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What is the meaning of DYN 11 on a transformer nameplate?
What does Dd0, Dyn11, YNd5 etc. mean?First symbol/symbols, capital letters: HV winding connection.Second symbol/symbols, small letters: LV winding connection.Third symbol, number: Phase displacement expressed as the clock hour number.Winding connection designationsHigh Voltage Always capital lettersDelta - DStar - SInterconnected star - ZNeutral brought out - NLow voltage Always small lettersDelta - dStar - sInterconnected star - zNeutral brought out - nPhase displacementPhase rotation is always anti-clockwise. (international adopted convention)Use the hour indicator as the indicating phase displacement angle. Because there are 12 hours on a clock, and a circle consists out of 360°, each hour represents 30°.Thus 1 = 30°, 2 = 60°, 3 = 90°, 6 = 180° and 12 = 0° or 360°.The minute hand is set on 12 o'clock and replaces the line to neutral voltage (sometimes imaginary) of the HV winding. This position is always the reference point.Because rotation is anti-clockwise, 1 = 30° lagging (LV lags HV with 30°)and 11 = 330° lagging or 30° leading (LV leads HV with 30°)To summarise:Dd0Delta connected HV winding, delta connected LV winding, no phase shift between HV and LV.Dyn11Delta connected HV winding, star connected LV winding with neutral brought out, LV is leading HV with 30°YNd5Star connected HV winding with neutral brought out, delta connected LV winding, LV lags HV with 150°
What is difference between ICT and Transformers in power system?
A CT is a measuring device but does not step up or step down voltage like a transformer will.
How to parallel the Dyn1 and Dyn11 Transformer?
you keep the hv & lv on the dyn11 tx straight in phasing. you then put a cross on any two phases on the hv side of the dyn1 tx, and do the same cross with the phases on the lv side of the tx. for instance lets say we cross a & c phases on the hv & lv sides of the dyn1 tx. now draw a diagram with the four tx, split them up, 2 x dyn1, 2 x dyn11. now on the diagram where you have dyn1 tx, change the the phase plates to read cba left to right, also change the lv side to match. leave the phase plates on the dyn11 tx alone to read abc left to right on both sides. now draw the cables going between them on the hv & lv sides. now if a phase always goes to a phase and b & c phases do the same it will all tie in. prove it to yourself and follow a phase threw all the tx's, do the same will b & c phases. I do it all the time at my job, works every time.
What does a primary substation do?
Primary substation - when the transformer is HV/MV or MV/MV. e.g. substation designed for 132kV/33kV or 230kV/22kV or 33kV/11kV etc stepped down for MV distribution (mainly for utilities and heacy industries) Secondary substation - when the transformer is HV/LV or MV/LV. e.g. substation designed for 11kV/400V or 6.6kV/400V etc stepped down for LV distribution (mainly for residential, commercial) sometime referred to as a kiosk substation.
Why oc test done in lv side?
In OC test , the equipments are connected in LV side since we need to get rated voltage . if it is cinnected in HV side the value of voltage will be less and current wil be more.Hence the ordinary instruments cannot measure this value of current
