Pub Date : 2018-04-18DOI: 10.1109/APEC.2018.8341373
M. Aly, E. Ahmed, M. Orabi, M. Shoyama
Multilevel inverters have attracted much industry and research concerns in photovoltaic (PV) applications. Although, it is demonstrated that power switching devices are subjected to unequal distribution of power losses and the reliability of multilevel inverters becomes low in accordance. Therefore, a new pulse width modulation (PWM) method is proposed in this paper for loss balancing in single phase five level inverters. The proposed method swaps the utilization of power components through the line period using the redundancy property between the switching states of T-type multilevel inverters. In addition, natural balance of voltages over DC link capacitors is achieved using the proposed method. The superiority of the proposed method is verified using simulation and experimental prototypes.
{"title":"An enhanced PWM method for loss balancing of five level T-type inverter in PV systems","authors":"M. Aly, E. Ahmed, M. Orabi, M. Shoyama","doi":"10.1109/APEC.2018.8341373","DOIUrl":"https://doi.org/10.1109/APEC.2018.8341373","url":null,"abstract":"Multilevel inverters have attracted much industry and research concerns in photovoltaic (PV) applications. Although, it is demonstrated that power switching devices are subjected to unequal distribution of power losses and the reliability of multilevel inverters becomes low in accordance. Therefore, a new pulse width modulation (PWM) method is proposed in this paper for loss balancing in single phase five level inverters. The proposed method swaps the utilization of power components through the line period using the redundancy property between the switching states of T-type multilevel inverters. In addition, natural balance of voltages over DC link capacitors is achieved using the proposed method. The superiority of the proposed method is verified using simulation and experimental prototypes.","PeriodicalId":113756,"journal":{"name":"2018 IEEE Applied Power Electronics Conference and Exposition (APEC)","volume":"129 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129174731","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 : 2018-04-18DOI: 10.1109/APEC.2018.8341004
S. Hasan, Benjamin Shaffer, Hassan A. Hassan, M. Scott, Y. Siwakoti, G. Town
This paper presents a new single-phase transformerless inverter providing common ground for grid-connected photovoltaic (PV) systems. It consists of 5 switches, one diode, one capacitor, one small inductor and a small filter at the output stage. A simple Unipolar Sinusoidal Pulse-Width Modulation (SPWM) technique is used to operate the proposed inverter to minimize losses, output current ripple, filter requirements and improve its electromagnetic compatibility (EMC). The proposed topology shares a common ground with the grid and a capacitor is utilized as a virtual DC bus to provide the negative power cycle of the inverter. The capacitor is charged regardless of any switching cycle using a dedicated switch which can in turn reduce the size of capacitor in relation to the switching frequency. The peak ac output voltage is equal to the input DC voltage which reduces the requirement of the high input DC voltages. Simulation and experimental results for a 1 kW prototype are presented to demonstrate the usefulness of the proposed topology.
