Unit Connected Generator with Diode Valve Rectifier Scheme

Abstract

A tl¡esis subnritted to thc Faculty of Craduate Studies of the University of Ma¡ritoba in partial fulfillment of the requirenrents of tl¡e degree of MASTER OF SCIENCE @ t98 7 Permissio¡r has been granted to the LIBRARY OF THE UNIVERSITY OF MAN¡TOBA to lend or sell copies of this thesis, to the NATIONAL L¡BRARY OF CANADA to microfitm rhis thesis a¡rd to lend or sell copies of the fìlm, and UNIVERSITY MICROF¡LMS to publish an abstracr of this rhesis. The author reserves otl¡er publication rights, and neither the thesis nor extensive extracts from it may be printed or otherwise reproduced without the author's writte¡l permission. by HVDC simulator at the University of Manitoba for verifying the performance with different protection schemes. Oigital simulation with the EMTDC program was also performed to compare the results with those achieved from analog simulation. The system was able to recover from a fault within about 1.5 second as can be seen from the results.

Distributed voltage and frequency control of off-shore wind farms connected with a diode based HVDC link

“…The transient behaviour of the distributed control system shows an improvement over previously published recovery times for HVDC systems with diode rectifiers (larger than 1.5s) [3].…”

“…T HE use of single generators connected to diode based HVDC rectifiers presents important advantages over traditional thyristor-based HVDC rectifier, including smaller conduction losses, smaller installation cost and higher reliability [1], [2], [3]. Moreover, the use of the rectifier transformer is no longer needed when the generators are directly connected to the diode rectifiers [2].…”

Diode-Based HVdc Link for the Connection of Large Offshore Wind Farms

“…voltage sags is similar to that obtained with thyristor-controlled rectifiers. These results represent a substantial improvement over previously published recovery times for HVdc systems with diode rectifiers (larger than 1.5 s) [3]. Moreover, the proposed control system allows for wind farm optimal power tracking and for offshore ac-grid self-start operation.…”

Impedance-based Stability Analysis for HVDC Diode-Rectifier Connected Off-shore Wind Farms

“…The connection of generation units to HVDC links using diode rectifiers has been proposed as a robust an efficient method for uni-directional transmission of generated power [1]- [3]. The direct connection of synchronous generators to HVDC diode rectifier stations present important technical disadvantages, as the relatively large delays on synchronous generator voltage control lead to very poor short-circuit performance [3].…”