Computer aided design of induction motor drives

Vector control offers the possibility of servo motor performance from robust induction motors, but at the cost of increasing the complexity of the controller. A typical drive system comprises a motor, an inverter and a controller. To limit costs it is necessary to reach a compromise between the performance of each component. Typically the cost of the motor is determined by the intended load and by the operating environment, but there is more flexibility in choice and design of the inverter and the controller. Some of the implementation details that must be traded off include the sampling rate of a digital controller, the sophistication of the control algorithms, the resolution of analogue to digital interfaces and the switching frequency of the inverter. By modelling the entire drive system on a computer, the `best´ compromise can be established. To do this requires an easy and meaningful measure of drive performance. Most of the literature presents graphs of shaft speed and current and voltage waveforms for a speed step or reversal. These results apply to specific load conditions and are difficult to compare