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Different magnetic materials for cores of DC chokes are considered and compared in this paper. Four components are designed using both manufacturer software and an improved Fast design approach. The compared materials are: ferrites (3F3), powder materials (sendust MS and Hi-Flux™ HF) and amorphous materials (Microlite 245). Recommendations are derived regarding the use of available design software...
This paper studies a buck converter based LED driver with a current control method. A wide input voltage range is considered as well as the power factor of the circuit. To improve the efficiency soft switching conditions are provided. Simulations and experimental investigation is carried out to obtain the converter performance relations. An advanced inductor design is applied in order to reduce the...
This paper highlights the importance of a BMS when operating with lithium-ion cells, especially within narrow SOA. A classification of BMSs is proposed based on four criteria. Based on the classification guidelines for optimal selection of a BMS for given application are also proposed. Using the guidelines an example BMS is selected and studied experimentally. The studied system operates within the...
The paper presents study and selection of components (power switches and inductor) of an inverter for induction heating. Power losses in the switches and inductor windings are considered. The comparative study is realized based on using three different types of power switches (IGBT's, MOSFET's and SiC-MOSFET's). Presented loss analyses leads to design requirements for selection of proper switches...
The paper presents loss analysis and improvements of a battery charging system for light electrical vehicles. Possible solutions and design approaches are presented for reducing weight and improving efficiency of the system. The charger system (1500W) consists of rectifier with inrush current limiting, PFC and resonant DC/DC converter. Presented loss analyses leads to selection of proper switches...
The paper presents comparative study of winding arrangements for power electronic transformers. The designs are based on an improved design algorithm consisting of 15 steps. Four different winding arrangements are considered for a transformer design, 1200W, 25kHz. The approaches applied are interleaved windings, fully wound winding layers and using Litz wire. The material used is ferrite (N87). A...
The paper presents a comparison of the power output of wind driven generators coupled to active and passive converter circuits at certain site in Bulgaria. A table compares the power output difference expressed in percent. Actual wind resource data gives the opportunity to have evaluation and analysis at three different heights. Advantages of active and passive control are derived and summarized....
This paper presents multiple stage braking circuits for wind turbines with a permanent magnet synchronous generator. The system combines both passive converter circuit coupled to a resistive braking circuit. The second one is an over voltage protection when an emergency situation of no load is detected. The power converter control and braking are simulated and the output power/frequency graphics are...
The aim of the paper is to design and to do the fine tuning of a passive converter from a permanent magnet wind generator to a fixed DC link. It shapes a torque speed curve with only passive elements like diodes, inductors and capacitors. The result is a power/frequency (power/speed) characteristic close to the optimal one for wind turbines. The proposed novel circuit has the advantage to be a reliable,...
In this article a three-phase BLDC motor controller for use in an Ultra-Light Electrical Vehicle is presented. The control is performed using a Programmable Logic Device (CPLD), which doesn't require any additional processor. In this way a robust and low-complexity control is obtained. For extending the speed range of the BLDC, a phase advance circuit is implemented as well. The power consumption...
An electric brake for wind turbine systems is proposed in this paper. Effective emergency electrical braking is needed if an overvoltage occurs due to grid failure. The derived circuits use high power thyristors corresponding to the high values of generated power from today's wind turbines. A practical confirmation with BLDC a generator is ongoing in the laboratory. The principle of operation is proved...
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