{"title":"Common-ground transformerless inverter for solar photovoltaic module","authors":"S. Hasan, Benjamin Shaffer, Hassan A. Hassan, M. Scott, Y. Siwakoti, G. Town","doi":"10.1109/APEC.2018.8341004","DOIUrl":"https://doi.org/10.1109/APEC.2018.8341004","url":null,"abstract":"This paper presents a new single-phase transformerless inverter providing common ground for grid-connected photovoltaic (PV) systems. It consists of 5 switches, one diode, one capacitor, one small inductor and a small filter at the output stage. A simple Unipolar Sinusoidal Pulse-Width Modulation (SPWM) technique is used to operate the proposed inverter to minimize losses, output current ripple, filter requirements and improve its electromagnetic compatibility (EMC). The proposed topology shares a common ground with the grid and a capacitor is utilized as a virtual DC bus to provide the negative power cycle of the inverter. The capacitor is charged regardless of any switching cycle using a dedicated switch which can in turn reduce the size of capacitor in relation to the switching frequency. The peak ac output voltage is equal to the input DC voltage which reduces the requirement of the high input DC voltages. Simulation and experimental results for a 1 kW prototype are presented to demonstrate the usefulness of the proposed topology.","PeriodicalId":113756,"journal":{"name":"2018 IEEE Applied Power Electronics Conference and Exposition (APEC)","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122540493","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 : 2018-04-18DOI: 10.1109/APEC.2018.8341039
Jinia Roy, R. Ayyanar
Due to their plug and play feature, easy installation, and higher power yield under partial shading conditions, microinverters have gained popularity in the roof-top-PV market. This paper explores a converter system for the transfomer-less microinverter with coupled inductor based interleaved boost as the dc-dc stage and half bridge voltage swing (HBVS) inverter as the dc-ac stage. The dc-dc stage is capable of offering high gain with a flexible choice of turns ratio of the coupled inductor but simultaneously maintaining a reduced voltage stress on the main switch. The HBVS inverter has the advantages of reduced capacitor requirement for 120 Hz power decoupling and being half-bridge derived, minimized capacitive-coupled common-mode ground currents. A 300 W GaN based inverter prototype with 30 V nominal dc input and 120 V, 60 Hz nominal ac output and operating at switching frequency of 200/100 kHz has been developed to validate the converter's operation in hardware.
{"title":"GaN based transformer-less microinverter with coupled inductor interleaved boost and half bridge voltage swing inverter","authors":"Jinia Roy, R. Ayyanar","doi":"10.1109/APEC.2018.8341039","DOIUrl":"https://doi.org/10.1109/APEC.2018.8341039","url":null,"abstract":"Due to their plug and play feature, easy installation, and higher power yield under partial shading conditions, microinverters have gained popularity in the roof-top-PV market. This paper explores a converter system for the transfomer-less microinverter with coupled inductor based interleaved boost as the dc-dc stage and half bridge voltage swing (HBVS) inverter as the dc-ac stage. The dc-dc stage is capable of offering high gain with a flexible choice of turns ratio of the coupled inductor but simultaneously maintaining a reduced voltage stress on the main switch. The HBVS inverter has the advantages of reduced capacitor requirement for 120 Hz power decoupling and being half-bridge derived, minimized capacitive-coupled common-mode ground currents. A 300 W GaN based inverter prototype with 30 V nominal dc input and 120 V, 60 Hz nominal ac output and operating at switching frequency of 200/100 kHz has been developed to validate the converter's operation in hardware.","PeriodicalId":113756,"journal":{"name":"2018 IEEE Applied Power Electronics Conference and Exposition (APEC)","volume":"294 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127561286","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 : 2018-04-18DOI: 10.1109/APEC.2018.8341356
Y. Siwakoti
Multilevel converters have seen an increasing popularity in the last decades, due to the increased power ratings, improved power quality, low switching losses, and reduced Electromagnetic Interference (EMI). Among them, the most popular ones are the Neutral Point Clamped (NPC) and the Flying Capacitor (FC) inverter topologies. Different derivatives of the NPC and FC are prevalent in the literature for various applications. However, the main drawback of the NPC and FC topologies is the high dc-link voltage, which has to be more than twice of the grid peak voltage for grid integration. Therefore, a front-end boost dc-dc converter is normally required before the inverter, which decreases the overall efficiency of the system. Single-stage dc-ac power converters with boost capabilities offer an interesting alternative compared to the two-stage approach. Considering this aspect, a novel 5-Level three-phase boost type inverter is introduced in this paper for general-purpose applications (e.g. rolling mills, fans, pumps, marine appliances, mining, tractions, and most prominently grid-connected renewable energy, etc.) which reduces the dc-link voltage requirement to half of the conventional 5-Level NPC, ANPC and 5-Level FC family. Whilst reducing the dc-link voltage requirement, the number of active and passive components are also reduced. The principle of operation and theoretical analysis supported by key simulation and experimental waveforms of a 1.5 kW prototype are presented to prove the concept of the proposed 5L-Boost-ANPC inverter.
