چكيده به لاتين
This thesis attempts to minimize the loss of copper-induced induction motor in all points of work on the torque speed page using the losses minimizing techniques in electric motors and drives.
Given that in vector control the rotor flux is in the direction of the d-axis and is produced only by ids, and the electromagnetic torque is generated by iqs, the control of the flux and the electromagnetic torque will be performed separately. In light loads, where most of the motor's operating time is in these loads, the motor does not need to be called flux and Therefore, by controlling rotor flux, we can put the ids in an optimal amount. In other words, by changing the motor's operating point from the nominal state to state with less torque by controlling the rotor flux, followed by controlling the stator current, the motor current or losses can be optimized And increased the efficiency of the induction motor. For this purpose, this thesis examines the angle between the stator current and the d-axis at all points of the speed-torque page and obtains an optimal value for this angle at different work points. According to the experimental results and calculations, the optimal angle entered the controlled algorithm and created a control scheme called the flux angle control in the induction motors.
The angle value will vary depending on the torque reference value. According to the calculations, the optimal value of this angle is constant for light loads (up to a specified torque) and its value depends on some motor parameters. And from that specified torque to the nominal load torque, this angle will start to increase, and in fact, in this range of torque, the rotor flux is nominal rotor flux.
