< class: center, middle # EE-568 Selected Topics in Electrical Machines ## Types of PM Machines ## Ozan Keysan [ozan.keysan.me](http://ozan.keysan.me) Office: C-113 <span class="meta">•</span> Tel: 210 7586 --- ### There are many PM topology classifications: -- ### With respect to flux direction: -- - ### Radial Flux - ### Axial Flux - ### Transverse Flux --- ### There are many PM topology classifications: ### With respect to Stator Core: -- - ### Iron-cored Machines - ### Air-cored (Coreless) Machines -- ### With respect to Rotor-Stator Position -- - ### Inner Rotor Machines - ### Outer (External) Rotor Machines - ### Dual Rotor Machines --- ### There are many PM topology classifications: ### With respect to PM placement: -- - ### Surface Mount PM - ### Interior PM - ### Concentrated Flux PM --- ### There are many PM topology classifications: -- ### With respect to Back-EMF -- - ### Brushless DC (BLDC) - ### Permanent Magnet Synchronous Machines (PMSM) --- --- ## Rotor-Stator Configuration -- ### Inner Rotor PM Machines <img src="./images/ee564/inner.png" alt="Drawing" style="width: 500px;"/> --- ## Rotor-Stator Configuration ### Outer (External) Rotor PM Machines <img src="https://i.stack.imgur.com/2Sh8s.jpg" alt="Drawing" style="width: 300px;"/> <img src="https://i.stack.imgur.com/tlpMV.jpg" alt="Drawing" style="width: 300px;"/> --- ## Rotor-Stator Configuration ### Outer (External) Rotor PM Machines <img src="./images/ee564/outer_rotor.png" alt="Drawing" style="width: 600px;"/> ## What are the challenges & advantages? --- ### Outer (External) Rotor PM Machines <img src="./images/ee564/outer_inner.jpg" alt="Drawing" style="width: 600px;"/> #### Have higher radius (more surface area and torque) ([Dana TM4 Sumo Motors](https://www.danatm4.com/technology/electric-motors/external-rotor-motor-technology/)) #### Can be easy to couple mechanically (i.e. [direct drive wind turbines](http://www.pengky.cn/zz-direct-drive-turbine/external-rotor-generator/external-rotor-generator.html), [reading](https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7538361)) #### Difficult to cool (especially with air cooling) --- ## Rotor-Stator Configuration ### Dual Rotor PM Machines -- <img src="./images/ee564/dual_rotor.png" alt="Drawing" style="width: 600px;"/> --- ## Rotor-Stator Configuration ### Dual Rotor PM Machines <img src="./images/ee564/dual_rotor2.png" alt="Drawing" style="width: 400px;"/> --- # Flux Direction -- <img src="./images/ee564/radial_axial_flux.png" alt="Drawing" style="width: 600px;"/> --- # Flux Direction -- <img src="./images/ee564/radial_axial_flux2.jpg" alt="Drawing" style="width: 700px;"/> ## What are the key differences? --- ## Axial Flux Machines -- - ### Have shorter axial length -- - ### Usually have higher radius (usually results in higher torque density) -- - ### Non-cancelling attraction forces between rotor and stator (for iron-cored machines) make the mechanical design difficult --- ## PM Rotor Types (Radial Flux) ## Surface Mount PM Machine -- <img src="./images/ee564/smpm.png" alt="Drawing" style="width: 800px;"/> --- ## PM Rotor Types (Radial Flux) ## Surface Mount PM Machine -- - ### Easy to manufacture -- - ### \\(L\_d = L\_q \\) No reluctance torque -- - ### Not suitable for very high speeds (centrifugal forces) -- - ### PM are not well protected against corrosion, mechanical damage etc. -- - ### Eddy currents on PM surface can be problematic for high frequencies --- ## PM Rotor Types ## Inset PM -- <img src="./images/ee564/inset_PM.png" alt="Drawing" style="width: 800px;"/> --- ## PM Rotor Types ## Inset PM -- - ### \\(L\_q > L\_d \\), has reluctance torque (higher torque density can be