{"title":"A new six-switch five-level boost-active neutral point clamped (5L-Boost-ANPC) inverter","authors":"Y. Siwakoti","doi":"10.1109/APEC.2018.8341356","DOIUrl":"https://doi.org/10.1109/APEC.2018.8341356","url":null,"abstract":"Multilevel converters have seen an increasing popularity in the last decades, due to the increased power ratings, improved power quality, low switching losses, and reduced Electromagnetic Interference (EMI). Among them, the most popular ones are the Neutral Point Clamped (NPC) and the Flying Capacitor (FC) inverter topologies. Different derivatives of the NPC and FC are prevalent in the literature for various applications. However, the main drawback of the NPC and FC topologies is the high dc-link voltage, which has to be more than twice of the grid peak voltage for grid integration. Therefore, a front-end boost dc-dc converter is normally required before the inverter, which decreases the overall efficiency of the system. Single-stage dc-ac power converters with boost capabilities offer an interesting alternative compared to the two-stage approach. Considering this aspect, a novel 5-Level three-phase boost type inverter is introduced in this paper for general-purpose applications (e.g. rolling mills, fans, pumps, marine appliances, mining, tractions, and most prominently grid-connected renewable energy, etc.) which reduces the dc-link voltage requirement to half of the conventional 5-Level NPC, ANPC and 5-Level FC family. Whilst reducing the dc-link voltage requirement, the number of active and passive components are also reduced. The principle of operation and theoretical analysis supported by key simulation and experimental waveforms of a 1.5 kW prototype are presented to prove the concept of the proposed 5L-Boost-ANPC inverter.","PeriodicalId":113756,"journal":{"name":"2018 IEEE Applied Power Electronics Conference and Exposition (APEC)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122770054","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 : 2018-04-18DOI: 10.1109/APEC.2018.8341291
U. Sankar, Ayan Mallik, A. Khaligh
A power factor correction (PFC) circuit is an essential requirement for AC-DC conversion to meet the strict grid quality standards. High efficiency and increased power density requirements have driven the industry towards bridgeless PFC circuits as a viable solution for front end rectification. Inherent electro magnetic interference (EMI) issues of an H-Bridge PFC topology has hindered the adaptation of this circuit. In this paper, a duty compensation method is proposed to reduce the harmonic content generated by switch node of an H-Bridge topology. The proposed control technique reduces the generated harmonics without addition of any hardware components helping to meet high power density requirements. A 1kW SiC-based laboratory prototype is designed to verify the proposed control technique. The experimental results show that an input power factor of 0.99 with a conversion efficiency of 96.5% and total harmonic distortion (THD) of 2.05 % can be achieved.
