Showing papers by "Robert J. Thomas published in 1988"
TL;DR: In this paper, the authors discuss techniques for improving the system security with respect to the minimum singular value index (SVI) and present a continuation technique that redistributes the system generation to the optimal operating condition.
Abstract: The problem of system collapse or blackout characterized by a local severe voltage depression is generally believed to be associated with inadequate VAR support at key busses. The authors discuss techniques for improving the system security with respect to this index. The effect of adding capacitors are examined. They also present a continuation technique that redistributes the system generation to the optimal operating condition with respect to the minimum singular value index. >
321 citations
TL;DR: State-of-the-art SVD computation schemes using large arrays of parallel processors that improve the computation speed linearly and quadratically are discussed and a comparison is made between the computationspeed and the number of arithmetic units required for various parallel architecture schemes as well as with the traditional serial computer.
Abstract: Several researchers have suggested characterising a power system voltage collapse using the singularity of the Jacobian of the network descripter load-flow equations. It has been proposed to use the minimum singular value of the Jacobian as a security index for monitoring how closely a power system is operating to a voltage instability. However, a singular value decomposition (SVD) computation is an iterative process with a number of arithmetic operations proportional to the cubic power of the matrix size. State-of-the-art SVD computation schemes using large arrays of parallel processors that improve the computation speed linearly and quadratically are discussed. A comparison is made between the computation speed and the number of arithmetic units required for various parallel architecture schemes as well as with the traditional serial computer. >
58 citations
TL;DR: The design and operational issues associated with the interconnection of windfarms using a controllable AC/DC/AC series-connected interface are explored in this paper, where the performance of rectifiers and converters is discussed, and computer simulation results are shown.
Abstract: The design and operational issues associated with the interconnection of windfarms using a controllable AC/DC/AC series-connected interface are explored. The study considers steady-state operation and transient effects for both the power network and the wind system. The performance of rectifiers and converters is discussed, and computer simulation results are shown. Overvoltages created within the inverter stations and protection against short circuits are discussed. >
22 citations