Automatic Power Factor Correction: International Research Journal of Engineering and Technology (IRJET)
Automatic Power Factor Correction: International Research Journal of Engineering and Technology (IRJET)
Automatic Power Factor Correction: International Research Journal of Engineering and Technology (IRJET)
© 2019, IRJET | Impact Factor value: 7.34 | ISO 9001:2008 Certified Journal | Page 474
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 09 | Sep 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.34 | ISO 9001:2008 Certified Journal | Page 475
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 09 | Sep 2019 www.irjet.net p-ISSN: 2395-0072
current, that can be suitably connected with measuring and indicate the numbers of the characters and the numbers of
recording instruments. C T that are used in the circuit also the lines. For example, a 16x2 LCD display contains 16
protects the measuring instruments from an exceptionally characters and 2 lines made available to use. Similarly, 20x4
higher voltage. C T are mostly used in metering devices. and LCD display indicates 20 characters and 4 lines made
also, in protective relays accessible for use. In this project a 16x2 LCD display, is
considered.
4.4 Capacitor bank
5. HARDWARE IMPLEMENTATION
Shunt capacitor banks basically is utilized for the
improvement of the P F in electrical network. Capacitor banks The P C B was made-up as per the diagram and then all the
are also used for the improvement of the voltage stability and components were soldered. The Potential transformer,
decrease network losses. Shunt capacitor banks are not Current Transformer, capacitor bank were soldered properly
expensive. Shunt capacitors installation can be done easily at their respective places. microcontroller was programmed
anywhere on the network. Depending on the necessity of by using a burner. The C T is connected in series with load
reactive power, capacitor bank which consist of shunt and capacitor bank. Microcontroller determines both
capacitors are made ON or OFF. With the usage of relays the magnitudes and phase difference of AC voltage and current .
switching can be done by manual way or automatically. Based on the measured values using formula P F of load is
calculated. The liquid crystal display is used to display the
4.5 Microcontroller improved P.F.
An embedded system is not effective without logical
processing. The microcontrollers take the responsibility of
logical processing hence can be seen as a heat of an
embedded system. They do majority of the work starting
from taking the data or instructions in, processing it
according the programme written and finally provide the
output to complete the required function. It is worthy to
mention another positive characteristic of the embedded
system such as chip memory. This allows the system to store
some temporarily variables during the processing procedures
to smoothen the process. The PIC microcontroller
PIC16f877a is one of the most well-known microcontrollers.
This microcontroller is very suitable to use. The main benefit
is that it can be write or can be erased as many times as
possible because it uses FLASH memory technology.
4.6 Relay unit
Relay unit contains a relay driver and some relays. The relay
unit controls the high-power circuit from a low power circuit
because microcontroller’s output cannot control direct
switching of capacitors. Relay is defined as an electrically
Fig -3: Hardware of Automatic Power Factor Control
operated switch. When there is a need to control in a circuit
by a low power signal in such cases relays are used. Current
that passes from coil of relay generates a magnetic field that 6. Results
gets attracted towards lever and then the switch contacts are Figure 3 shows the whole hardware of Automatic Power
changed. Connections of relay's switch are Common, Factor Control Unit used for improving power factor. One of
Normally Open (NO), normally closed (NC). the results is discussed below. Figure 3, when inductive load
Relay coil is not operated by the current provided by the was applied i.e. Choke is used in this case the measured P.F
output of microcontroller as current is insufficient. Relay was found to be 0.85 Lagging (refer the figure 4) and In
driver ULN2003 is used for the operation of the relay. Figure 5, the P F is increased to 0.99 by adding capacitor in
ULN2003 is a mono-lithic higher voltage and higher current parallel. The result shows the working and idea of Automatic
Darlington transistor array. Power Factor Correction by using capacitors.
7. CONCLUSION
This project is implemented to automatically correct power
factor. Microcontroller used helps to sense the Power Factor
by monitoring the load of the system, and according to the
lagging behavior of P F because of type of load it will perform
the control action by switching capacitor bank through
different relays and improves the Power Factor of the load.
By improving Power Factor electricity bill can be reduced.
REFERENCES
© 2019, IRJET | Impact Factor value: 7.34 | ISO 9001:2008 Certified Journal | Page 477