EPE Association: NORpie 2000 - Topic 13: POWER CONVERTERS AND CONTROL II

NORpie 2000 - Topic 13: POWER CONVERTERS AND CONTROL II
You are here: EPE Documents > 05 - EPE Supported Conference Proceedings > NORpie - Proceedings > NORpie 2000 > NORpie 2000 - Topic 13: POWER CONVERTERS AND CONTROL II

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   Designing a Novel Control Strategy Approach Based on Harmonic Elimination Techniques for Power Converters
By D. Ilea; M. Cernat; D. Stoia; M. Munroe [View]
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Abstract: This paper presents a theoretical study and practical investigation concerned with the design, simulation and practical implementation of a novel operating control strategy for Power Frequency Converters ( PFC ) - Induction machine (IM) drive system. This power electronics system is incorporating a controlled PFC which supplies an usually IM for "on-line" control driving of industrial conveyors. The main objective of this research work is focused to excel the “mechanical gears” performances by using this novel digital control strategy approach based on optimal PWM techniques for the PFC - IM drive system. A special control integrated circuit ( IC ) has been developed using the state–of-the-art field- programmable gate array (FPGA) technology, namely using a single FPGA - XC 4010 from Xilinx. Inc. This novel control strategy approach for the PFC - IM drive system embeds the efficiency of energy conversion and has economic advantages concerning the low prices for investment rate.

   A Steady-State Comparison of Unidirectional Three-Phase Rectifiers
By T. Viitanen; H. Tuusa [View]
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Abstract: This paper describes the first part of the steady-state simulation results of a project aiming at the further development of unidirectional three-phase rectifiers. The main goals of this project are to reduce the line current harmonics and to be able to adjust the DC-link voltage. The component count and cost are also taken into consideration. Simulated rectifier topologies are the conventional 6-pulse rectifier, single-switch boost-rectifier, three-switch (half bridge) boost-rectifier and single-switch buck-boost rectifier. These topologies are designed to operate at 50kW rated power so that the total harmonic line current distortion is within the limits stipulated in the technical report IEC 61000-3-4. The DC-link voltage in the active topologies is set at 650V. Constant duty-cycle open loop control is applied at a switching frequency of 3.5kHz. On the basis of the simulation results, the power losses and voltage and current ratings of the components needed in the main circuits and filters are determined. With the help of these results, the four rectifier topologies are compared.

   Series-connected VSC for Voltage Sag Mitigation: Operation with Unbalanced Load and Evaluation of Filtering Capability
By Ambra Sannino; Jan Svensson [View]
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Abstract: In this paper, the operation of a series-connected VSC for voltage sag mitigation is simulated and tested by using the actual measurement of an unbalanced sag with a considerable phase shift. The effectiveness of the adopted control technique, which also implements an algorithm to compensate for the effect of the converter output filter, is verified when supplying both balanced and unbalanced loads. Moreover, the capability of the series compensator to attenuate low-frequency voltage harmonics is analysed.

   Current Sharing Properties of SiC Pin-Diodes Compared to SI Pin-Diodes
By Frode Kleveland; Tore M. Undeland [View]
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Abstract: This paper is a theoretical work where the main objective is to reveal some of the typical characteristic properties of a SiC pin diode device. Calculations of Vsat are performed for different breakdown voltages, current densities and temperatures. Loss levels are also an issue. For comparision, similar calculations are also performed for Si.

   Comparison of Sigma Delta Modulators used in Multilevel Converters
By M. Lau; P. F. Sørensen; P. Jensen; S. Munk-Nielsen [View]
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Abstract: Soft switched three phase inverters have low switching loss and dv/dt which are desirable quality’s for various applications such as motor drives and UPS systems. Unfortunately, the natural selection of modulation strategy is a discrete delta modulator, which have a variable switching frequency, thus making it harder to design filters. This paper give an overview of the various types of delta modulators and compare the strong and weak points relative to standard PWM. Four three level sigmadelta modulators are simulated in Saber and the performance is evaluated.

