Microcontroller-based inverter topology integrated in PV systems

2015 ◽  
Vol 34 (1) ◽  
pp. 132-150 ◽  
Author(s):  
Mounir Bouzguenda ◽  
Tarek Selmi ◽  
Adel Gastli ◽  
Ahmed Masmoudi
Keyword(s):  
Leakage Current ◽  
Control Strategy ◽  
Design Methodology ◽  
Leakage Currents ◽  
Zero Crossing ◽  
Content Type ◽  
Pv Systems ◽  
High Conversion Ratio ◽  
Inverter Topology ◽  
Practical Implications

Purpose – The purpose of this paper is to study the problem of the leakage currents in transformerless inverter topologies. It proposes a novel topology and how important the adopted control strategy on the power quality produced by the inverter. Design/methodology/approach – The paper presents an investigation of a novel transformerless inverter topology. It adopted a control strategy in which the DC source is disconnected from the inverter when the zero vectors of the control are applied. By using such control strategy, the electrical efficiency of the whole system was improved and the leakage current was significantly reduced. Findings – The paper provides a solution to minimize the leakage current in transformerless inverter topologies. Besides, the problem of zero-crossing distortions was totally eliminated. Research limitations/implications – Because of the high conversion ratio of the boost converter, the efficiency of the whole system needs to be enhanced. Practical implications – The paper includes the experimental results of the proposed topology which are in good match with the simulation results. Originality/value – This paper identifies a need to study the leakage current phenomena in transformerless inverter topologies.

Customer-differentiated triadic interaction based on decoupling points

2017 ◽  
Vol 10 (2) ◽  
pp. 185-205 ◽  
Author(s):  
Joakim Wikner ◽  
Jenny Bäckstrand ◽  
Eva Johansson
Keyword(s):  
Supply Chain ◽  
Control Strategy ◽  
Design Methodology ◽  
Customer Requirements ◽  
Content Type ◽  
Triadic Interaction ◽  
Customer Order ◽  
Material Classification ◽  
And Control ◽  
Practical Implications

Purpose The integration of supply chains together with the disintegration of individual actors in the supply chain shifts the focus from actors to challenges in the interaction between actors. This paper aims to identify risk strategies for different supplier interactions in triadic configurations to outline supply strategies. Design/methodology/approach Companies participating in a research project recounted the challenges they faced regarding the integration of customer order-based management and supply from a triad perspective. Six triad configurations were identified, based on the literature, resulting in three risk strategies, which were empirically illustrated in practice by the participating companies. Findings A key finding is that a triad perspective for a customer-differentiated approach to supplier interaction results in a material classification that highlights the circumstances in which to apply “balance efficiency”, “postpone”, “balance responsiveness” and “speculate” supply strategies. Research limitations/implications The research has focused on process drivers and controllability, and the results may require careful interpretation when there is a mix of standardized and customized products because further interaction differentiation may then be required. Practical implications The strategies developed herein provide guidelines for differentiated supplier interaction with explicit focus on triads where customer actors directly influence supplier actors. This approach highlights how outsourcing must be carefully executed when supplier actors are involved in delivery to customer orders. Originality/value The paper sheds new light on how customer requirements impact supplier interaction in terms of decoupling points related to both delivery strategy and control strategy. The study also presents a novel application of the Kraljic matrix in in terms of risk strategies in different triad configurations.

scholarly journals Current balancing of cascaded H-bridge converters for PV systems with partial shading

2015 ◽  
Vol 34 (6) ◽  
pp. 1879-1895 ◽  
Author(s):  
Diego Iannuzzi ◽  
Mario Pagano ◽  
Luigi Piegari ◽  
Pietro Tricoli
Keyword(s):  
Control Strategy ◽  
Partial Shading ◽  
Content Type ◽  
Pv Systems ◽  
Grid Connection ◽  
Original Contribution ◽  
Scientific Papers ◽  
Converter Topology ◽  
Power Balancing ◽  
Practical Implications

