Data Evaluation of Novel Modular Wheelchair Motor

This paper presents data evaluation for a novel surface-mounted permanent magnet synchronous machine with unbalanced three-phase winding system for wheelchair application. The novel permanent magnet synchronous machine is made of modular design. It means that stator is divided into several arc-shaped modules but in its case rotor of the machine remains undivided. Division of the stator is made in manner that allows each stator module act as a separate stator. This property allows user to vary assistance level of the wheelchair by adding or removing stator modules. Permanent magnet synchronous machines (PMSM) are tightly bonded with their control system because it's in the most cases are not able to run separately. Nowadays the most popular control method for this machines type is field oriented control (FOC) which allows controlling permanent magnet synchronous machine within wide range of working parameters. To ensure proper work of FOC of PMSM it is necessary to know several constant input parameters which states machine's behavior and plays a "skeleton" role in mathematical model of PMSM. This paper also describes an analytical and numerical (represented by finite element method - FEM) ways of determination of these parameters. All these procedures are performed on a test prototype of novel machine which is made with unbalanced three-phase winding system. Experimentally, analytically and numerically gathered parameters show acceptable coincidence which allows to simplify initial stage design process of modular PMSMs by using more analytical and numerical methods.