132kV is step down to 33kV or 11kV over two 3 windings transformer of capacity 20/31.5MVA 132kV/33kV/11kV.
The two feeders at 132kV are of 100% capacity
An ON LOAD TAP CHANGER (OLTC) which is controlled by automatic voltage regulator to provide a constant secondary voltage of 11kV irrespective of primary incoming feeder voltage in a range of 138.6kV to 99kV.
Surge arresters are used to protect the apparatus insulation from lightning surges and switching surges.
Surge arresters are usually connected between phase and ground in distribution system; near the terminals of the large medium voltage machines and in HV, EHV, HVDC substations.
Two types of Surge Arresters:
1. Gapping Silicon Carbide Surge Arresters
2. Zinc Oxide Gapless Arresters.
EQUIPMENT IN POWER DISTRIBUTION S.No Equipment Functions 1 Bus bars Incoming and outgoing circuits are connected to bus bars 2. Lightening arrestors To discharge lightning over voltages and switching over voltages to earth 3. Shunt reactor in E.H.V substations To provide reactive power compensation during low loads. 4. Series reactors To reduce the short circuit currents or starting currents. 5. Neutral Grounding Resistor To limit the earth fault currents. 6. Coupling Capacitor To provide connection between high voltage line and line carrier currents equipment.
S.No Equipment Functions 7. Line Trap To prevent high frequency signal from entering other zones 8. Shunt Capacitors To provide compensations to reactive loads of lagging power factors. 9. Power Transformers To step-up or step-down the voltage and transfer power from one A.C voltage to other A.C voltage at same frequency. 10. Series Capacitors Compensation of series reactors of long lines.
Monitoring and reports also reveal at what times there were particularly high loads.
From here strategies can be developed to avoid such critical situations.
Load shedding modules in an energy management system offer the possibility of specifying a "turn-off strategy" which states precisely which consumers may be turned off at all and in which order.
Load forecasting gives you a preview of your company’s load curve, it stores knowledge about the production processes’ behavior in typical production situations from several hours to several days ahead.
They make use of flame-retardant inorganic insulating materials which free these transformers from all restrictions that apply to oil-filled electrical equipment, such as oil-collecting pits, fire walls, fire extinguishing equipment, etc.
Dry Type Transformers are installed wherever oil-filled units cannot be used