Pub Date : 2020-11-06DOI: 10.1109/HVDC50696.2020.9292850
Ying Xu, Zheng Zhao, B. Yue, Xuan Li
China is rich in offshore wind power resources. With the development of offshore wind power resources near the coast and the continuous improvement of technology, the development and utilization of offshore wind power resources away from the coast has become an inevitable trend. Voltage sourced converters high voltage direct current (VSC-HVDC) transmission is the best technical method to complete the collection and transmission of offshore wind power resources away from the coast. The transient overvoltage level of the VSC-HVDC system is an important factor in determining the insulation level of the equipment, air clearance and project costs. This paper adopts PSCAD/EMTDC simulation analysis method, and conducts research based on a real offshore wind power transmission project via VSC-HVDC under construction. This paper analyzes the characteristics of typical faults, as well as the transient overvoltage levels at key locations of both offshore converter station and onshore converter station under different operating conditions. The influences of different operating conditions on the overvoltage level are analyzed. Studies have shown that due to the capacitance effect of long-distance DC submarine cables, the fault characteristics and transient overvoltage duration of the DC system are far from the previous VSC-HVDC projects. Protection strategy, transmission power, switching strategy of DC energy dissipation device will all affect transient overvoltage. The feature of cable overvoltage is studied. The maximum transient overvoltage levels between terminals, phases and poles are obtained. The research conclusions can provide a theoretical basis for the development of equipment and the layout of converter stations. Furthermore, it also provides a reference for the follow-up offshore wind power transmission projects.
{"title":"Research on Transient Overvoltage Characteristics of VSC-HVDC Transmission System Connecting to Large-scale Offshore Wind Farm","authors":"Ying Xu, Zheng Zhao, B. Yue, Xuan Li","doi":"10.1109/HVDC50696.2020.9292850","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292850","url":null,"abstract":"China is rich in offshore wind power resources. With the development of offshore wind power resources near the coast and the continuous improvement of technology, the development and utilization of offshore wind power resources away from the coast has become an inevitable trend. Voltage sourced converters high voltage direct current (VSC-HVDC) transmission is the best technical method to complete the collection and transmission of offshore wind power resources away from the coast. The transient overvoltage level of the VSC-HVDC system is an important factor in determining the insulation level of the equipment, air clearance and project costs. This paper adopts PSCAD/EMTDC simulation analysis method, and conducts research based on a real offshore wind power transmission project via VSC-HVDC under construction. This paper analyzes the characteristics of typical faults, as well as the transient overvoltage levels at key locations of both offshore converter station and onshore converter station under different operating conditions. The influences of different operating conditions on the overvoltage level are analyzed. Studies have shown that due to the capacitance effect of long-distance DC submarine cables, the fault characteristics and transient overvoltage duration of the DC system are far from the previous VSC-HVDC projects. Protection strategy, transmission power, switching strategy of DC energy dissipation device will all affect transient overvoltage. The feature of cable overvoltage is studied. The maximum transient overvoltage levels between terminals, phases and poles are obtained. The research conclusions can provide a theoretical basis for the development of equipment and the layout of converter stations. Furthermore, it also provides a reference for the follow-up offshore wind power transmission projects.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133564510","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 : 2020-11-06DOI: 10.1109/HVDC50696.2020.9292723
Jinlu Liu, Wenjie Chen, Xin Ma, Ru Zhang, Ruitao Yan
DC microgrids get a lot of attention because of its good characteristics. DC-DC converter is necessary in DC microgrids to interface energy. The dual active bridge (DAB) converter is one of most promising DC-DC converters. But when the normalized voltage gain is far from 1, the DAB converter is difficult to realize soft switching. In this paper, the neutral point clamped (NPC) dual-active-bridge (DAB) converter with a blocking capacitor is adopted. This converter is able to work in different modes to achieve wide zero voltage switching (ZVS) range. A ZVS range optimization strategy is proposed based on ZVS range analysis in different modes. This strategy makes the NPC DAB converter work in the optimal mode. The simulation results show this strategy is effective.
