MICROCONTROLLERBASED

DIRECTIONAL MHO RELAY

Presented by:

Ganesh C

Mohan K M

Yerriswamy A

04/10/2023Electrical Department PES University

INTRODUCTION

04/10/2023Electrical Department PES University

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 occurrence2. Sensing of fault3. Isolation of faulted section

Unit Generator-Tx zone

Bus zoneLine zone

Bus zone

Transformer zone

Transformer zone

Bus zone

Generator

~XFMR Bus Line Bus XFMR Bus Mot

or

Motor zone

04/10/2023Electrical Department PES University

• Primary protection

• Backup protection

Classification of relays based on application1. Under voltage, under current & under power relays2. Over voltage, over current & over power relays3. Directional or reverse current relay4. Differential relay5. Distance relay

TYPES OF PROTECTION

04/10/2023Electrical Department PES University

Project focus

• Distance relay1. Impedance relay2. Mho relay3. Reactance relay

Mho relay is a distance relay with inherent directional element.

04/10/2023Electrical Department PES University

• It has 3 zones of protections1. Zone 1: 80-85% of protected line2. 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

04/10/2023Electrical Department PES University

• Zone 1: Instantaneous

• Zone 2: 0.5 sec

• Zone 3: 1 sec

TRIPPING TIME

04/10/2023Electrical Department PES University

BLOCK DIAGRAM

VOLTAGE INPUT

CURRENT INPUT

ZERO CROSSING DETECTOR

MICROCONTROLLER

KEYPAD

CONTACT

LCD

ANALOG TO DIGITAL

CONVERTER

Yset<Ymessared*cos()

REQUIREMENTS

• ATMEGA 328 MICRO CONTROLLER (Arduino)• MULTISIM/PROTEUS SIMULATOR• Current sensor• Voltage sensor• ZCD (zero crossing detector)• Breaker/contactor• Electrical load

04/10/2023Electrical Department PES University

04/10/2023Electrical Department PES University

Reference• [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.

04/10/2023Electrical Department PES University

THANK YOU

04/10/2023Electrical Department PES University

Time schedule2

7th Jan • Selection of

Project• Simulating

and Designing of Power factor measurement

15

th F

eb • Hardware

building and testing of ZCD

• Programming of measurement of Power angle

7th M

ar • Simulation

and designing of Voltage and current measurement

• Programming for measurement and ADC

29

th M

ar • Hardware

building and testing Relay