Sustainable rural electrification through solar PV DC microgrids—An architecture-based assessment

Solar photovoltaic (PV) direct current (DC) microgrids have gained significant popularity during the last decade for low cost and sustainable rural electrification. Various system architectures have been practically deployed, however, their assessment concerning system sizing, losses, and operational efficiency is not readily available in the literature. Therefore, in this research work, a mathematical framework for the comparative analysis of various architectures of solar photovoltaic-based DC microgrids for rural applications is presented. The compared architectures mainly include (a) central generation and central storage architecture, (b) central generation and distributed storage architecture, (c) distributed generation and central storage architecture, and (d) distributed generation and distributed storage architecture. Each architecture is evaluated for losses, including distribution losses and power electronic conversion losses, for typical power delivery from source end to the load end in the custom village settings. Newton–Raphson method modified for DC power flow was used for distribution loss analysis, while power electronic converter loss modeling along with the Matlab curve-fitting tool was used for the evaluation of power electronic losses. Based upon the loss analysis, a framework for DC microgrid components (PV and battery) sizing was presented and also applied to the various architectures under consideration. The case study results show that distributed generation and distributed storage architecture with typical usage diversity of 40% is the most feasible architecture from both system sizing and operational cost perspectives and is 13% more efficient from central generation and central storage architecture for a typical village of 40 houses. The presented framework and the analysis results will be useful in selecting an optimal DC microgrid architecture for future rural electrification implementations

Control and Stability of Residential Microgrid with Grid-Forming Prosumers

The rise of the prosumers (producers-consumers), residential customers equipped with behind-the-meter distributed energy resources (DER), such as battery storage and rooftop solar PV, offers an opportunity to use prosumer-owned DER innovatively. The thesis rests on the premise that prosumers equipped with grid-forming inverters can not only provide inertia to improve the frequency performance of the bulk grid but also support islanded operation of residential microgrids (low-voltage distribution feeder operated in an islanded mode), which can improve distribution grids’ resilience and reliability without purposely designing low-voltage (LV) distribution feeders as microgrids. Today, grid-following control is predominantly used to control prosumer DER, by which the prosumers behave as controlled current sources. These grid-following prosumers deliver active and reactive power by staying synchronized with the existing grid. However, they cannot operate if disconnected from the main grid due to the lack of voltage reference. This gives rise to the increasing interest in the use of grid-forming power converters, by which the prosumers behave as voltage sources. Grid-forming converters regulate their output voltage according to the reference of their own and exhibit load sharing with other prosumers even in islanded operation. Making use of grid-forming prosumers opens up opportunities to improve distribution grids’ resilience and enhance the genuine inertia of highly renewable-penetrated power systems. Firstly, electricity networks in many regional communities are prone to frequent power outages. Instead of purposely designing the community as a microgrid with dedicated grid-forming equipment, the LV feeder can be turned into a residential microgrid with multiple paralleled grid-forming prosumers. In this case, the LV feeder can operate in both grid-connected and islanded modes. Secondly, gridforming prosumers in the residential microgrid behave as voltage sources that respond naturally to the varying loads in the system. This is much like synchronous machines extracting kinetic energy from rotating masses. “Genuine” system inertia is thus enhanced, which is fundamentally different from the “emulated” inertia by fast frequency response (FFR) from grid-following converters. Against this backdrop, this thesis mainly focuses on two aspects. The first is the small-signal stability of such residential microgrids. In particular, the impact of the increasing number of grid-forming prosumers is studied based on the linearised model. The impact of the various dynamic response of primary sources is also investigated. The second is the control of the grid-forming prosumers aiming to provide sufficient inertia for the system. The control is focused on both the inverters and the DC-stage converters. Specifically, the thesis proposes an advanced controller for the DC-stage converters based on active disturbance rejection control (ADRC), which observes and rejects the “total disturbance” of the system, thereby enhancing the inertial response provided by prosumer DER. In addition, to make better use of the energy from prosumer-owned DER, an adaptive droop controller based on a piecewise power function is proposed, which ensures that residential ESS provide little power in the steady state while supplying sufficient power to cater for the demand variation during the transient state. Proposed strategies are verified by time-domain simulations

