Results 121 to 130 of about 344 (172)

An Enhanced Strategy to Inhibit Commutation Failure in Line-Commutated Converters

IEEE Transactions on Industrial Electronics, 2020
Failure of the commutation process is a serious malfunction in line-commutated high-voltage direct current (HVdc) converters, which mainly occurs due to inverter ac faults and may lead to outage of the HVdc system. In this paper, an improved strategy is developed that functions based on the SIEMENS HVdc control system under normal conditions and ...
Sohrab Mirsaeidi, Xinzhou Dong
openaire   +1 more source

Commutation configurations for the protection of a line commutated converter

PESC '88 Record., 19th Annual IEEE Power Electronics Specialists Conference, 2003
Methods of protecting a line-commutated converter and load in the event of line-induced converter faults are investigated. The protection philosophy is classified in terms of the DC load type. Protection is found to be comprised of a two-part process, namely, detecting a fault and implementing corrective action during the postfault period.
F.P. Dawson, S.B. Dewan
openaire   +2 more sources

Line inductance measurement by using commutation time in line commutated converters

Electrical Engineering, 2009
Finding line inductance using wiring diagrams of the network is usually difficult or even impossible. In general, line inductance has to be measured in a simple nondisruptive way without service interruption. Several line inductance measurement techniques have been suggested previously, but they suffer from a number of limitations.
openaire   +1 more source

A Backup Protection Algorithm for Bipolar Line-Commutated Converter HVDC Lines

IEEE Systems Journal, 2021
This article proposes a new backup protection algorithm for bipolar high voltage alternative current (HVdc) lines using two-end synchronized sampled currents. Unlike traditional differential protection, the proposed algorithm can be applied to detect and recognize the faulted poles directly without the requirements for long time delay.
openaire   +1 more source

Line-Commutated Converters and Inverters

1977
The method by which AC supply voltage is used for the commutation of conducting SCRs has been discussed in Chapter 6; it is very convenient for both rectification and inversion in phase-controlled bridge circuits and midpoint-connection circuits. This method of commutation is referred to as class F type of commutation (see Chapter 8), and is also known
openaire   +1 more source

Control and Performance of a Self-Commutated GTO Converter Operating in Parallel With Line-Commutated Thyristor Converters

IEEE Transactions on Industrial Electronics, 2004
Recently, static var generators (SVGs) or static synchronous compensators based on self-commutated converters have been put into practical use for the purpose of compensation for reactive power, power swings damping, and/or voltage control in power systems.
S. Tamai, S. Murakami, R. Uchida, H. Akagi   +3 more
openaire   +1 more source

CLOSED MATHEMATICAL DESCRIPTION OF LINE COMMUTATED CONVERTER-DRIVES

IFAC Proceedings Volumes, 1983
Abstract By shifting the solution of problems to the software of microprocessors any complex control structure in electrical drive engineering can be executed. This essential presumption for solving the problem this way is the exact mathematical description of the drive system in order to enable the microprocessor to get deeper insight into the state
openaire   +1 more source

Generalized analysis of line commutated converters and close relatives

1987 IEEE Power Electronics Specialists Conference, 1987
Various schemes have been proposed to improve the power displacement factor and distortion of large ac to dc converters by using either free-wheeling diodes and thyristors or forced commutation devices operating at low frequency. This paper presents a generalized analysis of those converters and shows that various existing configurations can be ...
G. Olivier, G.-E. April, S. Manias, C. Ismail El Hadjri   +3 more
openaire   +1 more source

MULTI-STEP LINE- AND SELF-COMMUTATED SINGLE-PHASE BRIDGE CONVERTER

IFAC Proceedings Volumes, 1977
Abstract By means of fully controllable multi-step two-pulse bridge convertors d.c. loads as inverters or d.c. machines can be fed with variable voltage and current at increased line side power factor. These connections can be used for both rectifier- and inverter operation. Resistance braking is possible.
openaire   +1 more source

Investigation of line-commutated three-phase converters with impedance unbalance

Proceedings of the 2010 Electric Power Quality and Supply Reliability Conference, 2010
Current converters operated in unbalanced electrical three-phase systems will generally work asymmetrically, which causes the appearance of non-characteristic harmonics and therefore higher distortion levels. In this paper unbalances are considered, that are caused by asymmetrical AC-line short-circuit impedances, which are usually a result of ...
M. Weiland, G. Herold, T. Freudenstein
openaire   +1 more source