AMAZON multi-meters discounts AMAZON oscilloscope discounts
Typical designs
The remainder of this section is devoted to illustrations of typical transformers from the smallest to the largest sizes (see Figures 112 to 143). These are shown with different types of tanks and with different terminal arrangements, and are typical of modern practice in the design of power transformers.
FIG. 114 Single-phase 11 kV, 50 Hz, pole-mounted transformers. Rated 16-50
kVA (Allenwest Brentford Ltd)
FIG. 115 Three-phase 500 kVA, 11 kV, 50 Hz substation transformer showing
the provision made for mounting LV fuse-gear on the left and an HV ring main
unit on the right (ABB Power T&D Ltd)
FIG. 116 Three-phase 750 kVA, 11 000/395 V, 50 Hz sealed-type transformer
with welded cover; viewed from HV side. The HV cable box is attached to a disconnecting
chamber (ABB Power T&D Ltd)
FIG. 117 Three-phase 750 kVA, 11/3.3 kV transformer fitted with conservator,
Buchholz relay and explosion vent. Tappings over a range _2.5 percent to _7.5
percent are brought out to an off-circuit selector switch (ABB Power T&D
Ltd)
FIG. 118 Three-phase dry-type mining transformer 3300/1130-565 V, 50 Hz.
High-voltage SF6 switchgear is mounted on the near end of the tank with LV
chamber containing earth-leakage equipment at far end (Brush Transformers Ltd)
FIG. 119 Three-phase 11 kV, 50 Hz dry-type nitrogen-fitted sealed transformer
(Allenwest Brentford Ltd)
FIG. 120 Three-phase 1750 kVA, 13 800/480 V, 50 Hz core and windings. HV
tappings brought to an off-circuit tap selector (Bonar Long Ltd)
FIG. 121 Three-phase 1500 kVA, 13.8/3.3 kV, 50 Hz core and windings. HV tappings
at _2.5 percent and _5 percent taken from the HV disc-type windings (Bonar
Long Ltd)
FIG. 122 Three-phase 6 MVA, 600/3450 V, 50 Hz core and windings with HV tappings
brought to an off-circuit selector. The HV disc winding is arranged in two
parallel halves to reduce axial forces (ABB Power T&D Ltd)
FIG. 123 Core windings of three single-phase units each rated at 10 000 A
and designed for rectifier testing duty (Allenwest Brentford Ltd)
FIG. 124 Two 90 MVA, 385/18.7 kV units in service at CERN (The European Organization
for Nuclear Research). The units provide power for what is claimed to be the
world's largest nuclear particle accelerator; a 400 GeV proton synchroton.
The units have to withstand three million pulses per year at a peak load of
148 MW, 50 percent above their nominal rating (Hawker Siddeley Power Transformers
Ltd)
FIG. 125 Frame and windings of a three-phase air-cored reactor, 20 MVA, 11/6.6
kV, 4 percent _ 50 Hz, shown out of its tank (ABB Power T&D Ltd)
FIG. 126 Lowering the core and windings of a 148 MVA, 275 kV, 50 Hz, three-phase
generator transformer into its tank (ABB Power T&D Ltd)
FIG. 127 Three-phase 60 MVA, 132/33 kV, 50 Hz core and windings showing the
outer tapping winding and the tapping leads assembly (ABB Power T&D Ltd)
FIG. 128 Core and windings of 46 MVA, 72.8/11.5 kV, 50 Hz, three-phase transformer
with tappings brought out for connection to on-load tapchanger (ABB Power T&D
Ltd)