Patent ID: 9285400
Filing Date: 2016-03-15
CPC Classification: G01R,H02P

Claim Text:
1. A method for determining current in a polyphase machine connected to a DC voltage source and having a DC link provided with a DC-link capacitor and, per phase, a high-side switch and a low-side switch, the method comprising: performing a measurement of a voltage curve across the DC-link capacitor; and determining, based on the measured voltage curve, at least one of a current of the DC voltage source and a phase current, wherein voltage jumps occurring in the measured voltage curve are evaluated to determine the at least one of the current of the DC voltage source and the phase current; wherein the polyphase machine is controlled by center-aligned control, so that each of the voltage jumps occurs in response to each of a plurality of switching operations, so that there is a linearly rising voltage curve or a linearly falling voltage curve between two of successive ones of the voltage jumps, wherein an abrupt current variation occurs in response to each of the switching operations, and wherein a constant current characteristic curve occurs between two of successive ones of the abrupt current variations.