Space vector modulation and field oriented control: using transputers and signal processing for speed control of induction motors

The authors describe an implementation of a field-oriented induction motor control system using space vector modulation (SVM). The control strategy relies on using transformations which enable the complex dynamic structure of an induction motor to be simplified and controlled using conventional controller design techniques. These transformations require high-speed processing if the sampling criteria are to be met. If SVM is to be implemented in software, which is desirable for resolution and flexibility, a system with substantial processing speed will be required if inverter switching frequencies of 5-10 kHz are to be achieved. The above throughput requirements dictate the use of a multiprocessor system, which is difficult to implement with conventional microprocessor architectures. Transputers and occam, on the other hand, offer high processing speeds and straightforward multiprocessing, so that the necessary throughput can be achieved by using faster transputers or by using more transputers with minimal software changes and overhead. The authors examine some of the issues involved in designing this system and present some of the results obtained to date