{"title":"A zero voltage switching range optimization strategy for NPC Dual-Active-Bridge Converter","authors":"Jinlu Liu, Wenjie Chen, Xin Ma, Ru Zhang, Ruitao Yan","doi":"10.1109/HVDC50696.2020.9292723","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292723","url":null,"abstract":"DC microgrids get a lot of attention because of its good characteristics. DC-DC converter is necessary in DC microgrids to interface energy. The dual active bridge (DAB) converter is one of most promising DC-DC converters. But when the normalized voltage gain is far from 1, the DAB converter is difficult to realize soft switching. In this paper, the neutral point clamped (NPC) dual-active-bridge (DAB) converter with a blocking capacitor is adopted. This converter is able to work in different modes to achieve wide zero voltage switching (ZVS) range. A ZVS range optimization strategy is proposed based on ZVS range analysis in different modes. This strategy makes the NPC DAB converter work in the optimal mode. The simulation results show this strategy is effective.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114709880","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 : 2020-11-06DOI: 10.1109/HVDC50696.2020.9292714
Shiyi Sun, Lin Zhou, X. Xi
DC power grid has been considered as a better choice for large-scale new energy grid connection and long-distance transmission, which can effectively improve the stability and reliability of power grid. High voltage DC-DC converter, as one of the key devices connecting different voltage levels of DC system, plays the role of voltage matching, power flow control, fault isolation and so on. The paper proposed an improved single-phase DC-DC converter based on modular multilevel converter(MMC). It is a DC/AC/DC system with the intermediate medium frequency transformer. DC input voltage is inverted by VSC to intermediate frequency AC voltage, and then boosted by transformer. Finally, stable DC voltage is output by MMC rectification. The low voltage side adopts constant reactive power control, while the high voltage side adopts constant AC voltage control. With the midfrequency transformer, larger ratio can be got. In addition, properly increasing the AC frequency can reduce the volume and loss of the transformer and other passive components used in the circuit. The proposed topology structure and control strategy is validated by MATLAB SIMULINK simulation.
{"title":"An Improved DC-DC Converter Based on MMC","authors":"Shiyi Sun, Lin Zhou, X. Xi","doi":"10.1109/HVDC50696.2020.9292714","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292714","url":null,"abstract":"DC power grid has been considered as a better choice for large-scale new energy grid connection and long-distance transmission, which can effectively improve the stability and reliability of power grid. High voltage DC-DC converter, as one of the key devices connecting different voltage levels of DC system, plays the role of voltage matching, power flow control, fault isolation and so on. The paper proposed an improved single-phase DC-DC converter based on modular multilevel converter(MMC). It is a DC/AC/DC system with the intermediate medium frequency transformer. DC input voltage is inverted by VSC to intermediate frequency AC voltage, and then boosted by transformer. Finally, stable DC voltage is output by MMC rectification. The low voltage side adopts constant reactive power control, while the high voltage side adopts constant AC voltage control. With the midfrequency transformer, larger ratio can be got. In addition, properly increasing the AC frequency can reduce the volume and loss of the transformer and other passive components used in the circuit. The proposed topology structure and control strategy is validated by MATLAB SIMULINK simulation.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117309650","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 : 2020-11-06DOI: 10.1109/HVDC50696.2020.9292899
Baomin Fang, Y. Jiao, Ling Dong, W. Zhou, H. Nian
This paper uses the virtual synchronous generator (VSG) control based energy storage to enhance the stability of sending terminal in line line-commutated converter (LLC) based high voltage direct current (HVDC) transmission systems. LCC-HVDC are widely utilized in China to transmit renewable power generation from western area to the east in thousands kilometers distance. However, the reports of stability about HVDC and renewable power generation occur in recent decades. Based on the impedance theory, this paper analyzes the small signal stability of HVDC sending terminal. Recently, because of flexibility and functionality of supporting grid, power electronics based energy storage is attracting a wide-spread attention. The impedance model of virtual synchronous generator control (VSG) based energy storage is introduced in this manuscript. The impedance analysis indicates that the VSG based energy storage can improve the stability of HVDC sending terminal. Based on the impedance model, the capacity of energy storage is also analyzed. To illustrate the correctness and effectiveness of impedance analysis, the simulation results are given in the manuscript.
