Pub Date : 2012-06-25DOI: 10.1109/PEDG.2012.6254047
M. Mao, Shi-Ting Weng, Fuyang Liu, Liuchen Chang, M. Ding, Hongbin Wu
A novel control method based on the proportional resonant differential (PRD) control is proposed for the grid-connected current source inverter (CSI) used in the direct drive permanent magnet synchronous wind generation system. By the optimal design of the parameters of the PRD controller in two-phase stationary frame, the CSI system can realize zero steady-state error control and effectively damp the resonance caused by its output LC filter just by feeding back the grid-connected current. This not only greatly simplifies the controller design but also enhances the stability of the system. Simulation results show grid-connected CSI with this method has fast dynamic response and good steady-state performances.
{"title":"A novel PRD control method damping resonance in grid-connected three-phase SVPWM current source inverter","authors":"M. Mao, Shi-Ting Weng, Fuyang Liu, Liuchen Chang, M. Ding, Hongbin Wu","doi":"10.1109/PEDG.2012.6254047","DOIUrl":"https://doi.org/10.1109/PEDG.2012.6254047","url":null,"abstract":"A novel control method based on the proportional resonant differential (PRD) control is proposed for the grid-connected current source inverter (CSI) used in the direct drive permanent magnet synchronous wind generation system. By the optimal design of the parameters of the PRD controller in two-phase stationary frame, the CSI system can realize zero steady-state error control and effectively damp the resonance caused by its output LC filter just by feeding back the grid-connected current. This not only greatly simplifies the controller design but also enhances the stability of the system. Simulation results show grid-connected CSI with this method has fast dynamic response and good steady-state performances.","PeriodicalId":146438,"journal":{"name":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125156698","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 : 2012-06-25DOI: 10.1109/PEDG.2012.6253978
M. Savaghebi, J. Vasquez, A. Jalilian, Josep M. Guerrero
In this paper, a hierarchical control scheme is proposed for enhancement of Sensitive Load Bus (SLB) voltage quality in microgrids. The control structure consists of primary and secondary levels. The primary control level comprises Distributed Generators (DGs) local controllers. Each of these controllers includes a selective virtual impedance loop which is considered to improve sharing of fundamental and harmonic components of load current among the DG units. The sharing improvement is provided at the expense of increasing voltage unbalance and harmonic distortion. Thus, the secondary control level is applied to manage the compensation of SLB voltage unbalance and harmonics by sending proper control signals to the primary level. DGs compensation efforts are controlled locally at the primary level. The system design procedure for selecting proper control parameters is discussed. Simulation results are provided in order to demonstrate the effectiveness of the proposed control scheme.
{"title":"Secondary control for compensation of voltage harmonics and unbalance in microgrids","authors":"M. Savaghebi, J. Vasquez, A. Jalilian, Josep M. Guerrero","doi":"10.1109/PEDG.2012.6253978","DOIUrl":"https://doi.org/10.1109/PEDG.2012.6253978","url":null,"abstract":"In this paper, a hierarchical control scheme is proposed for enhancement of Sensitive Load Bus (SLB) voltage quality in microgrids. The control structure consists of primary and secondary levels. The primary control level comprises Distributed Generators (DGs) local controllers. Each of these controllers includes a selective virtual impedance loop which is considered to improve sharing of fundamental and harmonic components of load current among the DG units. The sharing improvement is provided at the expense of increasing voltage unbalance and harmonic distortion. Thus, the secondary control level is applied to manage the compensation of SLB voltage unbalance and harmonics by sending proper control signals to the primary level. DGs compensation efforts are controlled locally at the primary level. The system design procedure for selecting proper control parameters is discussed. Simulation results are provided in order to demonstrate the effectiveness of the proposed control scheme.","PeriodicalId":146438,"journal":{"name":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122551415","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 : 2012-06-25DOI: 10.1109/PEDG.2012.6254010
M. Rahiminejad, C. Diduch, M. Stevenson, Liuchen Chang
This paper proposes a detection method for open-circuit faults in a 3-phase uncontrolled rectifier that forms the input stage of a single-phase current controlled power converter. The rectifier is driven by a 3-phase wind generator with variable amplitude and frequency. The algorithm is based on fault signatures embedded within the output voltage ripple of the rectifier. It is demonstrated that seven different classes of open circuit faults can be detected and isolated.
