EPE Association: EPE 1999 - Topic 05g: Converter Machine Interactions

EPE 1999 - Topic 05g: Converter Machine Interactions
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1999 - Conference > EPE 1999 - Topic 05: ELECTRICAL MACHINES AND ADJUSTABLE SPEED DRIVES > EPE 1999 - Topic 05g: Converter Machine Interactions

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   A Study of Harmonics Reduction by Active Filter in PWM VSI Induction Motor Drives
By V. Lanfranchi; D. Depernet; C. Goeldel [View]
[Download]

Abstract: This paper deals with harmonics compensation in order to improve induction motor performances. The proposed method uses both active filtering techniques and optimised PWM (Pulse Width Modulation) waveforms. In addition, optimisation of PWM waveforms is effective with power supply and active filter too. This harmonics compensation takes into account the whole frequency range of induction motor in adjustable speed drive.

   ASM Double Star System Instability in DC Line
By S. Fortuna; N. Palazzoli [View]
[Download]

Abstract: In 3 kV DC railway locomotives, with double star asynchronous motors and 2-point converters, the recent investigations have shown a system instability in some operating conditions. The phenomenon is due to the spatial placement of the motor windings, as confirmed by a detailed study and by several power lab measurements.

   Effect of the PWM voltage on Induction motors stator windings
By B. Oyegoke; P. Lampola [View]
[Download]

Abstract: Inverters, with progressive electronic components, such as IGBT using PWM technique, cause extremely steep and frequent peaks in the output voltage. These peaks impose large stresses on the winding insulation. In this paper, the multiconductor transmission line and the scatter matrix method are used for predicting the magnitude of the voltage stress due to the steep fronted inverter output voltage in the stator windings. Results of the voltage distribution in the form winding and the random winding are presented. In order to validate the method adopted, the simulated results are compared with the experimental results.

   Electromagnetic Torque Harmonics for On-Line Interturn Shortcircuits Detection in Squirrel Cage Induction Motors
By M. G. Melero; M. F. Cabanas; F. R. Faya; C. H. Rojas; J. Solares [View]
[Download]

Abstract: This paper describes a new method for on-line detection of interturn shortcircuits in squirrel cage induction motors. This method is based in the identification of some harmonic components in electromagnetic torque (E.T.) spectrum. The following study shows the result of comparing theoretical components in E.T. spectrum for a healthy machine with those which appear in the cases of interturn shortcircuits of different severities. As a conclusion to the study, some E.T. harmonics reveal the variability of detecting whether this type of failure exists.

   Mitigation of Torque Transients of Power Enhanced Alternators Produced by a Novel Windings Turnover Converter for Automotive Networks
By M. Hofmann; R. Blümel [View]
[Download]

Abstract: Today’s synchronous claw-pole alternators with full-wave diode bridge rectifier are the state-of-theart power source for automotive applications. This paper discusses a way of enhancing the power output along with the efficiency of such an alternator without changing its magnetic properties. This is accomplished with a novel windings turnover converter which supports the extremely wide speed range of this application. The enhanced alternator is compared to a standard alternator of identical volume. The transients occuring at windings turnover under load are shown. Finally a method of smoothening these transients while switching is presented.

   Modular Vector Drive System: Implications for Magnetic Motor Design
By P. Lesage; D.W.J. Pulle; M Alaküla; L. Gertmar [View]
[Download]

Abstract: Sensorless operation of conventional eld oriented asynchronous drives around the zero stator frequency region is problematic due to lack of information for the flux observer. A novel modular vector drive circumvents this problem by ensuring that operation of individual modules is outside said region. This paper examines from a magnetic perspective how the motor is aected by this type of operation. An analytical and nite element based approach is presented which determines the flux density distribution in the modularised motor. Results from these studies concludes that its magnetic behavior is signicantly changed when operation takes place in the zero frequency region. This implies that the motor design must be adapted to allow this type of modular drive control.

