This document describes the design of an automatic phase selector system. The system continuously monitors the three input phases and connects the load to the active phase using a relay. If one phase fails, the load is automatically switched to another available phase within seconds. The system aims to provide uninterrupted power to critical loads in the event of a phase failure. It uses a microcontroller to check phase availability and control the relay switching. The system was tested successfully and provides reliable phase switching without requiring a backup power source.

2. content
 Abstract
 Introduction
 Literature survey
 Block diagram
 Block diagram description
 Hardware requirement
 Software requirement
 Conclusion
 Advantage
 Application
 References

3. Abstract
 Phase absence is a very common and severe problem in any industry, home or
office. Many times one or two phases may not be live in three phase supply.
Because of this, many times, some electrical appliances will be on in one room
and OFF in another room. This creates a big disturbance to our routine work.
 Power Failure is common problem. it hampers the production of industry ,
construction work of new plants and building . It is often noticed that power
interruption in distribution system is about 70% for single phase faults while
other two phases are in normal condition. Thus, in any commercial or domestic
power supply system where 3 phases is available, an automatic phase selector
system is required for uninterrupted power to critical loads in the event of
power failure in any phase.
 There is no requirement of backup power supply in that case. also there is no
time consumption as the phase is changed automatically within a few seconds.


4. Introduction
 Now-a-days every institution needs automation. As a part of college
automation, we have decided to do a project Phase absence is a very
common and severe problem in any industry, home or office. Many
times one or two phases may not be live in three phase supply. Because
of this, many times, some electrical appliances will be on in one room
and OFF in another room. This creates a big disturbance to our routine
work.
 This project is designed to check the availability of any live phase, and
the load will be connected to the particular live phase only. Even a
single phase is available, and then also, the load will be in ON
condition. This project is designed with AT328 MCU. This controller
continuously checks for live condition of all phases connected to it, and
the controller connects the load to the active phase using a Relay. This
relay is driven with a transistor.


5. AIM & OBJECTIVE
 Main aim of project is automatic phase switch which
give input as 230v ac to input power to single phase
output application.
 To design system which does not require backup like
generator.
 To design system which operate automatically.
 To implement system which work uninterrupted
power for critical Loads in power failure condition.

6. LITERATURE SURVEY
 DESIGN AND IMPLEMENTATION OF AUTOMATIC THREE
PHASE CHANGER USING LM324 QUAD INTEGRATED CIRCUIT
 Author :- Oduobuk, E. J., Ettah, E. B. , Ekpenyong, E. E.
 Design and implementation of an automatic three phase changer
using LM324 quad integrated circuit was carried out. The system was
designed and simulated using (Multisim). The circuit components
were mounted a Vero board. LM324 integrated circuit (comparator)
and 2N2222 transistors were used as active components alongside other
passive components. Result shows that, when the three phase a.c
inputs: Red phase ( ), yellow phase ( ) and blue phase ( ) from public
utility supply was fed to the system, the system compared the inputs
with regard to phase imbalances, and the input with the highest
voltage appears across the output. It also changes over from one phase
to another immediately the circuit senses further phase imbalance.


7. Block diagram

8. BLOCK DIAGRAM DESCRIPTION
 In this project we continuously on Load using three phase .
 If all phase are present microcontroller turn on Load on
phase 1.at that on LCD display as “Phase 1 selected ”
 If first phase absence, Load automatically shift to phase 2
with the help of relay circuit.
 Same if first two phase absent microcontroller shift that
load to phase 3 with the help of rely circuit.
 System will display selected phase on LCD.
 This project uses regulated 5v, 750mA power supply. 7805, a
three terminal voltage regulator is used for voltage
regulation. Bridge type full wave rectifier is used to rectify
the ac output of secondary of 230/12v step down
transformer.

9. HARDWARE REQUIREMENT
 AT328 Microcontroller
 LCD Display
 Relay circuit
 Load
 Step Down Transformers.
 Comparators.
 Switching Devices.

10. SOFTWARE REQUIREMENT
 Keil IDE
 Flash Magic
 Proteus

11. POWER SUPPLY
 The input to the circuit is applied from the regulated
power supply. The a.c. input i.e., 230V from the mains
supply is step down by the transformer to 12V and is
fed to a rectifier. The output obtained from the
rectifier is a pulsating d.c voltage. So in order to get a
pure d.c voltage, the output voltage from the rectifier is
fed to a filter to remove any a.c components present
even after rectification. Now, this voltage is given to a
voltage regulator to obtain a pure constant dc voltage

12. CONCLUSION
 In this system we automatically shift phase if any
phase absence .
 It tested on hardware with some trial n error
conditions.
 We make some truth table for it n using truth table we
checking failure condition & depend on that condition
we shift phase automatically.
 The system operates smoothly as expected. It is
reliable, durable and portable. The cost involved in
developing it, makes it much more affordable than
comparable product.

13. ADVANTAGE
 Automatic Switching Of The Load Will Decrease
Human Errors.
 Controller Will See That The Load Is Balanced At
Every Instant Of Time.
 The Switching Time Is Less Because Of Which The
Fault Duration On The System Is Very Less.

14. APPLICATIONS:
 Can be used in industries and commercial complexes
 Can be used near distribution transformers to switch
the load between phases automatically.

15. REFERENCES
 Himadri Sil “Design Of Automatic Phase Selector From
Any Available Three Phase With The Use Of Logic Gate
And Relay Driver” Ijiet , June 2016 .
 Bhanu Bhawesh “Automatic Phase Changer” minor report
on Automatic phase changer.
 Oduobuk, E. J., Ettah, E. B. , Ekpenyong, E. E. “Design
And Implementation Of Automatic Three Phase Changer
Using Lm324 Quad Integrated Circuit” International
Journal of Engineering and Technology Research Vol. 2,
No. 4, April 2014.
 en.wikipedia.org/
 www.goggle.com

16. Thank You….