{"title":"Design and implementation of a four-phase converter with digital current sharing control for battery charger","authors":"Sheng-Yuan Ou, Liang Yen Liu","doi":"10.1109/INTLEC.2015.7572268","DOIUrl":"https://doi.org/10.1109/INTLEC.2015.7572268","url":null,"abstract":"This paper designs and implements a charger with high output current for EV batteries, the structure of the charger is formed of a four-phase interleaved buck converter with synchronous rectification and associated with the digital controller, in which the current sharing control is realized. The interleaved control scheme can reduce the output ripple and decrease the power component stress in battery charger application. In addition, synchronous rectification is utilized to improve power efficiency of the interleaved buck converter. This paper uses TMS32F28035 by TI as the digital controller to control the implemented four-phase buck converter to perform interleaved control, charging function and current sharing control. The specification of the used Yttrium Lithium battery is 20V/40Ah for experiments. The validity of the charger formed of the designed interleaved buck converter is conducted with the experiment results for constant current 40A output and the verification of current sharing control.","PeriodicalId":211948,"journal":{"name":"2015 IEEE International Telecommunications Energy Conference (INTELEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131179422","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}
S. Watanabe, Y. Sagara, S. Yamane, S. Aso, K. Kokura, S. Ikeda, M. Mori
{"title":"A novel simple technology for power switching in HVDC system","authors":"S. Watanabe, Y. Sagara, S. Yamane, S. Aso, K. Kokura, S. Ikeda, M. Mori","doi":"10.1109/INTLEC.2015.7572354","DOIUrl":"https://doi.org/10.1109/INTLEC.2015.7572354","url":null,"abstract":"In this paper, a novel simple power switching method for dc switching devices is proposed to apply to HVDC system of more than 380 V DC. The method extends and extinguishes an arc between electrical contacts when opening power circuit. In addition, the power circuit can be disconnected even if the current direction reverses. The method is composed simply by using a unique combination of a small magnet, a rod-like iron core and an insulator. Moreover, it is able to prevent thermal demagnetization of the magnet, and besides, the method does not require a strong force and large magnet by using the core as a magnetic medium. In validation experiment, it was confirmed that the control to make the arc collide with an insulator in the method enhances the current interruption performance more than the case using an extinguishing gas. Furthermore, it was demonstrated to disconnect a power circuit of 800 V 20 A DC by using an actual device.","PeriodicalId":211948,"journal":{"name":"2015 IEEE International Telecommunications Energy Conference (INTELEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130948373","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}
M. Nonogaki, Ken Ozeki, T. Babasaki, K. Hirose, Nobuyuki Yoshizawa
{"title":"A feasibility study on a regional energy business","authors":"M. Nonogaki, Ken Ozeki, T. Babasaki, K. Hirose, Nobuyuki Yoshizawa","doi":"10.1109/INTLEC.2015.7572287","DOIUrl":"https://doi.org/10.1109/INTLEC.2015.7572287","url":null,"abstract":"In Japan, the liberalization of the electricity retail market is starting in April 2016. Consumers will be able to choose the retail electric suppliers from which to buy. In Germany which domestic electricity market was fully liberalized in 1998, Stadt Werke (local power companies) has maintained more than 20% of the retail electric market share. We studied the feasibility of a regional energy business in which a isolated energy network system can be deployed. The result shows that if regional energy companies sell only electricity, expenditures are larger than the revenues; therefore, the business balance becomes negative. However, when regional energy companies can reach the total overall energy efficiency levels as high as 80% by adding heat supply to selling electricity, revenue can be balanced to the total cost and the energy companies can run as a profitable energy supply business, even in the small community business area.","PeriodicalId":211948,"journal":{"name":"2015 IEEE International Telecommunications Energy Conference (INTELEC)","volume":"373 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133545353","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":"New switching control technique to improve the efficiency under light load condition for LLC converter with large magnetizing inductance","authors":"Y. Lai, Shau-Wei Chen","doi":"10.1109/INTLEC.2015.7572269","DOIUrl":"https://doi.org/10.1109/INTLEC.2015.7572269","url":null,"abstract":"The main theme of this paper is to propose a switching control method for LLC converter with larger