This might be a dump question but I get lost every time I have to do something on a generator. I must calculate the steady state fault current (energy of fault) of a bus being fed by both the utility and two small 13 MW MV generators. I have the AVR settings. It states: "Current Limiter...
I would appreciate any comment on the type of CT to be used for a Z-transformer (NEC / Earthing Transformer) protection scheme. The Earthing Transformer is connected to a generator bus and therefore needs separate winding protection. I will use delta connected CTs to prevent zero sequence...
Hi,
Does anyone have some experience with ERA 69-30 and how their derating factors were derived. I do not have access to this document.
I have modeled some 11kV XLPE cables according to IEC287 and confirmed the values with the cable manufacturer. However, most cable manufacturers refer to...
Hi,
I am currently designing a MV switchboard controling 3x500kW motors. PFC is done by connecting capacitors directly onto the 3.3kV busbar. Worst case scenario will be at least one stage (286kVAr) with one 500kW running with a trip on the incomer/11kV feeder. No load current of the motor...
I would appreciate any comments on the use of surge protection on open ended cables. I am doing a MV (11 kV) substation design connected to ring feeders that will be split during normal operating conditions. Long lengths of cables (up to 1500m) might be energised but not connected to a...
I would appreciate some help on determining the steady state fault current for Diesel Generators. The Diesel Generators (415V) is feeding through step-up transformers (Dyn - 11/0.4kV) onto an high impedance earthed 11 kV network (isolated from utility supply). The manufacturer provides the...
