Resolver Emulation for PMSMs Using Low Cost Hall-Effect Sensors

Control of permanent magnet synchronous machines (PMSMs) requires absolute rotor position measurement/estimation, as well as the magnet polarity detection for the machine start-up, encoders/resolvers being normally used for this purpose. However, these sensors can account for a large portion of the overall drive cost, and require additional room and cabling, therefore penalizing the size and reliability of the drive. This article proposes a method to emulate a resolver in machines using low cost Hall-effect sensors. The proposed Hall-effect resolver system is a new type of angular position sensor for PMSMs. This allows to control machines which do not include a resolver from inverters which require a resolver signal to operate.