EPE Association: EPE-PEMC 2000 - Topic 01e: AC and DC Power Supplies

EPE-PEMC 2000 - Topic 01e: AC and DC Power Supplies
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 01e: AC and DC Power Supplies

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   A Simple Inductorless AC-line Voltage Autotransformer with Inductive Loads Driving Capability
By Kosev J., Arsov Goce L. [View]
[Download]

Abstract: Possibilities for practical implementations of the simplest inductorless autotransformer [1] are investigated while preserving or possibly improving its main characteristics: small and lightweight. Some typical loads are concerned -- half wave and full wave rectifiers with capacitive and inductive filters, and AC capacitive and inductive loads. It is shown that rectifiers can be connected to the transformer as is and regulation at wide input voltage variations can be accomplished. Unlike other regulated rectifiers voltage boosting can be obtained. Modifications are made to enable AC reactive loads driving. A practical circuit is designed with microcontroller as switch-driving waveforms generator. Further modifications based on intelligent switching algorithm are done and autotransformer space and weight improvements are obtained.

   Active Current Rectifier Mathematical Model
By Shreiner R.T., Efimov A.A., Kalygin A.I. [View]
[Download]

Abstract: The paper represents the transistor based active current rectifier working in a PWM mode vector mathematical model. Active current rectifier has certain advantages output current management, energy recuperation, supply line power factor management and forming near sinusoidal line currents. Developed model can be used for electrical drives vector control system synthesis. Represented approach also can be applied to self-excited current inverter operating mode analysis. The simulation results are presented.

   Comparison of Current Spectrum of a Unity Power Factor Current Source Rectifier
By Cesnak L., Krištof R., Ráèek V.* [View]
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Abstract: Different pulse width modulation strategies based on sinusoidal pulse width modulation for three phase AC to DC current source rectifier working with unity power factor are tested. The frequency spectrum analysis of the input line current is presented. The switching frequency of the power transistors is in the noiseless zone above 19kHz. Two different simulation programs are used to guarantee good results. One of the modulation method is applied to a real converter and measured results are compared with the simulation results.

   High Efficiency Multiphase PWM DC to AC Inverter
By Edelmoser K., Himmelstoss F. [View]
[Download]

Abstract: In case of low voltage (e.g. battery powered solar) inverter applications very high primary current values will occure. To improve the over all efficiency of the inverter and to reduce the input capacitor a synchronized multi phase PWM concept was choosen. This new solution will improve the disadvantage of parallel operation of output switches in the power stages in conventional converters with modern current sharing techniques. Due to the reduced current in each of the paralleled output stages the efficiency will increase significantly. The ripple of the input current is shared between the different stages which can help to reduce the input capacitor. Also the resulting frequency rises with the number of used stages. This leads to a more silent (EMV) design. In this paper a 12V / 1kW converter is described. It's power stage consists of four PWM halfe-bridges operating in parallel. Each output stage switches at 80kHz with a phase delay of 45° to the previous. The maximum peak current of each output stage is only about 50A. So very cheap mass products can be used as power switches. The concept is well suited for solar and renewable energy as well as aerospace applications.

   Low Voltage Distorsion AC Switching Power Supply
By Delli Colli V., Di Stefano R. [View]
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Abstract: The paper describes the operation of a novel AC source for low power applications with quasi-sinusoidal voltage. The converter allows a simple control implementation and its characteristics are particularly suitable for factory test applications. The proposed solution is based on the control of the charge status of a capacitor, that is achieved by a current mode controlled input stage and a current source controlled bridge that fed the capacitor. In the paper the basic idea is presented and an ideal mathematical model is reported and discussed. By means of an experimental prototype the basic behaviour of the device is explained in detail. Emphasis is gigen about the analysis of the switching process.

   Stabilization on the Unbalance DC Voltages of the PWM Rectifiers in High Power Cascade
By Chibani R., Berkouk E.M., Manesse G.M.* [View]
[Download]

Abstract: This study concerns the working principle of a P.M synchronous machine (PMSM) fed by a five level NPC VSI. This inverter has two PWM rectifiers as DC sources. After presenting the model of the inverter and its control strategy, we used it in the speed control of the PMSM (supposing that its DC sources are ideal). Then we present the PWM rectifier model and use two of them as DC sources of the five level NPC VSI in the previous cascade and show the performances obtained. Those performances show perfectly the problem associated to the fluctuation of the input DC voltages. In the last part of this paper, we propose a solution to stabilize the unbalance DC voltages of those rectifiers and to obtain good performances.

