EPE Association: EPE-PEMC 2000 - Topic 01h: General Section

EPE-PEMC 2000 - Topic 01h: General Section
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2000 - Conference > EPE-PEMC 2000 - Topic 01: Power Converters > EPE-PEMC 2000 - Topic 01h: General Section

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   A Diagnostic System for Asymmetries in Bridge Converters
By Strobl B. [View]
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Abstract: Converter circuits can be regarded as networks with time variant elements. Under normal conditions these elements have symmetrical behavior, faults lead to asymmetries. Using the transformation to the Symmetrical Space Phasor Components equivalent networks are obtained which are decoupled for symmetrical conditions. Faults couple these equivalent networks in a characteristic way. In this contribution this is shown by example of a six-pulse converter. The Symmetrical Space Phasor domain makes the interior behavior of the converter clear. The affect of faults to the asymmetrical parts of the converter currents can be explained easily. Every kind of fault leads to correlations between the components which are typical for the fault. This makes a diagnosis of faults in converters possible. In order to detect the small amounts of the asymmetrical parts in the converter voltages and currents a high-resolution measurement equipment was built. It was used to confirm the theoretical results by experimental investigations with a six-pulse converter.

   Analysis and Synthesis of Power Converters by Means of a Main Topological Matrix
By Artemenko M.E., Sherepenko M.A. [View]
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Abstract: The main topologic matrix of a circuit graph is a general-purpose instrument for identification, analyses and synthesis of switch converters. The problems of a filled main topological matrix (MTM) association with the equations of a state for the electronic circuit, correlation interval MTM and the creation of oriented graphs are considered in the paper. The algorithm of automated creation of the state equations for the electronic circuit of converters and the algorithm of elements orientation of the circuit for obtaining oriented graphs are developed.

   Efficiency Consideration of Hard and DC Link Soft Switching Inverters
By Dawidziuk J. [View]
[Download]

Abstract: The paper evaluates the efficiency of soft switching inverters. Four types of soft switching inverters, including actively clamped resonant dc link, clamped mode resonant pole, quasi-resonant zero voltage switching, and auxiliary switch commutated resonant pole inverters, were compared. The efficiency of the hard switching inverter is calculated for the baseline comparison. Evaluation results show that the quasi-resonant zero voltage switching, actively clamped resonant dc link, and auxiliary switch commutated resonant pole inverters have the highest efficiency, and the clamped mode resonant pole inverter has the poorest efficiency. The actual energy saving, however can be further improved by optimization of circuit components and selection of the inverter switching algorithm in actual implementations.

   Losses Caused by Blanking Time in IGBT Converters
By Èeøovský Z., Javurek J. [View]
[Download]

Abstract: The paper deals with blanking time of IGBT's. The blanking time should be long enough to prevent the short currents which can flow across the converter branch and damage the devices. The short blanking time raises the losses. The long blanking time can distort the converter voltage shape curve so that torque pulsation may occur. The paper shows the method how to analyse the losses and how to find the shortest possible blanking time.

   New Possibilities of the Direct Frequency Conversion Process in the Rectifier Mode
By Rutmanis L., Stabulnieks J., Ribickis L.* [View]
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Abstract: The rectifier mode of the direct frequency conversion process is considered both for the ideal sinusoidal process and for a real one. Based on the analysis and estimation of these processes, some conversion methods are proposed, which are designed for improving the quality of converter output voltage.

   Trapezoidal Current Resonant Generators
By Pilaciñski J. [View]
[Download]

Abstract: In the paper the sequentially switched resonant circuits designed to generate the quasi-trapezoidal high power current pulses are presented. The methods of the current pulse shaping as well as operation of some selected thyristor circuits comprising the resonant branches connected in parallel or in inverse-parallel are described. A shape of the output current pulse has been analysed by determining accuracy of mapping the shorter base and the falling edge of the pulse. Some examples of selected generator models are reported.

EPE-PEMC 2000 - Topic 01h: General Section
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2000 - Conference > EPE-PEMC 2000 - Topic 01: Power Converters > EPE-PEMC 2000 - Topic 01h: General Section
	[return to parent folder]

	A Diagnostic System for Asymmetries in Bridge Converters By Strobl B.	[View] [Download]
Abstract: Converter circuits can be regarded as networks with time variant elements. Under normal conditions these elements have symmetrical behavior, faults lead to asymmetries. Using the transformation to the Symmetrical Space Phasor Components equivalent networks are obtained which are decoupled for symmetrical conditions. Faults couple these equivalent networks in a characteristic way. In this contribution this is shown by example of a six-pulse converter. The Symmetrical Space Phasor domain makes the interior behavior of the converter clear. The affect of faults to the asymmetrical parts of the converter currents can be explained easily. Every kind of fault leads to correlations between the components which are typical for the fault. This makes a diagnosis of faults in converters possible. In order to detect the small amounts of the asymmetrical parts in the converter voltages and currents a high-resolution measurement equipment was built. It was used to confirm the theoretical results by experimental investigations with a six-pulse converter.

	Analysis and Synthesis of Power Converters by Means of a Main Topological Matrix By Artemenko M.E., Sherepenko M.A.	[View] [Download]
Abstract: The main topologic matrix of a circuit graph is a general-purpose instrument for identification, analyses and synthesis of switch converters. The problems of a filled main topological matrix (MTM) association with the equations of a state for the electronic circuit, correlation interval MTM and the creation of oriented graphs are considered in the paper. The algorithm of automated creation of the state equations for the electronic circuit of converters and the algorithm of elements orientation of the circuit for obtaining oriented graphs are developed.

	Efficiency Consideration of Hard and DC Link Soft Switching Inverters By Dawidziuk J.	[View] [Download]
Abstract: The paper evaluates the efficiency of soft switching inverters. Four types of soft switching inverters, including actively clamped resonant dc link, clamped mode resonant pole, quasi-resonant zero voltage switching, and auxiliary switch commutated resonant pole inverters, were compared. The efficiency of the hard switching inverter is calculated for the baseline comparison. Evaluation results show that the quasi-resonant zero voltage switching, actively clamped resonant dc link, and auxiliary switch commutated resonant pole inverters have the highest efficiency, and the clamped mode resonant pole inverter has the poorest efficiency. The actual energy saving, however can be further improved by optimization of circuit components and selection of the inverter switching algorithm in actual implementations.

	Losses Caused by Blanking Time in IGBT Converters By Èeøovský Z., Javurek J.	[View] [Download]
Abstract: The paper deals with blanking time of IGBT's. The blanking time should be long enough to prevent the short currents which can flow across the converter branch and damage the devices. The short blanking time raises the losses. The long blanking time can distort the converter voltage shape curve so that torque pulsation may occur. The paper shows the method how to analyse the losses and how to find the shortest possible blanking time.

	New Possibilities of the Direct Frequency Conversion Process in the Rectifier Mode By Rutmanis L., Stabulnieks J., Ribickis L.*	[View] [Download]
Abstract: The rectifier mode of the direct frequency conversion process is considered both for the ideal sinusoidal process and for a real one. Based on the analysis and estimation of these processes, some conversion methods are proposed, which are designed for improving the quality of converter output voltage.

	Trapezoidal Current Resonant Generators By Pilaciñski J.	[View] [Download]
Abstract: In the paper the sequentially switched resonant circuits designed to generate the quasi-trapezoidal high power current pulses are presented. The methods of the current pulse shaping as well as operation of some selected thyristor circuits comprising the resonant branches connected in parallel or in inverse-parallel are described. A shape of the output current pulse has been analysed by determining accuracy of mapping the shorter base and the falling edge of the pulse. Some examples of selected generator models are reported.