In the paper is proposed an induction machine model that corresponds to operating conditions at the change of frequency. The applicability of simulation method for the analysis of its operation at the frequencies other than 50 Hz was examined. The operation of the induction machine which control parameter is the frequency of controlled current was particularly analyzed. 

The evaluation of the proposed model was performed using the adapted subprogram in the psbdrive MATLAB Simulink package. For the verification of the results, the method of verified simulation was used, as a part of the method which was derived from the artificial intelligence algorithm. It has been confirmed that by controlling the frequencies and current of the induction machine, the ability to work in overloads can be maintained and this type of control has certain advantages in the frequency regulation of the drive with variable loads.

The stochastic character of asymmetrical loads in power networks emerged due to non-simultaneous activation of phases of various single-phase and poly-phase receivers, nonlinear characteristics of transformers and other reasons have caused the occurrence of currents and voltages of zero sequence. These electrical quantities with currents and voltages of direct sequence in a negative sense affect the asymmetry of phase voltages in networks on places where loads are connected. In this paper, the presented load is induction machine with coil connection in star connected to generic distribution system TN. We analyze the possibilities of simple CL structures of filter in the role of the device for correction of asymmetries to a network, which can be entered by zero sequence current occurred for some reason in induction machine (mostly non-simultaneous switching of phase coils of induction machine).

The paper we presents mathematical model for analysis of transitional processes in three-phase induction motor, that is, wave forms of currents and voltages in time domain and phase coordinates. Model is suitable for relay protection of the motor from disturbances and for estimation of electrical energy quality in the distribution network. New constructions of induction motors present more progressive technical solutions comparing with classical variants and reliable entity only within selected system of protection from expected disturbances (failures and disorders followed by asymmetries). Measuring process is not required due to application of simulation in selected MATLAB package.