{"title":"Open-circuit fault diagnosis in 3-phase uncontrolled rectifiers","authors":"M. Rahiminejad, C. Diduch, M. Stevenson, Liuchen Chang","doi":"10.1109/PEDG.2012.6254010","DOIUrl":"https://doi.org/10.1109/PEDG.2012.6254010","url":null,"abstract":"This paper proposes a detection method for open-circuit faults in a 3-phase uncontrolled rectifier that forms the input stage of a single-phase current controlled power converter. The rectifier is driven by a 3-phase wind generator with variable amplitude and frequency. The algorithm is based on fault signatures embedded within the output voltage ripple of the rectifier. It is demonstrated that seven different classes of open circuit faults can be detected and isolated.","PeriodicalId":146438,"journal":{"name":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122639373","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 : 2012-06-25DOI: 10.1109/PEDG.2012.6254033
Jie Zhang, R. Yokoyama, Jinhua She
One problem with a single-voltage source, three-level inverter is the drafting of its neutral-point voltage. This may occur during transition or when unbalanced loads are connected to the inverter system. Variation of neutral-point voltage may greatly deteriorate the power quality. In this paper, we employ an equivalent-input-disturbance approach to deal with this problem. By adding an extra neutral leg, the control problem of neutralpoint voltage is converted to a disturbance rejection problem. This method suppresses the variation of the neutral-point voltage to a small level and reduces the capacity of capacitors. Simulation results show the effectiveness of the method.
{"title":"Neutral-point voltage control for a three-level DC-AC inverter using equivalent-input-disturbance approach","authors":"Jie Zhang, R. Yokoyama, Jinhua She","doi":"10.1109/PEDG.2012.6254033","DOIUrl":"https://doi.org/10.1109/PEDG.2012.6254033","url":null,"abstract":"One problem with a single-voltage source, three-level inverter is the drafting of its neutral-point voltage. This may occur during transition or when unbalanced loads are connected to the inverter system. Variation of neutral-point voltage may greatly deteriorate the power quality. In this paper, we employ an equivalent-input-disturbance approach to deal with this problem. By adding an extra neutral leg, the control problem of neutralpoint voltage is converted to a disturbance rejection problem. This method suppresses the variation of the neutral-point voltage to a small level and reduces the capacity of capacitors. Simulation results show the effectiveness of the method.","PeriodicalId":146438,"journal":{"name":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124747270","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 : 2012-06-25DOI: 10.1109/PEDG.2012.6253998
F. Yu, Ying Fan, M. Cheng, Guowen Hu
Islanding detection (ID) is a mandatory function for PV grid-connected converters. The traditional Sandia frequency shift method for ID becomes ineffective under certain parallel RLC loads. To alleviate this problem, a new methodology to optimize the frequency shift parameter Ks is proposed, and a novel non-detection zone (NDZ) mapping method is presented to map the NDZ influenced by each electrical parameter in this paper. An instability criterion relied on phase equilibrium principle algorithm is presented under specific loads to analyze the relationship between parameters and the reduction of NDZ. The proposed algorithm can keep the frequency of inverter output voltage deviating until the protection circuit is triggered with lower harmonic current. Single-phase photovoltaic grid-connected simulation system and experimental platform are constructed according to IEEE Std. 2000-929. Both the simulation and experimental results prove the robustness and effectiveness of the proposed parameter optimization algorithm.
{"title":"Parameter design optimization for Sandia frequency shift islanding detection method","authors":"F. Yu, Ying Fan, M. Cheng, Guowen Hu","doi":"10.1109/PEDG.2012.6253998","DOIUrl":"https://doi.org/10.1109/PEDG.2012.6253998","url":null,"abstract":"Islanding detection (ID) is a mandatory function for PV grid-connected converters. The traditional Sandia frequency shift method for ID becomes ineffective under certain parallel RLC loads. To alleviate this problem, a new methodology to optimize the frequency shift parameter Ks is proposed, and a novel non-detection zone (NDZ) mapping method is presented to map the NDZ influenced by each electrical parameter in this paper. An instability criterion relied on phase equilibrium principle algorithm is presented under specific loads to analyze the relationship between parameters and the reduction of NDZ. The proposed algorithm can keep the frequency of inverter output voltage deviating until the protection circuit is triggered with lower harmonic current. Single-phase photovoltaic grid-connected simulation system and experimental platform are constructed according to IEEE Std. 2000-929. Both the simulation and experimental results prove the robustness and effectiveness of the proposed parameter optimization algorithm.","PeriodicalId":146438,"journal":{"name":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121783017","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 : 2012-06-25DOI: 10.1109/PEDG.2012.6254045
Yongheng Yang, F. Blaabjerg
The highly increasing penetration of single-phase photovoltaic (PV) systems pushes the grid requirements related to the integration of PV power systems to be updated. These upcoming regulations are expected to direct the grid-connected renewable generators to support the grid operation and stability both under grid faulty conditions and under normal operations. Grid synchronization techniques play an important role in the control of single-phase systems in order to fulfill these demands. Thus, it is necessary to evaluate the behaviors of grid synchronization methods in single phase systems under grid faults. The focus of this paper is put on the benchmarking of synchronization techniques, mainly about phase locked loop (PLL) based methods, in single-phase PV power systems operating under grid faults. Some faulty mode cases are studied at the end of this paper in order to compare these methods. It is concluded that the Enhanced PLL (EPLL) and the Second Order Generalized Integrator based PLL (SOGI-OSG PLL) technique are the most promising candidates for future single-phase PV systems due to their fast adaptive-filtering characteristics.
