Title :
Analysis of a static transfer switch with respect to transfer time
Author :
Mokhtari, Hossein ; Dewan, Shashi B. ; Iravani, M. Reza
Author_Institution :
Dept. of Electr. & Comput. Eng., Toronto Univ., Ont., Canada
fDate :
1/1/2002 12:00:00 AM
Abstract :
Thyristor-based static transfer switches (STSs) are used in uninterruptible power supply systems and in distribution networks to provide connection to alternate sources of AC power for critical loads when the main sources fail. However, performance of STSs from a transfer-time point of view has not been reported in the technical literature. This performance evaluation is a complex issue due to the dependence of the transfer time on gating scheme and commutation between thyristors. This paper provides a thorough analysis of a fast gating strategy for STS systems. It derives analytical expressions to estimate the transfer time for different operating conditions and identifies the worst case scenario(s) in which maximum transfer time occurs. The analytical results are validated based on time-domain simulation studies using a PSCAD/EMTDC package for a medium-voltage system. The simulation results are verified based on comparison with those obtained from an experimental setup
Keywords :
commutation; distribution networks; power semiconductor switches; power system analysis computing; switchgear; switching; thyristors; uninterruptible power supplies; PSCAD/EMTDC package; alternate AC power sources; commutation; computer simulation; distribution networks; fast gating strategy; gating scheme; medium-voltage power system; operating conditions; performance evaluation; thyristor-based static transfer switches; time-domain simulation; transfer time analysis; uninterruptible power supply systems; worst case scenario; Analytical models; EMTDC; Medium voltage; PSCAD; Packaging; Sociotechnical systems; Switches; Thyristors; Time domain analysis; Uninterruptible power systems;
Journal_Title :
Power Delivery, IEEE Transactions on