achieved) -- - ### Magnets are easier to mount in place -- - ### Leakage flux can be tricky --- ## PM Rotor Types ## Interior PM -- <img src="./images/ee564/interior_PM.png" alt="Drawing" style="width: 800px;"/> --- ## PM Rotor Types ## Interior PM -- - ### Suitable for high speed operation -- - ### Magnets are well protected for corrosion and mechanical impacts -- - ### Flux barriers should be used to minimize leakage flux --- ## PM Rotor Types ## Flux Concentrating PM -- <img src="./images/ee564/flux_concentration.png" alt="Drawing" style="width: 800px;"/> --- ## PM Rotor Types ## Flux Concentrating PM -- <img src="./images/ee564/inset_shaft.png" alt="Drawing" style="width: 600px;"/> --- ## PM Rotor Types ## Flux Concentrating PM -- - ### Many different combinations are available -- - ### A flux density higher than the remanence flux density can be obtained -- - ### Can have significant reluctance torque assist, depending on geometry -- - ### Suitable for high-speed operation --- ## Details of Flux Barriers (Tesla IPM) <img src="./images/ee564/tesla_ipm.png" alt="Drawing" style="width: 600px;"/> --- ## IPM motors for EVs <img src="./images/ee564/ipm_ev.png" alt="Drawing" style="width: 600px;"/> #### [Synchronous Reluctance Motor for Traction Applications](http://www.refreedrive.eu/wp-content/downloads/2018_Coiltech_ReFreeDrive_UnivLAquila_SynchronousReluctanceMotorForTractionApplications.pdf) --- ## IPM motors for EVs <img src="./images/ee564/ipm_ev2.png" alt="Drawing" style="width: 800px;"/> #### [Synchronous Reluctance Motor for Traction Applications](http://www.refreedrive.eu/wp-content/downloads/2018_Coiltech_ReFreeDrive_UnivLAquila_SynchronousReluctanceMotorForTractionApplications.pdf) #### [BMW-i3 Electric Motor Production](https://www.youtube.com/watch?v=dJZagXcLo1w) --- ## Synchronous Reluctance Machines -- <img src="https://www07.abb.com/images/librariesprovider100/default-album/ie5_synrm_web.jpg" alt="Drawing" style="width: 600px;"/> --- ## Synchronous Reluctance Machines -- <img src="./images/ee564/synch_reluctance.png" alt="Drawing" style="width: 800px;"/> --- ## Synchronous Reluctance Machines <img src="./images/ee564/rel_parameters.png" alt="Drawing" style="width: 800px;"/> --- ## PM assisted Synchronous Reluctance Machines -- <img src="./images/ee564/pm_assisted_synch.png" alt="Drawing" style="width: 800px;"/> --- ## PM assisted Synchronous Reluctance Machines -- <img src="./images/ee564/pm_assisted2.png" alt="Drawing" style="width: 800px;"/> --- ## PM assisted Synchronous Reluctance Machines <img src="./images/ee564/pm_assisted.png" alt="Drawing" style="width: 750px;"/> --- ## Axial Flux Machines <img src="./images/ee564/axial_pm_types.png" alt="Drawing" style="width: 700px;"/> --- # Single Sided Axial Flux Machines <img src="./images/ee564/single_sided_axial.png" alt="Drawing" style="width: 750px;"/> --- # Internal Rotor Axial Flux Machine <img src="./images/ee564/internal_rotor_axial.png" alt="Drawing" style="width: 750px;"/> --- # Double Sided Inner Stator Axial Flux Machine <img src="./images/ee564/double_axial.png" alt="Drawing" style="width: 750px;"/> --- ## Multi-Stage Axial Flux Machine <img src="./images/ee564/multi_stage_axial.png" alt="Drawing" style="width: 750px;"/> --- ## Transverse Flux Machine <img src="./images/ee564/transverse_flux.png" alt="Drawing" style="width: 600px;"/> --- ## Transverse Flux Machine <img src="./images/ee564/double_transverse_flux.png" alt="Drawing" style="width: 750px;"/> --- ## Transverse Flux Machine <img src="./images/ee564/transverse.png" alt="Drawing" style="width: 750px;"/> --- ## You can download this presentation from: [keysan.me/ee564](http://keysan.me/ee564)