2019 IEEE International Electric Machines & Drives Conference (IEMDC)
There is only a single practical method to determine the losses of converted-fed electrical machi... more There is only a single practical method to determine the losses of converted-fed electrical machines. The method is based on mechanical output and electrical input power measurements. When this method is used, the loss measurement uncertainty is a function of the efficiency. The electrical motor efficiency increases non-linearly with increasing rated power. Therefore, the higher the rated power of the motor is the more care should be laid in the analysis of the efficiency measurement results. Here, a workflow starting from measurement instruments' data sheet information to final measurement uncertainty result is presented for three converted-fed induction motors with different rated power of 15 kW, 37 kW and 75 kW. The results are applicable for all rotating field machines regardless of technology.
2018 XIII International Conference on Electrical Machines (ICEM), 2018
This paper describes a typical engineering procedure to analyze the energy efficiency of the desi... more This paper describes a typical engineering procedure to analyze the energy efficiency of the designed induction motor. 2D FEM is used to obtain 5 kW induction motor losses. The analysis is performed at four different stator frequencies. The effect of the stator and rotor end regions are taken into account by circuit elements. The values of the parameters to model the end effects are first calculated analytically and later used as parameters in the analysis. The simulated loss components are compared with the ones obtained with IEC segregation of losses method at each supply frequency. Special interest is paid to iron losses. According to simulations and measurements, the utilized IEC loss segregation method gives consistent results.
IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society, 2017
Permanent magnet track linear motor drives offer a cost-effective motion control solution in nume... more Permanent magnet track linear motor drives offer a cost-effective motion control solution in numerous industrial manufacturing processes, covering a wide range of material handling and conveyor applications. To further reduce the initial costs of a permanent magnet track linear motor drive system, discontinuous magnet tracks can be considered. However, in a discontinuous magnet track, the armature has to face regions with and without permanent magnets, thereby resulting in edge crossings, where the armature is only partly overlapping with the permanent magnets. As a result, both the cogging force and electromechanical forces cause high disturbances at the edge crossings, having a major impact on the performance of the motion controllers. In this paper, disturbances of a nonsalient permanent magnet linear motor with a discontinuous magnet track are studied. An experimental test setup for the estimation of disturbance forces at the edge is presented. The behavior of the estimated disturbance forces at the edge crossings is also evaluated by a FEM model and compared with the experimental results.
2018 XIII International Conference on Electrical Machines (ICEM), 2018
The major loss components of the induction motor; stator copper losses, rotor copper losses, iron... more The major loss components of the induction motor; stator copper losses, rotor copper losses, iron losses, mechanical losses and additional load losses are presented here as a function of the rated power and international efficiency (IE) classification. The loss components are determined following the guidelines given in IEC 60034-2-1 based on data available in the test reports of the manufacturer and the performance is analyzed using catalog values. An updated, more realistic distribution of modern induction motor loss components is presented.
2017 19th European Conference on Power Electronics and Applications (EPE'17 ECCE Europe), 2017
Considering the effect of current and voltage frequency content in the power-hardware-in-loop (PH... more Considering the effect of current and voltage frequency content in the power-hardware-in-loop (PHIL) simulation of water electrolyzers is studied as the AC components may cause additional losses in the electrolyzer stack. A transistor based power supply is used to excite DC current with selected AC components for an alkaline electrolyzer and a PHIL simulator. The practical current and voltage waveforms are analyzed, and the possibilities to take the power quality aspects in consideration in the PHIL simulation is discussed.
