Performance and operability of an electrically driven propulsor

This manuscript discusses the operation of an electrically driven fan for a hybrid-electric propulsion system for BAe-146 aircraft. The thrust requirement is fed into an integrated cycle and aerodynamic design tool for the sizing of a ducted fan as one of the main propulsors, podded under the wing as a replacement for a turbofan engine. The electric motor design is initiated with the torque and speed requirements and with the dimensional constraints arising from the driven fan geometry. The fan operation and aerodynamic design are derived by changing the fan pressure ratio and hub-to-tip ratio to obtain a 2-D design space. Surface-mounted permanent magnet electric motor designs are mapped on the 2-D fan design space. The design and operational flexibility of the system is investigated through three scenarios. In the first scenario, the aircraft rate of climb is changed to downsize the electric motor. In the second scenario, the electric motor rated frequency is changed to increase the power density and in the third scenario the electric motor current density is changed for the same purpose. The investigated three scenarios provide design and operational guidelines for reducing the weight of the electric motor for a direct drive application.

Features of an induction motor design taking into account the possible operation in the mode of electrical asymmetry of the windings resistances

The paper examines the operation of large high-voltage induction motors used as an electric drive of critical installations in enterprises with a continuous production cycle. The theoretical foundations of the appearance of a dip in the mechanical characteristic of an induction motor in the mode of winding resistances asymmetry are considered. The developed power supply device for an induction motor with torque dip compensation at electrical asymmetry of phase windings appears is presented. The necessity of introducing a service factor is formulated to take into account the decrease in the total level of the electromagnetic torque in such operating modes, which is carried out at the stage of the motor design beginning.