   Overvoltages Caused By Step-up Transformer and Long Cables in Medium Voltage Inverter Drives
By J. Pontt; E. Perelli; J. Rodriguez; S. Fuentes; B. González; L. Sanhueza; I. Quezada [View]
[Download]

Abstract: Failure of the winding isolation of two 13.8 kV three-phase induction motor fan drives fed by a PWM medium voltage inverter through a step-up transformer and cables longer than 400 meters motivated this study. Each motor drives a fan for air-ventilation of an underground copper mine at Codelco El Teniente, Chile. The isolation failure suggested that overvoltages values higher than expected were generated. In order to the better understanding of the phenomena, a modelling and simulation for the analysis of the harmonic motor overvoltages caused by step-up transformers and long cables in a medium voltage inverter drive was carried on. The simulation results confirmed that the natural resonant modes of the electric system feeding the motor terminals can be excited by the harmonic voltages applied by the PWM inverter. The solution proposed by the vendor was the application of a damping low pass filter between the inverter and step-up transformer. The study verified that the proposed filter helps to reduce the voltage stressing of the motor winding isolation. Because another similar fan-drive application were at the setting-up, a direct measurement of the motor terminal voltages was agreed in order to verify the overvoltages generation and proper isolation coordination with the motor windings. The measurements, made with broad range frequency capacitive transducers and a high-voltage probe, confirmed the predictions given by the modeling and simulation study.

   Power Quality Impact on Thermal Behaviour and Life Expectancy of Three-Phase Induction Motors
By O. C. Nascimento Souto; J. C. de Oliveira; L. M. Neto [View]
[Download]

Abstract: This paper deals with thermal behaviour analysis of three-phase induction motors under non ideal supply conditions. The motors are of squirrel cage type and the non ideal conditions are associated to harmonics, unbalances, voltage sag and swell, etc... The studies are carried out using a comprehensive methodology which handles electrical, mechanical and thermal models in a simultaneous way. The approach is then implemented into a time domain programme known as SABER simulator. Computational studies are then performed to evaluate motor temperature rise and life reduction under non ideal conditions.

   Shaft Voltages and Bearing Currents - New Phenomena in Inverter Driven Induction Machines
By H.-J. Conraths; F. Gießler; H-D. Heining [View]
[Download]

Abstract: With the introduction of new, fast switching semiconductors (IGBT) in modern inverter technology some years ago, several authors reported an increase in premature motor bearing failure due to bearing currents. As a result, the problem of bearing currents and shaft voltages in inverter drives became of major interest in research and industrial application. A lot of theoretical and experimental examinations have been made to clear the problem, but many aspects are still under discussion. The present paper summarizes the theoretical background and shows numerous experimental results with lowand high-voltage ac drives. Some simulations show that the new phenomena relate to the design and configuration of the whole drive, not only of the motor itself. Actual measures against bearing currents and future strategies are summarized.

   Sine Wave Filter for PWM-Inverter Driven Solid-Rotor Induction Motors
By J. Huppunen; J. Pyrhönen [View]
[Download]

Abstract: Inverter output harmonics create great amount of losses in a solid-rotor induction motor. An output filter for a PWM-inverter is introduced to smoothen the inverter output wave forms. The efficiency of the solid-rotor induction motor will increase remarkably. The filter is designed so that it also compensates the magnetising current of the motor, thus the poor power factor of the solid-rotor induction motor does not affect to inverter sizing. The EMC-matters, voltage stress in stator windings and bearing currents are also examined. This paper focuses on the filter component selection and the filter design. Measurements of a 12 kW, 13500 rpm prototype are given.

   Subsystem Interaction Analysis in Power Distribution Systems of Next Generation Airlifters
By S. Chandrasekaran; D. K. Lindner; K. Louganski; D. Boroyevich [View]
[Download]

Abstract: Subsystem interaction in a simplified power distribution system of a next generation transport aircraft is addressed. Detailed analysis of interaction between an ElectroMechanical Actuator (EMA) connected to the DC bus of the power distribution system in a next generation transport aircraft with the bus regulator is presented. The classical impedance ration criterion is used to determine local stability arround an equilibrum point of each interface by observing the impedance characteristics of the source and load subsystems. Critical parameters that determine the local stability of the integrated system are identified. The loss of stability under large disturbances is presented to motivate the use of nonlinear stability analysis methods. Preliminary results of nonlinear stability analysis are presented.

   Transient Overvoltages at Inverter Fed Induction Motors
By R. Nuscheler; D. Potoradi [View]
[Download]

Abstract: This paper deals with the problem of transient overvoltages at the motor terminals and their effects inside the stator winding. A simulation model based on equivalent circuits for the subsystems PWM inverter, feeding cable and induction motor which is valid for a wide frequency range is described. The simulation model is verified by comparing typical simulation results to measurements. Additional simulations with the verified model show the influence of cable length, pulse pattern and suppressor circuits on the overvoltages at the motor terminals and across the first coil group (double-coil) of the stator winding.

