Intelligent phase selector

1. INTELLIGENT PHASE SELECTOR
For single phase from three phase supply

2. INTRODUCTION
 Power instability in developing countries creates the need
for automation of phase selection.
 Some regions experience fluctuation in power, phase
interruption which sometimes result in total power failure.
 To overcome this, the circuit consist of two main functions
which are Automatic phase changer and voltage indicator.
 If any one or two phases in three phase supply interrupted
or goes low and wants to work on normal voltages then this
circuit will give the solution.
 This system is designed to monitor presence of supply to the
three phase.

3. CONCEPT
 This project is capable of comparing 3 phase and
switching automatically to any of three phase
 This design is an efficient system that accurately
selects the best voltage/phase based on the
programmed logic such that, at every particular
point in time, the healthiest available phase from the
public utility supply is feed to the load and the
alternative channel can be engaged or selected to the
load only when there is total power failure.
 The microcontroller which is the logic center of this
circuit senses the 3 phases through a step down
network via RC circuit.
 This programmed switching and phase selection is
done in few microseconds without causing any
blackout.

4. COMPONENTS
 Arduino
 Relay
 LCD Display
 ULN2803
 RC circuit
 Fixed Power Supply
 Transformer
 Incandescent lamps

5. Arduino UNO
The Arduino Uno is a microcontroller board based on the ATmega328
(datasheet). It has 14 digital input/output pins (of which 6 can be used as
PWM outputs), 6 analog inputs, a 16 MHz ceramic resonator, a USB
connection, a power jack, an ICSP header, and a reset button.

6. RELAY
•Trigger Voltage (Voltage across coil) : 5V DC
•Trigger Current (Nominal current) : 70mA
•Maximum AC load current: 10A @ 250/125V AC
•Maximum DC load current: 10A @ 30/28V DC
•Compact 5-pin configuration with plastic moulding
•Operating time: 10msec Release time: 5msec
•Maximum switching: 300 operating/minute (mechanically)

7. LCD Display
A 16x2 LCD means it can display 16 characters per line and there are 2 such lines. In
this LCD each character is displayed in 5x7 pixel matrix. This LCD has two registers,
namely, Command and Data.

8. ULN2803
The ULN2803A is a high-voltage, high-current Darlington
transistor array. The device consists of eight npn Darlington pairs
that feature high-voltage outputs with common-cathode clamp
diodes for switching inductive loads. The collector-current rating
of each Darlington pair is 500 mA.

9. RC CIRCUIT
To generate low-voltage DC from AC to power the circuit, there are
many methods to convert AC voltage into DC. The most common
method is the use of a step-down transformer to reduce 230V AC
to a lower value AC. This is then rectified and made ripple-free by
using a transformerless power supply.
back

10. FIXED POWER SUPPLY
Component List :
Step down transformer
Voltage regulator
Capacitors
Diodes

11. Transformer
There is transformer block consist of 3 transformers in order to step-
down the 230V in each phase into 12V. Using rectification block we are
rectifying each phase voltage into DC voltages.
 Features of AC-DC Power Supply 220V-5V Transformer module:
 Input voltage: 220V ac
 Input current: 10-20 ma
 No-load power consumption: 0.2 W or less
 Precision of output voltage: DC5V(0.1 V or less)
 Output current: DC5V 500ma
 Output power: 3 W
 Efficiency: 80%

12. Incandescent Lamp
An incandescent light bulb, incandescent lamp or incandescent light
globe is an electric light with a wire filament heated until it glows. The
filament is enclosed in a bulb to protect the filament from oxidation.
Current is supplied to the filament by terminals or wires embedded in the
glass. A bulb socket provides mechanical support and electrical connections.

13. WORKING & BLOCK DIAGRAM
L1
L2
L3
ARDUINO
UNO
Load
Shifter
Using
Relay
RC
CKT
R
Y
B
LCD 16×2
POWER
SUPPLY
Transformer
Transformer
Transformer

14. CIRCUIT DIAGRAM

15. ADVANTAGES
 High switching speed
 Low power consumption
 Provides continuous power supply
 Less switching noise
 No manual errors
 Easy to install

16. DISADVANTAGES
 Switching happens only if there is a total power
failure
 Three phase loads cannot attach to this system
 There is an external supply require

17. FUTURE SCOPE
 In future, cost can be reduced so that it can be
marketable.
 If this project is installed in many places in same
area then it may suffer from unbalancing of
supply system, so in future system is develop like
that which maintain unbalancing, giving priority
to important places.

18. APPLICATIONS
 Continuous running of single phase loads
 Hostels and Hotels
 Street lights
 Offices and Industries
 Single phase motors

19. CONCLUSION
 By implementing this model, it automatically
shifts to the phase where correct voltage is
available.
 This project will improve the overall efficiency
of our power systems resident in needed
areas.

20. THANK YOU