Control of DC-DC converters is a complex task due to the inherent nonlinearity. There is intensive research in developing newer control strategies which should ensures stability of output voltage under varying load, input voltage and parameters variations. The paper is aimed to present possibilities of use fuzzy logic controller to control output voltage of a phase-shifted PWM (PS-PWM) soft-switching DC-DC converter. The converter is a full bridge DC-DC converter with a controlled output rectifier and an active snubber on the secondary side. Despite proven advantages of use of a fuzzy logic control for DC-DC converters, one of the main drawback can be considered computational demand, which could negatively affects the response of a converter on sudden changes of load and raise up the price of the converter, due that there is needed a microcontroller with higher computational capacity. To suppress the high computational demand of a FLC controller there is presented a look-up table controller, which is derived from the original FLC controller. In the paper are described two different suitable interpolation methods for look up table controller composition, and assessment of advantages and disadvantages of both methods.

The paper presents the study of an anti-lock braking system (ABS) that has been complemented by a fuzzy controller. The fuzzy controller was used to improve the braking performance of the vehicle, particularly in critical situations, for example, when braking a vehicle on wet road. The controller for the ABS was designed in the MATLAB/Simulink program. The designed controller was simulated on a medium-size vehicle model. During testing, three braking systems were simulated on the vehicle model. We compared the performance of a braking system without an ABS, a system with a threshold-based conventional ABS, and a braking system with the proposed ABS with a fuzzy controller. These three braking systems were simulation tested during braking the vehicle on a dry straight road and on a road with combined road adhesion. A maneuverability test was conducted, where the vehicle had to avoid an obstacle while braking. The results of each test are provided at the end of the paper.

The paper presents the design of a PI controller for a dc-dc converter with soft-switching. The dynamics of the dc-dc converter is approximated by a continuous-time second-order system. The continuous-time PI controller is then designed based on the required system dynamics criterion. The continuous-time PI controller is transformed into a discrete-time PI controller and implemented on ARM microprocessor STM32F746. The operation of the designed PI controller is verified by measurement on a laboratory model of a 2 kW soft-switching dc-dc converter.

The paper deals with a problem of speed estimation in a shaft sensorless field oriented control structure with induction motor that is based on neural modelling approach. Two different neural estimators were developed; one for observing the magnetic flux and the other one for observing motor angular speed. Structures of the artificial neural network estimators are based on measurable motor variables: components of stator current and voltage in rotating system x-y. Simulation results of the neural angular speed estimator were verified by a Real-Time system. In case of the Real-Time verification the developed neural estimator of rotor angular speed is based on measurable motor variables, components of stator current and voltages in d-q reference system.

Described in the paper is analysis of properties of synchronous motor with outer permanent magnets rotor. The motor, having an atypical construction, is powered by low voltage from a three phase frequency converter. It is suitable as a drive unit for direct power drives of small electric vehicles and electric wheelchairs. Theoretical analysis of the synchronous motor with outer permanent magnets rotor starts with the air gap space configuration. The present paper describes the main results from open-circuit and load simulation. The section of paper describes the mechanical construction of prototype of the synchronous machine. Experimental results of measurements of the machine prototype in the generatoric and motoric mode are described. Experimental measurements verified stability of the motor parameters at its loading.