You haven't seen this type of ppt this is by Mohan K M Ganesh C Yerriswamy A from PESIT Bangalore

1. MICROCONTROLLER
BASED
DIRECTIONAL MHO RELAY
Presented by:
Ganesh C
Mohan K M
Yerriswamy A

2. INTRODUCTION
4/14/2014Electrical Department PES University

3. POWER SYSTEM PROTECTION
• Main idea of protection is to remove faults as quickly as possible mean while
maintains the system stability.
• Under abnormal operating conditions protection is necessary for
 Safety of electrical equipments.
 Safety of human personnel.
• Sequence of events in relation with a fault
1. Fault occurrence
2. Sensing of fault
3. Isolation of faulted section
4/14/2014Electrical Department PES University
Unit Generator-Tx
zone
Bus zone
Line zone
Bus zone
Transformer
zone
Transformer
zone
Bus zone
Genera
tor
~
XFMR Bus Line Bus XFMR Bus Mot
or
Motor
zone

4. • Primary protection
• Backup protection
Classification of relays based on application
1. Under voltage, under current & under power relays
2. Over voltage, over current & over power relays
3. Directional or reverse current relay
4. Differential relay
5. Distance relay
4/14/2014Electrical Department PES University
TYPES OF PROTECTION

5. 4/14/2014Electrical Department PES University
• Distance relay
1. Impedance relay
2. Mho relay
3. Reactance relay
Mho relay is a distance relay with inherent directional element.

6. 4/14/2014Electrical Department PES University
• It has 3 zones of protections
1. Zone 1: 80-85% of protected line
2. Zone 2(minimum): 120% of protected line
Zone 2(maximum): < protected line + 50% of shortest second line
3. Zone 3F: 1.2(protected line + longest second line)
Zone 3R: 20% of protected line
MHO RELAY

7. • Zone 1: Instantaneous
• Zone 2: 0.5 sec
• Zone 3: 1 sec
4/14/2014Electrical Department PES University
TRIPPING TIME

8. 4/14/2014Electrical Department PES University
BLOCK DIAGRAM
VOLTAGE
INPUT
CURRENT
INPUT
ZERO CROSSING
DETECTOR
MICROCONTROLLER
KEYPAD
CONTACT
LCD
ANALOG TO
DIGITAL
CONVERTER

9. REQUIREMENTS
• ATMEGA 328 MICRO CONTROLLER (Arduino)
• MULTISIM/PROTEUS SIMULATOR
• Current sensor
• Voltage sensor
• ZCD (zero crossing detector)
• Breaker/contactor
• Electrical load
4/14/2014Electrical Department PES University

10. • [1] IEEE Tutorial Course, “Microprocessor Relays and Protection Systems”. The Institute of Electrical and
Electronics Engineers,INC., 1987
• [2] IEEE Tutorial Course, “Computer Relaying”, The Institute of Electrical and Electronics
Engineers, INC., 1979.
• [3] V. Gurevich, Electric Relays Principles and Applications, Taylor & Francis Group, LLC, 2006.
• [4] "MiPower Power System Analysis Software Package- User Manual," Power Research and Development
Consultants Pvt Ltd., Bangalore, India.
• [5] Bayindir R., Sagiroglu S., Colak I., An intelligent power factor corrector for power system using artificial
neural Networks, Electric Power Systems Research 79 (2009) 152–160.
• [6] Azcondo F. J., Diaz F. J., Branas C., Casanueva R.,Microcontroller Power Mode Stabilized Power Factor
Correction Stage for High Intensity Discharge Lamp Electronic Ballast, IEEE Transaction on Power
Electronics, Vol. 22, No. 3, 2007, 845-853.
• [7] Sagiroglu S., Colak I., Bayindir R., Power factor correction technique based on artificial neural
Networks, Energy Conversion and Management 47 (2006), 3204–3215.
4/14/2014Electrical Department PES University

11. 4/14/2014Electrical Department PES University

12. 27thJan
• Selection of
Project
• Simulating
and Designing
of Power
factor
measurement
15thFeb
• Hardware
building and
testing of ZCD
• Programming
of
measurement
of Power
angle
7thMar
• Simulation
and designing
of Voltage
and current
measurement
• Programming
for
measurement
and ADC
29thMar
• Hardware
building and
testing Relay
4/14/2014Electrical Department PES University