{"title":"Duty compensated reduced harmonic control for a single-phase H-bridge PFC converter","authors":"U. Sankar, Ayan Mallik, A. Khaligh","doi":"10.1109/APEC.2018.8341291","DOIUrl":"https://doi.org/10.1109/APEC.2018.8341291","url":null,"abstract":"A power factor correction (PFC) circuit is an essential requirement for AC-DC conversion to meet the strict grid quality standards. High efficiency and increased power density requirements have driven the industry towards bridgeless PFC circuits as a viable solution for front end rectification. Inherent electro magnetic interference (EMI) issues of an H-Bridge PFC topology has hindered the adaptation of this circuit. In this paper, a duty compensation method is proposed to reduce the harmonic content generated by switch node of an H-Bridge topology. The proposed control technique reduces the generated harmonics without addition of any hardware components helping to meet high power density requirements. A 1kW SiC-based laboratory prototype is designed to verify the proposed control technique. The experimental results show that an input power factor of 0.99 with a conversion efficiency of 96.5% and total harmonic distortion (THD) of 2.05 % can be achieved.","PeriodicalId":113756,"journal":{"name":"2018 IEEE Applied Power Electronics Conference and Exposition (APEC)","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122294050","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 : 2018-04-18DOI: 10.1109/APEC.2018.8341300
C. Huang, T. Liang, Kai-Hui Chen, Cheng-Yuan Li
The advantages of the flyback converter with the primary-side regulation (PSR) are small size and high efficiency at light load. However, when the PSR flyback converter operates in burst mode, the controller is not able to sense the output information. Therefore, it is not easy to control the output voltage precisely. An integrated circuit design for AC-DC flyback converter using primary-side controller with burst mode energy saving is proposed in this paper. As the load decreases, the flyback converter operates from discontinuous conduction mode to frequency reduction mode. At extremely light load, the flyback converter operates in burst mode. With the proposed control, the burst-on time is detected by the voltage across the auxiliary winding, and the burst-off time can be estimated to control the output voltage ripple. In the proposed control circuit, a capacitor is charged by a constant current source during the burst-on time, and the capacitor voltage is transferred to a controlled current. Therefore, the required burst-off time can be obtained by using the controlled current to charge another capacitor until it reaches the reference voltage. Finally, this controller is fabricated with TSMC 0.25 μm CMOS high voltage mixed signal general purpose process. The flyback converter with the input voltage range of 90–130 Vrms, the output voltage of 15 V, and the output power of 30 W is implemented to verify the feasibility of the proposed controller.
{"title":"Primary-side feedback control IC design for flyback converter with energy saving burst mode","authors":"C. Huang, T. Liang, Kai-Hui Chen, Cheng-Yuan Li","doi":"10.1109/APEC.2018.8341300","DOIUrl":"https://doi.org/10.1109/APEC.2018.8341300","url":null,"abstract":"The advantages of the flyback converter with the primary-side regulation (PSR) are small size and high efficiency at light load. However, when the PSR flyback converter operates in burst mode, the controller is not able to sense the output information. Therefore, it is not easy to control the output voltage precisely. An integrated circuit design for AC-DC flyback converter using primary-side controller with burst mode energy saving is proposed in this paper. As the load decreases, the flyback converter operates from discontinuous conduction mode to frequency reduction mode. At extremely light load, the flyback converter operates in burst mode. With the proposed control, the burst-on time is detected by the voltage across the auxiliary winding, and the burst-off time can be estimated to control the output voltage ripple. In the proposed control circuit, a capacitor is charged by a constant current source during the burst-on time, and the capacitor voltage is transferred to a controlled current. Therefore, the required burst-off time can be obtained by using the controlled current to charge another capacitor until it reaches the reference voltage. Finally, this controller is fabricated with TSMC 0.25 μm CMOS high voltage mixed signal general purpose process. The flyback converter with the input voltage range of 90–130 Vrms, the output voltage of 15 V, and the output power of 30 W is implemented to verify the feasibility of the proposed controller.","PeriodicalId":113756,"journal":{"name":"2018 IEEE Applied Power Electronics Conference and Exposition (APEC)","volume":"39 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132027152","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 : 2018-04-18DOI: 10.1109/APEC.2018.8341581
Hassan Abdelgabir, M. N. Shaheed, A. Elrayyah, Y. Sozer
A Nonlinear droop control has been introduced to establish an effective power sharing between the distributed generators without the need of communication links in microgrids (MGs). However, one of the missing studies in the literature is the effects of the nonlinear droop relations on the stability of the MGs. In this paper, the stability of an inverter based MG operating with the nonlinear frequency droop-control has been analyzed. Firstly, a particle swarm optimization technique (PSO) was used to optimize the nonlinear frequency droop relations for minimizing the operating cost of the MG. Secondly, a complete small-signal state-space model of the MG system with the optimized nonlinear droop relations has been developed and the model is updated periodically. The stability of the system is then checked automatically at different operating points. Small signal stability analysis of an islanded microgrid were performed using MATLAB/Simulink and the results were experimentally verified on an MG setup.
