Control apparatus of rotary electric machine and method therefor

A control apparatus for a rotary electric machine, the rotary electric machine comprising:

• a rotor;
• a stator disposed co-axially with the rotor, the stator including a multiphase stator winding provided with conductor portions arranged in positions facing the rotor at predetermined intervals in a circumferential direction thereof;
• and
• any one of,
• a first configuration having a first inter-conductor member between respective conductor portions in the circumferential direction, the first inter-conductor member using a magnetic material in which a saturation magnetic flux Bs satisfies a relationship of Wt×Bs Wm×BR, where Wt is a width dimension in the circumferential direction of a portion between respective conductor portions corresponding to one magnetic pole of a magnet portion of the rotor, Wm is a width dimension in the circumferential direction corresponding to the one magnetic pole, and Br is a residual magnetic flux density of the magnet portion,
• a second configuration having a second inter-conductor member between respective conductor portions in the circumferential direction, the second inter-conductor member using a non-magnetic material, and
• a third configuration having no inter-conductor member,
• wherein the control apparatus comprises:
• a drive circuit connected to the multiphase stator winding of the rotary electric machine, including a pair of switching elements controlling an energization state, provided for each of a corresponding one of a plurality of phases, the drive circuit supplying power to the multiphase stator winding by operating the pair of switching elements;
• and
• a control unit configured to:
• control the drive circuit such that a period where a conduction ratio of the pair of switching elements for one phase in the drive circuit is maintained at a constant value is a predetermined period greater than or equal to 120 degrees and less than 180 degrees in electrical angle, wherein
• the pair of switching elements is configured as a pair of an upper switching element and a lower switching element in which one switching element is connected to a high voltage side and the other switching element is connected to a low voltage side;
• gradually change the conduction ratio of the pair of the upper switching element and the lower switching element from a conduction ratio of a balanced state in which an average current of the stator winding is zero to the constant value;
• set a period, at each 180 degrees, including the predetermined period and the period where the conduction ratio is gradually changed;
• complementarily set, in a first period, conductivities of the upper switching element and the lower switching element;
• and
• set, in a second period subsequent to the first period, the conduction ratio of the upper switching element to be the conduction ratio of the lower switching element in the first period and the conduction ratio of the lower switching element to be the conduction ratio of the upper switching element in the first period.