{"title":"Atmospheric pressure argon plasma jets I – Measurements of spatial distribution for visible emission spectrum and vacuum ultraviolet","authors":"Susumu Suzuki, Kenji Teranishi, Haruo Itoh","doi":"10.1002/eej.23457","DOIUrl":"10.1002/eej.23457","url":null,"abstract":"<p>This paper describes the observed position dependent emission spectrum and vacuum ultraviolet (VUV) to clarify the optical structure of argon atmospheric pressure plasma jets (APJs). Visible emission spectra of argon, nitrogen, and OH molecules were measured as a function of position from the nozzle of plasma jet generator to gas flow direction. From the results, we realized that a certain electric field is required for producing high energy excited atoms of argon in the jet from the high voltage electrode in the device to the ground positioned at downstream side. Moreover, VUV was detected along the plasma jet through the downstream direction. Thus, we could picture that the light pattern of plasma jet of which intensity weaken depend to the distance from the nozzle is sustained by the above two factors with the present steady state experiments.</p>","PeriodicalId":50550,"journal":{"name":"Electrical Engineering in Japan","volume":"217 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139758034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Filament analysis based on mathematical morphology of surface dielectric barrier discharges in N2/O2 mixtures","authors":"Takuma Uemura, Atsushi Komuro, Ryo Ono","doi":"10.1002/eej.23461","DOIUrl":"10.1002/eej.23461","url":null,"abstract":"<p>In this paper, we measured the electrical potential distribution of surface dielectric barrier discharges (SDBD) caused by alternating voltage in synthetic air and nitrogen using the Pockels effect. It was shown that different potential distributions of filament thickness and length are generated in synthetic air and nitrogen. A filament analysis based on mathematical morphology was performed to quantify the geometric characteristics of the filaments produced in each gas atmosphere. The results show that the discharge filament thickness and the entropy in the filament direction depend on the oxygen ratio and the magnitude of the applied voltage.</p>","PeriodicalId":50550,"journal":{"name":"Electrical Engineering in Japan","volume":"217 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139758180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Experimental verification of voltage boost control in a hybrid system using D-EPC","authors":"Hiroki Matsuno, Hiromu Akiyama, Kantaro Yoshimoto, Tomoki Yokoyama","doi":"10.1002/eej.23460","DOIUrl":"10.1002/eej.23460","url":null,"abstract":"<p>A novel voltage boost system using DC-inputs direct electric-power converter (D-EPC) is proposed. D-EPC is an inverter that can control the distribution of power from two sources. In this study, a voltage boost system without boost chopper was developed using the power distribution control of D-EPC. The power distribution control can control the voltage of the smoothing capacitor in the D-EPC. The effectiveness of the proposed voltage boost system was verified using a prototype of the D-EPC circuit and controller.</p>","PeriodicalId":50550,"journal":{"name":"Electrical Engineering in Japan","volume":"217 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139757975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Transformer-less drive and operation stability analysis of dielectric barrier discharge using a double resonance circuit","authors":"Taichiro Tamida, Ryota Nagata, Taiga Itani","doi":"10.1002/eej.23455","DOIUrl":"10.1002/eej.23455","url":null,"abstract":"<p>A dielectric barrier discharge load (DBD) with a maintenance voltage of 1.5 kV has been successfully driven stably from a 48 V inverter only by resonance voltage boost and no transformer. The proposed circuit consists of a two-stage resonant circuit. The circuit operation is investigated using both prototyping measurement and circuit simulation, which shows that despite the high Q value, the design margin and operating stability of the circuit are extremely wide. It is found that this operational stability can be explained by considering the impedance characteristics of DBD. We believe that the circuit is suitable for driving discharge loads such as DBD in practical applications.</p>","PeriodicalId":50550,"journal":{"name":"Electrical Engineering in Japan","volume":"217 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138537540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A circuit model of electrical wiring nearby building structure for lightning surge analysis","authors":"Hideyuki Dei, Yoki Ikeda, Naoto Nagaoka","doi":"10.1002/eej.23456","DOIUrl":"10.1002/eej.23456","url":null,"abstract":"<p>A model expressing beams, pillars, and electrical wiring in a building for lightning surge simulation by circuit analysis method is proposed in this paper. The proposed model expresses the self-surge impedance of the electrical wiring as a function of the distance between conductors and the radius of the electrical wiring. The mutual impedance is expressed by the distance between the surfaces of a structure and a nearby wire instead of the distance between the conductor centers. In the case of two conductors having far different radii in proximity, the distribution of electromagnetic fields around the two conductors is similar in horizontal and vertical arrangements. Thus, the electrical wiring nearby pillars can be treated as a horizontal conductor. The circuit analysis results show that the voltage difference generated between the structure and the electrical wiring is calculated more precisely by the proposed model than by the conventional model.</p>","PeriodicalId":50550,"journal":{"name":"Electrical Engineering in Japan","volume":"217 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138537538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iori Uda, Satoshi Ogasawara, Koji Orikawa, Koji Kobayashi, Hiroshi Yoshida, Tatsuki Kashihara, Kohei Takada
