Investigation and Calculation of Electric Scooter Electromechanical Characteristics

Abstract

The design of an electric scooter is presented. The advisability of using an inverted motor with an external rotor, which is part of the wheel, is shown. Permanent magnets producing a large number of pole pairs are installed on the rotor inner surface facing the air gap. With such design, low scooter motion speeds can be obtained without the need of using mechanical gearboxes. The choice of the rotor main dimensions based on the specific tangential force is considered. The stator consists of a core body with a winding, usually a three-phase one. In scooter motors, it is advisable to use a concentrated winding with a fractional q, which is wound around the tooth to form a separate coil on it, belonging to one of the phases. In such winding, the end turns do not intersect; its end-winding parts are much shorter than they are in distributed windings. The stator winding is powered by an inverter controlled synchronously with the rotor rotation. The considered electromechanical converter is nothing but a conventional synchronous machine. Constant torque operation is not typical for the scooter motor. When the user changes the scooter operation mode, for example, in changing over to another track section, all processes develop similarly to those that take place in conventional DC motors. To confirm this, the calculation of the motor is given, and its parameters are determined. An algorithm for calculating the scooter mechanical and performance characteristics has been developed.