EPE Association: EPE 1999 - Topic 07b: Measurements Techniques

EPE 1999 - Topic 07b: Measurements Techniques
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1999 - Conference > EPE 1999 - Topic 07: MEASUREMENTS AND SENSORS > EPE 1999 - Topic 07b: Measurements Techniques

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   A New Current Probe with a Wide Bandwidth
By N. Karrer; P. Hofer-Noser; D. Henrard [View]
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Abstract: We present a new isolated current probe for power applications based on a Hall sensor as well as on a Rogowski coil. Employing these two sensors allows to eliminate the integrator circuit needed for the Rogowski signal. With this new probe DC currents as well as current transients with di/dt's of several kA/us can be measured.

   Adaptive Capturing Transient Signals Using Wavelets
By T. Asztalos; D. Isar; A. Isar [View]
[Download]

Abstract: When capturing transient signals, the maximum recording time of the measurement is limited by the high sample rate used to preserve input signal details. To obtain a maximum recording time keeping the details an adaptive compression must be performed. Such a method is proposed in this paper. The method is based on the use of the discrete wavelet transform. To optimise the compression ratio a criteria for the matching of the wavelets mother with the input signal is proposed. This matching problem is very important in the wavelet's literature. The correspondent wavelets mother searching method is described. Some simulations results are described. The superiority of the proposed compression method is proved.

   An Accurate Method for Power Loss Measurements in Energy Optimized Apparatus and Systems
By P. Hansen; F. Blaabjerg; K. D. Madsen; J. K. Pedersen; E. Ritchie [View]
[Download]

Abstract: A calorimetric wattmeter has been built at Aalborg University, Institute of Energy Technology. The wattmeter is designed to measure power losses in power electronic components and applications at fixed temperatures. High accuracy has been achieved by using active constraints and optimizing flow and temperature conditions in the cooling circuit.

   An Integrated Test System for AC Machine Drives Performance Analysis
By M. I. Giménez; J. M. Aller; F. Quintero; V. M. Guzmán; J. Restrepo; A. Bueno [View]
[Download]

Abstract: This work presents an integrated Test System specially designed as a test bed for the experiments required to validate different types of new strategies and control schemes, based on vector control theories, parametric estimation, and neural networks applied to AC machine drives, and to analyze the effect of these control strategies over the mains quality. The equipment includes the power stage with the rectifier, the inverter, the respective filters and the drive circuits, the instrumentation stage and the signal processing and control stage. Due to its high versatility, this test bed can be used both in research laboratories and postgraduate courses.

   Analysis and Identification of Faults in Bridge Converters Using the Symmetrical Space Phasor Components
By B. Strobl; W. Heinrich; G. Herold [View]
[Download]

Abstract: High power converters have to work with high reliability. It would be useful if these devices can be monitored during normal operation with low expenses in order to detect failures before they become hazardous events. In this paper it will be shown that this diagnosis can be done very easily by describing a converter circuit in the domain of the so-called Symmetrical Space Phasor Components. By this transformation networks with a cyclical behavior like converters, for example, can be transformed to equivalent networks which are decoupled for faultless operation. Faults lead to characteristic coupling between these networks. By measuring the voltages and currents of the converter with high accuracy equipment and processing the data with suitable algorithms it is possible to separate the components which correspond to each of the equivalent networks. By analysing this, conclusions about the fault can be drawn.

   Automated Test Bench for Electric Drives: Modular Layout of Soft- and Hardware
By Ch. Kuert; P. Germano; M. Jufer [View]
[Download]

Abstract: An automated modular test bench for electric drives and loads has been developed to analyse the behaviour and to extract electrical and mechanical parameters. Actually it allows to measure DC motors. The following three analysing functions to compute characteristic curves are actually available: torque as a function of the phase current; torque as a function of speed; efficiency as a function of torque separately for the electrical motor, its drive and both together. For a passive torque analysis, the following functions have been implemented: static and dynamic friction torque, inertia, torque as a function of position. Every part of the hardware is designed and connected to the rest of the test bench in a modular way. The software is written in a modular way in order to be able to integrate easily new hardware components. Each user’s working directory includes the configuration settings and results of the measurements. The modular structure of soft- and hardware allows future extensions for motors of another type like synchronous and induction motors, sensorless DC or stepper. The actual state of the project provides an interesting education tool and might be adapted for industrial purposes.

   Enhanced Sigma-Delta A/D Converter for High Performance Drives
By H-G. Köpken; D. Eckardt [View]
[Download]

Abstract: High performance variable speed drives require a precise motor current measurement. The enhanced sigma-delta converter achieves high speed and high accuracy and is insensitive to signal ripple and EMC due to its integral measurement characteristic. It provides both a fast 8 bit signal for over current and short circuit protection and a high precision 12/14 bit signal every 64 µs for the control loop. This paper presents the inner structure of the converter and the measurement results obtained with a prototype realization in a standard CMOS mixed-signal ASIC.

