Bo Sang, Lingshun Liu, T. Zhang, Yajie Liu, Junjie Zhu
{"title":"Two-stage Robust Economic Dispatch of Multi-microgrids under Expected Scenario","authors":"Bo Sang, Lingshun Liu, T. Zhang, Yajie Liu, Junjie Zhu","doi":"10.1109/HVDC50696.2020.9292683","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292683","url":null,"abstract":"With the increasing number of microgrids (MGs) connected to the distribution network system (DNS) in the region, the multi-microgrids (MMGs) is built in recent years. MMGs can effectively carry out energy interaction among MGs and improve the utilization rate of renewable energy. However, uncertainty will affect the energy interaction between MGs and the operation of MMGs. To solve this problem, a two-stage robust optimization (TRO) scheduling model for MMGs under expected scenario is first proposed in this paper. In the first stage (the uncertainty is unknown), the first-stage decision variables are obtained by taking the minimum operation of MMGs as the optimization objective in the expected scenarios, and then the robustness of the first-stage decision variables is determined by the robust test model (RTM) under the given uncertainty set. RTM is transformed based on two-stage zero-sum game theory and dual theory, a column and constraint generation algorithm (C&CG) is first used to test the robust feasibility of the first-stage decision variables. In the second stage (the uncertainty is known), the proposed model can obtain the second-stage decision variables without changing the first-stage decision variables. Case studies verify that the proposed model can effectively solve the impact of uncertainty on system operation, and has lower operation cost than the non-interactive MMGs.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"33 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":"114992973","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":"Frequency Trajectory Planning Based Transient Frequency Support of D-PMSG","authors":"Hongqing Liu, L. Xiong, Mingxian Li, Lei Liu","doi":"10.1109/HVDC50696.2020.9292781","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292781","url":null,"abstract":"The grid connection of large-scale wind power will reduce the equivalent inertia and damping of the system, resulting in a decrease in system frequency stability. The directly-driven permanent magnet synchronous generators (D-PMSG)-based wind turbine (WT) usually uses conventional PD control to support frequency, however, the related controller parameters are difficult to design, reducing economic benefits of WT power generation and slowing speed recovery. To this end, based on the analysis of the dynamic response of D-PMSG grid-tied system, this paper studies the dynamic influence and variation law of controller parameters on system frequency. A WT control strategy based on frequency trajectory planning (FTP) is proposed. The frequency fixed value determined by the power grid regulation is directly taken as the control target to carry out the FTP, and the WT auxiliary power output is controlled according to the planned frequency trajectory. The system frequency is supported quickly in the transient process, ensuring the safe and stable operation of the grid while realizing the economy of WT power generation. The effectiveness and economy of the proposed control strategy is verified by RT-LAB experiment.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"114 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":"117246266","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}
Yun Su, Shaohua Li, Binbin Li, Xiaoting Ma, Dongxiao Yao, Wang Zhang
{"title":"Control Strategies for Multi-Terminal DC Transmission System with Special Parallel Topology","authors":"Yun Su, Shaohua Li, Binbin Li, Xiaoting Ma, Dongxiao Yao, Wang Zhang","doi":"10.1109/HVDC50696.2020.9292876","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292876","url":null,"abstract":"With the development of high voltage direct current (HVDC) transmission technology, parallel converters have received increasing attentions. The multi-terminal dc (MTDC) system with parallel connection of converters is particularly advantageous when the transmission is built in stages or when it works under de-icing mode. The simplest MTDC topology with the parallel converters located in the same station is the subject of this paper. The characteristics of four-terminal HVDC system with parallel converters are analyzed. A new cooperation strategy is proposed which rectifiers control dc current, inverters control dc voltage and a per-unit dc current balancing control function applied to avoid an unambiguous operating dc voltage. This cooperation strategy not only simplifies the control system design for the 4-terminal HVDC transmission, retains the independence of the two 2-terminal HVDC systems to the utmost extent, but also any proportion power distribution among the two inverters is achieved. De-paralleling the second converter and paralleling the first converter are of special interest for parallel operation, the methods of doing this are also described. Finally, a case of 4-terminal HVDC system with the special topology validates the control strategies using PSCAD/EMTDC.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"63 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":"127121577","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}