Purpose – The purpose of this paper is to propose a new converter topology for integrating PV plants constituted by many panels into the grid. The converter is capable of implementing MPPT algorithms on different subset of modules and can balance the different energy supplied by panels differently irradiated. The output voltage presents a very low ripple also if small filters are used for grid connection. Design/methodology/approach – In the paper, at first the converter configuration is presented. Then a control strategy for obtaining, at the same time the distributed MPPT and the power balancing on the three phases is proposed. Finally, by means of numerical simulations, the good performances of the proposed converter are shown. Findings – The proposed converter, lent from MMC configurations, is deeply studied and a suitable control strategy is well analyzed in the paper. Analytical model for voltage and current balancing are given. Research limitations/implications – The analysis presented in the paper complete some studies started in the last years and partially presented in previous scientific papers. It reaches a final point and gives all the specific for the realization of the converter and of its control. Practical implications – The paper gives all the instrument to design and realize a PV power plant integrated into building façade. Originality/value – The converter and the control for voltage and current balancing presented in this paper represent a significant original contribution of this work.

scholarly journals A Novel DC-AC Inverter Topology to Eliminate Leakage Current

2018 ◽  
Vol 9 (4) ◽  
pp. 1733
Author(s):  
Tarek Selmi ◽  
Maher Rezgui
Keyword(s):  
Operating System ◽  
Energy Efficiency ◽  
Leakage Current ◽  
Solar Pv ◽  
Zero Crossing ◽  
Pv Systems ◽  
Simulation And Experiment ◽  
Inverter Topology

Experiments confirmed that Transformerless Inverters (TIs) deliver more reliability and higher energy efficiency. Nonetheless, one of the shortcomings of TIs is the leakage current that occurs between the photovoltaic (PV) string terminals and the ground. Such a drawback is justified by the non-galvanic isolation caused by the transformer being omitted. As such, this study is intended to develop a novel TI inverter topology for solar PV systems. The latter is meant to remove the leakage current and enhance the operating system of the entire PV conversion as well. Added to its null zero-crossing distortion and capability regarding energy efficiency, the developed TI, being validated by simulation and experiment, eradicated the leakage current.

Variance constrained trajectory tracking for tandem-rotor helicopters

2020 ◽  
Vol 92 (3) ◽  
pp. 398-403
Author(s):  
Firat Sal
Keyword(s):  
Fuel Consumption ◽  
Trajectory Tracking ◽  
Control Strategy ◽  
Design Methodology ◽  
Constrained Control ◽  
Variance Bounds ◽  
Content Type ◽  
Practical Implications

Purpose This paper aims to present novel results for trajectory tracking of tandem-rotor helicopters via variance-constrained controllers. Design/methodology/approach Regarding these purposes, linearized tandem-rotor helicopter models are benefitted. Findings Variance-constrained controllers are very beneficial for trajectory tracking of tandem-rotor helicopters while there exists variance bounds on outputs of interest. Practical implications Variance-constrained controllers can be used for cheaper tandem-rotor helicopter operations with high trajectory tracking quality. Originality/value Applying variance-constrained control strategy for tandem-rotor helicopters during trajectory tracking. This also causes less fuel consumption and green environment, and good trajectory tracking quality.

Consumer value creation through WhatsApp use

2019 ◽  
Vol 32 (4) ◽  
pp. 455-471
Author(s):  
Jorge Cruz-Cárdenas ◽  
Jorge Guadalupe-Lanas ◽  
Ekaterina Zabelina ◽  
Andrés Palacio-Fierro ◽  
Margarita Velín-Fárez ◽  
...  
Keyword(s):  
Latin American ◽  
Value Creation ◽  
Emotional Support ◽  
Design Methodology ◽  
Instant Messaging ◽  
Role Performance ◽  
Content Type ◽  
Consumer Value ◽  
Depth Interviews ◽  
Practical Implications

Purpose The purpose of this paper is to understand in-depth how consumers create value in their lives using WhatsApp, the leading mobile instant messaging (MIM) application. Design/methodology/approach The study adopts the perspective of customer-dominant logic (CDL) and uses a qualitative multimethod design involving 3 focus groups and 25 subsequent in-depth interviews. The research setting was Ecuador, a Latin American country. Findings Analysis and interpretation of the participants’ stories made it possible to identify and understand the creation of four types of value: maintaining and strengthening relationships; improving role performance; emotional support; and entertainment and fun. In addition, the present study proposes a conceptual model of consumer value creation as it applies to MIM. Practical implications Understanding the way consumers create value in their lives using MIM is important not only for organizations that offer MIM applications, but also for those companies that develop other applications for mobile phones or for those who wish to use MIM as an electronic word-of-mouth vehicle. Originality/value The current study is one of the first to address the topic of consumer behavior in the use of technologies from the perspective of CDL; this perspective enables an integrated qualitative vision of value creation in which the consumer is the protagonist.