Improving the Sustainability of Self-Consumption with Cooperative DC Microgrids

[EN] The development of microgrids is of great interest to facilitate the integration of distributed generation in electricity networks, improving the sustainability of energy production. Microgrids in DC (DC-MG) provide advantages for the use of some types of renewable generation and energy storage systems, such as batteries. In this article, a possible practical implementation of an isolated DC-MG for residential use with a cooperative operation of the different nodes is proposed. The main criterion is to achieve a very simple design with only primary control in a residential area. This application achieves a simple system, with low implementation costs, in which each user has autonomy but benefits from the support of the other users connected to the microgrid, which improves its reliability. The description of the elements necessary to create this cooperative system is one of the contributions of the work. Another important contribution is the analysis of the operation of the microgrid as a whole, where each node can be, arbitrarily, a consumer or an energy generator. The proposed structures could promote the use of small distributed generation and energy storage systems as the basis for a new paradigm of a more sustainable electricity grid of the future.This work has been partially supported by funds for research support of the Universitat Politècnica de ValènciaRoldán-Porta, C.; Roldán-Blay, C.; Escrivá-Escrivá, G.; Quiles Cucarella, E. (2019). Improving the Sustainability of Self-Consumption with Cooperative DC Microgrids. Sustainability. 11(19):1-22. https://doi.org/10.3390/su11195472S1221119Justo, J. J., Mwasilu, F., Lee, J., & Jung, J.-W. (2013). AC-microgrids versus DC-microgrids with distributed energy resources: A review. Renewable and Sustainable Energy Reviews, 24, 387-405. doi:10.1016/j.rser.2013.03.067Farhangi, H. (2010). The path of the smart grid. IEEE Power and Energy Magazine, 8(1), 18-28. doi:10.1109/mpe.2009.934876Brown, R. E., & Willis, H. L. (2006). The economics of aging infrastructure. IEEE Power and Energy Magazine, 4(3), 36-43. doi:10.1109/mpae.2006.1632452Asmus, P. (2010). Microgrids, Virtual Power Plants and Our Distributed Energy Future. The Electricity Journal, 23(10), 72-82. doi:10.1016/j.tej.2010.11.001Barreto, R. A. (2018). Fossil fuels, alternative energy and economic growth. Economic Modelling, 75, 196-220. doi:10.1016/j.econmod.2018.06.019Zhang, G., Li, Z., Zhang, B., & Halang, W. A. (2018). Power electronics converters: Past, present and future. Renewable and Sustainable Energy Reviews, 81, 2028-2044. doi:10.1016/j.rser.2017.05.290Lasseter, R. H. (s. f.). MicroGrids. 2002 IEEE Power Engineering Society Winter Meeting. Conference Proceedings (Cat. No.02CH37309). doi:10.1109/pesw.2002.985003Santacana, E., Rackliffe, G., Tang, L., & Feng, X. (2010). Getting Smart. IEEE Power and Energy Magazine, 8(2), 41-48. doi:10.1109/mpe.2009.935557Hatziargyriou, N., Asano, H., Iravani, R., & Marnay, C. (2007). Microgrids. IEEE Power and Energy Magazine, 5(4), 78-94. doi:10.1109/mpae.2007.376583Papadimitriou, C. N., Zountouridou, E. I., & Hatziargyriou, N. D. (2015). Review of hierarchical control in DC microgrids. Electric Power Systems Research, 122, 159-167. doi:10.1016/j.epsr.2015.01.006Paska, J., Biczel, P., & Kłos, M. (2009). Hybrid power systems – An effective way of utilising primary energy sources. Renewable Energy, 34(11), 2414-2421. doi:10.1016/j.renene.2009.02.018Salomonsson, D., & Sannino, A. (2007). Low-Voltage DC Distribution System for Commercial Power Systems With Sensitive Electronic Loads. IEEE Transactions on Power