Power Engineers Window

  Power Transmission From Point A to Point B by Mechanical System and Electrical System Point A and point B are connected by metallic SHAFT. Pont A and point B are connected by electric LINE.   Shaft has Driver Pulley at A Driven Pulley at B. Line has Sending Bus at A Receiving Bus at B.   Driver and Driven pulley rotates in Same Direction with Same RPM. Sending and Receiving Bus have Same Phase Sequence and Same Frequency.   Shaft gets mechanical twist due to power transfer. Line gets electrical twist due to power transfer.   Driven pulley is always Backward with respect to Driver pulley. Receiving Voltage is always Legging with respect to Sending Voltage.   Shaft Twist Angle between driver and driven pulley is Torsion Angle. Angle between sending and receiving voltage is Power Angle   Power transfer and twist relation is as per Stress Strain Diagram. Power transfer and twist relation is as per Power Angle...

  Phase Drop and Link to Live Phase in Distribution.   When one phase is out to distribution transformer, secondary LV voltages are disturbed. One phase has normal phase voltage but other two phases have half or little more or less than half the phase voltage. But when drop phase is linked to one of live phase, secondary LV voltage pattern is different as under. Consider one 11000/400 Volts Delta-Star distribution transformer. Out of three phase 11000 volts supply, one phase is open but linked to other phase as shown in the figure. When one phase is out to distribution transformer, secondary LV voltages are disturbed. One phase has normal phase voltage but other two phases have half or little more or less than half the phase voltage. But when drop phase is linked to one of live phase, secondary LV voltage pattern is different as under.   Transformer is delta-star having three primary coils connected in delta. B phase is open but linked to Y phase.  There is no cu...

  Phase Drop in Distribution System.   There may be the situation when one of the phases is not available to distribution transformer, may be due to operation DO-Fuse, Opening of jumper or purposely for load shedding etc. In this condition voltage on LV side is disturbed.   Consider 11000/400 Volts Delta-Star distribution transformer. Out of three phase 11000 volts supply, one phase is open as shown in the figure. There are three primary coils P1, P2 and P3 and three secondary coils S1, S2 and S3 assembled on three cores of transformer limbs A, B and C.  B is centre limb whereas A & C are side limbs as shown in figure.                           Case 1 When one phase say Y phase is open, primary P2 has normal line voltage V RB across it whereas primaries P1 and P3 are in series across line voltage V BR . The path of magnetic flux induced in the core is as shown in figure. As seen the flux p...

  Concept of Effective Unscheduled Interchange Rate in Availability Base Tariff   Introduction: Availability Base Tariff is tripartite tariff. Third part frequency linked unscheduled interchange rate indirectly provides open market for sale / purchase of power at desired rates without any agreement, consent or interaction with any agency. UI rate is variable from Rs 0.00 at 50.50 Hz to Rs 4.20 at 40.00 Hz. Any beneficiary can dump or draw power at prevailing rate. Consideration of effective UI rate was useful to Gujarat to fetch optimum benefit. Preface: Availability based tariff was introduced in India first time in western region from July 2002. Prime objective is to enforce self discipline by fiscal tool for power drawn/dump by beneficiary.   Energy cost is linked to (KWH) units but unit rate is determined by supply and demand condition at any time. Hence energy accounting is necessary in short time block. Therefore energy accounting in ABT is for 96 blo...