JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Power Systems & Switch Gear and Protection

Course Objectives:

• To study the physical and chemical properties of SF6.
• To introduce design criteria of Gas Insulated Substation (GIS).
• To comprehend the substation insulation co-ordination and protection schemes.
• To understand the source and effect of VFTO’s in GIS.
• To know various diagnostic methods of GIS.

Course Outcomes

After the completion of this course, the student will be to

• Develop the understanding of GIS equipment and their arrangements.
• Tto design the substation for present requirement with proper insulation coordination and protection against very fast transients.
• To perform various diagnostic methods of GIS.

UNIT - I

Introduction to GIS and Properties of Sf6: Characteristics of GIS- Introduction to SF6 - Physical properties-Chemical properties - Electrical properties-Specification of SF6 gas for GIS application - Handling of SF6 gas before use - Safe handling of SF6 gas in electrical equipment - Equipment for handling the SF6 Gas - SF6 and environment.

UNIT - II

Layout of GIS Stations: Advancement of GIS station - Comparison with Air Insulated Substation - Economics of GIS - User Requirements for GIS - Main Features for GIS - Planning and Installation components of a GIS station.

UNIT - III

Design and Construction of GIS Station: Introduction - Rating of GIS components - Design Features - Estimation of different types of Electrical Stresses - Design Aspects of GIS components - Insulation Design for Components - Insulation Design for GIS - Thermal Considerations in the Design of GIS - Effect of very Fast Transient Over-voltages (VFTO) on the GIS design - Insulation Coordination systems - Gas handling and Monitoring System Design.

UNIT - IV

Fast Transient Phenomena In GIS: Introduction - Disconnector Switching in Relation to Very fast Transients-Origin of VFTO-Propagation and Mechanism of VFTO-VFTO Characteristics- Effects of VFTO-Testing of GIS for VFTO.

UNIT - V

Special Problems in GIS and GIS Diagnostics : Introduction - particles their effects and their control- Insulating Spacers and their Reliability - SF6 Gas Decomposition - Characteristics of imperfections in insulation - Insulation Diagnostic methods - PD Measurement and UHF Method.

TEXT BOOK:

• 1. M. S. Naidu,” Gas Insulated Substations”- IK International Publishing House.