EPE Association: EPE 2014 - LS4c: Faults and Fault Tolerance

EPE 2014 - LS4c: Faults and Fault Tolerance
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2014 ECCE Europe - Conference > EPE 2014 - Topic 04: Electrical Machines and Drive Systems > EPE 2014 - LS4c: Faults and Fault Tolerance

   [return to parent folder]

   Analysis of rotor eddy current losses in slotless high-speed permanent magnet machines
By Sultan JUMAYEV [View]
[Download]

Abstract: Rotor eddy current losses are one of the main reasons of permanent magnet demagnetization in high-speed permanent magnet machines. In this paper the rotor eddy current losses of high-speed permanent magnet machines with different slotless windings have been analysed. The analysis of the losses was performed using 2D and 3D analytical models. In the study, test machines with different windings and the same torque production capability have been analysed. Presented paper shows the dependency of rotor eddy current losses on sine- and square-wave PWM supply voltages and rotor sleeve properties. Several recommendations for reduction of rotor eddy current losses in high-speed permanent magnet machines are given.

   Efficiently Modeling Rotor Eccentricity in Switched Relcutance Machines
By Andreas HOFMANN, Fang QI, Claude WEISS, Rik DE DONCKER [View]
[Download]

Abstract: Practical experience has shown that parasitic effects such as rotor eccentricity can have crucial influence on the performance of switched reluctance machines. Strong eccentricity can even be a knock-out criterion as it potentially causes additional acoustic noise and increased bearing wear. Nowadays only very few publications consider simulation methods without online finite-element analysis regarding the topic of rotor eccentricity. This paper develops a look-up table based representation of rotor eccentricity which uses time-consuming finite-element analysis only in a preprocessing step. Hence, different operating points can be calculated very fast. The standard models of centric machines were extended to cover static and rotating eccentricity. It was found that the type of coil connection determines whether a flux-based or a current-based model has to be applied. The simulation results show that coils which are connected in parallel are strongly preferable to a series-wound configuration. The parallel type greatly lowers the unbalanced magnetic pull such that acoustic noise and bearing wear is limited.

   Inductance Evaluation of Fractional Slot Permanent Magnet Synchronous Motors with non-overlapping Winding by Analytical Approaches
By Ilya PETROV, Pavel PONOMAREV, Sergey SHIRINSKII, Juha PYRHÖNEN [View]
[Download]

Abstract: Fractional slot permanent magnet synchronous machines with non-overlapping winding (FSPMSM) also known as tooth coil winding permanent synchronous machines (TCW PMSM) have gained intensive attention during the latest decade. Therefore, their design methods are constantly developed and improved. Numerical solution, i.e. finite element analysis (FEA), is still computationally heavy and time consuming, which makes it problematic to use this method in an optimization process. For this reason it is advantageous to use an analytical design method, for searching a design, which satisfies the needed characteristics of a PMSM, during the optimization process. Synchronous inductance is the major parameter of TCW PMSMs, which defines the overload capability of an electrical machine as well as its field weakening characteristics. Armature reaction, together with the permanent magnet flux linkage, specifies the voltage level, which is required for particular operating condition. Therefore, it is important to estimate this parameter as precisely as possible at early design stages. Low armature reaction should be favourable concerning the maximum reachable torque at the nominal speed. However, together with the reduction of the armature reaction, there is decrease of permanent magnet flux linkage, which is undesirable and in order to prevent it, the permanent magnet material amount must be increased.Here, the classical analytical approach of the inductance estimation is used, and a simple alternative to it is presented and evaluated. Also, a lumped model (LM) taking saturation into account has been created. The comparison and verification of the models are done by FEA and by the practical test setup of a 12-slot 10-pole TCW PMSM.

   Stimulating and detecting changes in the insulation health state of inverter fed ac machines
By Clemens ZOELLER, Markus VOGELSBERGER, Peter NUSSBAUMER, Thomas WOLBANK [View]
[Download]

Abstract: In modern traction drive applications condition monitoring is getting more and more important. Insulation health state monitoring can be done by evaluating the high frequency current response to voltage step excitation by the signal analyses of the current sensors, which are also used for the control of the machine. This reduces the costs and number of necessary system components. A change in the current response is, amongst others, correlated to a change through insulation degradation. The dominant influencing parameters of the high frequency current response of the machine are parasitic winding capacitances as well as insulation resistances, which are slowly changing over time if the insulation is deteriorated through different stresses, e.g. thermal or electrical. These slow changes can be monitored over long time period and give evidence if additional maintenance steps are required. Thus an unforeseeable outage of the traction drive system caused by damage of the machine can be prevented. Before the insulation state can be evaluated certain signal processing steps are necessary to increase the sensitivity. In this work the method of stimulation as well as detection of changes in the dominant parameters is verified on a 1.4MW induction machine.