2018 20th European Conference on Power Electronics and Applications (EPE'18 ECCE Europe), 2018
Hydrogen production is energy intensive, and hence, the efficiency of the process is essential. P... more Hydrogen production is energy intensive, and hence, the efficiency of the process is essential. Power electronics play an important role in energy efficiency of water electrolyzers. In general, the research requires real devices and handling of hydrogen. On the other hand, the water electrolyzer stack can be replaced by a power hardware-in-the-loop (PHIL) emulator that includes the same electrical characteristics as the real one. However, water electrolyzers are dynamic devices, and hence, the PHIL emulator should be able to realize the same bandwidth. Dynamics are important when studying DC power quality effects on water electrolyzers. The switching phenomena that can be seen after the utilized rectification are up to several kHz in frequency. This paper examines a dynamic PHIL test system for the purpose of emulation of water electrolyzers.
2017 IEEE 11th International Symposium on Diagnostics for Electrical Machines, Power Electronics and Drives (SDEMPED), 2017
Frequency-domain identification and parameter estimation methods are well established and commonl... more Frequency-domain identification and parameter estimation methods are well established and commonly applied for commissioning and diagnostics purposes in electric drives. In this paper, the feasibility of a recursive least squares parameter estimation algorithm from frequency-domain observations is studied. The identification problem is treated from two different perspectives: first, by estimating a discrete autoregressive model with exogenous terms (ARX) from the discrete Fourier transforms (DFTs) of the input-output signals obtained from the identification experiment and second, a nonparametric model that is fitted in terms of least squares regression. Both proposed identification approaches are studied by simulations and experimentally validated by a closed-loop-controlled servomechanism.
2018 XIII International Conference on Electrical Machines (ICEM), 2018
Direct-on-line motors are in the majority despite that an increasing number of new motor installa... more Direct-on-line motors are in the majority despite that an increasing number of new motor installations are equipped with frequency converter. However, regulations and environmental awareness are pushing the efficiency demands, and the dominant induction motor technology is approaching its practical efficiency limits. Direct-on-line synchronous reluctance motor technology provides an alternative to the induction motor technology with the capability to reach higher efficiency levels especially in low power range. This paper presents efficiency verification measurements using calorimetric method for two 45 kW direct-on-line synchronous reluctance motor prototypes. The results are compared with high-efficiency induction motors available in the market.
2018 20th European Conference on Power Electronics and Applications (EPE'18 ECCE Europe), 2018
Determination of losses accurately is challenging for today's high-efficiency power electroni... more Determination of losses accurately is challenging for today's high-efficiency power electronics and motors. Due to the limitations of the typically used input-output method, other loss measurement methods have been designed. Here, the efficiency of a direct-on-line induction motor prototype is determined using the IEC loss segregation method, the input-output method, and with a balance type calorimeter. The calorimetric results are further analyzed with the help of a mass flow meter that is used to verify the loss results obtained using the balance test.
2018 20th European Conference on Power Electronics and Applications (EPE'18 ECCE Europe), 2018
Water electrolysis may become a major application for power electronics, since hydrogen is a key ... more Water electrolysis may become a major application for power electronics, since hydrogen is a key element for energy storage, renewable hydrocarbons, fuels, and chemicals. Electrolyzers require DC power and their operation depends on electric conditioning. Electrolyzers typically operate at relatively low voltages and high currents, which can be challenging for power electronics. This paper studies the efficiency of alkaline water electrolysis and improvement of electrolyzers from the viewpoint of power electronics.
2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe), 2020
More and more commonly, the rotating field machine drives are equipped with a frequency converter... more More and more commonly, the rotating field machine drives are equipped with a frequency converter. The frequency converters enable the control of the magnetization state, torque and speed of the machine according to the needs of applications and, in principle, save energy. In turn, the pulse-width-modulation (PWM) creates additional harmonic losses over the fundamental losses in the machine. The harmonic power induced by the PWM is examined here in a case of 75 kW high efficiency squirrel-cage induction motor. The examination is carried out using an experimental setup with three commercial frequency converters at 30 different operation points of the motor. In each of the measurement points, the three-phase voltage and current waveforms are recorded as well as the corresponding electric power, current and voltage values. In the analysis, the harmonic power is segregated from the total electric power and examined as a function of the frequency, load and switching frequency.
