A current control technique for induction machine drives using integrated pilot current sensors in the low-side switches

A new current regulation algorithm is presented that achieves indirect field-oriented control (IFOC) for three-phase induction motor drives using current feedback information provided by three integrated pilot sensors in the three low-side inverter switches. A new regulator is required for this configuration of pilot sensors because each sensor can measure its phase current during only half-of each fundamental frequency cycle. A technique has been developed to reconstruct the three phase currents during the intervals when they are not measured so that the phase current can be used to achieve field-oriented control of the machine. Experimental results are provided to confirm the attractive performance characteristics of the proposed control technique during both steady-state and transient operation. Key application issues including the impact of errors in the estimated machine parameters are discussed.