Systems optimization of industrial nutrunners
In order to optimize motor systems deploying wide band-gap power semiconductors, accurate models for harmonic motor losses are required at the design stage.
Time: Mon 2017-03-27 12.15 - 15.00
Lecturer: Jonas Millinger, Ind. PhD Student, Atlas Copco / KTH, Stockholm
Location: Klassrummet, floor 7 at Osquldas väg 10, Stockholm (KTH main campus)
Slotless high-speed electrical motors are preferred in applications with elevated demands on high efficiency and low weight, such as industrial hand tools. Industrial tools require accurate motor control, achieved by connection to a Pulse-Width Modulated (PWM) power electronic converter. In order to suppress the undesired additional harmonic losses due to PWM-supply, conventional high-voltage (300V<) nutrunner systems deploy a large inductive filter, making these systems bulky and complex. However, the recent emerge of wide band-gap power-devices such as silicon carbide (SiC) and gallium nitride (GaN) transistors enable 5-10 times higher switching frequencies than their conventional silicon-based counterparts. Higher switching frequencies reduce the harmonic losses which may eliminate the need for the inductive filter, enabling significantly smaller and less complex systems. In order to optimize motor systems deploying wide band-gap power semiconductors, accurate models for harmonic motor losses are required at the design stage. Within this project, such models are developed for a 2-pole slotless high-speed motor, with the ultimate purpose being systems optimization of industrial nutrunners.