Download Energy Meter Working Principle

Electrical and Electronic Measurements& Instrumentation
10EE35
Energy Meter Working Principle; Electrical Meter Working:
Electric Meter, or Watt-hour Meter, a device that measures the quantity of electric energy.
One kilowatt hour is the quantity of electric energy needed to supply 1,000 watts of
electricity
for
a
span
of
one
hour.
An electrical power business uses electric meters to quantify the number of electricity
consumed by each. It bills the customer for the level of electricity and reads the meter
occasionally.
The most frequent kind is basically an electrical induction motor that drives a string of geared
wheels linked to gauges on the face of the meter. Such a meter was created with alternating
current to be used. It comprises a metal disc which is free to rotate between them and two
electromagnets. Current pulled through the building's electrical circuits powers directly by
current in the incoming power lines; the other, one electromagnet. The interaction causes the
disc to rotate. Two permanent magnets near the border brake of the disc the disc in this type
of manner the speed is proportional to the level drawn. As the disc rotates, it turns the chain
of geared wheels linked to the gauges on the face of the meter.
Diagram above shows how single phase energy meter works, similar will be applicable for
three phase energy meters.
Details of single phase meter working is as below:Single phase induction type energy meter is, in addition, popularly known as watt-hour
meter. This name is given to it. This post is concentrated about its functioning and its
constructional features. Induction type energy meter basically includes following
components:
1. Driving system
2. Moving system
3. Braking system
4. Registering system
Electrical and Electronic Measurements& Instrumentation
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Driving
system
A coil having large number of turns is wound on the middle limb of the shunt magnet.
This voltage coil has many turns and is ordered to be as highly inductive as potential. Quite
simply, the voltage coil creates a high ratio of inductance to resistance.
This induces thus the flux and the current, to lag the supply voltage by almost 90 degree.
Building
Single-phase
induction
kilowatt
hour
meter
-
Building
A flexible copper shading bands are provided on the central limb of the shunt magnet to make
supply voltage is approximately 90 degree and the phase angle displacement set up by shunt
magnet.
The copper shading bands may also be called the power factor compensator or compensating
loop. The flux produced by this magnet is proportional to, and in phase with the load current.
Moving
system
The moving system basically consists of a light rotating aluminium disc mounted on shaft or
a vertical spindle. A gear arrangement connects the rotating shaft that supports the aluminium
disk to the clock mechanism on the front to provide advice that used up energy.
The time varying (sinusoidal) fluxes generated by shunt and series magnet induce eddy
currents
in
the
aluminium
disc.
The interaction between both of these magnetic fields and eddy currents set up a driving
torque
in
the
disc.
The quantity of rotations of the disc is therefore proportional to the energy consumed by the
load in a particular time interval and is generally measured in kilowatt hours (Kwh).
Braking
The
disk
passes
between
the
magnet
system
gaps.
Redirecting a number there form or by shifting the position of the brake magnet, the rate of
the
rotating
disk
can
be
controlled.
Single-stage
induction
kilowatt
hour
meter
scheme
The counting or registering system basically consists of gear train, driven by pinion or worm
gear on the disc rotating shaft, which turns pointers that indicate on dials how many times the
disk
has
turned.
The energy meter thus discovers and adds or integrates all the instantaneous power values to
Electrical and Electronic Measurements& Instrumentation
ensure
Thus,
entire
this
energy
kind
of
used
over
meter
can
an
also
interval
be
10EE35
is
called
therefore
an
understood.
"integrating"
meter.
Working
of
Single
phase
induction
sort
Energy
Meter
The fundamental working of Single phase induction kind Energy Meter is just focused on two
mechanisms:
Mechanism of spinning of an aluminum disc which is made to rotate at a speed proportional
to
the
electricity.
Mechanism
Lets
and
have
a
Mechanism
Which
showing
look
of
is
the
over
these
turning
of
made
to
level
mechanism
rotate
an
in
transferred.
few
aluminum
to
the
words:
disc
electricity.
The metallic disk is acted upon by two coils. One coil is joined 0 r ordered in such a fashion
it produces a magnetic flux in proportion to the voltage and the other generates a magnetic
flux in proportion. 90 degrees delay the field of the voltage coil.
This creates eddy currents in the disk and the effect is such that there is a force applied on the
disc in proportion to the product of the instantaneous current and voltage.
A permanent magnet exerts an opposing force proportional to the speed of rotation of the disk
- this acts as a brake which causes the disk to stop spinning when electricity stops being
drawn rather than allowing it to spin faster and faster. This causes the disk to rotate to the
power
used.
Mechanism
According
of
displaying
to
the
amount
amount
of
energy
of
transferred
rotation.
The aluminum disc is supported by a spindle that has a worm gear which drives the cash
register. The register is a number of dials which record the level of energy used.
It should be noted that with the dial pointer type, adjacent pointers generally rotate in
opposite
ways
because
of
the
gearing
mechanism.
Electronic watt-hour meters are usually higher priced than versions that are electromechanical, but are more precise. They are able to supply such characteristics as the
capability to record individually the energy used up during different times of day and the
capacity to report meter readings by means of signs sent to the power company through the
power lines.