{"title":"Impedance-Based Modeling of a Three-level Converter Under Balanced and Unbalanced Condition for the Stability Analysis of Bipolar LVDC Grids","authors":"T. Roose, G. Van den Broeck, M. Alam, J. Beerten","doi":"10.23919/EPE20ECCEEurope43536.2020.9215675","DOIUrl":"https://doi.org/10.23919/EPE20ECCEEurope43536.2020.9215675","url":null,"abstract":"This paper presents an impedance-based assessment to identify potential instabilities in bipolar LVDC grids where the voltage is controlled by a three-level DC-DC converter. As an essential step to perform the assessment, the small-signal admittance matrix of the three-level DC-DC converter is analytically derived and verified by a non-linear switched model implemented in the EMT-type software PSCAD. It is shown that the converter admittance matrix exhibits non-passive behavior at frequencies above 500 Hz. Furthermore, the non-passivity is found to be dependent on the operating point of the converter. This behavior can negatively interact with resonances of bipolar LVDC systems, e.g. LC-filter resonances, leading to unstable high-frequency oscillations and system instability.","PeriodicalId":241752,"journal":{"name":"2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127953437","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}
R. Heydari, M. Golsorkhi, M. Savaghebi, T. Dragičević, F. Blaabjerg
{"title":"Communication-Free Secondary Frequency and Voltage Control of VSC-Based Microgrids: A High-Bandwidth Approach","authors":"R. Heydari, M. Golsorkhi, M. Savaghebi, T. Dragičević, F. Blaabjerg","doi":"10.23919/EPE20ECCEEurope43536.2020.9215874","DOIUrl":"https://doi.org/10.23919/EPE20ECCEEurope43536.2020.9215874","url":null,"abstract":"In this paper, a decentralized secondary control strategy for microgrids, with fast dynamic response is proposed. This high bandwidth approach is realized by applying a finite control set, model predictive control (FCS-MPC) at the primary control level of the voltage source converters (VSCs) control. At the upper control level, a novel decentralized secondary control structure is proposed to regulate the islanded microgrid voltage and frequency subsequent to load change, with no need of any communication infrastructure. The proposed control strategy, restores the microgrid frequency and voltage to the nominal value while maintaining accurate power-sharing of the droop mechanism. Experimental results are also provided to verify the effectiveness of the proposed approach.","PeriodicalId":241752,"journal":{"name":"2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127981872","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}
Amirouche Oumaziz, E. Sarraute, F. Richardeau, A. Bourennane
{"title":"Fail-safe switching-cells architectures based on monolithic on-chip fuse","authors":"Amirouche Oumaziz, E. Sarraute, F. Richardeau, A. Bourennane","doi":"10.23919/EPE20ECCEEurope43536.2020.9215608","DOIUrl":"https://doi.org/10.23919/EPE20ECCEEurope43536.2020.9215608","url":null,"abstract":"In this work, we propose a new concept of fail-safe switching cells based on the use of integrated fuses. These fuses allow the circuit to be partially isolated and reconfigured, which therefore becomes fault tolerant and prevents total shut down. We focused our work on the design and 3D simulation by finite elements method of monolithic fuses integrated on silicon substrate, taking into account static and dynamic specifications. Thermal management in steady state is improved by dielectric epoxy thermal insulation under each constriction of the fuse. Implementation and preliminary practical tests at medium voltage are reported. The effect of a coating using silicone gel around the fuses is analyzed to improve the cut-off capability.","PeriodicalId":241752,"journal":{"name":"2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125521786","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":"Unidirectional thyristor-based DC-DC converter for HVDC connection of offshore wind farms","authors":"P. le Métayer, P. Dworakowski, J. Maneiro","doi":"10.23919/EPE20ECCEEurope43536.2020.9215858","DOIUrl":"https://doi.org/10.23919/EPE20ECCEEurope43536.2020.9215858","url":null,"abstract":"This paper introduces a unidirectional MVDC-HVDC converter for ‘all DC’ connected offshore wind farms. This converter combines the low power losses of thyristor based converters and the control abilities of voltage source converters, together with low power electronics component count. A high step-up ratio is achieved by an input parallel output series configuration. The use of medium frequency is discussed and inductance design conditions are given. A control scheme is proposed and validated by simulations. The converter high efficiency is also observed. The presented analysis shows a potential feasibility and benefits of this novel unidirectional thyristor-based DC-DC converter.","PeriodicalId":241752,"journal":{"name":"2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)","volume":"220 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123040952","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}