scholarly journals Advantages and potential challenges of data management in e-maintenance

2019 ◽  
Vol 25 (3) ◽  
pp. 378-396 ◽  
Author(s):  
Arian Razmi-Farooji ◽  
Hanna Kropsu-Vehkaperä ◽  
Janne Härkönen ◽  
Harri Haapasalo
Keyword(s):  
Data Management ◽  
Design Methodology ◽  
Management Practices ◽  
Future Research ◽  
Conceptual Approach ◽  
Content Type ◽  
Different Types ◽  
Maintenance Systems ◽  
Industry Leader ◽  
Practical Implications

Purpose The purpose of this paper is twofold: first, to understand data management challenges in e-maintenance systems from a holistically viewpoint through summarizing the earlier scattered research in the field, and second, to present a conceptual approach for addressing these challenges in practice. Design/methodology/approach The study is realized as a combination of a literature review and by the means of analyzing the practices on an industry leader in manufacturing and maintenance services. Findings This research provides a general understanding over data management challenges in e-maintenance and summarizes their associated proposed solutions. In addition, this paper lists and exemplifies different types and sources of data which can be collected in e-maintenance, across different organizational levels. Analyzing the data management practices of an e-maintenance industry leader provides a conceptual approach to address identified challenges in practice. Research limitations/implications Since this paper is based on studying the practices of a single company, it might be limited to generalize the results. Future research topics can focus on each of mentioned data management challenges and also validate the applicability of presented model in other companies and industries. Practical implications Understanding the e-maintenance-related challenges helps maintenance managers and other involved stakeholders in e-maintenance systems to better solve the challenges. Originality/value The so-far literature on e-maintenance has been studied with narrow focus to data and data management in e-maintenance appears as one of the less studied topics in the literature. This research paper contributes to e-maintenance by highlighting the deficiencies of the discussion surrounding the perspectives of data management in e-maintenance by studying all common data management challenges and listing different types of data which need to be acquired in e-maintenance systems.

An exploratory empirical study of whistleblowing and whistleblowers

2020 ◽  
Vol 27 (3) ◽  
pp. 755-770
Author(s):  
Maria Krambia-Kapardis
Keyword(s):  
Statistical Analysis ◽  
Design Methodology ◽  
Research Topic ◽  
Due Date ◽  
Content Type ◽  
Unethical Behaviour ◽  
Eu Member States ◽  
European Directive ◽  
Original Survey ◽  
Practical Implications

Purpose The purpose of this study is to develop a profile of whistleblowers and to determine whether whistleblowing legislation would encourage those individuals to bring to light some illegal or unethical behaviour that otherwise would remain in the shadows. Design/methodology/approach Having identified whistleblowing correlation, a survey was carried out in Cyprus of actual whistleblowers and could-have-been whistleblowers. Findings Males between 46 and55 years of age, regardless of whether they have dependents or hold senior positions in organizations are significantly more likely to blow the whistle. However, could-have-been whistleblowers did not go ahead because they felt that the authorities would not act on their information. Research limitations/implications Because of the sensitive nature of the research topic and the fact that only whistleblowers or intended whistleblowers could participate in the study, the sample size is limited as a result. This, in turn, limits both the number of respondents in each category (actual and intended) as well as constrains the statistical analysis that could be carried out on the data. Practical implications It remains to be seen whether EU Member States shall implement the European Directive 2019/1937 on the protection of persons who report breaches of Union Law, in its entirety by the due date, namely December 2021. Originality/value This study provides a literature review of whistleblowing and reports an original survey against the backdrop of the European Directive.