2021 XVIII International Scientific Technical Conference Alternating Current Electric Drives (ACED), 2021
Pulse-width-modulated (PWM) voltage source inverters (VSI) are a common way to drive induction mo... more Pulse-width-modulated (PWM) voltage source inverters (VSI) are a common way to drive induction motors in variable speed applications. As switching hardware improves, motors are driven with increasing switching frequencies, extending the frequency range of PWM harmonics. Discrete Fourier Transform (DFT) can be used to analyze the differences in the active power spectrum as switching frequency is changed. This paper covers the basic methodology on DFT-based analysis of input power measurements. Analysis on the input active power spectrum of a PWM VSI driven 5-kW induction motor is conducted at different switching frequencies.
IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society, 2017
Electric motors play an important role in global efforts to reduce energy consumption as they acc... more Electric motors play an important role in global efforts to reduce energy consumption as they account for almost half of the total electrical energy usage in the world. The energy consumption of electric motors can be reduced by using more efficient motors and by applying frequency converters to feed the motors, thereby enabling accurate control according to the load. The induction motor has been — and still is — the dominant motor technology in the industry, but also more efficient motor technologies are available in the market. Considering industrial motors, the two most important competing technologies are probably permanent magnet synchronous motors and synchronous reluctance motors. This papers provides a comparison between the induction motor and synchronous reluctance motor technologies. The main differences between the two are covered and measurements are made with a frequency converter supply to compare the efficiencies over a wide operating range of 10–100% of rated torque and 10–140% of rated operating frequency.
IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society, 2016
Modular hardware-in-loop emulator for water electrolysers is developed to study the different ele... more Modular hardware-in-loop emulator for water electrolysers is developed to study the different electrolyser power supply electronics as well as the electrolyser, for example, as an adjustable load together with renewable electricity production or frequency control. An emulator up to 405 A of continuous current is built using commercially available power electronic converters. The design and the operating principle of the emulator are discussed. The experimental tests of emulator modules are reported.
2019 IEEE International Electric Machines & Drives Conference (IEMDC)
There is only a single practical method to determine the losses of converted-fed electrical machi... more There is only a single practical method to determine the losses of converted-fed electrical machines. The method is based on mechanical output and electrical input power measurements. When this method is used, the loss measurement uncertainty is a function of the efficiency. The electrical motor efficiency increases non-linearly with increasing rated power. Therefore, the higher the rated power of the motor is the more care should be laid in the analysis of the efficiency measurement results. Here, a workflow starting from measurement instruments' data sheet information to final measurement uncertainty result is presented for three converted-fed induction motors with different rated power of 15 kW, 37 kW and 75 kW. The results are applicable for all rotating field machines regardless of technology.
2018 XIII International Conference on Electrical Machines (ICEM), 2018
This paper describes a typical engineering procedure to analyze the energy efficiency of the desi... more This paper describes a typical engineering procedure to analyze the energy efficiency of the designed induction motor. 2D FEM is used to obtain 5 kW induction motor losses. The analysis is performed at four different stator frequencies. The effect of the stator and rotor end regions are taken into account by circuit elements. The values of the parameters to model the end effects are first calculated analytically and later used as parameters in the analysis. The simulated loss components are compared with the ones obtained with IEC segregation of losses method at each supply frequency. Special interest is paid to iron losses. According to simulations and measurements, the utilized IEC loss segregation method gives consistent results.
IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society, 2017
Permanent magnet track linear motor drives offer a cost-effective motion control solution in nume... more Permanent magnet track linear motor drives offer a cost-effective motion control solution in numerous industrial manufacturing processes, covering a wide range of material handling and conveyor applications. To further reduce the initial costs of a permanent magnet track linear motor drive system, discontinuous magnet tracks can be considered. However, in a discontinuous magnet track, the armature has to face regions with and without permanent magnets, thereby resulting in edge crossings, where the armature is only partly overlapping with the permanent magnets. As a result, both the cogging force and electromechanical forces cause high disturbances at the edge crossings, having a major impact on the performance of the motion controllers. In this paper, disturbances of a nonsalient permanent magnet linear motor with a discontinuous magnet track are studied. An experimental test setup for the estimation of disturbance forces at the edge is presented. The behavior of the estimated disturbance forces at the edge crossings is also evaluated by a FEM model and compared with the experimental results.
