The paper presents a method for estimation of converter drive parameters. This estimation encompassed three types of drives, i.e. a static Scherbius drive, a driver with a brushless direct current (BLDC) motor and a drive with a voltage inverter. For drive modelling and parameter estimation, the author implemented original program mes written in FORTRAN. As well as these, the paper describes an objective function applied for the estimation. The author also compares gradient and gradientless methods, chich are applied for minimization of the objective function. Finally, the author explains the estimation results for example drives, focusing on the coincidence of theoretical and empirical waveforms. The abovementioned procedure led to the general rule, which facilitates estimation efficiency.

This paper presents a computationally efficient method for modelling an impact of the converter drive on the power grid. The formalized variable structure method (FVSM) allows for comprehensive studies of the effect on the power grid and examining the relation between this effect and the number of drive and feeding line parameters. In order to obtain a comprehensive model along with the model of the power grid, the parameters that are applied originate from a drive of a coal-fired power station. These parameters have been determined based on assessment and estimation. The estimation process was conducted with the aid of a model that allows for the commutation of power electronic elements. The authors confirmed that the model was correct by comparing empirical and theoretical voltage and current waveforms. Harmonic content of the voltage and current in the power grid which feeds the drive are considered to be the measure of the converter drive impact on the power grid. The standard method for the reduction of a harmonic content in the voltage and current involves the application of line reactors and distribution or converter transformers. As an example, the authors determine the impact of the drive on the power grid with respect to the adopted parameters of the line reactor. This example presents FVSM abilities with regard to simulation of complex systems that contain power grid components and converter drives.