Transient Behaviour of VSC-HVDC Links with DC Breakers Under Faults

• In future high-voltage direct current (HVDC) systems, a large number of HVDC breakers will be required.In this paper, the influence of HVDC breakers on the transient performance of point-to-point HVDC links in both asymmetrical and symmetrical monopolar configuration with half-bridge modular multilevel converters is studied with simulations in PSCAD. As HVDC breakers, the active resonant breaker and ABB’s hybrid breaker are considered. The analyzed scenarios include DC line faults, DC bus faults, and AC faults between the converter and the transformer. The highest DC breaking capability is required during DC line faults in the asymmetric and symmetric monopole. The converter stress is highest for DC bus faults and unbalanced converter AC faults in the asymmetric monopole and for DC bus pole-to-pole faults in the symmetric monopole. During DC pole-to-ground faults in the symmetric monopole, the HVDC breaker combined with DC side arrestors yields the lowest overvoltage stress on the cable of the healthy pole. The fault current shapes depend strongly on the interaction of the converter and the travelling waves on the lines, and differ from the fault current shapes in typical HVDC breaker test circuits. Furthermore, the active resonant breaker and the ABB hybrid breaker perform similarly in the used benchmarks due to the very fast DC line fault detection.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Nyckelord

HVDC

Power transmission

Multilevel converters

Voltage Source Converter (VSC)

Fault handling strategy

Electrical Engineering

Elektro- och systemteknik

Publikations- och innehållstyp

ref (ämneskategori)

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