Analysis of methods for determining the rotor speed of asynchronous motors using spectrum of current consumption

The article describes two methods to estimate the rotor speed of the induction motor using special spectral components generated by the engine design. After you search for these components is possible to estimate the rotor slip. The aim is to compare these methods under different engine loads and to determine the most accurate method. The result is program algorithm for determining the rotational speed of the rotor of an induction motor, which can be used for a variety of practical tasks that require precise definition of speed, but there is no any access to moving parts to install the speed sensor or the use of sensors is undesirable revolutions.