Z. Pan, J. Deng, Jinwei Chu, Jinyin Zhang, Zhicheng Xie, C. Liang
{"title":"Research on Excitation Voltage Frequency and Amplitude Dependence of Iron Core Vibration of HVDC Converter Transformer","authors":"Z. Pan, J. Deng, Jinwei Chu, Jinyin Zhang, Zhicheng Xie, C. Liang","doi":"10.1109/HVDC50696.2020.9292749","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292749","url":null,"abstract":"This paper analyzed the magnetostrictive characteristics of iron core and stress mechanism of the silicon steel of HVDC converter transformer. Vibration test of iron core were carried out in the field and in the factory. And excitation voltage frequency and amplitude dependence of vibration acceleration signals of iron core were studied as well. This paper might provide certain support for fault detection for iron core based on vibration analysis technology.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"9 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":"126101345","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}
Xin Li, Liyin Zhang, Fei Liu, Yi Liang, Chaofan Lin, Huili Tian, Gengfeng Li, Z. Bie
{"title":"Data-driven real-time risk assessment of resilient distribution system during typhoon weather","authors":"Xin Li, Liyin Zhang, Fei Liu, Yi Liang, Chaofan Lin, Huili Tian, Gengfeng Li, Z. Bie","doi":"10.1109/HVDC50696.2020.9292744","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292744","url":null,"abstract":"Coastal distribution systems are vulnerable to typhoon weather. An efficient and accurate real-time risk assessment is very necessary in providing timely warning information for decision making. However, the conventional risk assessment methods are subject to varied typology, parameters and uncertainties. While in current data-driven methods, the effect of complex factors such as resilient resources and emergency response are difficult to be analytically incorporated in risk assessment procedure. To solve the problems, this paper proposes an improved data-driven real-time risk assessment method for resilient distribution systems during typhoon weather. A comprehensive risk-oriented database with 25 indexes is constructed based on practical experience in system operation. And then the effects of various complex factors on distribution system risk are characterized by entropy weights and gray correlation degrees. The case study on a modified 33-node system has validated the proposed method in real-time risk assessment. The whole scheme can be helpful for the software and hardware update of resilient distribution systems.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"48 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":"115355665","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":"High frequency development and discharge characteristics of SiO2 modified polyimide films","authors":"Z. Xing, Pengfei Wu, Helin Xu, Zi’an Ding, Jianhong Hao, Qingmin Li, Zhiyun Han, Yujin Guo, Ziwei Dong","doi":"10.1109/HVDC50696.2020.9292885","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292885","url":null,"abstract":"Polyimide can be used to coat insulation of high frequency power transformer. Surface discharge will lead to insulation failure. In this paper, nano-SiO2 particles containing 2%, 4%, 6%, 8% and 10% Si element were introduced into polyimide for nano composite modification (Si0, Si2, Si4, Si6, Si8, Si10). It is found that the lifetime of Si0 is the shortest and that of Si10 is the longest. The development process and characteristics of high-frequency surface discharge of Si0 and Si10 are studied. The results show that: in the process of high-frequency surface discharge of pin plate electrode, the damage caused by flashover is greater. The discharge at positive half cycle and polarity reversal is more severe. Compared with Si0, the amplitude and number of discharge of positive half cycle and overall of Si10 are smaller. At first, the discharge amplitude of Si10 is larger but the number of discharge is less. The discharge amplitude of two kinds of films fluctuates in the middle stage, and the discharge frequency of Si10 is more in the later stage. The discharge amplitude and frequency of Si0 are much higher than that of Si10, which leads to the rapid breakdown of Si0. Further research shows that resistivity of Si10 is less than that of Si0, so discharge of Si10 is more serious in the early stage. The material structure characteristics plays an important role in in the middle and late stage. The interface effect and light energy absorption caused by modification play an important role, so the discharge of Si0 is more serious.","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":"116435217","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":"Robust High-Power DC/DC Converter for HVDC Interconnections with Buck/Boost Capabilities","authors":"Yujie Zhang, Binbin Li, Shuxin Zhang, Xiaodong Zhao, Dianguo Xu","doi":"10.1109/HVDC50696.2020.9292745","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292745","url":null,"abstract":"In order to realize the acceptance and delivery of large-scale renewable energy, many countries have begun to construct multiple DC lines into multi-terminal power transmission or even DC grids. High-voltage and large-capacity DC/DC converters, as key equipment in future DC grids, have become a hot spot at home and abroad in recent years. This paper proposes a robust high-power DC/DC converter topology by organically combining the thyristors and the sub-modules, which has the advantages of low cost, high efficiency and buck/boost capability. Validity and effectiveness of the TSDC are verified by 150MW, 200kV/300kV simulation case study as well as the experimental tests from a 4.5kW, 300V/450V scaled down prototype.