{"title":"A complete small signal modelling and adaptive stability analysis of nonlinear droop-controlled microgrids","authors":"Hassan Abdelgabir, M. N. Shaheed, A. Elrayyah, Y. Sozer","doi":"10.1109/APEC.2018.8341581","DOIUrl":"https://doi.org/10.1109/APEC.2018.8341581","url":null,"abstract":"A Nonlinear droop control has been introduced to establish an effective power sharing between the distributed generators without the need of communication links in microgrids (MGs). However, one of the missing studies in the literature is the effects of the nonlinear droop relations on the stability of the MGs. In this paper, the stability of an inverter based MG operating with the nonlinear frequency droop-control has been analyzed. Firstly, a particle swarm optimization technique (PSO) was used to optimize the nonlinear frequency droop relations for minimizing the operating cost of the MG. Secondly, a complete small-signal state-space model of the MG system with the optimized nonlinear droop relations has been developed and the model is updated periodically. The stability of the system is then checked automatically at different operating points. Small signal stability analysis of an islanded microgrid were performed using MATLAB/Simulink and the results were experimentally verified on an MG setup.","PeriodicalId":113756,"journal":{"name":"2018 IEEE Applied Power Electronics Conference and Exposition (APEC)","volume":"163 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132635918","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 : 2018-04-18DOI: 10.1109/APEC.2018.8341035
Kerui Li, Yanfeng Shen, Yongheng Yang, Zian Qin, F. Blaabjerg
A transformerless single-phase symmetric Z-source HERIC inverter featuring low leakage currents is presented in this paper. It is an attempt to utilize the Highly Efficient and Reliable Inverter Concept (HERIC) and an impedance source (Z-source) network to maintain a constant common mode voltage and thus low leakage currents in PV applications. The symmetric Z-source HERIC inverter requires two extra active switches. Nevertheless, the operation frequency of the two switches is the line frequency, leading to negligible losses. More importantly, the performance in terms of low leakage currents and harmonics is improved. Experimental tests are performed to validate the analysis and performance of the proposed system.
{"title":"A transformerless single-phase symmetrical Z-source HERIC inverter with reduced leakage currents for PV systems","authors":"Kerui Li, Yanfeng Shen, Yongheng Yang, Zian Qin, F. Blaabjerg","doi":"10.1109/APEC.2018.8341035","DOIUrl":"https://doi.org/10.1109/APEC.2018.8341035","url":null,"abstract":"A transformerless single-phase symmetric Z-source HERIC inverter featuring low leakage currents is presented in this paper. It is an attempt to utilize the Highly Efficient and Reliable Inverter Concept (HERIC) and an impedance source (Z-source) network to maintain a constant common mode voltage and thus low leakage currents in PV applications. The symmetric Z-source HERIC inverter requires two extra active switches. Nevertheless, the operation frequency of the two switches is the line frequency, leading to negligible losses. More importantly, the performance in terms of low leakage currents and harmonics is improved. Experimental tests are performed to validate the analysis and performance of the proposed system.","PeriodicalId":113756,"journal":{"name":"2018 IEEE Applied Power Electronics Conference and Exposition (APEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115162095","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 : 2018-04-18DOI: 10.1109/APEC.2018.8341298
Ziwei Yu, Yinglai Xia, R. Ayyanar
This paper proposes a zero-voltage-transition (ZVT) technique for the full-bridge based bridgeless single-phase PFC. An auxiliary circuit consists of a small auxiliary inductor and two active switches is placed in parallel with the main filter inductor. The proposed ZVT technique has several advantages over the existing ZVT schemes including low ripple of the filter inductor current, natural zero-current-switching (ZCS) for the auxiliary switches, relatively less additional components and allowing unipolar or hybrid PWM modulation of the full-bridge converter. The effectiveness of the proposed scheme has been validated through hardware experiment. It shows that the proposed ZVT scheme can save approximately 40% of the power loss compared with the regular hard-switching operation.