Markus Muehlbauer, Samantha Klier, Herbert Palm, Oliver Sven Bohlen, Michael A. Danzer
{"title":"A Novel Power Flow Control Strategy for Heterogeneous Battery Energy Storage Systems Based on Prognostic Algorithms for Batteries","authors":"Markus Muehlbauer, Samantha Klier, Herbert Palm, Oliver Sven Bohlen, Michael A. Danzer","doi":"10.23919/EPE20ECCEEurope43536.2020.9215818","DOIUrl":"https://doi.org/10.23919/EPE20ECCEEurope43536.2020.9215818","url":null,"abstract":"This work focuses on a novel power flow control strategy (PFCS) for a heterogeneous multiple battery energy storage system (BESS) based on prognostic algorithms for batteries and the selection of proper prediction horizons for such algorithms. Unlike existing PFCS, the proposed control strategy copes with the transition between power balancing and state of charge balancing regardless of the scenario, the system configuration or the objective of the operator due to the adaptability of the prediction horizons. MATLAB/Simulink is used to conduct a simulation study based on a heterogeneous multiple BESS. Therefore, the novel PFCS is implemented in a validated simulation model to prove its advantages in terms of the performance and efficiency target indicator in different scenarios and system configurations. The results show, the performance can be enhanced regardless of the scenario or system configuration and the efficiency is at least as high as for the reference PFCS.","PeriodicalId":241752,"journal":{"name":"2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126281701","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":"Comparison of different Low Voltage Multilevel Converter Topologies for Distributed Power Generation","authors":"Ingmar Kaiser, H. Eckel","doi":"10.23919/EPE20ECCEEurope43536.2020.9215798","DOIUrl":"https://doi.org/10.23919/EPE20ECCEEurope43536.2020.9215798","url":null,"abstract":"Typically converters for distributed power generation built with IGBTs have a poor partial load efficiency. Multilevel converters with low voltage SI MOSFETs can be an attractive alternative regarding partial load efficiency and semiconductor cost. In this paper, different multilevel topologies with low voltage SI MOSFETs are compared.","PeriodicalId":241752,"journal":{"name":"2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122215981","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":"Compensation of Temperature Dependence in a Module Parasitic Based Current Measurement System","authors":"Frank Lautner, M. Bakran","doi":"10.23919/EPE20ECCEEurope43536.2020.9215655","DOIUrl":"https://doi.org/10.23919/EPE20ECCEEurope43536.2020.9215655","url":null,"abstract":"This paper presents a current sensing method, which evaluates the voltage across the parasitic resistance and inductance in power modules. Such a sensing method requires an appropriate low pass filter to achieve a signal that is proportional to the current to be measured. In inverter operation, however, the parasitic resistance in the measurement section is variable due to its temperature dependence. This requires firstly a temperature estimation for the measurement section in the semiconductor module and a correction of the deviations arising from that circumstance. At a first glance, three different possible temperature estimation methods seem possible. The first approach by using an additional temperature sensor is only considered as a trivial solution and not examined further. Its disadvantage is the additional component, which is then necessary for current measurement. The second and third method are investigated in detail, which is on the one hand the use of mostly present negative-temperature-coefficient (NTC) thermistors in the module and on the other hand, a completely new approach that exploits the temperature dependence of the sensed signal waveform. Both approaches were tested in inverter operation. They improve current sensing errors by means of module parasitics from ± 25 % to ±2...5%.","PeriodicalId":241752,"journal":{"name":"2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114081994","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":"Real-time Parameters Identification of Lithium-ion Batteries Model to Improve the Hierarchical Model Predictive Control of Building MicroGrids","authors":"Daniela Yassuda Yamashita, I. Vechiu, J. Gaubert","doi":"10.23919/EPE20ECCEEurope43536.2020.9215878","DOIUrl":"https://doi.org/10.23919/EPE20ECCEEurope43536.2020.9215878","url":null,"abstract":"Energy