2018 XIII International Conference on Electrical Machines (ICEM), 2018
The major loss components of the induction motor; stator copper losses, rotor copper losses, iron... more The major loss components of the induction motor; stator copper losses, rotor copper losses, iron losses, mechanical losses and additional load losses are presented here as a function of the rated power and international efficiency (IE) classification. The loss components are determined following the guidelines given in IEC 60034-2-1 based on data available in the test reports of the manufacturer and the performance is analyzed using catalog values. An updated, more realistic distribution of modern induction motor loss components is presented.
2017 19th European Conference on Power Electronics and Applications (EPE'17 ECCE Europe), 2017
Considering the effect of current and voltage frequency content in the power-hardware-in-loop (PH... more Considering the effect of current and voltage frequency content in the power-hardware-in-loop (PHIL) simulation of water electrolyzers is studied as the AC components may cause additional losses in the electrolyzer stack. A transistor based power supply is used to excite DC current with selected AC components for an alkaline electrolyzer and a PHIL simulator. The practical current and voltage waveforms are analyzed, and the possibilities to take the power quality aspects in consideration in the PHIL simulation is discussed.
2018 20th European Conference on Power Electronics and Applications (EPE'18 ECCE Europe), 2018
Hydrogen production is energy intensive, and hence, the efficiency of the process is essential. P... more Hydrogen production is energy intensive, and hence, the efficiency of the process is essential. Power electronics play an important role in energy efficiency of water electrolyzers. In general, the research requires real devices and handling of hydrogen. On the other hand, the water electrolyzer stack can be replaced by a power hardware-in-the-loop (PHIL) emulator that includes the same electrical characteristics as the real one. However, water electrolyzers are dynamic devices, and hence, the PHIL emulator should be able to realize the same bandwidth. Dynamics are important when studying DC power quality effects on water electrolyzers. The switching phenomena that can be seen after the utilized rectification are up to several kHz in frequency. This paper examines a dynamic PHIL test system for the purpose of emulation of water electrolyzers.
2017 IEEE 11th International Symposium on Diagnostics for Electrical Machines, Power Electronics and Drives (SDEMPED), 2017
Frequency-domain identification and parameter estimation methods are well established and commonl... more Frequency-domain identification and parameter estimation methods are well established and commonly applied for commissioning and diagnostics purposes in electric drives. In this paper, the feasibility of a recursive least squares parameter estimation algorithm from frequency-domain observations is studied. The identification problem is treated from two different perspectives: first, by estimating a discrete autoregressive model with exogenous terms (ARX) from the discrete Fourier transforms (DFTs) of the input-output signals obtained from the identification experiment and second, a nonparametric model that is fitted in terms of least squares regression. Both proposed identification approaches are studied by simulations and experimentally validated by a closed-loop-controlled servomechanism.
2018 XIII International Conference on Electrical Machines (ICEM), 2018
Direct-on-line motors are in the majority despite that an increasing number of new motor installa... more Direct-on-line motors are in the majority despite that an increasing number of new motor installations are equipped with frequency converter. However, regulations and environmental awareness are pushing the efficiency demands, and the dominant induction motor technology is approaching its practical efficiency limits. Direct-on-line synchronous reluctance motor technology provides an alternative to the induction motor technology with the capability to reach higher efficiency levels especially in low power range. This paper presents efficiency verification measurements using calorimetric method for two 45 kW direct-on-line synchronous reluctance motor prototypes. The results are compared with high-efficiency induction motors available in the market.
