JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Power Systems & Power Electronics

Course Objectives:

• To compare EHV AC and HVDC systems
• To analyze Graetz circuit and also explain 6 and 12 pulse converters
• To control HVDC systems with various methods and to perform power flow analysis in AC/DC systems
• To describe various protection methods for HVDC systems and Harmonics

Course Outcomes

After completion of this course the student is able to

• Compare EHV AC and HVDC system and to describe various types of DC links
• Analyze Graetz circuit for rectifier and inverter mode of operation
• Describe various methods for the control of HVDC systems and to perform power flow analysis in AC/DC systems
• Describe various protection methods for HVDC systems and classify Harmonics and design different types of filters

UNIT - I

Basic Concepts: Necessity of HVDC systems, Economics and Terminal equipment of HVDC transmission systems, Types of HVDC Links, Apparatus required for HVDC Systems, Comparison of AC and DC Transmission, Application of DC Transmission System, Planning and Modern trends in D.C. Transmission. Analysis of HVDC Converters: Choice of Converter Configuration, Analysis of Graetz circuit, Characteristics of 6 Pulse and 12 Pulse converters, Cases of two 3 phase converters in Y/Y mode – their performance.

UNIT - II

Converter and HVDC System Control: Principle of DC Link Control, Converters Control Characteristics, Firing angle control, Current and extinction angle control, Effect of source inductance on the system, Starting and stopping of DC link, Power Control. Reactive Power Control In HVDC: Introduction, Reactive Power Requirements in steady state, sources of reactive power- Static VAR Compensators, Reactive power control during transients.

UNIT - III

Power Flow Analysis in AC/DC Systems: Modelling of DC Links, DC Network, DC Converter, Controller Equations, Solution of DC load flow, P.U. System for DC quantities, solution of AC-DC Power flow-Simultaneous method-Sequential method.

R16 B.TECH EEE.

UNIT - IV

Converter Faults and Protection: Converter faults, protection against over current and over voltage in converter station, surge arresters, smoothing reactors, DC breakers, Audible noise, space charge field, corona effects on DC lines, Radio interference.

UNIT - V

Harmonics: Generation of Harmonics, Characteristics harmonics, calculation of AC Harmonics, Non- Characteristics harmonics, adverse effects of harmonics, Calculation of voltage and Current harmonics, Effect of Pulse number on harmonics Filters: Types of AC filters, Design of Single tuned filters –Design of High pass filters.

TEXT BOOKS:

• 1. “K. R. Padiyar”, HVDC Power Transmission Systems: Technology and system Interactions, New Age International (P) Limited, and Publishers, 1990.
• 2. “S K Kamakshaiah, V Kamaraju”, HVDC Transmission, TMH Publishers, 2011
• 3. “S. Rao”, EHVAC and HVDC Transmission Engineering and Practice, Khanna publications, 3rd Edition 1999.

REFERENCE BOOKS:

• 1. “Jos Arrillaga”, HVDC Transmission, The institution of electrical engineers, IEE power & energy series 29, 2nd edition 1998.
• 2. “E. W. Kimbark”, Direct Current Transmission, John Wiley and Sons, volume 1, 1971.
• 3. “E. Uhlmann”, Power Transmission by Direct Current, B. S. Publications, 2009 R16 B.TECH EEE.