{"title":"Synchronization in single-phase grid-connected photovoltaic systems under grid faults","authors":"Yongheng Yang, F. Blaabjerg","doi":"10.1109/PEDG.2012.6254045","DOIUrl":"https://doi.org/10.1109/PEDG.2012.6254045","url":null,"abstract":"The highly increasing penetration of single-phase photovoltaic (PV) systems pushes the grid requirements related to the integration of PV power systems to be updated. These upcoming regulations are expected to direct the grid-connected renewable generators to support the grid operation and stability both under grid faulty conditions and under normal operations. Grid synchronization techniques play an important role in the control of single-phase systems in order to fulfill these demands. Thus, it is necessary to evaluate the behaviors of grid synchronization methods in single phase systems under grid faults. The focus of this paper is put on the benchmarking of synchronization techniques, mainly about phase locked loop (PLL) based methods, in single-phase PV power systems operating under grid faults. Some faulty mode cases are studied at the end of this paper in order to compare these methods. It is concluded that the Enhanced PLL (EPLL) and the Second Order Generalized Integrator based PLL (SOGI-OSG PLL) technique are the most promising candidates for future single-phase PV systems due to their fast adaptive-filtering characteristics.","PeriodicalId":146438,"journal":{"name":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122064378","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 : 2012-06-25DOI: 10.1109/PEDG.2012.6254003
Honglin Zhou, M. Kuang, Jiandong Wu
This paper proposes a new rotor position and speed estimation method for sensorless control of PMSM in high speed range. In order to improve the dynamic performance of conventional back-EMF methods, the proposed method eliminates the Phase-Lock Loop (PLL) while at the same time, avoids the potential local loop that might cause system unstable in closed-loop sensorless control. Instead of directly filtering the fast-changing calculated rotor position signal, the proposed method first filters a slowly varying signal, i.e. the calculated initial rotor position, to obtain the estimated rotor position. Then the estimated initial rotor position is added to the calculated rotor position to form an unbiased estimation of rotor position. The simulation results of a typical 1.5MW direct drive wind turbine system illustrate that the steady-state performance of the proposed method is similar to conventional EPLL method but the dynamic performance for rotor position is considerably improved, owning to its forward structure.
{"title":"A rotor position and speed estimation method for sensorless control of permanent magnetic synchronous motor","authors":"Honglin Zhou, M. Kuang, Jiandong Wu","doi":"10.1109/PEDG.2012.6254003","DOIUrl":"https://doi.org/10.1109/PEDG.2012.6254003","url":null,"abstract":"This paper proposes a new rotor position and speed estimation method for sensorless control of PMSM in high speed range. In order to improve the dynamic performance of conventional back-EMF methods, the proposed method eliminates the Phase-Lock Loop (PLL) while at the same time, avoids the potential local loop that might cause system unstable in closed-loop sensorless control. Instead of directly filtering the fast-changing calculated rotor position signal, the proposed method first filters a slowly varying signal, i.e. the calculated initial rotor position, to obtain the estimated rotor position. Then the estimated initial rotor position is added to the calculated rotor position to form an unbiased estimation of rotor position. The simulation results of a typical 1.5MW direct drive wind turbine system illustrate that the steady-state performance of the proposed method is similar to conventional EPLL method but the dynamic performance for rotor position is considerably improved, owning to its forward structure.","PeriodicalId":146438,"journal":{"name":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122679507","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 : 2012-06-25DOI: 10.1109/PEDG.2012.6254082
S. Mazumder, S. Mehrnami
This paper covers the design and analysis of a compact inverter for photovoltaic (PV) and fuel-cell applications. The inverter is made up of two isolated Ćuk converters working differentially to create a 60-Hz sinusoidal output. This enables direct dc/ac conversion with low device count and yields a simple drive-circuitry. This configuration will lower converter cost and size and can achieve an estimated efficiency of ≥ 95%. Key topics covered in this paper include analysis of the inverter topology and its design.