{"title":"A simple ZVT auxiliary circuit for full-bridge based bridgeless single-phase PFC with hybrid PWM modulation scheme","authors":"Ziwei Yu, Yinglai Xia, R. Ayyanar","doi":"10.1109/APEC.2018.8341298","DOIUrl":"https://doi.org/10.1109/APEC.2018.8341298","url":null,"abstract":"This paper proposes a zero-voltage-transition (ZVT) technique for the full-bridge based bridgeless single-phase PFC. An auxiliary circuit consists of a small auxiliary inductor and two active switches is placed in parallel with the main filter inductor. The proposed ZVT technique has several advantages over the existing ZVT schemes including low ripple of the filter inductor current, natural zero-current-switching (ZCS) for the auxiliary switches, relatively less additional components and allowing unipolar or hybrid PWM modulation of the full-bridge converter. The effectiveness of the proposed scheme has been validated through hardware experiment. It shows that the proposed ZVT scheme can save approximately 40% of the power loss compared with the regular hard-switching operation.","PeriodicalId":113756,"journal":{"name":"2018 IEEE Applied Power Electronics Conference and Exposition (APEC)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128662358","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 : 2018-04-18DOI: 10.1109/APEC.2018.8341196
Hulong Zeng, F. Peng
In wireless power transfer (WPT) system, the resonant frequency of primary side and secondary side should be matched to maximize the power transferred and efficiency. However, in mass production, the variation of each component in the resonant circuit results in poor matching. One solution is to utilize a variable capacitor for self-tuning to compensate the variation. To implement a variable capacitor on a linear capacitor in power converters, most of the solutions chop part of the rated current by an auxiliary circuit. Therefore, the power rating of the auxiliary circuit is proportional to the percentage of capacitance variation, which generates considerable loss. On the other hand, non-linear capacitor, ceramic capacitor as an example, can change capacitance by varying DC bias. The auxiliary circuit to hold the DC bias only needs to supply the leakage current of the nonlinear capacitor, which is negligible. In this paper, an almost lossless auxiliary circuit for continuously varying DC bias is proposed. It is suitable for high power applications such as electric vehicles wireless charger. Experimental results based on a 100-W scale-down series resonant converter (SRC) with 20-cm air gap between the primary and secondary side are presented to illustrate the mechanism of this method.
{"title":"Non-linear capacitor based variable capacitor for self-tuning resonant converter in wireless power transfer","authors":"Hulong Zeng, F. Peng","doi":"10.1109/APEC.2018.8341196","DOIUrl":"https://doi.org/10.1109/APEC.2018.8341196","url":null,"abstract":"In wireless power transfer (WPT) system, the resonant frequency of primary side and secondary side should be matched to maximize the power transferred and efficiency. However, in mass production, the variation of each component in the resonant circuit results in poor matching. One solution is to utilize a variable capacitor for self-tuning to compensate the variation. To implement a variable capacitor on a linear capacitor in power converters, most of the solutions chop part of the rated current by an auxiliary circuit. Therefore, the power rating of the auxiliary circuit is proportional to the percentage of capacitance variation, which generates considerable loss. On the other hand, non-linear capacitor, ceramic capacitor as an example, can change capacitance by varying DC bias. The auxiliary circuit to hold the DC bias only needs to supply the leakage current of the nonlinear capacitor, which is negligible. In this paper, an almost lossless auxiliary circuit for continuously varying DC bias is proposed. It is suitable for high power applications such as electric vehicles wireless charger. Experimental results based on a 100-W scale-down series resonant converter (SRC) with 20-cm air gap between the primary and secondary side are presented to illustrate the mechanism of this method.","PeriodicalId":113756,"journal":{"name":"2018 IEEE Applied Power Electronics Conference and Exposition (APEC)","volume":"198 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131579831","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}
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