Bingyao Zheng, Fang Guo, A. Wen, T. Wei, Hang Wu, Miaoxian Zhou, R. Wang, G. Huang
With the development of distributed power supply and the increasing application of DC load, DC micro-grid can more effectively access to distributed power supply and DC load and it will be widely used in the future power grid. Because the DC micro-network can be connected to many distributed power sources, when a branch of the system fails, each power source will provide fault current to the fault point, which makes the current flowing on many circuit breakers rise rapidly, and leads to the protection misoperation. In this paper, the inter-pole fault of DC microgrid is taken as the research object, and the fault characteristics of DC microgrid are analyzed. On this basis, a protection scheme based on fault current controller is proposed to limit the current, so that the protection can operate accurately. Finally, the feasibility of the proposed scheme is verified by simulation with PSCAD/EMTDC.
{"title":"Research on DC Microgrid Protection Scheme Based on Fault Current Controller","authors":"Bingyao Zheng, Fang Guo, A. Wen, T. Wei, Hang Wu, Miaoxian Zhou, R. Wang, G. Huang","doi":"10.1145/3508297.3508321","DOIUrl":"https://doi.org/10.1145/3508297.3508321","url":null,"abstract":"With the development of distributed power supply and the increasing application of DC load, DC micro-grid can more effectively access to distributed power supply and DC load and it will be widely used in the future power grid. Because the DC micro-network can be connected to many distributed power sources, when a branch of the system fails, each power source will provide fault current to the fault point, which makes the current flowing on many circuit breakers rise rapidly, and leads to the protection misoperation. In this paper, the inter-pole fault of DC microgrid is taken as the research object, and the fault characteristics of DC microgrid are analyzed. On this basis, a protection scheme based on fault current controller is proposed to limit the current, so that the protection can operate accurately. Finally, the feasibility of the proposed scheme is verified by simulation with PSCAD/EMTDC.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130657247","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}
The telescope tape is one of the problems in the case study PVC tape factory. Historical data in 2021 perform the Telescope problem that occurs when transporting ships for a long time and the cumulative heat is a catalyst of Telescoping. The Six Sigma approach was applied to improve the process under five phases (DMAIC) to remedy this problem. Therefore, the researcher studied the process, analyzed the results from the cause-and-effect matrix, analyzed the potential causes of issues, and FMEA prioritized the rationales to solve. The experiment results revealed that adjusting the adhesive thickness and nip-pressure in the coating process were causes of high winding tension and Telescoping. Moreover, ageing temperature and time before cutting into tape can inhibit Telescope movement. After improvement by adjusting parameters in the process, the height of the core is downshifted and is in the manufacturing standard. Besides, the process capability was improved to Cp = 2.14 and Cpk = 1.35, which passed the 1.33 acceptance criteria of the factory. As a result, the improvement can reduce the occurrence of Telescope tape from 40% to 0% of the current waste.
{"title":"Core slide defect reduction of PVC tape by Six Sigma approach","authors":"P. Chutima, Thanida Katecha","doi":"10.1145/3508297.3508343","DOIUrl":"https://doi.org/10.1145/3508297.3508343","url":null,"abstract":"The telescope tape is one of the problems in the case study PVC tape factory. Historical data in 2021 perform the Telescope problem that occurs when transporting ships for a long time and the cumulative heat is a catalyst of Telescoping. The Six Sigma approach was applied to improve the process under five phases (DMAIC) to remedy this problem. Therefore, the researcher studied the process, analyzed the results from the cause-and-effect matrix, analyzed the potential causes of issues, and FMEA prioritized the rationales to solve. The experiment results revealed that adjusting the adhesive thickness and nip-pressure in the coating process were causes of high winding tension and Telescoping. Moreover, ageing temperature and time before cutting into tape can inhibit Telescope movement. After improvement by adjusting parameters in the process, the height of the core is downshifted and is in the manufacturing standard. Besides, the process capability was improved to Cp = 2.14 and Cpk = 1.35, which passed the 1.33 acceptance criteria of the factory. As a result, the improvement can reduce the occurrence of Telescope tape from 40% to 0% of the current waste.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130277334","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}
Abstract: It is discussed the characteristics of baseband transmission without interference and the relative principle of cosine roll-off system, and carried out simulation design and performance analysis of cosine roll-off system with MATLAB software. The simulation results show that the waveform has a long trailing tail after the addition of interference in the cosine roll-off system, the eye pattern has a smaller opening width, and the trace lines are blurred. The larger the roll-off factor is, the wider the eye pattern opening width is, the larger the bandwidth is, and the smaller the timing error is, which can make the digital baseband signal realize transmission without inter-symbol interference under the influence of noise. It has certain guiding significance to the transmission of actual baseband signal.
