The document summarizes a seminar presentation on high voltage direct current (HVDC) transmission systems. HVDC systems are used for high power transmission because AC power transmission is limited by line inductance and capacitance. The key components of an HVDC system include converter units, converter transformers, filters, reactive compensation, smoothing reactors, and transmission lines. The main types of HVDC systems discussed are monopolar, bipolar, and homopolar links. Bipolar links, which use two conductors of opposite polarity, are most commonly used. HVDC systems offer benefits like lower transmission losses and cost effectiveness but also have limitations such as costly terminal equipment and voltage transformation requirements.

1. SEMINAR
ON
HIGH VOLTAGE DIRECT CURRENT
(HVDC)
TRANSMISSION SYSTEM
PRESENTED BY
DIPJYOTI DAS
E-27/16

2. WHY HVDC ?
• The electric power is produced, transmitted and distributed as an AC power
• Transmission lines are long and operates at high or extra high voltages.
• The amount of AC power transmission through the line is restricted by its
inductance and capacitance
• To overcome this, a High Voltage DC (HVDC) transmission system is generally
employed for high power transmission.

3. SINGLE LINE DIAGRAM OF HVDC

5. COMPONENTS OF HVDC
• Converter Unit
• Converter Transformers
• Filters
• Reactive Compensation
• Smoothing Reactor
• Transmission Line

7. TYPES OF HVDC SYSTEM
• Monopolar Link
• Bipolar Link
• Homopolar Link

8. MONOPOLAR LINK
 In this arrangement, a single conductor is used and
earth is used as the return conductor
 Here only negative polarity is used.
 This system is not in use due to high return Current.

9. BIPOLAR LINK
 It uses two conductors one is a positive and
the other negative conductor of the same
magnitude
 It is the mostly used link
 In case of any fault in one of the conductor the
system switches to monopolar link and carries
50 % of the rated load

10. HOMOPOLAR LINK
 This is similar to that of bipolar link with same
polarity
 Here, only the returning path is the ground
 In case of any fault in one conductor,the healthy
conductor can supply power using the ground
return path

11. ADVANTAGES
• Cheaper in cost
• Lower transmission losses
• No skin effect

12. LIMITATIONS
• Costly terminal Equipments
• More maintenance of line insulators
• Voltage Transformation

13. CONCLUSION
• HVDC system has huge potential in future
• HVDC is more reliable
• If the terminal equipment costs are reduced then it will be economical to
implement

14. BIBLIOGRAPHY
• www.Wikipedia.com
• www.electronicshub.org
• A course is Power system by JB Gupta

15. THANK YOU