{"title":"Using Virtual Synchronous Generator Control Based Energy Storage to Enhance the Stability of Sending Terminal in LCC-HVDC System","authors":"Baomin Fang, Y. Jiao, Ling Dong, W. Zhou, H. Nian","doi":"10.1109/HVDC50696.2020.9292899","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292899","url":null,"abstract":"This paper uses the virtual synchronous generator (VSG) control based energy storage to enhance the stability of sending terminal in line line-commutated converter (LLC) based high voltage direct current (HVDC) transmission systems. LCC-HVDC are widely utilized in China to transmit renewable power generation from western area to the east in thousands kilometers distance. However, the reports of stability about HVDC and renewable power generation occur in recent decades. Based on the impedance theory, this paper analyzes the small signal stability of HVDC sending terminal. Recently, because of flexibility and functionality of supporting grid, power electronics based energy storage is attracting a wide-spread attention. The impedance model of virtual synchronous generator control (VSG) based energy storage is introduced in this manuscript. The impedance analysis indicates that the VSG based energy storage can improve the stability of HVDC sending terminal. Based on the impedance model, the capacity of energy storage is also analyzed. To illustrate the correctness and effectiveness of impedance analysis, the simulation results are given in the manuscript.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122690863","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 : 2020-11-06DOI: 10.1109/HVDC50696.2020.9292818
L. Wei, W. Hang, Chen Gen, Zhang Jian Wen, Cai Xu
The operating environment of offshore wind power is harsh, and the random fluctuation of wind power is large, which makes power devices easy to fail. Fault tolerant control is an effective means to improve the reliability and availability of wind power converters. Taking an open circuit fault of a parallel converter as an example, this paper analyzes the fault operation mechanism of a parallel wind power converter in detail. On this basis, a fault-tolerant control strategy based on negative-sequence current compensation is proposed, and a non-faulty converter module is used to compensate the negative-sequence current of the faulty converter module. When the system power is less than or equal to 0.5 pu, the maximum output power of the converter is realized under the condition of ensuring the current balance of the grid-connected side; when the system power is greater than 0.5pu, the negative sequence of the grid-side is controlled to minimum under the condition of outputting the maximum power. Finally, the correctness and feasibility of the control strategy theory are verified by simulation.
{"title":"Optimal Fault-tolerant Control for Improving the Availability of Parallel Wind Power Converters","authors":"L. Wei, W. Hang, Chen Gen, Zhang Jian Wen, Cai Xu","doi":"10.1109/HVDC50696.2020.9292818","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292818","url":null,"abstract":"The operating environment of offshore wind power is harsh, and the random fluctuation of wind power is large, which makes power devices easy to fail. Fault tolerant control is an effective means to improve the reliability and availability of wind power converters. Taking an open circuit fault of a parallel converter as an example, this paper analyzes the fault operation mechanism of a parallel wind power converter in detail. On this basis, a fault-tolerant control strategy based on negative-sequence current compensation is proposed, and a non-faulty converter module is used to compensate the negative-sequence current of the faulty converter module. When the system power is less than or equal to 0.5 pu, the maximum output power of the converter is realized under the condition of ensuring the current balance of the grid-connected side; when the system power is greater than 0.5pu, the negative sequence of the grid-side is controlled to minimum under the condition of outputting the maximum power. Finally, the correctness and feasibility of the control strategy theory are verified by simulation.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123862634","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 : 2020-11-06DOI: 10.1109/HVDC50696.2020.9292816
M. Feng, Chenxiang Gao, Jiangping Ding, Jianzhong Xu, Chengyong Zhao
This paper proposes a high-speed modeling architecture for fast electromagnetic transient (EMT) simulation of PETs. Unlike the existing modeling methods, the proposed technique recursively decreases the dimension order of the admittance matrix to obtain the generalized Norton equivalent of each phase leg. The final admittance matrix overlaid onto the external system admittance matrix has a dimension orders of magnitude remarkably smaller than that of the unreduced structure. By comparison with a detailed EMT model of a medium-voltage dc (MVDC) grid, the performance of the proposed scheme has been assessed in PSCAD/EMTDC under various working conditions. With negligible loss of accuracy, approximately one to two orders of magnitude speedup over a straightforward EMT program is achieved.