magnetizing inductance to improve the light load efficiency. The proposed switching technique is to replace conventional frequency modulation method which is with constant duty while regulating the output voltage by varying the switching frequency, with pulse-width modulation while retaining the special feature of zero-voltage switching. The proposed switching technique can further reduce the switching losses under light load condition by reducing the switching frequency as compared with that for frequency modulation. Experimental results are derived from a DSP-based LLC converter. The output voltage = 12V, input voltage = 400 V and output power = 720 W. The test results show that the proposed switching technique can improve the light load efficiency up to 30 % under light load condition.","PeriodicalId":211948,"journal":{"name":"2015 IEEE International Telecommunications Energy Conference (INTELEC)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131440986","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}
L. Ott, Yunchao Han, Bernd Wunder, Julian Kaiser, Fabian Fersterra, Matthias Schulz, M. Mârz
{"title":"An advanced voltage droop control concept for grid-tied and autonomous DC microgrids","authors":"L. Ott, Yunchao Han, Bernd Wunder, Julian Kaiser, Fabian Fersterra, Matthias Schulz, M. Mârz","doi":"10.1109/INTLEC.2015.7572406","DOIUrl":"https://doi.org/10.1109/INTLEC.2015.7572406","url":null,"abstract":"Droop Control has been a well-established control technique both in AC and DC power distribution grids for many years, because it provides a simple way to equally distribute the load current between remote power sources. With the increasing demand for low voltage DC microgrids supplying high-reliability equipment, like servers in data centers, to work both grid-tied and autonomously without a connection to the AC mains and fueled only by local renewable and conventional power sources, voltage droop control is facing new challenges. With power equipment being delivered from several manufacturers the demand for a communication less control scheme that only uses the voltage at the terminal point or the converter output current as an indicator how the control set point should be changed in order to satisfy the energy demand of the loads arises. In consequence, the commissioning time of the DC microgrid is greatly reduced since all components can be simply plugged together without the need for adaptions. An outline for such an inherently autonomous voltage droop control scheme to keep the system voltage within a narrow band of ± 10 % of its 380 VDC nominal value is given in the following paper by describing voltage droop control modelling basics and the selection of characteristic droop curves for different kinds of power sources as well as by giving simulative results from a small-scale DC microgrid.","PeriodicalId":211948,"journal":{"name":"2015 IEEE International Telecommunications Energy Conference (INTELEC)","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115233078","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":"Techno economic assessment of different electrochemical energy storage systems for use in Khorasan, Iran","authors":"M. Monfared, D. H. Heydary, A. Saeedi, Guohong Wu","doi":"10.1109/INTLEC.2015.7572387","DOIUrl":"https://doi.org/10.1109/INTLEC.2015.7572387","url":null,"abstract":"More effective electrical energy production requires more attentions to storage technologies. This paper analysis and compares different electrochemical energy storage technologies, in the terms of energy/power density, specific energy/power, efficiency, lifespan, cycle life, capital energy/power costs, scale, application, technical maturity, as well as environmental impacts. The pioneering countries in the use of these technologies have been introduced and the main technology which is used in these countries is highlighted. Considering the advantages and disadvantages of each of the electrochemical storage technologies and projects under construction, the most suitable for use in Khorasan power network as the actual case study, is suggested.","PeriodicalId":211948,"journal":{"name":"2015 IEEE International Telecommunications Energy Conference (INTELEC)","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124214053","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}
Hiroaki Miyoshi, T. Takeda, K. Yukita, Y. Goto, K. Ichiyanagi, T. Ushirokawa, Kazuhmi Yuasa
