Pub Date : 2023-05-01DOI: 10.1541/ieejjia.22006373
Ryuji Yamada, Akihiro Hino, Keiji Wada
A prototype bidirectional isolated DC-DC converter with an output of 3.6 kW, using GaN-HEMTs, employing a planar transformer and operating at a maximum frequency of 400 kHz, was developed and evaluated. Typical circuits for bidirectional isolated DC-DC converters are the LLC resonant converter and the dual active bridge (DAB), both of which have the disadvantage of low efficiency at light loads. In this paper, GaN-HEMTs were used as a rectifier device to reduce DAB losses with natural commutation under light loads, utilizing their no reverse recovery loss characteristics. Zero-voltage switching was achieved using the transformer excitation current as a lagging phase current on the input side. As a result of the efficiency comparison between the LLC resonant converter and DAB under the same components and input/output conditions, higher efficiency was obtained in DAB under most conditions. The maximum efficiency was 98.6%.
{"title":"Improvement of Efficiency in Bidirectional DC-DC Converter with Dual Active Bridge Using GaN-HEMT","authors":"Ryuji Yamada, Akihiro Hino, Keiji Wada","doi":"10.1541/ieejjia.22006373","DOIUrl":"https://doi.org/10.1541/ieejjia.22006373","url":null,"abstract":"A prototype bidirectional isolated DC-DC converter with an output of 3.6 kW, using GaN-HEMTs, employing a planar transformer and operating at a maximum frequency of 400 kHz, was developed and evaluated. Typical circuits for bidirectional isolated DC-DC converters are the LLC resonant converter and the dual active bridge (DAB), both of which have the disadvantage of low efficiency at light loads. In this paper, GaN-HEMTs were used as a rectifier device to reduce DAB losses with natural commutation under light loads, utilizing their no reverse recovery loss characteristics. Zero-voltage switching was achieved using the transformer excitation current as a lagging phase current on the input side. As a result of the efficiency comparison between the LLC resonant converter and DAB under the same components and input/output conditions, higher efficiency was obtained in DAB under most conditions. The maximum efficiency was 98.6%.","PeriodicalId":45552,"journal":{"name":"IEEJ Journal of Industry Applications","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135504402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1541/ieejjia.22007740
Keigo Arita, Yusuke Hayashi, Kazuto Takao
A capacitively coupled modular DC-DC power electronic transformer (DCPET) has been proposed. The proposed DCPET consists of capacitively coupled unregulated LLC resonant converter modules; these modules are connected in series-parallel combinations. The capacitive coupling topology is considered to be promising to develop highly efficient high-power-density converter modules, and the series-parallel connection of these modules smoothly achieves various voltage ratios of DCPETs. A trial design for a 48 V-48 V, 450 W capacitively coupled LLC converter module using GaN-FETs has been demonstrated, and the potential to achieve 99%, 15 W/cm3 has been confirmed. Moreover, the 48 V-384 V DCPET using eight 98.8%, 15 W/cm3 converter modules has been demonstrated, and the feasibility of the proposed topology has been verified. The proposed DCPET overcomes the stagnant relationship between the efficiency and the output power density of isolated converters, and the proposed topology contributes to the prevalence of power electronics equipment for the economical use of electric power.
{"title":"99%, 15W/cm<sup>3</sup> Capacitively Coupled Modular DCPET for Low-Voltage DC Power Supply Systems","authors":"Keigo Arita, Yusuke Hayashi, Kazuto Takao","doi":"10.1541/ieejjia.22007740","DOIUrl":"https://doi.org/10.1541/ieejjia.22007740","url":null,"abstract":"A capacitively coupled modular DC-DC power electronic transformer (DCPET) has been proposed. The proposed DCPET consists of capacitively coupled unregulated LLC resonant converter modules; these modules are connected in series-parallel combinations. The capacitive coupling topology is considered to be promising to develop highly efficient high-power-density converter modules, and the series-parallel connection of these modules smoothly achieves various voltage ratios of DCPETs. A trial design for a 48 V-48 V, 450 W capacitively coupled LLC converter module using GaN-FETs has been demonstrated, and the potential to achieve 99%, 15 W/cm3 has been confirmed. Moreover, the 48 V-384 V DCPET using eight 98.8%, 15 W/cm3 converter modules has been demonstrated, and the feasibility of the proposed topology has been verified. The proposed DCPET overcomes the stagnant relationship between the efficiency and the output power density of isolated converters, and the proposed topology contributes to the prevalence of power electronics equipment for the economical use of electric power.","PeriodicalId":45552,"journal":{"name":"IEEJ Journal of Industry Applications","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135752374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A control method for electric vehicle (EV) of a dual inverter system with one battery is proposed. The conventional dual inverter system consists of an open-end winding motor and two inverters, and each inverter is powered by an independent battery. In the case of a battery failure, it can be operated as a multi-level inverter by controlling the voltage of the smoothing capacitor on the failure side to half of the battery voltage, and improvement in system efficiency can be expected. However, it is difficult to maintain the capacitor voltage at half of the battery voltage across the entire operating region of the EV. Therefore, a control method that switches between single inverter operation and dual inverter operation according to the operating conditions, and respond to changes in the capacitor voltage during operation switching is developed. The developed control scheme is demonstrated by hardware in-loop simulation and an experimental vehicle.
