Electric motor control

A motor control method for a multiphase AC electric motor having a stator wound with a first stator winding set comprising three phases and a second stator winding set comprising three phases, the three phases of the first stator winding set and the three phases of the second stator winding set wound oppositely to one another in the stator, the method comprising:

• simultaneously switching a relatively high side of the inverter to a first phase of the first stator winding set and a relatively low side of the inverter to a corresponding first phase of the second stator winding set;
• wherein each phase of the first stator winding set is wound together in common slots in the stator with a corresponding phase of the second stator winding set;
• and
• wherein the first stator winding set and the second stator winding set each comprise turns that are alternately wound in the common slots.

A motor control system comprising:

• a multiphase AC electric motor having a stator wound with a first stator winding set comprising three phases and a second stator winding set comprising three phases, the three phases of the first stator winding set and the three phases of the second stator winding set wound oppositely to one another in the stator;
• a source of stored electrical energy;
• an inverter coupled to the source of stored electrical energy and the multiphase AC electric motor to provide switched electrical energy to the first stator winding set and the second stator winding set;
• a first driver configured to simultaneously switch a relatively high side of the inverter to a first phase of the first stator winding set and a relatively low side of the inverter to a corresponding first phase of the second stator winding set;
• and
• a second driver configured to simultaneously switch the relatively low side of the inverter to the first phase of the first stator winding set and the relatively high side of the inverter to the corresponding first phase of the second stator winding set;
• wherein
• the first stator winding set has a first neutral connection and the second stator winding set has a second neutral connection, the first neutral connection and the second neutral connection being separate neutral connections;
• wherein the first driver comprises a first gate driver and the second driver comprises a second gate driver;
• and
• wherein the first gate driver comprises a gate drive integrated circuit having a relatively high-voltage side and a relatively low-voltage side, the relatively high-voltage side referenced to two mutually-isolated ground references and the relatively low-voltage side referenced to a third ground reference.