2018 20th European Conference on Power Electronics and Applications (EPE'18 ECCE Europe), 2018
Determination of losses accurately is challenging for today's high-efficiency power electroni... more Determination of losses accurately is challenging for today's high-efficiency power electronics and motors. Due to the limitations of the typically used input-output method, other loss measurement methods have been designed. Here, the efficiency of a direct-on-line induction motor prototype is determined using the IEC loss segregation method, the input-output method, and with a balance type calorimeter. The calorimetric results are further analyzed with the help of a mass flow meter that is used to verify the loss results obtained using the balance test.
2018 20th European Conference on Power Electronics and Applications (EPE'18 ECCE Europe), 2018
Water electrolysis may become a major application for power electronics, since hydrogen is a key ... more Water electrolysis may become a major application for power electronics, since hydrogen is a key element for energy storage, renewable hydrocarbons, fuels, and chemicals. Electrolyzers require DC power and their operation depends on electric conditioning. Electrolyzers typically operate at relatively low voltages and high currents, which can be challenging for power electronics. This paper studies the efficiency of alkaline water electrolysis and improvement of electrolyzers from the viewpoint of power electronics.
2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe), 2020
More and more commonly, the rotating field machine drives are equipped with a frequency converter... more More and more commonly, the rotating field machine drives are equipped with a frequency converter. The frequency converters enable the control of the magnetization state, torque and speed of the machine according to the needs of applications and, in principle, save energy. In turn, the pulse-width-modulation (PWM) creates additional harmonic losses over the fundamental losses in the machine. The harmonic power induced by the PWM is examined here in a case of 75 kW high efficiency squirrel-cage induction motor. The examination is carried out using an experimental setup with three commercial frequency converters at 30 different operation points of the motor. In each of the measurement points, the three-phase voltage and current waveforms are recorded as well as the corresponding electric power, current and voltage values. In the analysis, the harmonic power is segregated from the total electric power and examined as a function of the frequency, load and switching frequency.
2021 XVIII International Scientific Technical Conference Alternating Current Electric Drives (ACED), 2021
Pulse-width-modulated (PWM) voltage source inverters (VSI) are a common way to drive induction mo... more Pulse-width-modulated (PWM) voltage source inverters (VSI) are a common way to drive induction motors in variable speed applications. As switching hardware improves, motors are driven with increasing switching frequencies, extending the frequency range of PWM harmonics. Discrete Fourier Transform (DFT) can be used to analyze the differences in the active power spectrum as switching frequency is changed. This paper covers the basic methodology on DFT-based analysis of input power measurements. Analysis on the input active power spectrum of a PWM VSI driven 5-kW induction motor is conducted at different switching frequencies.
IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society, 2017
Electric motors play an important role in global efforts to reduce energy consumption as they acc... more Electric motors play an important role in global efforts to reduce energy consumption as they account for almost half of the total electrical energy usage in the world. The energy consumption of electric motors can be reduced by using more efficient motors and by applying frequency converters to feed the motors, thereby enabling accurate control according to the load. The induction motor has been — and still is — the dominant motor technology in the industry, but also more efficient motor technologies are available in the market. Considering industrial motors, the two most important competing technologies are probably permanent magnet synchronous motors and synchronous reluctance motors. This papers provides a comparison between the induction motor and synchronous reluctance motor technologies. The main differences between the two are covered and measurements are made with a frequency converter supply to compare the efficiencies over a wide operating range of 10–100% of rated torque and 10–140% of rated operating frequency.
IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society, 2016
Modular hardware-in-loop emulator for water electrolysers is developed to study the different ele... more Modular hardware-in-loop emulator for water electrolysers is developed to study the different electrolyser power supply electronics as well as the electrolyser, for example, as an adjustable load together with renewable electricity production or frequency control. An emulator up to 405 A of continuous current is built using commercially available power electronic converters. The design and the operating principle of the emulator are discussed. The experimental tests of emulator modules are reported.
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