{"title":"Analysis of interference of electromagnetic noise in an electric compressor for vehicle air-conditioning systems with an integrated mechanical and electrical structure","authors":"Iori Uda, Satoshi Ogasawara, Koji Orikawa, Koji Kobayashi, Hiroshi Yoshida, Tatsuki Kashihara, Kohei Takada","doi":"10.1002/eej.23454","DOIUrl":"10.1002/eej.23454","url":null,"abstract":"<p>Since a motor drive system contains an inverter (high-voltage circuit) and gate drive circuits (low-voltage circit) with a switching regulator, electromagnetic noise is generated in each of these two circuits, and noise interference between these circuits can occur. This paper discusses noise interference between the high- and low-voltage circuits of an electric compressor system with an integrated mechanical and electrical structure. Analysis using LTspice shows that the experimental and analytical results are in good agreement when a very small stray capacitance occurs between the high- and low-voltage circuits. An experiment using an actual compressor showed that conducted noise above 20 MHz can be reduced by up to 10 dB by reducing the effect of stray capacitance between these circuits.</p>","PeriodicalId":50550,"journal":{"name":"Electrical Engineering in Japan","volume":"217 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138537541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Power factor control for inverters under high penetration of distributed generation","authors":"Yasuaki Yamada, Toshiya Nanahara, Kazuto Yukita","doi":"10.1002/eej.23452","DOIUrl":"10.1002/eej.23452","url":null,"abstract":"<p>The paper proposes a method to select a power factor for an inverter of distributed power generation systems to keep appropriate voltage of a power system with the high penetration of inverter-interfaced generation. The increase of inverter-interfaced power sources, such as wind and photovoltaic power generation, arouses concerns on the voltage fluctuations in a power system. While constant power factor control of an inverter has been studied as a means to stabilize the voltage of a power system, there still remains room to improve the control. The proposed method in the paper selects the power factor based on the <i>R</i>/<i>X</i> ratio of the looking-back impedance into the interconnected power system. By normalizing the related variables, a general formula is derived for the power factor, and the resultant relationship between the apparent power and voltage of an inverter becomes identical irrespective of the <i>R</i>/<i>X</i> ratio with the control. Sample studies show that, by operating an inverter with the power factor, voltage fluctuations are effectively suppressed even for a power system with the high penetration of inverter-interfaced generation.</p>","PeriodicalId":50550,"journal":{"name":"Electrical Engineering in Japan","volume":"216 4","pages":""},"PeriodicalIF":0.4,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136034227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Function and role of bus bar protection relay in distribution substation","authors":"Yuki Matsuda, Takayuki Inui","doi":"10.1002/eej.23451","DOIUrl":"10.1002/eej.23451","url":null,"abstract":"<p>Bus bar of substations are important equipment where multiple facilities are centrally connected, and the impact of a fault is significant. Therefore, bus bar protection relays have unique functions to correctly detect the point of fault, which allows high speed fault elimination and minimization of outage area. This paper describes functions and roles of bus bar protection relays applied in distribution substation of Kansai Transmission and Distribution. After describing the concept of installation of bus bar protection relays, recent trends in device development tailored to the bus bar configurations of substations and the unique functions of bus bar protection relays are introduced. The retrofit methods that are being increasingly applied as a renewal solution for bus bar protection relays are then described, as well as prospects for bus bar protection functions in the future IEC 61850 full-digital substations.</p>","PeriodicalId":50550,"journal":{"name":"Electrical Engineering in Japan","volume":"216 4","pages":""},"PeriodicalIF":0.4,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135738592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimization of train timetables and placement of charging facilities for battery-powered LRT","authors":"Kosuke Horiuchi, Masafumi Miyatake","doi":"10.1002/eej.23453","DOIUrl":"10.1002/eej.23453","url":null,"abstract":"<p>The energy consumption of a battery-powered train in an interstation depends on the running time and state of energy (SOE) at departure. In this paper, we develop an optimization method of train timetables to minimize energy consumption in line with several stations. The variables in this proposed optimization model are running, dwell, and charging times as real numbers and places of charging facilities as binaries. Additionally, we conducted a case study using the real-world light rail transit (LRT) route, vehicle, and onboard battery model to confirm the effectiveness. In the case study, the proposed method can optimize the timetable and placement of charging facilities by considering the track gradient and battery SOE.</p>","PeriodicalId":50550,"journal":{"name":"Electrical Engineering in Japan","volume":"216 4","pages":""},"PeriodicalIF":0.4,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135828484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fundamental experiment and numerical simulation of pre-ionized inert gas plasma MHD electrical power generation","authors":"Ork Kimsor, Yoshinobu Kodera, Yoshihiro Okuno","doi":"10.1002/eej.23449","DOIUrl":"10.1002/eej.23449","url":null,"abstract":"<p>The experiments of pre-ionized inert gas plasma MHD electrical power generation are conducted, and the performance and plasma behavior in the experimental generator are examined through time-dependent r-_ two-dimensional numerical simulation. In the experiment, an enthalpy extraction ratio of 4.01% has been obtained with a disk-shaped MHD generator with radio-frequency pre-ionization. In the numerical simulation, at an assumed inlet electron temperature around 5600 K (inlet ionization degree 0:10 × 10<sup>−4</sup>)_6600 K (1:36 × 10<sup>−4</sup>), the plasma structure is similar to the non-uniform structure observed in the experiment. An enthalpy extraction ratio around 2_5% matches well with that in the experiment. At a suitable inlet electron temperature of 7000 K (3:15 × 10<sup>−4</sup>)_8000 K (1:79 × 10<sup>−3</sup>), although non-uniform plasma structure still occurs, a high enthalpy extraction ratio over 10% is expected.</p>","PeriodicalId":50550,"journal":{"name":"Electrical Engineering in Japan","volume":"216 4","pages":""},"PeriodicalIF":0.4,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135538810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}