{"title":"Performance Simulation of Cosine Roll-off System Based on Eye Pattern","authors":"Xiaoqi Yin, Zhengmin Zhao, Liqun Huangfu","doi":"10.1145/3508297.3508336","DOIUrl":"https://doi.org/10.1145/3508297.3508336","url":null,"abstract":"Abstract: It is discussed the characteristics of baseband transmission without interference and the relative principle of cosine roll-off system, and carried out simulation design and performance analysis of cosine roll-off system with MATLAB software. The simulation results show that the waveform has a long trailing tail after the addition of interference in the cosine roll-off system, the eye pattern has a smaller opening width, and the trace lines are blurred. The larger the roll-off factor is, the wider the eye pattern opening width is, the larger the bandwidth is, and the smaller the timing error is, which can make the digital baseband signal realize transmission without inter-symbol interference under the influence of noise. It has certain guiding significance to the transmission of actual baseband signal.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114350164","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}
Yifeng Han, Tanghua Cheng, Xu Chai, Kun Yao, Jiang‐bo Jia
The mobile hoist is an important equipment of hydropower station, consisting of gate frame, trolley track, trolley, hydraulic automatic gripping beam, trolley track, trolley walking mechanism, trolley power supply device, trolley power supply device, ladder platform railing, driver's room, wind measurement device, trolley grounding device and electrical equipment, etc. It has a vital role for the normal drainage and flood control of steel gates, regulation of people's living water, irrigation of farmland, transportation of water conservancy and Hydroelectricity generation has a vital role. In this paper, for the requirements of Baihetan hydropower station inlet, 2×250kN large span gate machine is designed and its load test method is studied.
{"title":"Design and load test method of 2×250kN large-span hoist","authors":"Yifeng Han, Tanghua Cheng, Xu Chai, Kun Yao, Jiang‐bo Jia","doi":"10.1145/3508297.3508344","DOIUrl":"https://doi.org/10.1145/3508297.3508344","url":null,"abstract":"The mobile hoist is an important equipment of hydropower station, consisting of gate frame, trolley track, trolley, hydraulic automatic gripping beam, trolley track, trolley walking mechanism, trolley power supply device, trolley power supply device, ladder platform railing, driver's room, wind measurement device, trolley grounding device and electrical equipment, etc. It has a vital role for the normal drainage and flood control of steel gates, regulation of people's living water, irrigation of farmland, transportation of water conservancy and Hydroelectricity generation has a vital role. In this paper, for the requirements of Baihetan hydropower station inlet, 2×250kN large span gate machine is designed and its load test method is studied.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114744534","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}
The parallel gap are important equipment for lightning protection of the line, but they shorten the effective length of the insulator to a certain extent. Taking 220kV as an example, the influence of parallel gap on live working is analyzed through experiments and simulation. Firstly, the electric field distribution of the live working space with lightning parallel gap are analyzed by simulation, and the safety protection measures and requirements of the workers are put forward. Finally, the gap discharge test was carried of typical conditions of live working, and the discharge characteristics with parallel gap line were obtained. Then according to the insulation coordination method of live working, the minimum approach distance of live working on 220kV lines with parallel gap is 2.1m, which is 0.3m higher than requirement of the conventional lines. The results of this paper can guide live working safely and reliably on lines with parallel gap.
