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The majority of three‐phase dynamic transformer models used in commercially available electric power system transient simulation programs offer only saturated three‐phase transformer models built from three single‐phase transformer models. This paper sets out to deal with the modelling and transient analysis of a saturated three‐limb core‐type transformer.

Three iron core models I‐III are given by the current‐dependent characteristics of flux linkages. In the first model, these characteristics are given by a set of piecewise linear functions, which include saturation. In the second model, the piecewise linear functions are replaced by the measured nonlinear characteristic. The more complex third model is given by a set of measured flux linkage characteristics.

The behaviour of transformers used in electric power applications depends considerably on the properties of magnetically nonlinear iron core. The best agreement between the calculated and measured results is obtained by use of the most complex iron core model III, which takes into account magnetic cross‐couplings between different limbs, caused by saturation.

Measurement of the current‐dependent flux linkage characteristics of the 0.4 kV, 3.5 kVA laboratory transformer requires corresponding excitation of windings by three independent linear amplifiers. Current‐dependent flux linkage characteristics of the larger power transformer can be determined either by similar measurement with linear amplifiers of an appropriate power or by extracting them from the calculated magnetic field, which is done by the finite element method.

A three‐phase dynamic transformer model with the obtained iron core model III is suitable for the numerical analysis of nonsymmetric transient states in power systems.

This paper presents a three‐phase dynamic transformer model with an original iron core model III, which accounts for magnetic cross‐couplings between different limbs, caused by saturation.

The dynamic model of radial active magnetic bearings, which is based on the current and position dependent partial derivatives of flux linkages and radial force characteristics, is determined using the finite element method. In this way, magnetic nonlinearities and cross‐coupling effects are considered more completely than in similar dynamic models. The presented results show that magnetic nonlinearities and cross‐coupling effects can change the electromotive forces considerably. These disturbing effects have been determined and can be incorporated into the real‐time realization of nonlinear control in order to achieve cross‐coupling compensations.

Oscillations and related stability problems of synchronous generators are harmful and can lead to power outage. Studies have shown that currently available commercial applications of power system stabilizers (PSSs) do not ensure damping of modern generators operating in contemporary power systems at peak performances. The purpose of this paper is to contribute to development of the new PSS, which would replace currently used linear stabilizers.

A synthesis of theoretical research, numerical simulations and laboratory experiments was the basic framework.

Within a problem analysis, it was empirically confirmed that the currently used PSSs are not up to the needs of the present power systems. Based on an analysis of the contemporary solutions, it was found out that the most appropriate solutions are adaptive control and robust control. In this paper, the robust sliding mode theory was implemented for the PSS design.

The most notable restriction of rapid transfer of scientific solutions into a practice represents limited testing of proposed solutions on synchronous generators in power plants.

The new PSS which would replace currently used conventional stabilizers will have an exceptional value for all producers of the excitation systems.

The originality of the paper represents the development of the new robust sliding mode PSS and qualitative assessment of the developed stabilizer with two competitive stabilizers, i.e. the conventional linear- and advanced direct adaptive-PSS.