With regard to the development of power electronics, as well as control circuits, there have been various methods regarding the control of the electric motor drives themselves. This control is possible with the help of torque, load and speed of the electric motor. In speed control, there are a number of methods that aim to get the best possible output characteristics, and ultimately to make the whole system as efficient as possible. The most acceptable control method is to change the supply frequency, and consequently static frequency converters have found their wide application within the system. Great attention must be paid to the safety and protection of electric motor drives, in order to ensure the protection of persons in the vicinity of such a drive, and thereafter in order to prolong the proper operation of the machine. There are a number of conditions on which the control mode and type of motor are selected, those are: type of load, power factor, environmental conditions and maintenance costs. After analyzing these conditions, the functionality of the entire system is satisfied.