Power electronic devices and systems are becoming an increasingly common feature of power systems. Over the years many power electronic products have been developed and can be used to great effect in the alternating current (AC) transmission and distribution system. HVDC is in many respects the ultimate power electronics-based FACTS device which can act within an existing AC network or even replace parts of it. In evaluating the usefulness of HVDC it is important to remember the controllability which it adds to the power system in addition to its bulk power transfer capabilities. HVDC often provides the best of both worlds - support from a neighbouring network without the problems of synchronous interconnection.

Chapter Contents:

• 4.1 Introduction
• 4.2 HVDC transmission - a brief overview
• 4.3 General principles
• 4.4 Main components of HVDC links
• 4.4.1 Thyristor valves
• 4.4.2 Converter transformer
• 4.4.3 Control equipment
• 4.4.4 AC filters and reactive power control
• 4.4.5 Smoothing reactor and DC filter
• 4.4.6 Switchgear
• 4.4.7 Surge arresters
• 4.4.8 Valve cooling
• 4.4.9 Auxiliary supplies
• 4.5 Converter building
• 4.6 VSC HVDC
• 4.7 Economics
• 4.8 Power electronic support for AC systems
• 4.8.1 Static var compensators (SVCs)
• 4.8.2 STATCOM
• 4.8.3 Series compensators
• 4.8.4 Unified power flow controller (UPFC)
• 4.9 Power electronics for industrial applications
• 4.10 Conclusion
• References

Inspec keywords: HVDC power transmission; power electronics; HVDC power convertors

Other keywords: bulk power transfer capabilities; alternating current transmission system; AC distribution system; controllability; AC transmission system; power electronic systems; power electronics-based FACTS device; power system; HVDC; power electronic devices

Subjects: Power convertors and power supplies to apparatus; d.c. transmission; Power semiconductor devices