{"title":"Control Method of Dual Inverter System for EV with One Battery","authors":"Tomonori Kimura, Takahiro Yamada, Ryoya Kazaoka, Toshihiko Noguchi","doi":"10.1541/ieejjia.22007660","DOIUrl":"https://doi.org/10.1541/ieejjia.22007660","url":null,"abstract":"A control method for electric vehicle (EV) of a dual inverter system with one battery is proposed. The conventional dual inverter system consists of an open-end winding motor and two inverters, and each inverter is powered by an independent battery. In the case of a battery failure, it can be operated as a multi-level inverter by controlling the voltage of the smoothing capacitor on the failure side to half of the battery voltage, and improvement in system efficiency can be expected. However, it is difficult to maintain the capacitor voltage at half of the battery voltage across the entire operating region of the EV. Therefore, a control method that switches between single inverter operation and dual inverter operation according to the operating conditions, and respond to changes in the capacitor voltage during operation switching is developed. The developed control scheme is demonstrated by hardware in-loop simulation and an experimental vehicle.","PeriodicalId":45552,"journal":{"name":"IEEJ Journal of Industry Applications","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135752365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Operation delay of DC circuit breakers causes a voltage sag of several milliseconds in high-voltage DC (HVDC) grids. The DC voltage sag can cause an overcurrent in the DC side of the modular multilevel converter (MMC), resulting in halting the MMC. This study investigates a method to facilitate continuous operation of the half-bridge MMC during a DC voltage sag. The proposed method performs feedback control of the DC current during DC voltage sags by decreasing the DC and AC voltages of the half-bridge MMC. When the method is applied to symmetrical monopole HVDC systems, the MMC can maintain both its DC and AC currents within the rated range during the voltage sag caused by pole-to-ground faults. Simulation results obtained by a three-terminal HVDC grid verify the DC fault ride-through capability of the half-bridge MMC.
{"title":"DC Fault Ride-Through Control of Half-Bridge MMCs for the HVDC Grid with DC Circuit Breakers","authors":"Atsushi Chiba, Kenichiro Sano, Yushi Koyama, Kei Sekiguchi, Takahiro Ishiguro, Daichi Suzuki","doi":"10.1541/ieejjia.22006950","DOIUrl":"https://doi.org/10.1541/ieejjia.22006950","url":null,"abstract":"Operation delay of DC circuit breakers causes a voltage sag of several milliseconds in high-voltage DC (HVDC) grids. The DC voltage sag can cause an overcurrent in the DC side of the modular multilevel converter (MMC), resulting in halting the MMC. This study investigates a method to facilitate continuous operation of the half-bridge MMC during a DC voltage sag. The proposed method performs feedback control of the DC current during DC voltage sags by decreasing the DC and AC voltages of the half-bridge MMC. When the method is applied to symmetrical monopole HVDC systems, the MMC can maintain both its DC and AC currents within the rated range during the voltage sag caused by pole-to-ground faults. Simulation results obtained by a three-terminal HVDC grid verify the DC fault ride-through capability of the half-bridge MMC.","PeriodicalId":45552,"journal":{"name":"IEEJ Journal of Industry Applications","volume":"60 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135752373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1541/ieejjia.22007943
Sayuri Honda, Shuhei Shimada, Kosuke Tanaka, Kana Nakamura, Takehiro Imura, Katsuhiro Hata, Yoichi Hori
As a new space station succeeding the International Space Station (ISS), a lunar orbit manned base, called “Gateway,” is considered and manned lunar surface exploration via the Gateway is also studied. To realize manned lunar surface exploration, new technologies are required to overcome the severe condition of the lunar night. As one of these technologies, applying wireless power transfer (WPT) to a spacecraft, such as a rover, is proposed. The WPT system contributes to the improvement of heat insulation performance and is ideal for reducing the weight of the battery of the spacecraft. In addition, magnetic transmissive multi-layer insulation (MT-MLI) is developed to suppress the generation of eddy currents. In WPT experiments with MT-MLI, the power transmission efficiency between coils is 90 % or more. Furthermore, thermal vacuum tests demonstrate that the combination of WPT and MT-MLI reduces thermal leakage.