{"title":"High-Speed Modeling Architecture for Fast EMT Simulation of Power Electronic Transformers","authors":"M. Feng, Chenxiang Gao, Jiangping Ding, Jianzhong Xu, Chengyong Zhao","doi":"10.1109/HVDC50696.2020.9292816","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292816","url":null,"abstract":"This paper proposes a high-speed modeling architecture for fast electromagnetic transient (EMT) simulation of PETs. Unlike the existing modeling methods, the proposed technique recursively decreases the dimension order of the admittance matrix to obtain the generalized Norton equivalent of each phase leg. The final admittance matrix overlaid onto the external system admittance matrix has a dimension orders of magnitude remarkably smaller than that of the unreduced structure. By comparison with a detailed EMT model of a medium-voltage dc (MVDC) grid, the performance of the proposed scheme has been assessed in PSCAD/EMTDC under various working conditions. With negligible loss of accuracy, approximately one to two orders of magnitude speedup over a straightforward EMT program is achieved.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125409223","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 : 2020-11-06DOI: 10.1109/HVDC50696.2020.9292826
F. Peng, Qingming Xin, Bo Lei, Shukai Xu, Wei-huang Huang, Tao Liu
The sea-crossing Mindanao - Visayas Interconnection (MVIP) HVDC Project will help to increase the power reliability and optimize energy layout in the Philippines. In this paper, the overview information of the MVIP Project are introduced firstly. Then basic control strategy and operation modes are designed. In addition, two special steady-state control strategies are also elaborated, including low-power start control and power direction control. At last, a simulation model is established in PSCAD/EMTDC platform, and smooth start-up as well as steady-state operation are realized. The validity and feasibility of the proposed strategies are verified according to the case study.
{"title":"Steady-State Control Strategy of Mindanao-Visayas Interconnection HVDC Project in the Philippines","authors":"F. Peng, Qingming Xin, Bo Lei, Shukai Xu, Wei-huang Huang, Tao Liu","doi":"10.1109/HVDC50696.2020.9292826","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292826","url":null,"abstract":"The sea-crossing Mindanao - Visayas Interconnection (MVIP) HVDC Project will help to increase the power reliability and optimize energy layout in the Philippines. In this paper, the overview information of the MVIP Project are introduced firstly. Then basic control strategy and operation modes are designed. In addition, two special steady-state control strategies are also elaborated, including low-power start control and power direction control. At last, a simulation model is established in PSCAD/EMTDC platform, and smooth start-up as well as steady-state operation are realized. The validity and feasibility of the proposed strategies are verified according to the case study.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126165096","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 : 2020-11-06DOI: 10.1109/HVDC50696.2020.9292722
Shengli Guan, B. Zhu, Pengfei Cui, Huan Shen, Anbing Wu
With the promotion of technology and policy, wind power generation is developing towards large-scale and offshore. Due to the great amount of heat and high maintenance cost, higher requirements are put forward for the cooling system, among which the vibration is particularly important. In this paper, the vibration problem of the wind turbine in the generator cooling system is studied. The vibration experiment is carried out and found that the vibration can be effectively controlled only when the motor frequency is dynamically balanced in all the range; Strengthening the connection between the wind turbine and the bracket, the vibration velocity is reduced from 48.1mm/s to 12.4mm/s; The frequency corresponding to the peak vibration velocity is changed at the same time; According to the modal analysis, the range of the natural frequency of the wind turbine coincides with that of the motor frequency, causing the resonance. In the structural design of the wind turbine, the coincidence of natural frequency and motor frequency should be avoided; The simulation results are in agreement with experimental results. This two methods can effectively solve the vibration problem.
{"title":"Experimental investigation and simulation on vibration of wind turbine in cooling system of wind power generation","authors":"Shengli Guan, B. Zhu, Pengfei Cui, Huan Shen, Anbing Wu","doi":"10.1109/HVDC50696.2020.9292722","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292722","url":null,"abstract":"With the promotion of technology and policy, wind power generation is developing towards large-scale and offshore. Due to the great amount of heat and high maintenance cost, higher requirements are put forward for the cooling system, among which the vibration is particularly important. In this paper, the vibration problem of the wind turbine in the generator cooling system is studied. The vibration experiment is carried out and found that the vibration can be effectively controlled only when the motor frequency is dynamically balanced in all the range; Strengthening the connection between the wind turbine and the bracket, the vibration velocity is reduced from 48.1mm/s to 12.4mm/s; The frequency corresponding to the peak vibration velocity is changed at the same time; According to the modal analysis, the range of the natural frequency of the wind turbine coincides with that of the motor frequency, causing the resonance. In the structural design of the wind turbine, the coincidence of natural frequency and motor frequency should be avoided; The simulation results are in agreement with experimental results. This two methods can effectively solve the vibration problem.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125795088","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 : 2020-11-06DOI: 10.1109/HVDC50696.2020.9292788
L. Bao, Y. Mo, Dawei Yang, Minxiang Yang, Z. Shi, S. Jia
Flexible HVDC transmission has wide prospects in new energy grid connection and consumption, rail traction, and the urban distribution network in the future. Mechanical HVDC circuit breaker is one of the most potential breaking methods in the future due to its high current interruption ability and low on-state loss. Firstly, the parameters di/dt and du/dt which affect them breaking performance are analyzed in this paper. Then, the variation of voltage and current characteristics of a 10kV mechanical HVDC circuit breaker under different operating conditions are simulated with Matlab/Simulink. Finally, the impact of two typical circuit breaker failures on di/dt and du/dt were analyzed and compared.