{"title":"Study on the Influence of Parallel Gap on Electric Field Distribution and Live Working of 220kV Transmission Lines","authors":"Chen Chen, Yuqun Fang, Weinan Qin, X. Lei, Yong Peng","doi":"10.1145/3508297.3508301","DOIUrl":"https://doi.org/10.1145/3508297.3508301","url":null,"abstract":"The parallel gap are important equipment for lightning protection of the line, but they shorten the effective length of the insulator to a certain extent. Taking 220kV as an example, the influence of parallel gap on live working is analyzed through experiments and simulation. Firstly, the electric field distribution of the live working space with lightning parallel gap are analyzed by simulation, and the safety protection measures and requirements of the workers are put forward. Finally, the gap discharge test was carried of typical conditions of live working, and the discharge characteristics with parallel gap line were obtained. Then according to the insulation coordination method of live working, the minimum approach distance of live working on 220kV lines with parallel gap is 2.1m, which is 0.3m higher than requirement of the conventional lines. The results of this paper can guide live working safely and reliably on lines with parallel gap.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114797648","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}
Difficulty to assess the risk of the frequency stability control system (FSCS) lies in its complex structure and expected function. In this paper, a risk assessment model to the FSCS is proposed. From the improved probability-based weighted directed graph firstly established, the weighted adjacency matrix is obtained. To find the connectivity of any two nodes, the weighted fully connected matrix is introduced by the path search algorithm since the weighted adjacency matrix has no Boolean property. When assessing the risk of the FSCS, considering its hierarchical structure, redundant configuration of stations and ‘non-point-to-point’ instruction transmission characteristics, the corrected topology with N-1 contingency of the FSCS is established. Then the risk indices are defined from two perspectives of only the FSCS itself and its functional characteristics, while the latter reflects the ability of the FSCS to ensure the security and stability of the AC/ultra-high voltage DC (UHVDC) power system. The sensitivities of the risk indices to the FSCS devices and UHVDC components are quantified based on the risk assessment model. The numerical results of the typical test system are provided to validate the practical value and accuracy of the proposed model.
{"title":"Reliability Sensitivity Analysis to Frequency Stability Control System Based on Improved Probability Weighted Directed Graph","authors":"Yunsong Yan, N. Zhang, Wei Han, Shenghu Li, Jianfeng Ren, Chuang Song, Huimin Zhou","doi":"10.1145/3508297.3508330","DOIUrl":"https://doi.org/10.1145/3508297.3508330","url":null,"abstract":"Difficulty to assess the risk of the frequency stability control system (FSCS) lies in its complex structure and expected function. In this paper, a risk assessment model to the FSCS is proposed. From the improved probability-based weighted directed graph firstly established, the weighted adjacency matrix is obtained. To find the connectivity of any two nodes, the weighted fully connected matrix is introduced by the path search algorithm since the weighted adjacency matrix has no Boolean property. When assessing the risk of the FSCS, considering its hierarchical structure, redundant configuration of stations and ‘non-point-to-point’ instruction transmission characteristics, the corrected topology with N-1 contingency of the FSCS is established. Then the risk indices are defined from two perspectives of only the FSCS itself and its functional characteristics, while the latter reflects the ability of the FSCS to ensure the security and stability of the AC/ultra-high voltage DC (UHVDC) power system. The sensitivities of the risk indices to the FSCS devices and UHVDC components are quantified based on the risk assessment model. The numerical results of the typical test system are provided to validate the practical value and accuracy of the proposed model.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128591471","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}
The decline of system inertia caused by the integration of wind turbines (WTs) greatly threatens the frequency stability of power system. Virtual synchronous controlled (VSynC) wind turbines are thought to be one of the solutions of this problem because they can provide inertia to power system. Existing literature focuses on the impact of VSynC WTs on conventional synchronous generators (SGs), but the electromechanical oscillation caused by VSynC DFIG-Based WTs are rarely studied. In this paper, low frequency oscillation induced by VSynC DFIG-Based WTs is confirmed to exist. Then, a linearized model of VSynC DFIG-Based WTs is derived. The impact mechanism of operation areas and control parameters on low frequency oscillations is studied through the open-loop transfer function of a simple system with VSynC DFIG-based WT integrated. Finally, the analysis results are verified through time-domain simulation.