EPE 1999 - Topic 07b: Measurements Techniques
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1999 - Conference > EPE 1999 - Topic 07: MEASUREMENTS AND SENSORS > EPE 1999 - Topic 07b: Measurements Techniques
	[return to parent folder]

	A New Current Probe with a Wide Bandwidth By N. Karrer; P. Hofer-Noser; D. Henrard	[View] [Download]
Abstract: We present a new isolated current probe for power applications based on a Hall sensor as well as on a Rogowski coil. Employing these two sensors allows to eliminate the integrator circuit needed for the Rogowski signal. With this new probe DC currents as well as current transients with di/dt's of several kA/us can be measured.

	Adaptive Capturing Transient Signals Using Wavelets By T. Asztalos; D. Isar; A. Isar	[View] [Download]
Abstract: When capturing transient signals, the maximum recording time of the measurement is limited by the high sample rate used to preserve input signal details. To obtain a maximum recording time keeping the details an adaptive compression must be performed. Such a method is proposed in this paper. The method is based on the use of the discrete wavelet transform. To optimise the compression ratio a criteria for the matching of the wavelets mother with the input signal is proposed. This matching problem is very important in the wavelet's literature. The correspondent wavelets mother searching method is described. Some simulations results are described. The superiority of the proposed compression method is proved.

	An Accurate Method for Power Loss Measurements in Energy Optimized Apparatus and Systems By P. Hansen; F. Blaabjerg; K. D. Madsen; J. K. Pedersen; E. Ritchie	[View] [Download]
Abstract: A calorimetric wattmeter has been built at Aalborg University, Institute of Energy Technology. The wattmeter is designed to measure power losses in power electronic components and applications at fixed temperatures. High accuracy has been achieved by using active constraints and optimizing flow and temperature conditions in the cooling circuit.

	An Integrated Test System for AC Machine Drives Performance Analysis By M. I. Giménez; J. M. Aller; F. Quintero; V. M. Guzmán; J. Restrepo; A. Bueno	[View] [Download]
Abstract: This work presents an integrated Test System specially designed as a test bed for the experiments required to validate different types of new strategies and control schemes, based on vector control theories, parametric estimation, and neural networks applied to AC machine drives, and to analyze the effect of these control strategies over the mains quality. The equipment includes the power stage with the rectifier, the inverter, the respective filters and the drive circuits, the instrumentation stage and the signal processing and control stage. Due to its high versatility, this test bed can be used both in research laboratories and postgraduate courses.

	Analysis and Identification of Faults in Bridge Converters Using the Symmetrical Space Phasor Components By B. Strobl; W. Heinrich; G. Herold	[View] [Download]
Abstract: High power converters have to work with high reliability. It would be useful if these devices can be monitored during normal operation with low expenses in order to detect failures before they become hazardous events. In this paper it will be shown that this diagnosis can be done very easily by describing a converter circuit in the domain of the so-called Symmetrical Space Phasor Components. By this transformation networks with a cyclical behavior like converters, for example, can be transformed to equivalent networks which are decoupled for faultless operation. Faults lead to characteristic coupling between these networks. By measuring the voltages and currents of the converter with high accuracy equipment and processing the data with suitable algorithms it is possible to separate the components which correspond to each of the equivalent networks. By analysing this, conclusions about the fault can be drawn.

	Automated Test Bench for Electric Drives: Modular Layout of Soft- and Hardware By Ch. Kuert; P. Germano; M. Jufer	[View] [Download]
Abstract: An automated modular test bench for electric drives and loads has been developed to analyse the behaviour and to extract electrical and mechanical parameters. Actually it allows to measure DC motors. The following three analysing functions to compute characteristic curves are actually available: torque as a function of the phase current; torque as a function of speed; efficiency as a function of torque separately for the electrical motor, its drive and both together. For a passive torque analysis, the following functions have been implemented: static and dynamic friction torque, inertia, torque as a function of position. Every part of the hardware is designed and connected to the rest of the test bench in a modular way. The software is written in a modular way in order to be able to integrate easily new hardware components. Each user’s working directory includes the configuration settings and results of the measurements. The modular structure of soft- and hardware allows future extensions for motors of another type like synchronous and induction motors, sensorless DC or stepper. The actual state of the project provides an interesting education tool and might be adapted for industrial purposes.

	Enhanced Sigma-Delta A/D Converter for High Performance Drives By H-G. Köpken; D. Eckardt	[View] [Download]
Abstract: High performance variable speed drives require a precise motor current measurement. The enhanced sigma-delta converter achieves high speed and high accuracy and is insensitive to signal ripple and EMC due to its integral measurement characteristic. It provides both a fast 8 bit signal for over current and short circuit protection and a high precision 12/14 bit signal every 64 µs for the control loop. This paper presents the inner structure of the converter and the measurement results obtained with a prototype realization in a standard CMOS mixed-signal ASIC.