EPE 1999 - Topic 05g: Converter Machine Interactions
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1999 - Conference > EPE 1999 - Topic 05: ELECTRICAL MACHINES AND ADJUSTABLE SPEED DRIVES > EPE 1999 - Topic 05g: Converter Machine Interactions
	[return to parent folder]

	A Study of Harmonics Reduction by Active Filter in PWM VSI Induction Motor Drives By V. Lanfranchi; D. Depernet; C. Goeldel	[View] [Download]
Abstract: This paper deals with harmonics compensation in order to improve induction motor performances. The proposed method uses both active filtering techniques and optimised PWM (Pulse Width Modulation) waveforms. In addition, optimisation of PWM waveforms is effective with power supply and active filter too. This harmonics compensation takes into account the whole frequency range of induction motor in adjustable speed drive.

	ASM Double Star System Instability in DC Line By S. Fortuna; N. Palazzoli	[View] [Download]
Abstract: In 3 kV DC railway locomotives, with double star asynchronous motors and 2-point converters, the recent investigations have shown a system instability in some operating conditions. The phenomenon is due to the spatial placement of the motor windings, as confirmed by a detailed study and by several power lab measurements.

	Effect of the PWM voltage on Induction motors stator windings By B. Oyegoke; P. Lampola	[View] [Download]
Abstract: Inverters, with progressive electronic components, such as IGBT using PWM technique, cause extremely steep and frequent peaks in the output voltage. These peaks impose large stresses on the winding insulation. In this paper, the multiconductor transmission line and the scatter matrix method are used for predicting the magnitude of the voltage stress due to the steep fronted inverter output voltage in the stator windings. Results of the voltage distribution in the form winding and the random winding are presented. In order to validate the method adopted, the simulated results are compared with the experimental results.

	Electromagnetic Torque Harmonics for On-Line Interturn Shortcircuits Detection in Squirrel Cage Induction Motors By M. G. Melero; M. F. Cabanas; F. R. Faya; C. H. Rojas; J. Solares	[View] [Download]
Abstract: This paper describes a new method for on-line detection of interturn shortcircuits in squirrel cage induction motors. This method is based in the identification of some harmonic components in electromagnetic torque (E.T.) spectrum. The following study shows the result of comparing theoretical components in E.T. spectrum for a healthy machine with those which appear in the cases of interturn shortcircuits of different severities. As a conclusion to the study, some E.T. harmonics reveal the variability of detecting whether this type of failure exists.

	Mitigation of Torque Transients of Power Enhanced Alternators Produced by a Novel Windings Turnover Converter for Automotive Networks By M. Hofmann; R. Blümel	[View] [Download]
Abstract: Today’s synchronous claw-pole alternators with full-wave diode bridge rectifier are the state-of-theart power source for automotive applications. This paper discusses a way of enhancing the power output along with the efficiency of such an alternator without changing its magnetic properties. This is accomplished with a novel windings turnover converter which supports the extremely wide speed range of this application. The enhanced alternator is compared to a standard alternator of identical volume. The transients occuring at windings turnover under load are shown. Finally a method of smoothening these transients while switching is presented.

	Modular Vector Drive System: Implications for Magnetic Motor Design By P. Lesage; D.W.J. Pulle; M Alaküla; L. Gertmar	[View] [Download]
Abstract: Sensorless operation of conventional eld oriented asynchronous drives around the zero stator frequency region is problematic due to lack of information for the flux observer. A novel modular vector drive circumvents this problem by ensuring that operation of individual modules is outside said region. This paper examines from a magnetic perspective how the motor is aected by this type of operation. An analytical and nite element based approach is presented which determines the flux density distribution in the modularised motor. Results from these studies concludes that its magnetic behavior is signicantly changed when operation takes place in the zero frequency region. This implies that the motor design must be adapted to allow this type of modular drive control.

