By simply retrofitting the century old asymmetric electric machine circuit and control architecture package of MAGNAX, which comprises an “active” stator assembly, a “passive” rotor assembly of rare-earth permanent magnets (i.e., singly-fed), and an electronic controller derivative of field oriented control (FOC) that was only enhanced with packaging art available to all, such as the RE-PM YASA packaging form, with the patented, integrated, brushless, and symmetric electric machine circuit and control architecture of SYNCHRO-SYM, which comprises the MAGNAX active stator assembly under the same air-gap flux density, voltage, and speed but instead of the MAGNAX passive rotor assembly and FOC, an “active rotor assembly” with another directly excited multiphase winding set found on the active stator assembly (i.e., doubly-fed) as only possible with the SYNCHRO-SYM brushless real time emulation controller (BRTEC), the power density of the already highly optimized MAGNAX electric machine system would comparably double (with both the stator and rotor volumes equally contributing to electromechanical power conversion), its cost would halve, its efficiency would increase, its peak torque would at least quadruple, and the extravagant cost, safety and handling issues of rare-earth permanent magnets with persistent magnetism, geopolitical consequences, limited operational life expectancy, and environmentally unfriendly production would be eliminated.

NOTE: To conceptually simplify the conversion of MAGNAX, which has a very complexity Yokeless and Segmented Armature (YASA) axial flux form with two air-gaps and two rotor disk assemblies, each of which comprise bearings and an arrangement of RE-PMs mated to a solid back-iron plate for structural support and for closing the magnetic path, the retrofit did not account for replacing the two rotor disk assemblies with two active disk assemblies, each of which would comprise bearings and an arrangement of windings, which are similar to the MAGNAX active stator winding set but with half the number of the winding turns, mated to a laminated back-iron plate.

By retrofitting the original MAGNAX with SYNCHRO-SYM, which includes replacing the field oriented controller (FOC) derivative of the original MAGNAX with the brushless real time emulation controller (BRTEC) of SYNCHRO-SYM, the performance comparison between the original MAGNAX and SYNCHRO-SYM is an obviously equitable qualitative comparison that shows SYNCHRO-SYM provides at least twice the power density, half the loss per KW, and half the cost per KW as the original MAGNAX with the same design, packaging, materials (less RE-PMs), and winding techniques under the same rated air-gap flux density, speed, and voltage and frequency of excitation because both the stator and rotor, together, of only SYNCHRO-SYM actively contribute power to the electromechanical conversion process. Also, the retrofit of MAGNAX conveniently shows: 1) SYNCHRO-SYM operation, design, construction, and manufacture are straight-forward ready (like MAGNAX), 2) SYNCHRO-SYM uses off-the-shelf components without exotic components or materials, such as rare earth permanent magnets (like MAGNAX), 3) SYNCHRO-SYM is adaptable to legacy, off-the-shelf, fielded, or future electric machine systems with customary engineering and manufacturing (like MAGNAX), and 4) SYNCHRO-SYM doubles the effective performance of third party legacy or future electric machine design, packaging, material, winding, or construction techniques.

The same SYNCHRO-SYM retrofit comparison can be applied the century old asymmetric electric machine circuit and control technology that always comprises a “passive asymmetric rotor assembly” of rare earth permanent magnets (RE-PM), slip-induction dependent windings, reluctance saliencies, or DC field windings:

1. The “Synchronous Reluctance” electric machine system is sometimes described as a simple performance improving retrofit to the common slip-induction electric machine system by keeping the “active” power producing stator assembly but replacing (or retrofitting) the “passive” slip-induction rotor assembly with a “passive” synchronous reluctance (SyncR) rotor assembly (including any embedded rare-earth permanent magnets to smooth out its traditional issues of torque ripple and cogging) and by replacing the field oriented controller (FOC) with a more sophisticated derivative with reluctance waveform shaping. While keeping virtually the same continuous torque rating and the same system active power rating with nearly the same loss, size, and cost per KW of active power rating for a given air-gap flux density, voltage and frequency of excitation, and pole count, the resulting retrofit only eliminates the associated cost, size, and loss of the extraneous slip-induction rotor squirrel cage winding set. In contrast, the simple SYNCHRO-SYM retrofit also keeps the “active” power producing stator assembly, replaces the FOC with the BRTEC, and eliminates the associated cost, size, and loss of the extraneous rotor squirrel cage winding set but instead of incorporating a “passive reluctance rotor assembly,” incorporates an “active rotor assembly” that together with the active stator assembly, doubles the system active power rating, quadruples the peak torque, halves the loss, size, and cost per KW of active power rating, and eliminates the RE-PMs. 
   
   
2. Recently introduced, LinearLabs’ HET rare-earth permanent-magnet (RE-PM) electric machine system (RE-PM-EMS) claims a four rotor concept providing twice the torque density and triple the power density as other RE-PM-EMS, but after reviewing the video, the four rotor concept is actually a single rotor assembly (as other electric machines) but with four segmented RE-PM components completely surrounding the stator active winding set (i.e., so-called circumferential flux of HET) and as a result, end-turns are seemingly eliminated with the effective air-gap area doubled, which are admirable claims. Without critiquing the practicality of a completely air-gap surrounded (or floating) stator assembly, the performance claims, the stator winding complexity, or the structural complexity of the segmented rotor assembly, the performance claims of the century old asymmetric circuit and control architecture of LinearLabs’ HET motor would be doubled and the RE-PMs eliminated, if the HET was retrofitted with the new symmetric electric machine circuit and control architecture of SYNCHRO-SYM (as done with MAGNAX).
   
   
3. By retrofitting the Nidec motor with the patented symmetric circuit and control architecture of SYNCHRO-SYM while using the same materials, winding, packaging, manufacturing, and thermal management techniques, Nidec’s electric motor performance would again be doubled and its production cost halved, all without including the additional savings of eliminating expensive rare earth permanent magnets or without transforming manufacturing with MOTORPRINTER, which is the only high speed 3D Printer of amorphous or nanocrystalline axial-flux electric motors and generators.

READ LESS