{"title":"Low Frequency Oscillations Induced by Virtual Synchronous Controlled DFIG-Based Wind Turbines","authors":"Yun-Gang Zhou, Xiaojie Zhang, Wei He","doi":"10.1145/3508297.3508341","DOIUrl":"https://doi.org/10.1145/3508297.3508341","url":null,"abstract":"The decline of system inertia caused by the integration of wind turbines (WTs) greatly threatens the frequency stability of power system. Virtual synchronous controlled (VSynC) wind turbines are thought to be one of the solutions of this problem because they can provide inertia to power system. Existing literature focuses on the impact of VSynC WTs on conventional synchronous generators (SGs), but the electromechanical oscillation caused by VSynC DFIG-Based WTs are rarely studied. In this paper, low frequency oscillation induced by VSynC DFIG-Based WTs is confirmed to exist. Then, a linearized model of VSynC DFIG-Based WTs is derived. The impact mechanism of operation areas and control parameters on low frequency oscillations is studied through the open-loop transfer function of a simple system with VSynC DFIG-based WT integrated. Finally, the analysis results are verified through time-domain simulation.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130152991","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}
The neutral point of secondary circuits of Instrument transformers e.g., Capacitive Voltage Transformer and Current Transformer (CVT & CT) must be earthed, IEEE emphasises that the secondary of instrument transformer must be grounded to protect the connected equipment and to ensure safety of working personnel. It recommends grounding of all in-service secondary circuits at the first point of its application (for CVT, typically a relay or meter) to counter the rise in electrostatic potential in secondary circuit due to stray capacitance. On the contrary, if the secondary neutral point of CVT has multiple earthing, the output voltage is not a replication of primary voltage during fault. This leads to mal-operation or non-operation of protection relays. As no discrepancy in secondary voltages is sensed by relays during normal operation, hence multiple earthing remains unnoticed and thereby compromising the integrity of relay operation. In this case study the behaviour of CVT having multiple neutral earthing has been illustrated, based on the site experience along with disturbance records and relay data. This paper, based on field data and vectorial mathematical analytics establishes the causes of distortions in the CVT secondary voltages due to multiple earthing on its neutral, causing maloperation of protection/relay. Study conclusively brings out correlation between CVT secondary magnitude, phase angle and harmonic generation and suggests formulation of a suitable algorithm/logic in Intelligent electronics device (IEDs)/relay for automatic identification of problem. There is a global trend of automation in the Power system to improve reliability and security. Automatic identification of multiple earthing as illustrated in this paper is a step toward the assimilation of automation in the power system that helps in timely rectification of faults that otherwise cause maloperations or outage of important elements.
{"title":"A case study on Capacitive Voltage Transformer (CVT) behaviour on multiple earthing of CVT secondary circuit in a 400 kV Transmission line.","authors":"Y. S. Rana, Vibhay Kumar, S. Sharma, N. Kumar","doi":"10.1145/3508297.3508305","DOIUrl":"https://doi.org/10.1145/3508297.3508305","url":null,"abstract":"The neutral point of secondary circuits of Instrument transformers e.g., Capacitive Voltage Transformer and Current Transformer (CVT & CT) must be earthed, IEEE emphasises that the secondary of instrument transformer must be grounded to protect the connected equipment and to ensure safety of working personnel. It recommends grounding of all in-service secondary circuits at the first point of its application (for CVT, typically a relay or meter) to counter the rise in electrostatic potential in secondary circuit due to stray capacitance. On the contrary, if the secondary neutral point of CVT has multiple earthing, the output voltage is not a replication of primary voltage during fault. This leads to mal-operation or non-operation of protection relays. As no discrepancy in secondary voltages is sensed by relays during normal operation, hence multiple earthing remains unnoticed and thereby compromising the integrity of relay operation. In this case study the behaviour of CVT having multiple neutral earthing has been illustrated, based on the site experience along with disturbance records and relay data. This paper, based on field data and vectorial mathematical analytics establishes the causes of distortions in the CVT secondary voltages due to multiple earthing on its neutral, causing maloperation of protection/relay. Study conclusively brings out correlation between CVT secondary magnitude, phase angle and harmonic generation and suggests formulation of a suitable algorithm/logic in Intelligent electronics device (IEDs)/relay for automatic identification of problem. There is a global trend of automation in the Power system to improve reliability and security. Automatic identification of multiple earthing as illustrated in this paper is a step toward the assimilation of automation in the power system that helps in timely rectification of faults that otherwise cause maloperations or outage of important elements.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121240313","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}