Delivery, 22(3), 1620-1627. doi:10.1109/tpwrd.2006.883024Brenna, M., Foiadelli, F., Longo, M., & Abegaz, T. (2016). Integration and Optimization of Renewables and Storages for Rural Electrification. Sustainability, 8(10), 982. doi:10.3390/su8100982Khalid, M., Ahmadi, A., Savkin, A. V., & Agelidis, V. G. (2016). Minimizing the energy cost for microgrids integrated with renewable energy resources and conventional generation using controlled battery energy storage. Renewable Energy, 97, 646-655. doi:10.1016/j.renene.2016.05.042Mahdavyfakhr, M., Rashidirad, N., Hamzeh, M., Sheshyekani, K., & Afjei, E. (2017). Stability improvement of DC grids involving a large number of parallel solar power optimizers: An active damping approach. Applied Energy, 203, 364-372. doi:10.1016/j.apenergy.2017.06.044Lazzari, R., Piegari, L., Grillo, S., Carminati, M., Ragaini, E., Bossi, C., & Tironi, E. (2018). Selectivity and security of DC microgrid under line-to-ground fault. Electric Power Systems Research, 165, 238-249. doi:10.1016/j.epsr.2018.09.001Salomonsson, D., Soder, L., & Sannino, A. (2009). Protection of Low-Voltage DC Microgrids. IEEE Transactions on Power Delivery, 24(3), 1045-1053. doi:10.1109/tpwrd.2009.2016622Shuai, Z., Fang, J., Ning, F., & Shen, Z. J. (2018). Hierarchical structure and bus voltage control of DC microgrid. Renewable and Sustainable Energy Reviews, 82, 3670-3682. doi:10.1016/j.rser.2017.10.096Van den Broeck, G., Stuyts, J., & Driesen, J. (2018). A critical review of power quality standards and definitions applied to DC microgrids. Applied Energy, 229, 281-288. doi:10.1016/j.apenergy.2018.07.058Anand, S., Fernandes, B. G., & Guerrero, J. (2013). Distributed Control to Ensure Proportional Load Sharing and Improve Voltage Regulation in Low-Voltage DC Microgrids. IEEE Transactions on Power Electronics, 28(4), 1900-1913. doi:10.1109/tpel.2012.2215055Radwan, A. A. A., & Mohamed, Y. A.-R. I. (2012). Linear Active Stabilization of Converter-Dominated DC Microgrids. IEEE Transactions on Smart Grid, 3(1), 203-216. doi:10.1109/tsg.2011.2162430Che, Y., Zhou, J., Lin, T., Li, W., & Xu, J. (2018). A Simplified Control Method for Tie-Line Power of DC Micro-Grid. Energies, 11(4), 933. doi:10.3390/en11040933Huang, Y., Yang, L., Liu, S., & Wang, G. (2018). Cooperation between Two Micro-Grids Considering Power Exchange: An Optimal Sizing Approach Based on Collaborative Operation. Sustainability, 10(11), 4198. doi:10.3390/su10114198González, A., Riba, J.-R., & Rius, A. (2015). Optimal Sizing of a Hybrid Grid-Connected Photovoltaic–Wind–Biomass Power System. Sustainability, 7(9), 12787-12806. doi:10.3390/su70912787Maleki, A., Rosen, M., & Pourfayaz, F. (2017). Optimal Operation of a Grid-Connected Hybrid Renewable Energy System for Residential Applications. Sustainability, 9(8), 1314. doi:10.3390/su9081314Roldán-Blay, C., Escrivá-Escrivá, G., & Roldán-Porta, C. (2019). Improving the benefits of demand response participation in facilities with distributed energy resources. Energy, 169, 710-718. doi:10.1016/j.energy.2018.12.102Mao, M., Jin, P., Chang, L., & Xu, H. (2014). Economic Analysis and Optimal Design on Microgrids With SS-PVs for Industries. IEEE Transactions on Sustainable Energy, 5(4), 1328-1336. doi:10.1109/tste.2014.2327067Elrayyah, A., Cingoz, F., & Sozer, Y. (2015). Construction of Nonlinear Droop Relations to Optimize Islanded Microgrid Operation. IEEE Transactions on Industry Applications, 51(4), 3404-3413. doi:10.1109/tia.2014.2387484Meng, L., Shafiee, Q., Ferrari Trecate, G., Karimi, H., Fulwani, D., Lu, X., & Guerrero, J. M. (2017). Review on Control of DC Microgrids. IEEE Journal of Emerging and Selected Topics in Power Electronics, 1-1. doi:10.1109/jestpe.2017.2690219Huang, H.