Electromagnetic compatibility issues of variable speed drives

The paper is focused on the adverse effects of variable speed drives (VSD). The harmonic components of converter´s taken current are investigated. The paper also deals with transient motor overvoltage. A very important part of the analysis is a model of the system, especially determination of motor high frequency characteristics. Several representations (one-phase and three-phase) of the motor and the cable suitable for determination of transient overvoltage have been proposed. Factors contributing to motor overvoltage are described. Influence of cable length, rise time of voltage pulses and motor characteristics is investigated. The results are compared with data obtained from a lot of experiments and simulations.