{"title":"Proposal and Evaluation of High-Heat Insulation System for Spacecraft by Using WPT","authors":"Sayuri Honda, Shuhei Shimada, Kosuke Tanaka, Kana Nakamura, Takehiro Imura, Katsuhiro Hata, Yoichi Hori","doi":"10.1541/ieejjia.22007943","DOIUrl":"https://doi.org/10.1541/ieejjia.22007943","url":null,"abstract":"As a new space station succeeding the International Space Station (ISS), a lunar orbit manned base, called “Gateway,” is considered and manned lunar surface exploration via the Gateway is also studied. To realize manned lunar surface exploration, new technologies are required to overcome the severe condition of the lunar night. As one of these technologies, applying wireless power transfer (WPT) to a spacecraft, such as a rover, is proposed. The WPT system contributes to the improvement of heat insulation performance and is ideal for reducing the weight of the battery of the spacecraft. In addition, magnetic transmissive multi-layer insulation (MT-MLI) is developed to suppress the generation of eddy currents. In WPT experiments with MT-MLI, the power transmission efficiency between coils is 90 % or more. Furthermore, thermal vacuum tests demonstrate that the combination of WPT and MT-MLI reduces thermal leakage.","PeriodicalId":45552,"journal":{"name":"IEEJ Journal of Industry Applications","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135801480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1541/ieejjia.22007760
Kodai Okazaki, Kan Yang, Kan Akatsu
Permanent magnet synchronous motors (PMSMs) are widely utilized for many purposes owing to their high efficiency. Such frequent applications require less noise and fewer vibrations. This work focuses on multi-three-phase PMSMs that can independently control the current among winding groups to suppress the vibrations caused by air gap imbalances, which must be detected for suppression control. The representative effects of air gap imbalance include static and dynamic eccentricities. Dynamic eccentricity varies the air gap length in time; therefore, the instantaneous detection of the air gap length condition is necessary for suppression control. We propose a method that instantaneously detects dynamic eccentricity using the fundamental and fourth-order harmonic components of no-load line-line voltages, which are easily measurable in practical manufacturing processes. The proposed real-time detection method is applied to a finite element analysis (FEA) model with dynamic eccentricity, and confirm its detection ability is confirmed experimentally.
{"title":"Real-time Dynamic Eccentricity Detection by Analyzing Harmonic Components of No-load Line-line Voltages in Multi-three-phase PMSMs","authors":"Kodai Okazaki, Kan Yang, Kan Akatsu","doi":"10.1541/ieejjia.22007760","DOIUrl":"https://doi.org/10.1541/ieejjia.22007760","url":null,"abstract":"Permanent magnet synchronous motors (PMSMs) are widely utilized for many purposes owing to their high efficiency. Such frequent applications require less noise and fewer vibrations. This work focuses on multi-three-phase PMSMs that can independently control the current among winding groups to suppress the vibrations caused by air gap imbalances, which must be detected for suppression control. The representative effects of air gap imbalance include static and dynamic eccentricities. Dynamic eccentricity varies the air gap length in time; therefore, the instantaneous detection of the air gap length condition is necessary for suppression control. We propose a method that instantaneously detects dynamic eccentricity using the fundamental and fourth-order harmonic components of no-load line-line voltages, which are easily measurable in practical manufacturing processes. The proposed real-time detection method is applied to a finite element analysis (FEA) model with dynamic eccentricity, and confirm its detection ability is confirmed experimentally.","PeriodicalId":45552,"journal":{"name":"IEEJ Journal of Industry Applications","volume":"4 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135753425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1541/ieejjia.22008056
Tatsuo Nishimura, Koji Nishizawa, Yoshihiro Miyama, Hideaki Arita
In this paper we propose a compact magnetic rotation angle sensor which comprises a permanent magnet, Hall-effect sensors, and partial arc-shaped stator located in a large-diameter traction motor to reduce the size and weight of automotive vehicles. The proposed rotation angle sensor removes a specific harmonic component of the leakage flux from the electric motor by converting the signal from three-phase to two-phase using three Hall-effect sensors. The design concept of the rotation angle and its magnetic design results are shown in this study. A prototype of the proposed rotation angle sensor was created and its weight, size, and magnetic performances were measured. The measurement results achieved a 38 and 33 % weight and volume reduction, respectively, compared with a conventional variable reluctance resolver. Furthermore, the experimental results demonstrated that the angle position of the motor can be detected in line with the electromagnetic design and target of the angle error.
