US Patent 11251737 Control device

A control device for an electric motor having a first set of coil windings arranged to form a first sub motor and a second set of coil windings arranged to form a second sub motor, wherein current flow in the first set of coil windings is controlled using a first pulse width modulation, PWM, having a first switching sequence and current flow in the second set of coil windings is controlled using a second PWM having a second switching sequence, the control device comprising means arranged to measure the current flow in each of the first set of coil windings, wherein upon determining that the sum of the current flow in the first set of coil windings is substantially non zero, deriving the first PWM values from voltage values used to generate the second PWM.