Motor system and control method

A system comprising:

• a motor having a plurality of windings, a rotor and a stator magnetically coupled to the rotor, wherein the plurality of windings is configured such that the number of poles of the motor can be dynamically adjustable by adjusting currents flowing through the plurality of windings;
• a plurality of power converters connected to respective windings, wherein the plurality of power converters and the plurality of windings are arranged into a plurality of symmetric groups controlled by a plurality of modulators synchronized by a plurality of interleaved clocks, and wherein gate drive signals in each symmetric group are synchronized to a clock;
• and
• a controller configured to decide a plurality of operating parameters of the motor to optimize a set of performance parameters of the system.

A method comprising:

• detecting operating parameters of a motor system comprising a plurality of windings, a rotor, a stator magnetically coupled to the rotor and a plurality of power converters connected to the plurality of windings;
• determining, by a controller, a suitable pole number and a preliminary set of operating variables based upon the operating parameters;
• reducing operating stresses of the motor system gradually;
• and
• after reducing the operating stresses, configuring the plurality of power converters so as to adjust the number of poles of the motor system according to the suitable pole number.