Patent ID: 9093942
Filing Date: 2015-07-28
Classification: H02K,H02P,Y10T

Abstract:
1. A system comprising: a variable frequency drive including a rectifier, a DC bus, and an inverter, the inverter including a plurality of inverter legs; and an electric motor operatively connected with the inverter, the motor including a main winding and an auxiliary winding, the main winding connected with a first leg of the inverter at a first main winding node and connected with a second leg of the inverter at a second main winding node, the auxiliary winding connected with a third leg of the inverter at a first auxiliary winding node and connected with the second leg of the inverter at a second auxiliary winding node; wherein the third leg of the inverter includes a plurality of switching devices and a capacitor selectably electrically connectable with the first auxiliary winding node by switching one or more of the switching devices; wherein the third leg of the inverter comprises a first switching device, a second switching device, a third switching device, and a fourth switching device connected in series between a first rail of the DC bus and a second rail of the DC bus; the capacitor is connected to a first inverter node between the first switching device and the second switching device and connected to a second inverter node between the third switching device and the fourth switching device; and the first auxiliary winding node is connected with the third leg of the inverter at a node intermediate the second switching device and the third switching device.