Apparatus and method for controlling drive of three-phase multiplex winding motor

A control apparatus for a three-phase multiplex winding motor, comprising:

• a plurality of inverters, each inverter operatively driving a corresponding winding couple of multiplex windings of the motor;
• a plurality of controllers whose number corresponds to that of the inverters, each controller controlling an operation of a corresponding one of the inverters, each controller including:
• a decoupling voltage calculator for calculating d-axis and q-axis voltage setting values V.sub.1 d* and V.sub.1 q* on the basis of an excitation instruction value Io*, a torque instruction value I.sub.T *, d-axis-and-q-axis current instruction values i.sub.1 d* and i.sub.1 q* which are quotients of the excitation instruction value Io* and the torque instruction value I.sub.T * divided respectively by the multiplex number N of the winding couples of the motor, and a power supply frequency .omega. which is an addition of a slip frequency .omega.s to a rotor revolution frequency .omega.r;
• a d-axis-and-q-axis current controller for performing proportional-and-integration calculations for respective deviations between d-axis current instruction value i.sub.1 d* and its detected value iid and between q-axis current instruction value i.sub.1 q* and its detected value i.sub.1 q so as to derive d-axis and q-axis voltage errors .DELTA.V.sub.1 d and .DELTA.V.sub.1 q ;
• and a plurality of PWM circuits, each PWM circuit receiving d-axis and q-axis voltages V.sub.1 d and V.sub.1 q as d-axis and d-axis voltage instructions and generating and outputting gate signals to the corresponding one of the inverters according to the d-axis and g-axis voltage instructions so as to control the operation of the corresponding one of the inverters, the d-axis and d-axis voltages being respective additions of the d-axis and q-axis voltage setting values V.sub.1 d* and V.sub.1 q* received from the decoupling voltage calculator to d-axis-and-q-axis voltage errors .DELTA.V.sub.1 d and .DELTA.V.sub.1 q outputted from the d-axis-and-q-axis current controller.