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 FOC 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