Page 242 - Electrician - TT (Volume 1)

ELECTRICIAN - CITS

ii The transformer, switch and switch gears, generators has to carry more current to meet the same power with
low power factor. It will again effect the size, cost, efficiency and life of the machine and apparatus.
iii The prime mover capacity will also be effected with low power factor, as the alternator has to induce more
power to meet the demand at low power factor.
iv Low power factor will effect the voltage regulation of generator, transformer, transmission line side.
Advantages of power factor improvement

i The output capacity of the prime mover is better utilized.
ii The output of alternator is increased.
iii The kW output of transformer and line are increased.
iv Efficiency of plant is increased.
v The voltage regulation is also improved.

vi The machines generator, transformer, line etc. Will carry less cross-sectional area for the same power to be
transmitted and utilized for improved power factor than low power factor.
Power factor improvement methods
• For Power factor improvement purpose, Static capacitors are connected in parallel with those devices which
work on low power factor.
• These static capacitors provides leading current which neutralize (totally or approximately) the lagging
inductive component of load current (i.e. leading component neutralize or eliminate the lagging component of
load current) thus power factor of the load circuit is improved.

Synchronous Condenser
• When a Synchronous motor operates at No-Load and over-exited then it’s called a synchronous Condenser.
Whenever a Synchronous motor is over-exited then it provides leading current and works like a capacitor.

• When a synchronous condenser is connected across supply voltage (in parallel) then it draws leading current
and partially eliminates the re-active component and this way, power factor is improved. Generally, synchronous
condenser is Used To Improve The Power Factor In Large Industries

Phase Advancer
• Phase advancer is a simple AC exciter which is connected on the main shaft of the motor and operates with
the motor’s rotor circuit for power factor improvement. Phase advancer is used to improve the power factor of
induction motor in industries.
Advantages of power factor correction
• Increases equipment life.
• Save on utility cost.

• Enhance equipment operation by improving voltage.
• Improve energy efficiency.
• Power Factor Penalty Is Reduced

Single phase power measurement
Single phase power refers to the distribution of alternating current electric power using a system in which all the
voltages of the supply vary in corresponding exactly.
Single phase distribution is used when loads are mostly lighting and heating ,with few large electric motors

A single phase supply connected to an alternating current electric motor does not produce a revolving magnetic
field, single phase motors need additional circuitsforstarting and such motors are uncommon above 10 or 20KW

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CITS : Power - Electrician & Wireman - Lesson 38-40 CITS : Power - Electrician & Wireman - Lesson 38-40