{"title":"Light-Weight and Compact Magnetic Rotation Angle Sensor with Partial Arc Stator Using Three Hall-Effect Sensors","authors":"Tatsuo Nishimura, Koji Nishizawa, Yoshihiro Miyama, Hideaki Arita","doi":"10.1541/ieejjia.22008056","DOIUrl":"https://doi.org/10.1541/ieejjia.22008056","url":null,"abstract":"In this paper we propose a compact magnetic rotation angle sensor which comprises a permanent magnet, Hall-effect sensors, and partial arc-shaped stator located in a large-diameter traction motor to reduce the size and weight of automotive vehicles. The proposed rotation angle sensor removes a specific harmonic component of the leakage flux from the electric motor by converting the signal from three-phase to two-phase using three Hall-effect sensors. The design concept of the rotation angle and its magnetic design results are shown in this study. A prototype of the proposed rotation angle sensor was created and its weight, size, and magnetic performances were measured. The measurement results achieved a 38 and 33 % weight and volume reduction, respectively, compared with a conventional variable reluctance resolver. Furthermore, the experimental results demonstrated that the angle position of the motor can be detected in line with the electromagnetic design and target of the angle error.","PeriodicalId":45552,"journal":{"name":"IEEJ Journal of Industry Applications","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135752366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1541/ieejjia.22007910
Koji Orikawa, Shogo Nishikawa, Satoshi Ogasawara
This paper proposes a load test method for high-frequency transformers using two power supplies. In this method, the two power supplies need to supply only the power losses of the transformer because the power is circulated between the primary and secondary sides. Hence, this load test can be performed on high-frequency transformers with capacity higher than that of the power supply without requiring a high-frequency load. The experimental results show that the load test method can be applied to a transformer under a 100 kHz sinusoidal voltage/current using two power supplies with a capacity of 50 VA/unit, which is much smaller than the rated capacity of the transformer, i.e., 900 VA. Furthermore, the load test can be performed at all power factors from 0 to 1. In addition, the experimental results show that using the proposed method, the accuracy of power loss measurement is improved compared with the existing method that obtains the power loss by subtracting the output power from the input power of the transformer.
{"title":"Load Test Method Using Two Power Supplies for High-Frequency Transformers","authors":"Koji Orikawa, Shogo Nishikawa, Satoshi Ogasawara","doi":"10.1541/ieejjia.22007910","DOIUrl":"https://doi.org/10.1541/ieejjia.22007910","url":null,"abstract":"This paper proposes a load test method for high-frequency transformers using two power supplies. In this method, the two power supplies need to supply only the power losses of the transformer because the power is circulated between the primary and secondary sides. Hence, this load test can be performed on high-frequency transformers with capacity higher than that of the power supply without requiring a high-frequency load. The experimental results show that the load test method can be applied to a transformer under a 100 kHz sinusoidal voltage/current using two power supplies with a capacity of 50 VA/unit, which is much smaller than the rated capacity of the transformer, i.e., 900 VA. Furthermore, the load test can be performed at all power factors from 0 to 1. In addition, the experimental results show that using the proposed method, the accuracy of power loss measurement is improved compared with the existing method that obtains the power loss by subtracting the output power from the input power of the transformer.","PeriodicalId":45552,"journal":{"name":"IEEJ Journal of Industry Applications","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135562993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"IEEJ Journal of Industry Applications","authors":"","doi":"10.1541/ieejjia.12.l3_1","DOIUrl":"https://doi.org/10.1541/ieejjia.12.l3_1","url":null,"abstract":"","PeriodicalId":45552,"journal":{"name":"IEEJ Journal of Industry Applications","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136048384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-01DOI: 10.1541/ieejjia.22007527
Norihito Kimura, Hiroaki Yuasa
This paper presents a method for measuring the iron loss of ferrite cores under compressive stress. Moreover, a novel methodology is proposed for analyzing the local heat generation of ferrite cores for wireless power transfer by considering an increase in the iron loss because of compressive stress. The effectiveness of the proposed analysis method is experimentally verified.
{"title":"Local Heat Generation Analysis Method of Ferrite Cores for Wireless Power Transfer Coil Considering Compressive Stress","authors":"Norihito Kimura, Hiroaki Yuasa","doi":"10.1541/ieejjia.22007527","DOIUrl":"https://doi.org/10.1541/ieejjia.22007527","url":null,"abstract":"This paper presents a method for measuring the iron loss of ferrite cores under compressive stress. Moreover, a novel methodology is proposed for analyzing the local heat generation of ferrite cores for wireless power transfer by considering an increase in the iron loss because of compressive stress. The effectiveness of the proposed analysis method is experimentally verified.","PeriodicalId":45552,"journal":{"name":"IEEJ Journal of Industry Applications","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135752367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}