-H., Hsieh, C.-Y., Liao, J.-Y., & Chen, K.-H. (2011). Adaptive Droop Resistance Technique for Adaptive Voltage Positioning in Boost DC–DC Converters. IEEE Transactions on Power Electronics, 26(7), 1920-1932. doi:10.1109/tpel.2010.2095508Nasirian, V., Moayedi, S., Davoudi, A., & Lewis, F. L. (2015). Distributed Cooperative Control of DC Microgrids. IEEE Transactions on Power Electronics, 30(4), 2288-2303. doi:10.1109/tpel.2014.2324579Wang, P., Lu, X., Yang, X., Wang, W., & Xu, D. (2016). An Improved Distributed Secondary Control Method for DC Microgrids With Enhanced Dynamic Current Sharing Performance. IEEE Transactions on Power Electronics, 31(9), 6658-6673. doi:10.1109/tpel.2015.2499310Ma, J., Yuan, L., Zhao, Z., & He, F. (2017). Transmission Loss Optimization-Based Optimal Power Flow Strategy by Hierarchical Control for DC Microgrids. IEEE Transactions on Power Electronics, 32(3), 1952-1963. doi:10.1109/tpel.2016.2561301Ren, L., Qin, Y., Li, Y., Zhang, P., Wang, B., Luh, P. B., … Gong, T. (2018). Enabling resilient distributed power sharing in networked microgrids through software defined networking. Applied Energy, 210, 1251-1265. doi:10.1016/j.apenergy.2017.06.006Liang Che, & Shahidehpour, M. (2014). DC Microgrids: Economic Operation and Enhancement of Resilience by Hierarchical Control. IEEE Transactions on Smart Grid, 5(5), 2517-2526. doi:10.1109/tsg.2014.2344024Lasseter, R. H. (2011). Smart Distribution: Coupled Microgrids. Proceedings of the IEEE, 99(6), 1074-1082. doi:10.1109/jproc.2011.2114630Wang, H., & Huang, J. (2018). Incentivizing Energy Trading for Interconnected Microgrids. IEEE Transactions on Smart Grid, 9(4), 2647-2657. doi:10.1109/tsg.2016.2614988Wang, H., & Huang, J. (2016). Cooperative Planning of Renewable Generations for Interconnected Microgrids. IEEE Transactions on Smart Grid, 7(5), 2486-2496. doi:10.1109/tsg.2016.2552642Kasaei, M. J., Gandomkar, M., & Nikoukar, J. (2017). Optimal management of renewable energy sources by virtual power plant. Renewable Energy, 114, 1180-1188. doi:10.1016/j.renene.2017.08.010Gao, Y., Cheng, H., Zhu, J., Liang, H., & Li, P. (2016). The Optimal Dispatch of a Power System Containing Virtual Power Plants under Fog and Haze Weather. Sustainability, 8(1), 71. doi:10.3390/su8010071Khan, Z. A., & Jayaweera, D. (2017). Approach for smart meter load profiling in Monte Carlo simulation applications. IET Generation, Transmission & Distribution, 11(7), 1856-1864. doi:10.1049/iet-gtd.2016.2084Photovoltaic Geographical Information Systemhttp://re.jrc.ec.europa.eu/pvg_tools/en/tools.htmlWang, J.-Y., Qian, Z., Zareipour, H., & Wood, D. (2018). Performance assessment of photovoltaic modules based on daily energy generation estimation. Energy, 165, 1160-1172. doi:10.1016/j.energy.2018.10.047International Electrotechnical Commission, IEC 60364, Electrical Installations of Buildings—Part 5: Selection and Erection of Electrical Equipmenthttps://webstore.iec.ch/publication/1878Chang, Y.-C., Chang, H.-C., & Huang, C.-Y. (2018). Design and Implementation of the Battery Energy Storage System in DC Micro-Grid Systems. Energies, 11(6), 1566. doi:10.3390/en11061566Deilami, S., Masoum, A. S., Moses, P. S., & Masoum, M. A. S. (2011). Real-Time Coordination of Plug-In Electric Vehicle Charging in Smart Grids to Minimize Power Losses and Improve Voltage Profile. IEEE Transactions on Smart Grid, 2(3), 456-467. doi:10.1109/tsg.2011.2159816Olivares, D. E., Mehrizi-Sani, A., Etemadi, A. H., Canizares, C. A., Iravani, R., Kazerani, M., … Hatziargyriou, N. D. (2014). Trends in Microgrid Control. IEEE Transactions on Smart Grid, 5(4), 1905-1919. doi:10.1109/tsg.2013.229551