How Phillips saw the light

2020 ◽  
Vol 36 (8) ◽  
pp. 29-31
Keyword(s):  
Design Methodology ◽  
Reading Time ◽  
Daily Basis ◽  
Business World ◽  
Content Type ◽  
Freak Show ◽  
The World ◽  
Pertinent Information ◽  
The One ◽  
Practical Implications

Purpose Reviews the latest management developments across the globe and pinpoints practical implications from cutting-edge research and case studies. Design/methodology/approach This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context. Findings The problem with developing a reputation of being something of an oracle in the business world is that all of a sudden, everyone expects you to pull off the trick of interpreting the future on a daily basis. Like a freak show circus act or one-hit wonder pop singer, people expect you to perform when they see you, and they expect you to perform the thing that made you famous, even if it is the one thing in the world you don’t want to do. And when you fail to deliver on these heightened expectations, you are dismissed as a one trick pony, however good that trick is in the first place. Originality/value The briefing saves busy executives and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to-digest format.

scholarly journals Examining the accounts of oil spills crises in Nigeria through sensegiving and defensive behaviours

2020 ◽  
Vol 33 (8) ◽  
pp. 2053-2076 ◽  
Author(s):  
Osamuyimen Egbon ◽  
Chijoke Oscar Mgbame
Keyword(s):  
Policy Implication ◽  
Design Methodology ◽  
Oil Spills ◽  
Burden Of Proof ◽  
Multinational Companies ◽  
External Factors ◽  
Content Type ◽  
Political Dynamics ◽  
Defensive Behaviours ◽  
Practical Implications

PurposeThe paper examines how oil multinational companies (MNCs) in Nigeria framed accounts to dissociate themselves from causing oil spills.Design/methodology/approachThe authors utilised data from relevant corporate reports, external accounts and interviews, and used sensegiving with defensive behaviours theoretical framing to explore corporate narratives aimed at altering stakeholders' perceptions.FindingsThe corporations gave sense to their audience by invoking scapegoating blame avoidance narrative in attributing the cause of most oil spills in Nigeria to outsiders (sabotage), despite potentially misclassifying the sabotage-corrosion dichotomy. Corporate stance was reinforced through justifying narrative, which suggested that multi-stakeholders jointly determined the causes of oil spills, thus portraying corporate accounts as transparent, credible and objective.Research limitations/implicationsThe socio-political dynamics in an empirical setting affect corporate accounts and how those accounts appear persuasive, implying that such contextual factors merit consideration when evaluating corporate accounts. For example, despite contradictions in corporate accounts, corporate attribution of oil spills to external factors appeared persuasive due to the inherently complicated socio-political dynamics.Practical implicationsWith compensation to oil spills' victims only legally permitted for non-sabotage-induced spills alongside the burden of proof on the victims, the MNCs are incentivised to attribute most oil spills to sabotage. On policy implication, accountability would be best served when the MNCs are tasked both with the burden of proof and a responsibility to demonstrate their transparency in preventing oil spills, including those caused by sabotage.Originality/valueCrisis situations generate multiple and competing perspectives, but sensegiving and defensive behaviours lenses enrich our understanding of how crisis-ridden companies frame narratives to alter stakeholders' perceptions. Accounts-giving therefore partly satisfies accountability demands, and acts as sensegiving signals aimed at reframing/redefining existing perceptions.

OCIE issues risk alert on the most frequently identified advisory fee and expense compliance issues

2018 ◽  
Vol 19 (4) ◽  
pp. 1-3
Author(s):  
Robert Van Grover
Keyword(s):  
Design Methodology ◽  
Best Practice ◽  
Investment Management ◽  
Content Type ◽  
Informed Decisions ◽  
Policies And Procedures ◽  
The Us ◽  
Investment Advisers ◽  
Practical Implications

Purpose To summarize and interpret a Risk Alert issued on April 12, 2018 by the US SEC’s Office of Compliance Inspections and Examinations (OCIE) on the most frequent advisory fee and expense compliance issues identified in recent examinations of investment advisers. Design/methodology/approach Summarizes deficiencies identified by the OCIE staff pertaining to advisory fees and expenses in the following categories: fee billing based on incorrect account valuations, billing fees in advance or with improper frequency, applying incorrect fee rates, omitting rebates and applying discounts incorrectly, disclosure issues involving advisory fees, and adviser expense misallocations. Findings In the Risk Alert, OCIE staff emphasized the importance of disclosures regarding advisory fees and expenses to the ability of clients to make informed decisions, including whether or not to engage or retain an adviser. Practical implications In light of the issues identified in the Risk Alert, advisers should assess the accuracy of disclosures and adequacy of policies and procedures regarding advisory fee billing and expenses. As a matter of best practice, advisers should implement periodic forensic reviews of billing practices to identify and correct issues relating to fee billing and expenses. Originality/value Expert guidance from experienced investment management lawyer.

Sign in / Sign up

Export Citation Format

Share Document