EPE Association: EPE 1989 - 06 - Lecture Session 1.6: SYSTEMS ENGINEERING

EPE 1989 - 06 - Lecture Session 1.6: SYSTEMS ENGINEERING
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 06 - Lecture Session 1.6: SYSTEMS ENGINEERING

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   POWER MEASURING SYSTEM WITH OPTICAL LINKS FOR POWER ELECTRONIC EQUIPMENT
By H.-K. Spielbauer; M. Michel [View]
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Abstract: The use of inverters with high switching frequency and power, causes problems of measuring the power and efficiency, because of the resulting EMI and high order harmonics. A measuring system is described, which meets these requirements. Inverter input/output current i(t) and voltage v(t) are measured by a coaxial shunt and a voltage probe. The signals are amplified, digitized and transmitted via an optical link to a signal processing unit by small measuring transducers, supplied from batteries. All necessary computations are done by the signal processor and the results are displayed on a PC-screen. This concept combines velocity and noise immunity by moving intelligence from the transducer to the data processing unit. An error analysis is included.

   MARGIN IN THE JUNCTION-TEMPERATURE-RISE OF SEMICONDUCTOR-VALVE-ASSEMBLIES CAUSED BY THE STANDARD LOAD-DUTIES FOR TEST FOR MOTOR-DRIVE-SYSTEMS
By Y. Ikeda; M. Ubukata; J. Itsumi [View]
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Abstract: During last ten years, two kinds of the current rating systems concerning the equivalent load cycles and / or the test-duties for the semiconductor-valve-assemblies applied to the DC motor-drive-systems have been proposed. One is going to be published as the new Standard of the International Electrotechnical Commission after a long discussion of about twenty years, and the other was published as the Standard of the Japanese Electrotechnical Committee with much reference to the old IEC document around ten years ago. The paper discusses systematically the level of the margin in the junction-temperature-rises of the valves used for the assemblies designed strictly under the two rating-systems for various kinds of load-cycles as well as for the various transient thermal impedances and for the various dissipation characteristics. lt has been found that the IEC method introduces more margin in the junction-temperature-rise, in other words, it does overestimation of the capacity of the assemlies, particularly in cases of high peak - to - r.m.s.-current-ratio, low r.m.s.- to average-current-ratio and also relatively short load-cycle-period.

   A CASE STUDY OF THE ELECTROMECHANICAL ANALYSIS OF THE AUDIBLE NOISE IN AN INVERTER FED INDUCTION MOTOR
By R. Belmans; W. Geysen [View]
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Abstract: A computerized scheme is used to analyse the audible noise of an induction motor fed by a frequency inverter. Starting from the frequency spectrum of the inverter voltage, and accounting for the winding lay-out of the squirrel cage induction motor, the electromagnetically generated force components are calculated . Harmonic effects due to slatting and saturation are taken into consideration. A high audible noise level is to be expected if one of the frequencies of the electromagnetically generated force cornponents coincides with one of the natural frequencies of the stator assembly. The calculation of these natural frequencies is performed using the finite element method coupled with CAD techniques at the input and the output. The model analysis technique is used for experimental verification of the natural frequencies.

   AN AC-DC CONVERTER WITH LOW MAINS CURRENT DISTORTION AND MINIMIZED CONDUCTED EMISSIONS
By M. Albach [View]
[Download]

Abstract: An ac-dc converter with both modulated switching frequency and modulated duty cycle is presented. Using a combination of a feedforward and feedback control strategy a sinusoidal input current can be achieved by the duty cycle modulation. The mains current distortion is far below the limits specified by IEC regulations. Based on an analytical calculation of the conducted emissions (differential mode), which takes into account the quasi-peak measurement according to ClSPR / 2 / , the modulation of switching frequency has been optimized and results in a level of conducted interference voltages, which is more than 20 dB lower compared with constant frequency operation.

   ADAPTIVE AND SELF-TUNING CONTROL OF ELECTRICAL DRIVES
By A. Dittrich; R. SchÃ¶nfeld [View]
[Download]

Abstract: Opportunities of realization of adaptive and self-tuning drives are compared. The explicit self-tuning controller is investigated together with a model of controlled system. Rules of tuning, strategies of optimization and practical results are told.