{"title":"Study on suppressing variation of storage battery power in micro grid using flywheel","authors":"Hiroaki Miyoshi, T. Takeda, K. Yukita, Y. Goto, K. Ichiyanagi, T. Ushirokawa, Kazuhmi Yuasa","doi":"10.1109/INTLEC.2015.7572297","DOIUrl":"https://doi.org/10.1109/INTLEC.2015.7572297","url":null,"abstract":"In recent years, storage batteries have been introduced to suppress fluctuations in the output power of renewable energy sources. The lifetime of batteries used in these systems varies based on the operational methods used. In this study, we investigated the effects of introducing a flywheel into a microgrid comprising photovoltaic equipment, batteries, and a load. The flywheel reduced the maximum charge and discharge power of relative frequency of the battery.","PeriodicalId":211948,"journal":{"name":"2015 IEEE International Telecommunications Energy Conference (INTELEC)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114424451","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":"Performance characteristics of digital current detector in DC-DC converter","authors":"Y. Furukawa, S. Maeda, F. Kurokawa, I. Colak","doi":"10.1109/INTLEC.2015.7572329","DOIUrl":"https://doi.org/10.1109/INTLEC.2015.7572329","url":null,"abstract":"The purpose of this paper is to present a performance characteristics of digital current detector in dc-dc converter. The digital peak current mode control dc-dc converter using the voltage-controlled oscillator (VCO) has already proposed. The peak current is detected by using VCO in the proposed method. The gain of amplifier in the current detector affects to the input voltage range of VCO. Also, it affects the transient response. They are discussed by analysing and simulation.","PeriodicalId":211948,"journal":{"name":"2015 IEEE International Telecommunications Energy Conference (INTELEC)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114594655","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":"Solar powered base station with a multiple-input modified inverse Watkins-Johnson converter","authors":"Jeongtae Kim, Sungwoo Bae","doi":"10.1109/INTLEC.2015.7572457","DOIUrl":"https://doi.org/10.1109/INTLEC.2015.7572457","url":null,"abstract":"A worldwide mobile network has consumed high volume of energy because of its high speed broadband growth (e.g., LTE, LTE-A, and 5G). Wireless telecommunication service providers have strived for reducing an operating expenditure (i.e., electricity cost) because an urban base station (BTS) consumes more power as these data uses of mobile subscribers increase. In order to reduce an operating cost of BTS, mobile service providers and researchers have been studied for a green BTS which uses less electricity from the utility power grid for its normal operation with renewable or alternative energy sources such as photovoltaic panels, wind generators, fuel cells, and energy storage systems. However, a green BTS may increase the total cost of ownership because these renewable and alternative energy sources typically requires high capital expenditure in the installation stage. To reduce this initial capital expenditure, this paper presents a BTS power stage system design and control method with a multiple-input modified inverse Watkins-Johnson converter of which advantage is a cost-effective solution with a high boost voltage gain. The considered energy sources in this green BTS was a photovoltaic module and energy storage system. The proposed BTS power converter and control method were verified with SPICE simulation results.","PeriodicalId":211948,"journal":{"name":"2015 IEEE International Telecommunications Energy Conference (INTELEC)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124724309","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}
D. Sato, J. Itoh, Tomoki Watanabe, K. Kawagoe, N. Yamada, Koji Kato
{"title":"Development of magnetic coupling with variable thrust structure for flywheel energy storage system in long lifetime UPS","authors":"D. Sato, J. Itoh, Tomoki Watanabe, K. Kawagoe, N. Yamada, Koji Kato","doi":"10.1109/INTLEC.2015.7572479","DOIUrl":"https://doi.org/10.1109/INTLEC.2015.7572479","url":null,"abstract":"This paper introduces the flywheel energy storage system (FESS) in a long lifetime uninterruptible power supply. The first prototype FESS (3.0-MJ) uses low cost ball bearings and general purpose induction motor in terms of cost reduction. From the experimental results, it is confirmed that the charge and discharge efficiency of the FESS is 60.7% (charge 80.7%, discharge 75.1%). In order to improve the efficiency and lifetime, a permanent magnet synchronous motor, a spherical spiral groove bearing and a magnetic coupling with variable thrust structure are applied to the second prototype. The estimated charging efficiency is achieved to 86.9% and the estimated discharging efficiency is achieved to 82.8% at the second prototype. Then, the thrust of the proposed magnetic coupling is analyzed by the finite element method (FEM). As a result, the thrust can be changed by 11.1% with the electromagnet. In addition, the thrust analysis results are evaluated by using the prototype electromagnet.","PeriodicalId":211948,"journal":{"name":"2015 IEEE International Telecommunications Energy Conference (INTELEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129868233","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}