Yingguang Li, Z. Zhou, Biren Lin, Hao Zhang, Weifeng Huo
With the increase of electricity demand, the overheating phenomenon of the oil-immersed transformer in operation is increasing. In view of the insufficient heat dissipation capacity of the existing ONAN transformer, it is essential to research the heat dissipation enhancement measures of the transformer. The heat transfer process of oil-immersed transformer is firstly analyzed, and the air-side heat transfer coefficient of radiator (hair) is pointed out to be the crucial parameter limiting the heat dissipation capacity of the ONAN transformer. Then, a two-dimensional axisymmetric thermal-fluid coupling model of transformer is established to explore the relationship between hair and transformer internal temperature, and obtain the better hair. Finally, a heat dissipation enhancement measure based on falling film flow is put forward in this paper, and the simulation experiment platform is built to obtain the hair. The results show that the falling film flow measure can achieve the better hair, reduce the top-oil temperature and the hot-spot temperature of the transformer effectively. The proposal of the heat dissipation enhancement measure based on falling film flow can provide a new solution to meet the overload operation requirements of transformers and reduce the probability of ONAN transformer overheating.
{"title":"A Heat Dissipation Enhancement Measure for Transformer Based on Falling Film Flow","authors":"Yingguang Li, Z. Zhou, Biren Lin, Hao Zhang, Weifeng Huo","doi":"10.1145/3508297.3508313","DOIUrl":"https://doi.org/10.1145/3508297.3508313","url":null,"abstract":"With the increase of electricity demand, the overheating phenomenon of the oil-immersed transformer in operation is increasing. In view of the insufficient heat dissipation capacity of the existing ONAN transformer, it is essential to research the heat dissipation enhancement measures of the transformer. The heat transfer process of oil-immersed transformer is firstly analyzed, and the air-side heat transfer coefficient of radiator (hair) is pointed out to be the crucial parameter limiting the heat dissipation capacity of the ONAN transformer. Then, a two-dimensional axisymmetric thermal-fluid coupling model of transformer is established to explore the relationship between hair and transformer internal temperature, and obtain the better hair. Finally, a heat dissipation enhancement measure based on falling film flow is put forward in this paper, and the simulation experiment platform is built to obtain the hair. The results show that the falling film flow measure can achieve the better hair, reduce the top-oil temperature and the hot-spot temperature of the transformer effectively. The proposal of the heat dissipation enhancement measure based on falling film flow can provide a new solution to meet the overload operation requirements of transformers and reduce the probability of ONAN transformer overheating.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126762588","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}
Abstract: This paper reports a blue-free LED bulb with green light LED chip and orange and red phosphor coating on the chip. The green light LED chip has a wavelength of 525nm. The orange and red phosphors on LED chip have peak wavelength of 590nm and 620nm respectively. The green LED chip with orange and red phosphors produces blue free amber light which is more beneficial to human sleep compared to light with blue wavelength.
{"title":"Blue Light Free LED Chip and Bulb","authors":"Bonnie Lu, Amanda Lu, Jicun Lu","doi":"10.1145/3508297.3508328","DOIUrl":"https://doi.org/10.1145/3508297.3508328","url":null,"abstract":"Abstract: This paper reports a blue-free LED bulb with green light LED chip and orange and red phosphor coating on the chip. The green light LED chip has a wavelength of 525nm. The orange and red phosphors on LED chip have peak wavelength of 590nm and 620nm respectively. The green LED chip with orange and red phosphors produces blue free amber light which is more beneficial to human sleep compared to light with blue wavelength.","PeriodicalId":285741,"journal":{"name":"2021 4th International Conference on Electronics and Electrical Engineering Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130627994","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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