EPE 1989 - 06 - Lecture Session 1.6: SYSTEMS ENGINEERING
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1989 - Conference > EPE 1989 - 06 - Lecture Session 1.6: SYSTEMS ENGINEERING
	[return to parent folder]

	POWER MEASURING SYSTEM WITH OPTICAL LINKS FOR POWER ELECTRONIC EQUIPMENT By H.-K. Spielbauer; M. Michel	[View] [Download]
Abstract: The use of inverters with high switching frequency and power, causes problems of measuring the power and efficiency, because of the resulting EMI and high order harmonics. A measuring system is described, which meets these requirements. Inverter input/output current i(t) and voltage v(t) are measured by a coaxial shunt and a voltage probe. The signals are amplified, digitized and transmitted via an optical link to a signal processing unit by small measuring transducers, supplied from batteries. All necessary computations are done by the signal processor and the results are displayed on a PC-screen. This concept combines velocity and noise immunity by moving intelligence from the transducer to the data processing unit. An error analysis is included.

	MARGIN IN THE JUNCTION-TEMPERATURE-RISE OF SEMICONDUCTOR-VALVE-ASSEMBLIES CAUSED BY THE STANDARD LOAD-DUTIES FOR TEST FOR MOTOR-DRIVE-SYSTEMS By Y. Ikeda; M. Ubukata; J. Itsumi	[View] [Download]
Abstract: During last ten years, two kinds of the current rating systems concerning the equivalent load cycles and / or the test-duties for the semiconductor-valve-assemblies applied to the DC motor-drive-systems have been proposed. One is going to be published as the new Standard of the International Electrotechnical Commission after a long discussion of about twenty years, and the other was published as the Standard of the Japanese Electrotechnical Committee with much reference to the old IEC document around ten years ago. The paper discusses systematically the level of the margin in the junction-temperature-rises of the valves used for the assemblies designed strictly under the two rating-systems for various kinds of load-cycles as well as for the various transient thermal impedances and for the various dissipation characteristics. lt has been found that the IEC method introduces more margin in the junction-temperature-rise, in other words, it does overestimation of the capacity of the assemlies, particularly in cases of high peak - to - r.m.s.-current-ratio, low r.m.s.- to average-current-ratio and also relatively short load-cycle-period.

	A CASE STUDY OF THE ELECTROMECHANICAL ANALYSIS OF THE AUDIBLE NOISE IN AN INVERTER FED INDUCTION MOTOR By R. Belmans; W. Geysen	[View] [Download]
Abstract: A computerized scheme is used to analyse the audible noise of an induction motor fed by a frequency inverter. Starting from the frequency spectrum of the inverter voltage, and accounting for the winding lay-out of the squirrel cage induction motor, the electromagnetically generated force components are calculated . Harmonic effects due to slatting and saturation are taken into consideration. A high audible noise level is to be expected if one of the frequencies of the electromagnetically generated force cornponents coincides with one of the natural frequencies of the stator assembly. The calculation of these natural frequencies is performed using the finite element method coupled with CAD techniques at the input and the output. The model analysis technique is used for experimental verification of the natural frequencies.

	AN AC-DC CONVERTER WITH LOW MAINS CURRENT DISTORTION AND MINIMIZED CONDUCTED EMISSIONS By M. Albach	[View] [Download]
Abstract: An ac-dc converter with both modulated switching frequency and modulated duty cycle is presented. Using a combination of a feedforward and feedback control strategy a sinusoidal input current can be achieved by the duty cycle modulation. The mains current distortion is far below the limits specified by IEC regulations. Based on an analytical calculation of the conducted emissions (differential mode), which takes into account the quasi-peak measurement according to ClSPR / 2 / , the modulation of switching frequency has been optimized and results in a level of conducted interference voltages, which is more than 20 dB lower compared with constant frequency operation.

	ADAPTIVE AND SELF-TUNING CONTROL OF ELECTRICAL DRIVES By A. Dittrich; R. SchÃ¶nfeld	[View] [Download]
Abstract: Opportunities of realization of adaptive and self-tuning drives are compared. The explicit self-tuning controller is investigated together with a model of controlled system. Rules of tuning, strategies of optimization and practical results are told.