Demand Side Management Studies on Distributed Energy Resources: A Survey

The number of distributed environmentally friendly energy sources and generators necessitates new operating methods and a power network board to preserve or even increase the efficiency and quality of the power supply. Similarly, the growth of matriculates promotes the formation of new institutional systems, in which power and power exchanges become increasingly essential. Because of how an inactive entity traditionally organizes distribution systems, the DG’s connection inevitably changes the system’s qualifications to which it is connected. As a consequence of the Distributed Generation, this presumption is currently legal and non-existent. This article glides on demand side management and analysis on distributed energy resources. Investigation of DSM along with zonal wise classification has been carried out in this survey. Its merits and applications are also presented

Demand side management studies on distributed energy resources: A survey

The number of distributed environmentally friendly energy sources and generators necessitates new operating methods and a power network board to preserve or even increase the efficiency and quality of the power supply. Similarly, the growth of matriculates promotes the formation of new institutional systems, in which power and power exchanges become increasingly essential. Because of how an inactive entity traditionally organizes distribution systems, the DG’s connection inevitably changes the system’s qualifications to which it is connected. As a consequence of the Distributed Generation, this presumption is currently legal and non-existent. This article glides on demand side management and analysis on distributed energy resources. Investigation of DSM along with zonal wise classification has been carried out in this survey. Its merits and applications are also presented.Universidad Tecnológica de Bolíva

Hierarchical control of dc microgrids with constant power loads

This dissertation proposes general methodologies for designing hierarchical control schemes for dc microgrids loaded by constant power loads (CPLs). CPLs form a major proportion of the system loads in many microgrids. Without proper control, CPLs present destabilizing effect at the dc microgrid. In addition to stable operation of microgrid, proper current sharing among paralleled sources is essential. The proposed hierarchical control strategy consists of two control levels. The lower level consists of droop-based primary controllers which enables current-sharing among paralleled sources and also damps limit cycle oscillations due to CPLs. The higher level consists of secondary controller which compensates for voltage deviations due to primary controller. This higher level is implemented either as autonomous controllers or as a centralized controller. In the case of autonomous secondary controllers, they operate alongside of primary controllers in each of the paralleled converters. In the case of centralized secondary controller, a remote secondary controller uses a high speed communication link to communicate to local controllers. Interfacing sources with different characteristics and voltage ranges necessitates the use of complex converter topologies. As an initial step towards implementing hierarchical control scheme for such microgrids with CPLs, a linear controller is proposed for dc microgrids with standalone SEPIC, Cuk and Zeta converters. During the first stage of the two stage controller, limit cycle oscillations are damped by inserting a virtual resistance in series with the converter input inductor. During the second stage, an integral controller is added to the first stage to compensate for voltage deviations. For microgrids containing different converter topologies, stability of equilibrium points is examined and stability conditions are derived and explained. Experiments performed on a prototype microgrid are used to verify the proposed control laws. Expanding study on stability of microgrids, the maximum real power load in a dc microgrid bus is traced geometrically. The generalized circle diagram approach used in a conventional power system is modified for this purpose. The different types of buses present in a dc microgrid are described and the locus of operating points is obtained. The proposed method is verified by simulations on an example dc microgrid.Electrical and Computer Engineerin

Inter-Microgrid Operation: Power Sharing, Frequency Restoration, Seamless Reconnection and Stability Analysis

