ELECTRICAL PROPULSION MOTORS
Polarix has developed a family of electric motors for aviation and terrestrial propulsion. The technology’s distinct features which sets it apart from present electro-mechanical systems is in its unique distributed inverter-electromechanics architecture.
Polarix Arrayed Controlled Turn-less Structures (ACTS) Motor
The Polarix ACTS motor is a revolutionary development and technology disruptor to electric motors in general and to propulsion motors in particular. Its patented innovative motor architecture features the integration, control and matching of a plurality of miniature inverters with corresponding electro-mechanical elements. The electromechanical elements are turn-less are turn-less, and each of these structures is formed by 3 single conductors shorted at one end and with their dedicated inverter at the other. Their arraying in both cylindrical and axial motor configurations are shown in Figure 1.
This architecture has the following advantages:
Specific Power: The turn-less 3-conductor elements result in a very small pole pair width; less than 4mm per pole, which in turn, results in a very high specific power (kW/kg).
Reliability: The massively parallel architecture with its independent inverter control for each element makes the resulting system virtually failure proof.
Efficiency: The conductor filling factor; the absence of external winding connections; and the extremely low inductance reduces both the dissipation and the reactive power. Furthermore, the individual inverters allow for partial power operation by reducing the number of operating units rather than the conventional more dissipative pulse width modulation (PWM).
Peripheral Control: The individual inverters allows for active feedback bearing function.
Polarix Inverter Technology
Integral to the motor technology is the Polarix inverter. The individual distributed inverter has a unique folded geometry, where the upper and lower halves of the H-bridge are folded around a micro-channel cooler shown in Figure 2a with the upper and the lower half shown in Figure 2b. Each inverter has the width of a pole-air of the electro-mechanical elements of ~8mm.
Each folded inverter generates 6kW, 3-phase power at 40V line voltage and 150A phase current. A 100kW range propulsion motor uses around 25 inverters and arranged as shown in Figure 1. Each inverter incudes a buck circuit to match the external power supply voltage (in the few hundreds of volts range) to the 20V to 40V of the turn-less elements.
Motor Propulsion Application
Propulsion motors fall into two categories: (1) propeller driving hub motors and automotive propulsion; and (2) rim motors driving internal fans. Figure 3a shows an axial hub motor with a single stator and two rotors. Figure 3b shows a rim motor driving a fan configuration.