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"14 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":"114419151","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":"Operational Test System of Current-Source Actively Commutated Converter","authors":"Jinhu Luo, Fei Xu, Zixin Li, Kedong Luan, Fanqiang Gao, Cong Zhao, Ping-Jian Wang, Yao-hua Li, Qian Chen, Longlong Chen","doi":"10.1109/HVDC50696.2020.9292689","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292689","url":null,"abstract":"With the development of semiconductor, the current source actively commutated converter (ACC) provides a new solution for HVDC. Before the engineering application, the voltage and current stresses of ACC under different operational conditions should be tested first. Building a full-circuit test platform to test the valves is very resource-intensive, thus an operational test system of ACC with the low power requirement is proposed in this paper. It consists of a low-voltage high-current source, a low-current high-voltage source, a resonant circuit, and multiple auxiliary valves and is the improvements of thyristor valves test circuit. The simulation verification shows that the proposed method can better test the voltage and current stresses of ACC in various operational conditions with a low power rate. It can be applied to ACC-HVDC engineering construction.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"30 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":"121870796","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":"Research on the control strategy of multi-terminal low frequency transmission system for island power supply scenes","authors":"Zhengxiong Ma, L. Ning, Jingwen Han","doi":"10.1109/HVDC50696.2020.9292825","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292825","url":null,"abstract":"In recent years, with the rapid development of the national economy, the national electricity consumption has increased significantly. Under the scenario of island power supply, the contradiction of insufficient transmission capacity is particularly prominent. Therefore, it is necessary to increase the transmission capacity of the existing lines or to build new transmission lines. As a new type of transmission technology, low-frequency transmission technology has the advantages of relatively increased transmission capacity, no circuit breaker technology bottleneck, and the energy release rate of low-frequency AC (LFAC) system is significantly lower than that of DC system. Therefore, LFAC transmission technology is a very competitive transmission technology in island power supply scenario. This paper analyzes the advantages and disadvantages of various transmission technologies, studies the control strategy of AC-AC converter and the coordinated control strategy of multi-terminal LFAC power grid. The master-slave control strategy of multi-terminal LFAC transmission system is proposed. The simulation model of four -terminal LFAC transmission system is established in PSCAD / EMTDC. Through the simulation analysis of the proposed control strategy, the feasibility and effectiveness of the control strategy are verified.","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":"128518360","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}
Zhe Chen, Miao Zhu, Chuanchuan Hou, N. Dai, X. Cai
{"title":"Voltage Source Rectifiers with Power Synchronization Control","authors":"Zhe Chen, Miao Zhu, Chuanchuan Hou, N. Dai, X. Cai","doi":"10.1109/HVDC50696.2020.9292878","DOIUrl":"https://doi.org/10.1109/HVDC50696.2020.9292878","url":null,"abstract":"In this paper, a novel control method of voltage source rectifiers (VSRs) is proposed. The method can be generally applied for all VSRs, and the phase-locked loop (PLL) can be replaced effectively. Different from existed work, the proposed method utilizes the internal synchronization mechanism in ac systems, which is similar to the operation of a synchronous machine. By using this type of power synchronization rectifying control (PSRC), the VSR avoids the instability caused by a standard phase locked loop in a weak ac system connection. The control method is verified by time simulation.","PeriodicalId":298807,"journal":{"name":"2020 4th International Conference on HVDC (HVDC)","volume":"93 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":"124661527","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}