Study of dynamic regimes for low power direct current motors

This paper brings contributions by increasing the precision of the dynamic regime characteristics computation, for low power direct current motors. The machine inductivities are computed in conditions of magnetic saturation and the value of the useful magnetic flux is established for high loads, taking the armature reaction into consideration. By means of the parameters such determined, the dynamic of the motor behaviour is studied when supplying by a voltage varying by an imposed law, for constant or variable resistant torque. There has been settled a program based on the methods of numerical computation, which makes possible to solve the integraldifferential equations with variable coefficients, by the fourth order Runge-Kutta method. This way, the pre-determination of the dynamic regime behaviour of low power direct current motors can be established with high precision. The results obtained by simulation are compared to those determined by experimental tests. The paper brings some completions over the authors´ other papers because it simulates more exactly the magnetic field curve in the presence of the slots and of the magnetic saturation and it presents a computation method for the excitation winding inductivity for the shunt motor and for the series one.