{"title":"A low-device-count single-stage direct-power-conversion solar microinverter for microgrid","authors":"S. Mazumder, S. Mehrnami","doi":"10.1109/PEDG.2012.6254082","DOIUrl":"https://doi.org/10.1109/PEDG.2012.6254082","url":null,"abstract":"This paper covers the design and analysis of a compact inverter for photovoltaic (PV) and fuel-cell applications. The inverter is made up of two isolated Ćuk converters working differentially to create a 60-Hz sinusoidal output. This enables direct dc/ac conversion with low device count and yields a simple drive-circuitry. This configuration will lower converter cost and size and can achieve an estimated efficiency of ≥ 95%. Key topics covered in this paper include analysis of the inverter topology and its design.","PeriodicalId":146438,"journal":{"name":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","volume":"307 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122803947","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 : 2012-06-25DOI: 10.1109/PEDG.2012.6254050
N. Orlando, R. Mastromauro, Marco Liserre, D. Cafagna, G. Grassi
This paper deals with a small wind turbine system (WTS) constituted by a permanent magnet synchronous generator (PMSG) connected to the grid via a back-to-back converter. The Low Voltage Ride through (LVRT) requirements for the WTS are described and the nonlinear dynamics of a grid-side converter is analyzed in the presence of voltage sags. The study shows that new chaotic phenomena are generated when the size of the dc-link capacitor is reduced. The reported time waveforms and state-space attractors clearly highlight that the system becomes chaotic during the voltage sag, being stable before and after the occurrence of the disturbance. Finally, the chaotic behavior is validated via the 0-1 test for chaos, thus confirming the novel phenomenon described herein.
{"title":"New chaotic phenomena occurring during voltage sags in small wind turbine systems based on back-to-back converters","authors":"N. Orlando, R. Mastromauro, Marco Liserre, D. Cafagna, G. Grassi","doi":"10.1109/PEDG.2012.6254050","DOIUrl":"https://doi.org/10.1109/PEDG.2012.6254050","url":null,"abstract":"This paper deals with a small wind turbine system (WTS) constituted by a permanent magnet synchronous generator (PMSG) connected to the grid via a back-to-back converter. The Low Voltage Ride through (LVRT) requirements for the WTS are described and the nonlinear dynamics of a grid-side converter is analyzed in the presence of voltage sags. The study shows that new chaotic phenomena are generated when the size of the dc-link capacitor is reduced. The reported time waveforms and state-space attractors clearly highlight that the system becomes chaotic during the voltage sag, being stable before and after the occurrence of the disturbance. Finally, the chaotic behavior is validated via the 0-1 test for chaos, thus confirming the novel phenomenon described herein.","PeriodicalId":146438,"journal":{"name":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124293156","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 : 2012-06-25DOI: 10.1109/PEDG.2012.6254106
Cam Pham, T. Kerekes, R. Teodorescu
Photovoltaic (PV) installation is suited for the residential environment and the generation pattern follows the distribution of residential power consumption in daylight hours. In the cases of unbalance between generation and demand, the Smart PV with its battery storage can absorb or inject the power to balance it. High efficient bidirectional converter for the battery storage is required due high system cost and because the power is processed twice. A 1.5kW prototype is designed and built with CoolMOS and SiC diodes, >;95% efficiency has been obtained with 200 kHz hard switching.
{"title":"High efficient bidirectional battery converter for residential PV systems","authors":"Cam Pham, T. Kerekes, R. Teodorescu","doi":"10.1109/PEDG.2012.6254106","DOIUrl":"https://doi.org/10.1109/PEDG.2012.6254106","url":null,"abstract":"Photovoltaic (PV) installation is suited for the residential environment and the generation pattern follows the distribution of residential power consumption in daylight hours. In the cases of unbalance between generation and demand, the Smart PV with its battery storage can absorb or inject the power to balance it. High efficient bidirectional converter for the battery storage is required due high system cost and because the power is processed twice. A 1.5kW prototype is designed and built with CoolMOS and SiC diodes, >;95% efficiency has been obtained with 200 kHz hard switching.","PeriodicalId":146438,"journal":{"name":"2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130136824","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}