	Overvoltages Caused By Step-up Transformer and Long Cables in Medium Voltage Inverter Drives By J. Pontt; E. Perelli; J. Rodriguez; S. Fuentes; B. González; L. Sanhueza; I. Quezada	[View] [Download]
Abstract: Failure of the winding isolation of two 13.8 kV three-phase induction motor fan drives fed by a PWM medium voltage inverter through a step-up transformer and cables longer than 400 meters motivated this study. Each motor drives a fan for air-ventilation of an underground copper mine at Codelco El Teniente, Chile. The isolation failure suggested that overvoltages values higher than expected were generated. In order to the better understanding of the phenomena, a modelling and simulation for the analysis of the harmonic motor overvoltages caused by step-up transformers and long cables in a medium voltage inverter drive was carried on. The simulation results confirmed that the natural resonant modes of the electric system feeding the motor terminals can be excited by the harmonic voltages applied by the PWM inverter. The solution proposed by the vendor was the application of a damping low pass filter between the inverter and step-up transformer. The study verified that the proposed filter helps to reduce the voltage stressing of the motor winding isolation. Because another similar fan-drive application were at the setting-up, a direct measurement of the motor terminal voltages was agreed in order to verify the overvoltages generation and proper isolation coordination with the motor windings. The measurements, made with broad range frequency capacitive transducers and a high-voltage probe, confirmed the predictions given by the modeling and simulation study.

	Power Quality Impact on Thermal Behaviour and Life Expectancy of Three-Phase Induction Motors By O. C. Nascimento Souto; J. C. de Oliveira; L. M. Neto	[View] [Download]
Abstract: This paper deals with thermal behaviour analysis of three-phase induction motors under non ideal supply conditions. The motors are of squirrel cage type and the non ideal conditions are associated to harmonics, unbalances, voltage sag and swell, etc... The studies are carried out using a comprehensive methodology which handles electrical, mechanical and thermal models in a simultaneous way. The approach is then implemented into a time domain programme known as SABER simulator. Computational studies are then performed to evaluate motor temperature rise and life reduction under non ideal conditions.

	Shaft Voltages and Bearing Currents - New Phenomena in Inverter Driven Induction Machines By H.-J. Conraths; F. Gießler; H-D. Heining	[View] [Download]
Abstract: With the introduction of new, fast switching semiconductors (IGBT) in modern inverter technology some years ago, several authors reported an increase in premature motor bearing failure due to bearing currents. As a result, the problem of bearing currents and shaft voltages in inverter drives became of major interest in research and industrial application. A lot of theoretical and experimental examinations have been made to clear the problem, but many aspects are still under discussion. The present paper summarizes the theoretical background and shows numerous experimental results with lowand high-voltage ac drives. Some simulations show that the new phenomena relate to the design and configuration of the whole drive, not only of the motor itself. Actual measures against bearing currents and future strategies are summarized.

	Sine Wave Filter for PWM-Inverter Driven Solid-Rotor Induction Motors By J. Huppunen; J. Pyrhönen	[View] [Download]
Abstract: Inverter output harmonics create great amount of losses in a solid-rotor induction motor. An output filter for a PWM-inverter is introduced to smoothen the inverter output wave forms. The efficiency of the solid-rotor induction motor will increase remarkably. The filter is designed so that it also compensates the magnetising current of the motor, thus the poor power factor of the solid-rotor induction motor does not affect to inverter sizing. The EMC-matters, voltage stress in stator windings and bearing currents are also examined. This paper focuses on the filter component selection and the filter design. Measurements of a 12 kW, 13500 rpm prototype are given.

	Subsystem Interaction Analysis in Power Distribution Systems of Next Generation Airlifters By S. Chandrasekaran; D. K. Lindner; K. Louganski; D. Boroyevich	[View] [Download]
Abstract: Subsystem interaction in a simplified power distribution system of a next generation transport aircraft is addressed. Detailed analysis of interaction between an ElectroMechanical Actuator (EMA) connected to the DC bus of the power distribution system in a next generation transport aircraft with the bus regulator is presented. The classical impedance ration criterion is used to determine local stability arround an equilibrum point of each interface by observing the impedance characteristics of the source and load subsystems. Critical parameters that determine the local stability of the integrated system are identified. The loss of stability under large disturbances is presented to motivate the use of nonlinear stability analysis methods. Preliminary results of nonlinear stability analysis are presented.

	Transient Overvoltages at Inverter Fed Induction Motors By R. Nuscheler; D. Potoradi	[View] [Download]
Abstract: This paper deals with the problem of transient overvoltages at the motor terminals and their effects inside the stator winding. A simulation model based on equivalent circuits for the subsystems PWM inverter, feeding cable and induction motor which is valid for a wide frequency range is described. The simulation model is verified by comparing typical simulation results to measurements. Additional simulations with the verified model show the influence of cable length, pulse pattern and suppressor circuits on the overvoltages at the motor terminals and across the first coil group (double-coil) of the stator winding.