storage systems are key elements for enabling the design of MicroGrids in buildings, specially to deal with stochastic renewable energy resources and to promote peak shifting. However, inaccuracies in the batteries' mathematical models due to temperature and ageing effects can reduce the performance of a MicroGrid system. To tackle these uncertainties, this article presents a two-level hierarchical model predictive controller empowered with a data-driven algorithm for real-time model identification of Lithium-ion batteries. The objective is to enhance their state of charge estimation and to make their maximum use without damaging them. The results demonstrate that it improves up to three times the accuracy of state-of-charge estimation and increases about 3% the annual building MicroGrid self-consumption rate. Furthermore, the division of the building MicroGrid energy management system into two hierarchical levels soften the drawbacks arise from the inaccuracies of day-ahead data prediction while reducing the computational cost. The proposed architecture guarantees higher energetic autonomy indexes than a conventional rule-based controller in all scenarios under study.","PeriodicalId":241752,"journal":{"name":"2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115316943","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}
A. Putkonen, N. Nevaranta, O. Liukkonen, M. Niemelä, O. Pyrhönen
{"title":"Speed Sensorless Commissioning of Resonating Mechanical System in Electric Drives","authors":"A. Putkonen, N. Nevaranta, O. Liukkonen, M. Niemelä, O. Pyrhönen","doi":"10.23919/EPE20ECCEEurope43536.2020.9215908","DOIUrl":"https://doi.org/10.23919/EPE20ECCEEurope43536.2020.9215908","url":null,"abstract":"Artificial excitation signal based commissioning routines has been widely applied for the identification of the resonating mechanical system in electric drives. The commissioning tests encountered in the industry are mostly related to the detection of the first resonating mode, to be more specific, to the estimation of the two-mass-system model approximation needed for the velocity PI controller tuning. A standard identification procedure uses the torque reference as an input signal and the output is the measured velocity signal obtained from the encoder. However, most of the industrial drives are based on sensorless operation, thus there is no possibility to measure the velocity, but some information from the mechanical system is needed for the control design. This paper addresses to the issues related to the speed sensorless identification under closed loop control. A closed loop identification routine where a pseudo random binary sequence (PRBS) is superposed to the velocity control output is studied experimentally by considering a standard commercial frequency converter in sensorless mode driving an induction machine that is connected to resonating mechanical system.","PeriodicalId":241752,"journal":{"name":"2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)","volume":"9 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123782007","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}
Martin Weicker, Guilherme Bello, Dennis Kampen, A. Binder
{"title":"Influence of system parameters in variable speed AC-induction motor drives on parasitic electric bearing currents","authors":"Martin Weicker, Guilherme Bello, Dennis Kampen, A. Binder","doi":"10.23919/EPE20ECCEEurope43536.2020.9215613","DOIUrl":"https://doi.org/10.23919/EPE20ECCEEurope43536.2020.9215613","url":null,"abstract":"High frequency bearing currents are a parasitic phenomenon that affects inverter-fed induction machines, causing damage and wear to the mechanical bearings, which might lead to unexpected failures, increase of the machine downtime and reduction of its lifespan. This paper describes how the bearing currents are affected by changes in the components of the electrical circuit that feeds the induction machine. The referred system consists of: Two-level voltage source inverter, different passive filters (a) common-mode ring filter, b) common-mode ring filter with small phase-to-ground capacitances, c) differential mode filter, d) dual-mode filter and e) du/dt-filter), different motor supply cables (shielded vs. unshielded cables with lengths of 50 m, 150 m or 300 m) and the two different induction motors (rated power of 11 kW and 15 kW, respectively). So, in total sixty system arrangements were tested. The highest reduction of bearing currents was measured with the dual-mode filter in all cable configurations.","PeriodicalId":241752,"journal":{"name":"2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123787244","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}