The modern era is characterized by the use of electric drives, both in industrial plants and in households. Industrial plants, as large plants, are large consumers of electricity and, given the various restrictions on environmental pollution and energy consumption (energy efficiency), there was a need to introduce some novelties within such plants in order to reduce electricity consumption. The reduction in electricity consumption was achieved by the introduction of innovations in the form of electric motor drive management technology based on changes in the speed of rotation of the electric motor. Such devices contribute to significant improvement, both in terms of reducing energy consumption, and in terms of less load on certain parts of the electric motor system, which with the use of new technology works smoothly and most of the time actively, without shutting down. Changes in the speed of rotation are achieved by modern technology of frequency converters, the installation of which has increasingly started to be implemented in households within air conditioning systems. The thesis presents various systems of electric motor drives, their theory of operation, how they work in practice, and their modernization by installing frequency converters within electric motor systems. The theory of frequency converters is presented in detail, the use of which in practice is represented by a further example in which the influence of frequency converters on the energy efficiency of a home system is shown in a simple form along with the calculation of the cost of installation and profitability.