EPE-PEMC 2000 - Topic 01e: AC and DC Power Supplies
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 01e: AC and DC Power Supplies
	[return to parent folder]

	A Simple Inductorless AC-line Voltage Autotransformer with Inductive Loads Driving Capability By Kosev J., Arsov Goce L.	[View] [Download]
Abstract: Possibilities for practical implementations of the simplest inductorless autotransformer [1] are investigated while preserving or possibly improving its main characteristics: small and lightweight. Some typical loads are concerned -- half wave and full wave rectifiers with capacitive and inductive filters, and AC capacitive and inductive loads. It is shown that rectifiers can be connected to the transformer as is and regulation at wide input voltage variations can be accomplished. Unlike other regulated rectifiers voltage boosting can be obtained. Modifications are made to enable AC reactive loads driving. A practical circuit is designed with microcontroller as switch-driving waveforms generator. Further modifications based on intelligent switching algorithm are done and autotransformer space and weight improvements are obtained.

	Active Current Rectifier Mathematical Model By Shreiner R.T., Efimov A.A., Kalygin A.I.	[View] [Download]
Abstract: The paper represents the transistor based active current rectifier working in a PWM mode vector mathematical model. Active current rectifier has certain advantages output current management, energy recuperation, supply line power factor management and forming near sinusoidal line currents. Developed model can be used for electrical drives vector control system synthesis. Represented approach also can be applied to self-excited current inverter operating mode analysis. The simulation results are presented.

	Comparison of Current Spectrum of a Unity Power Factor Current Source Rectifier By Cesnak L., Krištof R., Ráèek V.*	[View] [Download]
Abstract: Different pulse width modulation strategies based on sinusoidal pulse width modulation for three phase AC to DC current source rectifier working with unity power factor are tested. The frequency spectrum analysis of the input line current is presented. The switching frequency of the power transistors is in the noiseless zone above 19kHz. Two different simulation programs are used to guarantee good results. One of the modulation method is applied to a real converter and measured results are compared with the simulation results.

	High Efficiency Multiphase PWM DC to AC Inverter By Edelmoser K., Himmelstoss F.	[View] [Download]
Abstract: In case of low voltage (e.g. battery powered solar) inverter applications very high primary current values will occure. To improve the over all efficiency of the inverter and to reduce the input capacitor a synchronized multi phase PWM concept was choosen. This new solution will improve the disadvantage of parallel operation of output switches in the power stages in conventional converters with modern current sharing techniques. Due to the reduced current in each of the paralleled output stages the efficiency will increase significantly. The ripple of the input current is shared between the different stages which can help to reduce the input capacitor. Also the resulting frequency rises with the number of used stages. This leads to a more silent (EMV) design. In this paper a 12V / 1kW converter is described. It's power stage consists of four PWM halfe-bridges operating in parallel. Each output stage switches at 80kHz with a phase delay of 45° to the previous. The maximum peak current of each output stage is only about 50A. So very cheap mass products can be used as power switches. The concept is well suited for solar and renewable energy as well as aerospace applications.

	Low Voltage Distorsion AC Switching Power Supply By Delli Colli V., Di Stefano R.	[View] [Download]
Abstract: The paper describes the operation of a novel AC source for low power applications with quasi-sinusoidal voltage. The converter allows a simple control implementation and its characteristics are particularly suitable for factory test applications. The proposed solution is based on the control of the charge status of a capacitor, that is achieved by a current mode controlled input stage and a current source controlled bridge that fed the capacitor. In the paper the basic idea is presented and an ideal mathematical model is reported and discussed. By means of an experimental prototype the basic behaviour of the device is explained in detail. Emphasis is gigen about the analysis of the switching process.

	Stabilization on the Unbalance DC Voltages of the PWM Rectifiers in High Power Cascade By Chibani R., Berkouk E.M., Manesse G.M.*	[View] [Download]
Abstract: This study concerns the working principle of a P.M synchronous machine (PMSM) fed by a five level NPC VSI. This inverter has two PWM rectifiers as DC sources. After presenting the model of the inverter and its control strategy, we used it in the speed control of the PMSM (supposing that its DC sources are ideal). Then we present the PWM rectifier model and use two of them as DC sources of the five level NPC VSI in the previous cascade and show the performances obtained. Those performances show perfectly the problem associated to the fluctuation of the input DC voltages. In the last part of this paper, we propose a solution to stabilize the unbalance DC voltages of those rectifiers and to obtain good performances.