Field-oriented control is now 25 years old. It dominates the landscape of motor control. FOC was a substantial, if not revolutionary, step forward in control that propelled motor control efficiency and performance ahead in the 80’s. Fundamentally, it simplified control and closure of high-speed current loops in motor controls by making the output fundamental frequency somewhat irrelevant in the control loop and gain structure. FOC is, however, 80’s technology and has given us about all it can in the way of efficiency and performance.
Depending on the characteristics and construction of an AC motor, it is not always a good idea to be oriented to the field. It is better to be oriented to the vector that will produce the most amount of torque. Academia has been working with newer and more computationally-intensive control algorithms to better control the current/torque vector.
Power and Control Design is working on these technologies to further advance the state-of-the-art in motor control technologies and how they would apply to efficient power conversion and control.