Course Objectives:

1.      To give overview of power system protection requirements.

2.      To give an overview of digital protection using different types of static relays, its application to modern power system and apparatus

3.      To study the operation of relays using microcontrollers

Introduction: Overview of protection systems and relaying, concept of digital simulation of relaying signals. Current and Voltage Transducers: their features and characteristics under steady state and transient conditions.


Static Relays: Overview of Electromechanical Relays and their operating characteristics, Static Relays and comparison with electromechanical relays, Mathematical theory of relay as a comparator, operating principles and characteristics of various static relays like overcurrent relay, Distance relay, Switched distance relay, Directional relay, Poly-phase relay, Frequency relay.


Digital Protection of Bus-bar, Transformer and Generator Systems: High impedance and low impedance differential protection schemes, Protection schemes for bus-bar, transformer and generator


Digital Protection of Transmission Line Systems: Distance protection system and characteristics, Differential line protection, Phase comparison line protection, Use of line carrier and communication links.


Digital Protection Scheme for Distribution Systems: Protection criteria for distribution system, Features of directional and non-directional protection schemes for distribution system


Relay Setting and coordination: Coordination of overcurrent, Distance and directional relay, Integrated relaying operation in power system. Real-time considerations, Adaptive relaying, Integrated substation protection and control, Introduction to IEC protocols.


Microcontroller/DSP based protection: Signal conditioning, Sampling and analog to digital conversion, Hardware realization- Microcontroller/DSP based, Relaying algorithms, Software considerations, Applications for Digital protection schemes for transmission lines, Generators and transformers,


Laboratory Work:

Experiments on differential relay, overcurrent relay, differential protection for generator, transformer and transmission lines, Simulation of protection schemes using SIMULINK, Operation and control of relays through microprocessor/microcontrollers.


Course Learning Outcomes (CLO):

On the completion of the course, the student will be able

1.      To knowing static relays and its types.

2.      To analyse the digital protection schemes for transmission lines, generators and transformers.

3.      To simulate the protection schemes for radial and mesh connected systems.

4.      To realize relaying algorithms with different relay settings and on microcontrollers or microprocessors.

Recommended Books:

1.      Johns, A.T.  and Salman, S.K., Digital Protection for Power Systems, IEE Power Series (1995).

2.      Rao, T.S.M., Power System Protection: Static Relays, Tata McGraw Hill Publishing Company (2008).  

3.      Wu, Q.H., Lu, Z., Ji, T.Y., Protective Relaying for Power Systems using Mathematical Morphology, Springer (2009).