{"title":"Research on Interrupting Processes of A 10 kV Mechanical HVDC Circuit Breaker","authors":"L. Bao, Y. Mo, Dawei Yang, Minxiang Yang, Z. Shi, S. Jia","doi":"10.1109/HVDC50696.2020.9292788","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292788","url":null,"abstract":"Flexible HVDC transmission has wide prospects in new energy grid connection and consumption, rail traction, and the urban distribution network in the future. Mechanical HVDC circuit breaker is one of the most potential breaking methods in the future due to its high current interruption ability and low on-state loss. Firstly, the parameters di/dt and du/dt which affect them breaking performance are analyzed in this paper. Then, the variation of voltage and current characteristics of a 10kV mechanical HVDC circuit breaker under different operating conditions are simulated with Matlab/Simulink. Finally, the impact of two typical circuit breaker failures on di/dt and du/dt were analyzed and compared.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128713052","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 : 2020-11-06DOI: 10.1109/HVDC50696.2020.9292863
Wang Weiwang, He Jiefeng, Wang Xin, L. Ying, Li Shengtao
In this paper, the voltage, electric field, and dielectric loss of the high frequency transformer used in power electronic transformer are studied. According to the finite element method (FEM), the influence of the voltage and harmonic components on the electric field distribution and dielectric loss of the high frequency transformer were calculated. The results show that the voltage of high frequency transformer winding to the ground is greater than that of winding terminal voltage at the top module of the cascade structure. Moreover, the former voltage contains lots of high order harmonics. The insulation between the windings suffers from the nonsinusoidal periodic voltages with multi-harmonics. The superposition of the harmonic stresses enhances the electric field distortion in the insulation, which probably causes partial discharges and insulation failure. The electric field respect to the high voltage winding to the ground with harmonics presents high values at the end of the windings and between the turns. The dielectric losses of the insulation under the high-frequency field are much higher than that of power frequency (50 Hz). It is mainly caused by the switching frequency and the high electric field. This work is of great significance to the insulation design of high voltage and large capacity power electronic transformer.
{"title":"Analysis of Electric Field Stress and Dielectric Loss in Insulation of Magnetic Component for Cascaded Power Electronic Transformer","authors":"Wang Weiwang, He Jiefeng, Wang Xin, L. Ying, Li Shengtao","doi":"10.1109/HVDC50696.2020.9292863","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292863","url":null,"abstract":"In this paper, the voltage, electric field, and dielectric loss of the high frequency transformer used in power electronic transformer are studied. According to the finite element method (FEM), the influence of the voltage and harmonic components on the electric field distribution and dielectric loss of the high frequency transformer were calculated. The results show that the voltage of high frequency transformer winding to the ground is greater than that of winding terminal voltage at the top module of the cascade structure. Moreover, the former voltage contains lots of high order harmonics. The insulation between the windings suffers from the nonsinusoidal periodic voltages with multi-harmonics. The superposition of the harmonic stresses enhances the electric field distortion in the insulation, which probably causes partial discharges and insulation failure. The electric field respect to the high voltage winding to the ground with harmonics presents high values at the end of the windings and between the turns. The dielectric losses of the insulation under the high-frequency field are much higher than that of power frequency (50 Hz). It is mainly caused by the switching frequency and the high electric field. This work is of great significance to the insulation design of high voltage and large capacity power electronic transformer.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128851132","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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