 26, 2018 | Edvard
Gas insulated substations (GIS) use circuit breakers, disconnect switches and grounding switches, and have various means of indicating their position, either opened or closed, so the same as in AIS…....
Nov 23, 2018 | Edvard
The installation of a dedicated substation to serve a plant actually involves an interface between the utility and the plant. Close coordination between utility and plant personnel is essential so… Read more
Nov 21, 2018 | Edvard
Polarity is very important for the operation of transformers and protection equipment. A clear understanding of polarity is useful in understanding and analyzing of transformer connections and operation as well… Read more
Nov 19, 2018 | Edvard
In previous article we described how overcurrent, restricted earth fault (REF) and differential protection of a transformer can be applied and explained their schemes. This part continues with other, also… Read more
Nov 14, 2018 | Edvard
The problems relating to transformer temperature rise above an assumed maximum ambient temperature require some means of protection. Let’s summarize the problems and the possible forms of transformer protection that… Read more
Nov 12, 2018 | Edvard
Generator sets have specific features that must be taken into account for protection against electric shocks. Mobile sets cannot be connected to earth and their connection by means of a… Read more
Nov 08, 2018 | Edvard
Because of great harmfulness of greenhouse effect, SF6 gas has to be limited. It is necessary to develop high voltage vacuum circuit breaker to replace SF6 circuit breaker. Insulating structure…...
Nov 07, 2018 | Ali Sepehri
Ungrounded systems are power systems with no intentionally applied grounding. However, they are grounded by the natural capacitance of the system to ground. Thus, the fault current level is very… Read more
Nov 05, 2018 | Edvard
