Energy demands are steadily increasing as the world's population continues to grow. Automobiles are primary transportation means in a large portion of the world. The combination of fuel consumption by automobiles along with the shrinking fossil fuel reserves makes the development of new more energy efficient technologies crucial. Electric vehicle technologies have been studied and are still being studied today as a means of improving fuel efficiency. To that end, this work studies the effect of switching frequency on the efficiency of a hybrid electric vehicle traction drive, which contains both an internal combustion engine as well as electric motor. Therefore improving the efficiency of the electric motor and its drive will help improve the viability of alternative vehicle technologies. Automobiles spend the majority of their operational time in the lower speed, lower torque region. This work focuses on efficiency improvements in that region. To estimate the efficiency trend, the system is modeled and then tested both electrically and thermally. The efficiency is shown to increase at lower switching frequencies. The experimental results show that there are some exceptions, but the basic trend is the same. / Master of Science

This master’s thesis describes the structural design of pallet conveyor for the transport pallet unit between the ground floor and upper storey of warehouse buildings, according to given technical parameters. The work includes design and functional solution for driven roller track. It solves lifting of frame cage and roller track and the pallet unit, using traction gearless drive. There is used cable transfer 2:1. Frame cage is equipped with a mandatory safety gear. The design is verified strength calculations of the frame lift and frame cage. Part of the thesis is the drawing documentation.

This thesis describes the design of a laboratory model of the bridge crane, which will be further used for Internal Combustion Engines to identify the forces in and verificationof control algorithms, automated crane. The aim of this thesis is to design a bridge and a cat laboratory bridge crane with a carrying capacity of 10 kg and work area 2 m x 2 m x 3 m crane mostly of lightweight aluminum profiles. Furthermore, it includes variousdrives and drive for the lifting mechanism.

A drive design for an electric bike with brushed DC disk motor is proposed in this thesis. Especially the design of a DC/DC converter with DSC control is described. The converter can operate as step-down and step-up too. Minimum dimensions and sufficient power for riding without human assistance were the main demands on the design.

The topic of this diploma thesis is a traction drive of electrocar with fuel cell. The drive is supplied with hydrogen fuel cell with power of 2 kW. The traction drive consists of the three-phase DC/AC converter and the asynchronous machine. The main part of this work is a creation of the mathematical model of the traction drive in program Matlab–Simulink.

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