Results 221 to 230 of about 28,705 (265)

Wide-area protection against voltage collapse

IEEE Computer Applications in Power, 1997
A wide-area protection system against long-term voltage collapse was designed, implemented, tested, modified, and commissioned. The system is based on the present SCADA system in southern Sweden, which has been complemented with input signals and equipment to execute action orders from the protection system.
B. Ingelsson, P.-O. Lindstrom, D. Karlsson, G. Runvik, J.-O. Sjodin   +4 more
openaire   +1 more source

Voltage instability/collapse - an overview

IEE Colloquium on Voltage Collapse, 1997
Voltage instability and voltage collapse are a frequent concern on heavily stressed power systems. This paper contains an overview of what, in the author's view, are the main aspects to be considered when addressing such problems. Also included in the paper is a review of some of the analytical tools that are available for voltage stability analysis ...
openaire   +1 more source

INDUCTION MACHINE MODELS NEAR VOLTAGE COLLAPSE

Electric Machines & Power Systems, 1997
ABSTRACT A steady-state stability criterion based on the concept of synchronizing torque coefficient is presented for induction machines and various first-order models of small and large induction machines are derived near voltage collapse. In large induction machines, dynamic structural changes occur in the vicinity of voltage collapse, leading to a ...
M. TALEB, S. AHMED-ZAID, W. W. PRICE
openaire   +1 more source

Voltage collapse and its avoidance

IEE Colloquium on Voltage Collapse, 1997
This paper discusses the phenomenon which leads to voltage collapse. It describes how automatic control equipment may exacerbate the decay of system voltage levels, with specific reference to the automatic tap changing of supply transformers. It addresses the factors which affect the onset of such behaviour, and operational requirements for the ...
openaire   +1 more source

Voltage collapse phenomena in wind parks

18th International Conference and Exhibition on Electricity Distribution (CIRED 2005), 2005
Wind power is rapidly growing in the world. For reasons of economy the network interconnection is often designed without redundancy. This means that the nominal power of the transformer to the transmission system is in the range of the nominal power of all wind generators of a wind farm. Short circuit faults are in power systems unavoidable and cause a
G. Brauner, M. Heidl, D. Tiefgraber, M. Weniger, H. Haidvogl   +4 more
openaire   +1 more source

Clustering techniques for voltage collapse detection

Electric Power Systems Research, 1993
Abstract Power system voltage stability may be defined as the ability of a system to maintain load voltage magnitudes within specified operating limits under steady-state conditions. When this ability is lost, the system experiences severe drops in its voltage profile.
Luis Vargas, Victor H. Quintana
openaire   +1 more source

A stochastic based voltage collapse indicator

IEEE Transactions on Power Systems, 1993
The voltage collapse of a power system is analyzed as the result of the eventual push of the system operating point beyond the boundary of voltage security due to random fluctuations in the system load characteristics. The effect of different fluctuation intensity levels at load buses on the eventual voltage collapse of a power system is studied with ...
C.O. Nwankpa, R.M. Hassan
openaire   +1 more source

Time-domain simulation investigates voltage collapse

IEEE Computer Applications in Power, 1993
Fast and slow power system dynamic performance is illustrated with two examples from actual electric utility systems. These examples were chosen to characterize a local reactive power shortage and radial system performance, respectively. In both cases, a critical disturbance is examined.
R.J. Koessler, J.W. Feltes
openaire   +1 more source

An optimal strategy against voltage collapse

[1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems, 2002
An optimal strategy is presented to offer a preliminary solution to the growing concern of voltage collapse. The optimal strategy will maximize the power transfer within a given system while minimizing the necessary amount of shunt reactive power (VAr) support before voltage collapse is encountered.
V. Ajjarapu, P.L. Lau
openaire   +1 more source

SVC behaviour under voltage collapse conditions

IEEE Transactions on Power Systems, 1992
Under stressed conditions, it may be necessary for a power system to operate at a point where a voltage-susceptance characteristic has a negative slope. The authors demonstrate that static VAR compensators (SVCs) can extend stable operation into that region.
I.A. Hiskens, C.B. McLean
openaire   +1 more source