Electrification in the rural areas sometimes become very challenging due to area accessibility and economic concern. Standalone Microgrids (MGs) play a very crucial role in these kinds of a rural area where a large power grid is not available. The intermittent nature of distributed energy sources and the load uncertainties can create a power mismatch and can lead to frequency and voltage drop in rural isolated community MG. In order to avoid this, various intelligent load shedding techniques, installation of micro storage systems and coupling of neighbouring MGs can be adopted. Among these, the coupling of neighbouring MGs is the most feasible in the rural area where large grid power is not available. The interconnection of neighbouring MGs has raised concerns about the safety of operation, protection of critical infrastructure, the efficiency of power-sharing and most importantly, stable mode of operation. Many advanced control techniques have been proposed to enhance the load sharing and stability of the microgrid. Droop control is the most commonly used control technique for parallel operation of converters in order to share the load among the MGs. But most of them are in the presence of large grid power, where system voltage and frequency are controlled by the stiff grid. In a rural area, where grid power is not available, the frequency and voltage control become a fundamental issue to be addressed. Moreover, for accurate load sharing a high value of droop gain should be chosen as the R/X ratio of the rural network is very high, which makes the system unstable. Therefore, the choice of droop gains is often a trade-off between power-sharing and stability. In the context, the main focus of this PhD thesis is the fundamental investigations into control techniques of inverter-based standalone neighbouring microgrids for available power sharing. It aims to develop new and improved control techniques to enhance performance and power-sharing reliability of remote standalone Microgrids. In this thesis, a power management-based droop control is proposed for accurate power sharing according to the power availability in a particular MG. Inverters can have different power setpoints during the grid-connected mode, but in the standalone mode, they all need their power setpoints to be adjusted according to their power ratings. On the basis of this, a power management-based droop control strategy is developed to achieve the power-sharing among the neighbouring microgrids. The proposed method helps the MG inverters to share the power according to its ratings and availability, which does not restrict the inverters for equal power-sharing. The paralleled inverters in coupled MGs need to work in both interconnected mode and standalone mode and should be able to transfer between modes seamlessly. An enhanced droop control is proposed to maintain the frequency and voltage of the MGs to their nominal value, which also helps the neighbouring MGs for seamless (de)coupling. This thesis also presents a mathematical model of the interconnected neighbouring microgrid for stability and robustness analysis. Finally, a laboratory prototype model of two MGs is developed to test the effectiveness of the proposed control strategies

Predictive Energy Management of Islanded Microgrids with Photovoltaics and Energy Storage

Islanded microgrids powered primarily by photovoltaic (PV) arrays present a challenging control problem due to the intermittent production and the relatively close scale between the sources and the loads. Energy storage in such microgrids plays an important role in balancing supply with demand, and in extending operation during periods when the PV supply is not available or insufficient. The efficient operation of such microgrids requires effective management of all resources. A predictive energy management strategy can potentially avoid or effectively mitigate upcoming outages. This thesis presents an energy management system (EMS) for such microgrids. The EMS uses a predictive approach to set operational schedules in order to (a) prolong the supply to critical system loads and (2) minimize the chances and duration of system-wide outages, specifically through pre-emptive load shedding. Online weather forecast data has been combined with the PV system model to assess potential energy production over a 48 hour period. These predictions, along with load forecasts and a model of the energy storage system, are used to predict the state-of-charge of the storage devices and characterize potential power shortages. Pre-emptive load shedding is subsequently planned and executed to avert outages or minimize the duration of unavoidable outages. A bounding technique has also been proposed to account for uncertainties in estimates of the stored energy. The EMS has been implemented using an event-driven framework with network communication. The approach has been validated through simulations and experiments using recorded real-world solar irradiance data. The results show that the outage durations have been reduced by a factor of 87% to 100% for an example operating scenario, selected to demonstrate the features of the scheme. The impact of uncertainties in the prediction models has also been investigated, specifically for the PV system rating and the battery capacity. A technique has been developed to compensate for such uncertainties by analyzing the data streams from the source and storage units. The technique is applied to the developed EMS strategy, where it is able to shorten the total outage duration by a factor of 12% over a 42-day scenario exhibiting a variety of irradiance conditions

Operation and control strategy of coupled microgrid clusters

A standalone remote area microgrid may frequently experience overloading due to lack of sufficient power generation or excessive renewable-based generation that can cause unacceptable voltage and frequency deviation. This can lead the microgrid to operate with less resiliency and reliability. Such problems are conventionally alleviated by load-shedding or renewable curtailment. Alternatively, autonomously operating microgrids in a geographical area can be provisionally connected to each other to facilitate power exchange for addressing the problems of overloading or overgeneration. The power exchange link among the microgrids can be of different types such as a three-phase ac, a single-phase ac, or a dc-link. Power electronic converters are required to interconnect such power exchange networks to the three-phase ac microgrids and control the power-sharing amongst them. Such arrangement is also essential to interconnect microgrid clusters to each other with proper isolation while maintaining autonomy if they are operating in different standards. In this thesis, the topologies, and structures of various forms of power exchange links are investigated and appropriate operation and control frameworks are established under which power exchange can take place properly. A decentralised control mechanism is employed to facilitate power-sharing without any data communication. The dynamic performance of the control mechanism for all the topologies is illustrated through simulation studies in PSIM® while the stability and robustness of the operation are evaluated using numerical studies in MATLAB®