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  • Author: Zoja Raud x
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Abstract

The majority of testing cycles for the vehicle comparison is the long-term cycles and could not be used for the short-term transient mode imitations. Also, all the used nowadays testing cycles were designed for internal combustion engine vehicles and take into account not only energy and mechanical aspects, but also pollution and internal combustion engine characteristics. The paper presents a collection of sample signals developed to explore and simulate multiple system impacts to emulate different reference and load conditions. The study describes the major driving modes, such as the constant-speed cruising, speeding up and braking, typical parking regimes, uphill and downhill motion, and taking a turn. The developed testing equipment and software are described. Responses of the battery vehicle drives to the changeable controls and disturbances were studied in the laboratory test bench. The set of test cycles prepared in the frame of the ABB control arrangement was applied to the system evaluation and assessment. The developed methodology can be recommended to adjust the electric drives for different kinds of testing equipment. Experimental validation of the described approach has demonstrated the broad possibilities for the steady-state and transient modes of vehicle quality evaluation. It suits for recommendations that can be made with regard to the tuning of the drive regulators, control looping, sensor allocation, and feedback arrangements.

Abstract

The paper is devoted to the centrifugal pumps represented the most popular type of pumping equipment used in different areas. The pressure control approach for variable speed driven (VSD) parallel connected centrifugal pumps is reported. The goal of the study is optimization of some quality indices, such as efficiency, consumed power, productivity, energy carrier temperature, heat irradiation, etc. One of them – efficiency – has been studied in the paper more carefully. The mathematical model of pumping process is discussed and a vector-matrix description of the multi-pump application is given. The program-based pressure control system is developed which productivity is changed by regulating the number of working pumps. The paper introduces new pressure control algorithms based on the working point estimation intended for programmable logical controllers (PLC). Experiments prove correctness of the offered methodology.

Abstract

This research addresses some personalization aspects of education in electrical engineering. Its goal is to help students and educators evaluate the complexity of the disciplines they have chosen for studying and optimize the order of the learned courses and topics. A new instrument, namely, an educational thesaurus, is presented and its assembling procedure is shown. The offered educational thesauri implemented in the labs and integrated in the exercises have become smart platforms suitable for design and management of the students’ individual knowledge domains. The ontology-based Web manuals in Electronics and Power Electronics for the Bachelor study cycle have been introduced. An example of ontology graph to be applied within the Master study cycle has been developed and explained in the paper. According to the authors’ investigation, the decrease of stress caused by the new educational environment and achievement of success in learning were observed thanks to the individual knowledge domain organization proposed in this study.