Petr Chlebis

Modern instruments for increasing the efficiency of the energy transfer in electric vehicles

This paper describes the high efficiency drive unit for an EV, which is designed with accessible solutions for the efficiency increasing. Synchronous utilization of ultracapacitors and three-level inverter brings considerable power savings and enhancement longevity for a lithium battery pack. The total loss and EMI comparison between the two-level and three-level inverter and power measurements on the EV drive unit are presented at the conclusion part of this paper.

Control algorithms of propulsion unit with induction motors for electric vehicle

The article deals with the research of algorithms for controlling electronic differential and differential lock of an electrically driven vehicle. The simulation part addresses the deve ...

The design and operation of a liquid cooled voltage inverter for an accumulation unit

This paper deals with the power design and operation of an 80kW, high efficient reversible voltage inverter (RVI) for electric energy accumulation based systems. The energy converter is characterized by its dynamic responses on desired energy flow direction changes and is built as a liquid cooled system. The theoretical part of this paper describes the power design of IGBT transistors and DC link capacitors, as well as the application of the 3D CAD and 3D FEM systems, which have been used for constructional arrangement designing and thermal/CFX analyses. The ripple current and thermal dimensioning of the capacitor battery was simulated in the OrCAD PSpice electronic circuit simulator. The practical part of this paper shows the utilization of whole energy converter in the accumulator switchboard, as well as the examples of converters operation in cases of battery charging and discharging to the grid. The main practical utilization possibilities of presented device are in the renewable energy plants, active charging stations or smart grid systems targeted on the electric energy accumulation.

Design of experimental liquid heat sink for high power electronic

This article deals with issue of fluid heat sinks for power electronics. In the introduction there are listed different kinds of heat sinks depending on the complexity of heat sink structure. From this split the group of fluid heat sinks is selected. Chapter of cooling media is based on this chapter. The proposal of special liquid heat sink has been implemented from previous chapters. This heat sink is designed to create turbulent flow of fluid in cooling duct. The thermal simulations are subsequently carried out in this heat sink. Individual simulations are conducted for constant power loss. The simulation of one part of the heat sink is carried out and the whole simulation of heat sink with 3 capacity modules consisting of six IGBT transistors is conducted. Further the simulations of currently accessible fluid heat sinks WP16 and KL494 are provided. All results of simulations are shown in tables.

ZCS concept of single-phase traction supply converters

At the present time the major part of traction systems uses single-phase 25kV/50Hz or 15kV/16,66Hz circuitry to traction vehicles supply. The supply stations of traction systems were made in different ways like rotary converters, cycloconverters and actually DC-link converters. The paper compares the static converter features and introduces the new concept of current-type soft switching DC-link frequency converter. This concept uses the three-phase zero current switch pulse rectifier, current-type, as a modern input unit of current indirect frequency converters including soft switching. The converter has many advantages e.g. the low emissions of harmonic components into the mains, the controlled power factor, the convenient current control in the DC link and low switching losses. This type of converter solves some problems of EMC and can control the converter power factor on the mains side. The suitable delta modulation of the converter is also described in the paper. The measured results were done in the application of the realized pulse rectifier as the input unit of the zero current switching indirect frequency converter with the series resonant DC link.

Support of peripheral areas in the Moravian-Silesian region using micro-hydroelectric power plants

This paper deals with the possibilities of energy use of small watercourses that would allow supplying adjacent infrastructure or tourist facilities through small hydroelectric power plants sufficiently enough for these facilities to be comfortable tourist locations and allow creating an attractive environment. It deals with the concepts of small hydroelectric power plants to supply local micro-grid networks using solid state inverters, storage structures and cheap pump turbines.

Optimization of converter design for photovoltaics with accumulation

This paper deals with the design of converter for cooperation of photovoltaic strings with accumulator. During the design, the system optimization is focused on the dimensions of the DC/DC converter, which provides the link between photovoltaics and accumulator. Design optimization of the system is based on the topology, devices and material optimization of the suggested solution whereas ensuring the required functions. The critical point of design is relatively high battery voltage at the output side of the proposed DC/DC converter and the necessity of parallel cooperation of the modules to the battery. At the end of this paper, there is 3D design of suggested solution.

Optimization of Water Cooling for a Converter

In construction of converters, there are still increasing demands for smaller dimensions of these converters. This fact leads to increased density of power dissipation on one square mm of a heat sink. The heat raised by this effect has to be removed and the structure of the heat sink must be properly designed to deal with this problem. This article is based on this topic and also it is focused to analysis of thermal field of the heat sink. The analysis, which was executed by multi-physics software with finite elements methods, counts with various placements of power modules. To execute this analysis, 3D models were created in 3D CAD software, transported to multi-physics software and described with other parameters, which specify the whole heat sink to details. In simulations, we counted with changes in initial temperature, various placement of power modules and changes in flow rate of cooling water. Simulations were performed without power modules. Based on previous steps, simulation with power modules was performed to compare the influence of the power modules to thermal field on a heat sink. Results of these simulations can serve to optimization in construction of converters before real construction.