A New Protection Scheme for Static Transfer Switch Using Quasi Resonant Turn-Off Technique
Conference
Bose, V, Habib, HF, Belcastro, CA et al. (2023). A New Protection Scheme for Static Transfer Switch Using Quasi Resonant Turn-Off Technique
. 10.1109/IAS54024.2023.10406367
Bose, V, Habib, HF, Belcastro, CA et al. (2023). A New Protection Scheme for Static Transfer Switch Using Quasi Resonant Turn-Off Technique
. 10.1109/IAS54024.2023.10406367
In data center systems, critical loads need a power supply without interruptions. The system is fed from a main source and switched to an alternate source if power quality issues arise with the main source. The transfer time is critical to ensure continuous load operation. A static transfer switch (STS) is used to perform this transfer and traditional STSs use Silicon Controlled Rectifier (SCR) devices. SCRs can handle large surge currents. The main challenge with SCRs is that the turn-off is slow as it requires a zero current condition. In this work, a new technique using a quasi-resonant circuit to turn off the SCR is proposed. Transfer from the main source to the alternate source can be completed in less than 10 msec. The proposed circuit and its operation during fault conditions and transfer are explained in detail. The suggested circuit is explained during the whole clearing time and describes the operation during different time periods till the fault is cleared and isolated from the system. Several schemes are presented to utilize the number of quasi-resonant turn-off circuits. The system is simulated in PSIM software to show the improved results using the proposed method. Simulation shows that transfer can be completed in less than 10 msec using the proposed method compared to up to 17 msec using existing state-of-the-art STS.
