Power switching system

A power switching system comprising a first power supply and a second power supply with three-phase AC power, the power switching system comprising:

• a first power switch assembly comprising a first switch, a second switch, and a third switch, sequentially connected to a first phase, a second phase, and a third phase of the first power supply,
• a second power switch assembly comprising a fourth switch, a fifth switch, and a sixth switch, sequentially connected to a first phase, a second phase, and a third phase of the second power supply, and
• a three-phase transformer comprising a first winding, a second winding, and a third winding, wherein the first winding, the second winding, and the third winding of the three-phase transformer are connected in a wye structure to form one common node and three nodes, and the common node is grounded, wherein a first node is connected to the first switch and the fourth switch, a second node is connected to the second switch and the fifth switch, and a third node is connected to the third switch and the sixth switch,
• wherein the power switching system is configured to provide a forced commutation procedure for switching the first power supply to the second power supply, comprising:
• turning off the first switch, the second switch, and the third switch connected to the first power supply,
• detecting magnetic flux of the first winding, the second winding, and the third winding, and selecting one winding with the fastest flux switching as a fastest flux switching winding,
• turning on one of the fourth switch, the fifth switch, and the sixth switch connected to the fastest flux switching winding, and
• turning on the remaining two of the fourth switch, the fifth switch, and the sixth switch.