NORpie 2000 - Topic 13: POWER CONVERTERS AND CONTROL II
You are here: EPE Documents > 05 - EPE Supported Conference Proceedings > NORpie - Proceedings > NORpie 2000 > NORpie 2000 - Topic 13: POWER CONVERTERS AND CONTROL II
	[return to parent folder]

	Designing a Novel Control Strategy Approach Based on Harmonic Elimination Techniques for Power Converters By D. Ilea; M. Cernat; D. Stoia; M. Munroe	[View] [Download]
Abstract: This paper presents a theoretical study and practical investigation concerned with the design, simulation and practical implementation of a novel operating control strategy for Power Frequency Converters ( PFC ) - Induction machine (IM) drive system. This power electronics system is incorporating a controlled PFC which supplies an usually IM for "on-line" control driving of industrial conveyors. The main objective of this research work is focused to excel the “mechanical gears” performances by using this novel digital control strategy approach based on optimal PWM techniques for the PFC - IM drive system. A special control integrated circuit ( IC ) has been developed using the state–of-the-art field- programmable gate array (FPGA) technology, namely using a single FPGA - XC 4010 from Xilinx. Inc. This novel control strategy approach for the PFC - IM drive system embeds the efficiency of energy conversion and has economic advantages concerning the low prices for investment rate.

	A Steady-State Comparison of Unidirectional Three-Phase Rectifiers By T. Viitanen; H. Tuusa	[View] [Download]
Abstract: This paper describes the first part of the steady-state simulation results of a project aiming at the further development of unidirectional three-phase rectifiers. The main goals of this project are to reduce the line current harmonics and to be able to adjust the DC-link voltage. The component count and cost are also taken into consideration. Simulated rectifier topologies are the conventional 6-pulse rectifier, single-switch boost-rectifier, three-switch (half bridge) boost-rectifier and single-switch buck-boost rectifier. These topologies are designed to operate at 50kW rated power so that the total harmonic line current distortion is within the limits stipulated in the technical report IEC 61000-3-4. The DC-link voltage in the active topologies is set at 650V. Constant duty-cycle open loop control is applied at a switching frequency of 3.5kHz. On the basis of the simulation results, the power losses and voltage and current ratings of the components needed in the main circuits and filters are determined. With the help of these results, the four rectifier topologies are compared.

	Series-connected VSC for Voltage Sag Mitigation: Operation with Unbalanced Load and Evaluation of Filtering Capability By Ambra Sannino; Jan Svensson	[View] [Download]
Abstract: In this paper, the operation of a series-connected VSC for voltage sag mitigation is simulated and tested by using the actual measurement of an unbalanced sag with a considerable phase shift. The effectiveness of the adopted control technique, which also implements an algorithm to compensate for the effect of the converter output filter, is verified when supplying both balanced and unbalanced loads. Moreover, the capability of the series compensator to attenuate low-frequency voltage harmonics is analysed.

	Current Sharing Properties of SiC Pin-Diodes Compared to SI Pin-Diodes By Frode Kleveland; Tore M. Undeland	[View] [Download]
Abstract: This paper is a theoretical work where the main objective is to reveal some of the typical characteristic properties of a SiC pin diode device. Calculations of Vsat are performed for different breakdown voltages, current densities and temperatures. Loss levels are also an issue. For comparision, similar calculations are also performed for Si.

	Comparison of Sigma Delta Modulators used in Multilevel Converters By M. Lau; P. F. Sørensen; P. Jensen; S. Munk-Nielsen	[View] [Download]
Abstract: Soft switched three phase inverters have low switching loss and dv/dt which are desirable quality’s for various applications such as motor drives and UPS systems. Unfortunately, the natural selection of modulation strategy is a discrete delta modulator, which have a variable switching frequency, thus making it harder to design filters. This paper give an overview of the various types of delta modulators and compare the strong and weak points relative to standard PWM. Four three level sigmadelta modulators are simulated in Saber and the performance is evaluated.