X. Jiang, B. Fardanesh, D. Maragal, G. Stefopoulos, J. Chow, Michael P. Razanousky
{"title":"Improving performance of the non-iterative direct state estimation method","authors":"X. Jiang, B. Fardanesh, D. Maragal, G. Stefopoulos, J. Chow, Michael P. Razanousky","doi":"10.1109/PECI.2014.6804562","DOIUrl":"https://doi.org/10.1109/PECI.2014.6804562","url":null,"abstract":"This paper describes continuing work on a new method for state estimation of a non-linear AC power system in a direct, non-iterative manner. This method is based on the Kipnis-Shamir relinearization technique that is used to solve over-defined sets of polynomial equations. The technique transforms the equations to a higher dimension linear space which allows the states to be solved in a non-iterative manner. Given sufficiently accurate measurements, this new state calculation method provides the same results as traditional iterative state estimation methods, and the proposed method does not require an initial guess of system states. Compared to previous works on the topic, this paper presents a more detailed description and analysis of the solution process, and how some of the characteristics of the solution process can be used to improve the computation speed of this new state estimation method. Preliminary test results using an improved MATLAB implementation of the method are included.","PeriodicalId":352005,"journal":{"name":"2014 Power and Energy Conference at Illinois (PECI)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115946812","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":"Control of single switch inverters","authors":"S. Hegde, A. Izadian","doi":"10.1109/PECI.2014.6804560","DOIUrl":"https://doi.org/10.1109/PECI.2014.6804560","url":null,"abstract":"This paper presents a control approach for a single switch inverter. The inverter exhibits non-minimum phase behavior in some of the operating modes. A dual feedforward controller was employed with an adaptive PI controller to obtain perfect tracking performance. The controller successfully isolates the non-minimum phase part of the system from the minimum phase. Both separated minimum phase and non-minimum phase sub-systems were used in the dual feedforward scheme to generate desired references. The non-minimum phase dynamics are transformed to minimum phase by using an inverse system transfer function as parallel compensator. The adaptive PI controller was used to track the voltage references.","PeriodicalId":352005,"journal":{"name":"2014 Power and Energy Conference at Illinois (PECI)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126099804","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":"A new concept of multilevel converter motor drive with modular design and split winding machine","authors":"Jiyao Wang, Yehui Han","doi":"10.1109/PECI.2014.6804550","DOIUrl":"https://doi.org/10.1109/PECI.2014.6804550","url":null,"abstract":"A new multilevel converter topology is proposed in this paper. It reduces the component quantity and overcomes several disadvantages of existing multilevel converter topologies. The proposed converter is flexible in design and the output voltage levels are easily expanded. The detailed topology, its advantages, critical techniques, simulation and experimental results are presented in this paper.","PeriodicalId":352005,"journal":{"name":"2014 Power and Energy Conference at Illinois (PECI)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131593152","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":"Symmetrical components and power analysis for a two-phase microgrid system","authors":"M. Alibeik, E. D. dos Santos, F. Blaabjerg","doi":"10.1109/PECI.2014.6804548","DOIUrl":"https://doi.org/10.1109/PECI.2014.6804548","url":null,"abstract":"This paper presents a mathematical model for the symmetrical components and power analysis of a new microgrid system consisting of three wires and two voltages in quadrature, which is designated as a two-phase microgrid. The two-phase microgrid presents the following advantages: 1) constant power through the power line at balanced condition; 2) two voltages available by using a three-wire system; 3) optimized voltage utilization compared to a three-phase system; and 4) a direct connection of both symmetrical two-phase and single-phase machines. Unlike the unbalanced three-phase system, which can be represented by three sets of symmetrical components, the unbalanced two-phase system is broken up into only two symmetrical components. Simulation results are employed to demonstrate the feasibility of the theoretical study.","PeriodicalId":352005,"journal":{"name":"2014 Power and Energy Conference at Illinois (PECI)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123432588","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}
Scott G. Ghiocel, J. Chow, R. Quint, D. Kosterev, D. Sobajic
{"title":"Computing measurement-based voltage stability margins for a wind power hub using the AQ-bus method","authors":"Scott G. Ghiocel, J. Chow, R. Quint, D. Kosterev, D. Sobajic","doi":"10.1109/PECI.2014.6804570","DOIUrl":"https://doi.org/10.1109/PECI.2014.6804570","url":null,"abstract":"In PV-curve-based voltage stability analysis, it is known that the Newton-Raphson power flow Jacobian matrix becomes increasingly ill-conditioned as the maximum loading condition is reached. In many cases, the power flow diverges before the maximum loading condition is reached. In previous work, we proposed a novel method to alleviate the ill-conditioning issue in the power flow by reformulating the problem using a new AQ bus type [1]. For an AQ bus, the voltage angle and reactive power consumption are specified. For steady-state voltage stability analysis, the angle separation between the swing bus and AQ bus is adjusted to indirectly control power transfer. This reformulation alters the Jacobian matrix such that it is nonsingular at the critical voltage point. In this work, we use the AQ-bus method to compute the PV curves for a real power system including a wind power hub with multiple wind power plants. The network has two transfer paths and reactive power compensation from switched shunts. We use measurements to construct voltage stability models for the wind power plants and external system. The switched shunts are modeled in the AQ-bus power flow according to their operational guidelines. Using this real system, we demonstrate the capability of the AQ-bus method to compute voltage stability margins for multiple transfer paths and complex injections.","PeriodicalId":352005,"journal":{"name":"2014 Power and Energy Conference at Illinois (PECI)","volume":"121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126863000","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":"Analysis and control of PMSG-based wind turbine with Vienna rectifier near current zero crossings","authors":"M. Johnson, D. Aliprantis","doi":"10.1109/PECI.2014.6804551","DOIUrl":"https://doi.org/10.1109/PECI.2014.6804551","url":null,"abstract":"Permanent-magnet synchronous generators are used widely in wind turbine applications. Recently, the Vienna rectifier was proposed as the generator-side converter, due to its improved efficiency and reliability. However, since the voltage output in this topology is dependent on the polarity of the currents, erroneous voltage space vectors are generated when phase currents are in the vicinity of zero, which in turn creates an undesirable component of torque ripple on the machine. In this paper, the phenomenon is analyzed, and a control method that solves this issue is proposed. The obtained improvement in current and torque ripple decreases the fatigue of the turbine's mechanical drivetrain. Simulation results verify the efficacy of the control.","PeriodicalId":352005,"journal":{"name":"2014 Power and Energy Conference at Illinois (PECI)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128492984","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}