This document defines and describes various power quality issues including blackouts, voltage sags, interruptions, spikes, swells, harmonic distortion, surges, flickering, fluctuations, noise, and unbalance. It provides causes and impacts of these issues. Power quality deals with continuity of supply and quality of voltage according to IEEE definitions. Addressing power quality issues leads to economic and stable operation of power systems while improving power factor and reducing electricity costs.

1. SUBMITTED BY:
ASHVANEE KUMAR MITTAL
4th year ,EE
12EGJEE020
SUBMITTED TO
Mr. MANISH MEWARA
Dept. of EE

2.  Defination
 Blackout
 Voltage sag
 Very short interruption
 Long interruptions
 Voltage spikes
 Voltage swell
 Harmonic distortion
 Voltage surges
 Flickering
 Voltage fluctuation
 Noise
 Voltage unbalance
 Impacts on environment and society

3.  The IEEE define power quality as the ability of
a system or an equipment to function
satisfactory in its electromagnetic
enviornment without introducing intolerable
electromagnetic disturbance to anything in
that environment.
 Power quality deals with
1. Continuity of the supply.
2. Quality of the voltage.

4. It is short or long term loss of electric power to
an area.
Causes:
• Faults at power station.
• Damege to electrical transmission line,
substations or other parts of the distrution
system.
• Short circuit, or the overloading of
electricity mains

5.  Description: a decrease of the normal voltage
level between 10 and 90% of the nominal rms
voltage at the power frequency, for duration of
0.5 cycle to 1 minute.

6.  Description: total interruption of electrical
supply for duration from millisecond to one
or two second.

7.  Description: total interruption of electrical
supply for duration greater than 1to 2
second.
 Causes: equipment failure in the power
system network, storms and striking lines,
fire, human error, bad coordination or failure
of protection device

8.  In electrical engineering ,spikes are fast
,short duration electrical transient in voltage
Causes:
• Lightning strikes
• Power outage
• Tripped circuit breakers
• Short circuits

9.  Description: momentry increase of the
voltage, at the power frequency,outside the
normal tolerances, with deuration of more
than one cycle and typically less than a few
second.
 Causes: start/stop of heavy loads,badly
dimensioned power sources ,badly regulated
transformers.

10.  Description: voltage
or current
waveforms assume
non sinusoidal
shape. the waveform
corresponds to the
sum of different sine
waves with different
magnitude and
phase, having
frequencies that are
multiples of power
system frequency.

11.  It is a voltage rise that endangers the
insulation of electric equipment.
 Types
 Lightning surges
 System generated surges.
 Causes:
 Shutdown of heavily loaded circuits.
 Switching events such as the connection or
disconnection of a current and short
circuiting to ground

12.  It is a visible change in brightness of a lamp
due to rapid fluctuations in the voltage of the
power supply .
 Causes:
 It increase as the size of the changing load
become larger with respect to the prospective
short circuit current available at the point of
common connection.
 effects:
 Reduction in life of electrical equipment

13.  Description: oscillation of voltage value,
amplitude modulated by a signal with
frequency of 0 to 30 hz.
 Causes: arc furnace, frequent start/stop of
electric motor, oscillating loads.

14.  Description: superimposing of high frequency
signals on the waveform of the power system
frequency.
 Causes: electromagnetic interferences provoked
by hertzian waves such as microwaves, television
diffusion, radiation due to welding machines,arc
furnaces.

15.  Description: a voltage variation in a three
phase system in which the three voltage
magnitudes or the phase angle differences
between them are not equal.

16.  The mitigation of all the power quality related
issues leads to the economic operation of the
power system.
 The elimination of harmonics and other
issues leads to the proper operation of the
system, thereby eliminating the unwanted
vibration and keeping the system stable.
 The power factor is improved, this leads to a
heavy savage in the cost of electricity bill.