PLECS 1.3 Online Help |
Detailed model of a brushless DC machine excited by permanent magnets.
Machines
A brushless DC machine is a type of permanent magnet synchronous machine in which the back electromotive force (EMF) is not sinusoidal but has a more or less trapezoidal shape. Additionally, the variation of the stator inductance with the rotor position is not necessarily sinusoidal.
The machine operates as a motor or generator; the sign of the mechanical torque determines the mode of operation (positive for motoring, negative for generating). In the component icon, phase a of the stator winding is marked with a dot.
The back EMF voltages are determined by a shape function ke and the mechanical rotor speed !m. The shape function in turn is expressed as a fourier series of the electrical rotor angle