EPE 2014 - LS4c: Faults and Fault Tolerance
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2014 ECCE Europe - Conference > EPE 2014 - Topic 04: Electrical Machines and Drive Systems > EPE 2014 - LS4c: Faults and Fault Tolerance
	[return to parent folder]

	Analysis of rotor eddy current losses in slotless high-speed permanent magnet machines By Sultan JUMAYEV	[View] [Download]
Abstract: Rotor eddy current losses are one of the main reasons of permanent magnet demagnetization in high-speed permanent magnet machines. In this paper the rotor eddy current losses of high-speed permanent magnet machines with different slotless windings have been analysed. The analysis of the losses was performed using 2D and 3D analytical models. In the study, test machines with different windings and the same torque production capability have been analysed. Presented paper shows the dependency of rotor eddy current losses on sine- and square-wave PWM supply voltages and rotor sleeve properties. Several recommendations for reduction of rotor eddy current losses in high-speed permanent magnet machines are given.

	Efficiently Modeling Rotor Eccentricity in Switched Relcutance Machines By Andreas HOFMANN, Fang QI, Claude WEISS, Rik DE DONCKER	[View] [Download]
Abstract: Practical experience has shown that parasitic effects such as rotor eccentricity can have crucial influence on the performance of switched reluctance machines. Strong eccentricity can even be a knock-out criterion as it potentially causes additional acoustic noise and increased bearing wear. Nowadays only very few publications consider simulation methods without online finite-element analysis regarding the topic of rotor eccentricity. This paper develops a look-up table based representation of rotor eccentricity which uses time-consuming finite-element analysis only in a preprocessing step. Hence, different operating points can be calculated very fast. The standard models of centric machines were extended to cover static and rotating eccentricity. It was found that the type of coil connection determines whether a flux-based or a current-based model has to be applied. The simulation results show that coils which are connected in parallel are strongly preferable to a series-wound configuration. The parallel type greatly lowers the unbalanced magnetic pull such that acoustic noise and bearing wear is limited.

	Inductance Evaluation of Fractional Slot Permanent Magnet Synchronous Motors with non-overlapping Winding by Analytical Approaches By Ilya PETROV, Pavel PONOMAREV, Sergey SHIRINSKII, Juha PYRHÖNEN	[View] [Download]
Abstract: Fractional slot permanent magnet synchronous machines with non-overlapping winding (FSPMSM) also known as tooth coil winding permanent synchronous machines (TCW PMSM) have gained intensive attention during the latest decade. Therefore, their design methods are constantly developed and improved. Numerical solution, i.e. finite element analysis (FEA), is still computationally heavy and time consuming, which makes it problematic to use this method in an optimization process. For this reason it is advantageous to use an analytical design method, for searching a design, which satisfies the needed characteristics of a PMSM, during the optimization process. Synchronous inductance is the major parameter of TCW PMSMs, which defines the overload capability of an electrical machine as well as its field weakening characteristics. Armature reaction, together with the permanent magnet flux linkage, specifies the voltage level, which is required for particular operating condition. Therefore, it is important to estimate this parameter as precisely as possible at early design stages. Low armature reaction should be favourable concerning the maximum reachable torque at the nominal speed. However, together with the reduction of the armature reaction, there is decrease of permanent magnet flux linkage, which is undesirable and in order to prevent it, the permanent magnet material amount must be increased.Here, the classical analytical approach of the inductance estimation is used, and a simple alternative to it is presented and evaluated. Also, a lumped model (LM) taking saturation into account has been created. The comparison and verification of the models are done by FEA and by the practical test setup of a 12-slot 10-pole TCW PMSM.

	Stimulating and detecting changes in the insulation health state of inverter fed ac machines By Clemens ZOELLER, Markus VOGELSBERGER, Peter NUSSBAUMER, Thomas WOLBANK	[View] [Download]
Abstract: In modern traction drive applications condition monitoring is getting more and more important. Insulation health state monitoring can be done by evaluating the high frequency current response to voltage step excitation by the signal analyses of the current sensors, which are also used for the control of the machine. This reduces the costs and number of necessary system components. A change in the current response is, amongst others, correlated to a change through insulation degradation. The dominant influencing parameters of the high frequency current response of the machine are parasitic winding capacitances as well as insulation resistances, which are slowly changing over time if the insulation is deteriorated through different stresses, e.g. thermal or electrical. These slow changes can be monitored over long time period and give evidence if additional maintenance steps are required. Thus an unforeseeable outage of the traction drive system caused by damage of the machine can be prevented. Before the insulation state can be evaluated certain signal processing steps are necessary to increase the sensitivity. In this work the method of stimulation as well as detection of changes in the dominant parameters is verified on a 1.4MW induction machine.