Microgrids

This paper deals with the design of a hierarchical control scheme for complex islanded Alternate Current (AC) microgrids. The proposed solution relies on the combined use of Model Predictive Control (MPC) and Sliding Mode Control (SMC). The model of the microgrid includes several Distributed Generation Units (DGus), affected by unknown load dynamics and modelling uncertainties. Moreover, they are connected according to an arbitrary complex and meshed topology, taking into account the interconnecting line dynamics. The proposed control scheme consists of two control loops. A centralized MPC supervisor generates the voltage reference values for each DGu, while fulfilling input and state constraints on the basis of a reduced order model of the plant. A Suboptimal Second Order Sliding Mode (SSOSM) control is locally designed for each DGu to track, in a decentralized way, the voltage references generated by the supervisor. Simulation results confirm the effectiveness of the proposed control scheme.

A compendium of the authors' recently published results, this book discusses sliding mode control of uncertain nonlinear systems, with a particular emphasis on advanced and optimization based algorithms. The authors survey classical sliding mode control theory and introduce four new methods of advanced sliding mode control. They analyze classical theory and advanced algorithms, with numerical results complementing the theoretical treatment. Case studies examine applications of the algorithms to complex robotics and power grid problems. Advanced and Optimization Based Sliding Mode Control: Theory and Applications • is the first book to systematize the theory of optimization based higher order sliding mode control and illustrate advanced algorithms and their applications to real problems; • presents systematic treatment of event-triggered and model based event-triggered sliding mode control schemes, including schemes in combination with model predictive control; • presents adaptive algorithms as well as algorithms capable of dealing with state and input constraints; and • includes simulations and experimental results obtained by applying the presented control strategies to real complex systems. This book is suitable for students and researchers interested in control theory. It will also be attractive to practitioners interested in implementing the illustrated strategies. It is accessible to anyone with a basic knowledge of control engineering, process physics, and applied mathematics.

Technology advancement for renewable energy resources and its integration to the distribution network (DN) has garnered substantial interest in the last few decades. Integrating such resources has proven to reduce power losses and improve the reliability of DN. However, the growing number of these resources in DN has imposed additional operational and control issues in voltage regulation, system stability, and protection coordination. Incorporation of various types of distributed generators (DG) into DN causes significant changes in the system. These including new fault current sources, new fault levels, a blinding effect in the protection scheme, reduction in the reach of relays, and decrement in the detection of low-level fault currents for existing relays. Such changes will jeopardize the effectiveness of the entire protection scheme in the DN. This research aims to propose a robust protection scheme in which the relay coordination settings are optimized based on the network layout. The potential impacts of DGs on the DN are mitigated by utilizing a user-defined overcurrent-based relay characteristic to obtain the minimum operating time while satisfying protection coordination constraints. A hybrid optimization algorithm based on Metaheuristic and Linear Programming that has the capability to attain the optimal solution and reduces computational time is proposed in this work. The performance of the proposed technique is tested on radial DN integrated with microgrid (MG). The results obtained show the proposed technique has successfully reduced the relay operating time while meeting the protection coordination requirements for dynamic operating modes of a network. KEYWORDS: Power system Protection; Radial Distribution Network ; Power System Optimizations; Relay operating time; Distributed Generators (DG)

The increasing share of distributed generation (DG) units in electrical power systems has a significant impact on the operation of the distribution networks, which are increasingly being confronted with congestion and voltage problems. This demands a coordinated approach for integrating DG in the network, allowing the DG units to actively contribute to frequency and voltage regulation. Microgrids can provide such coordination by aggregating DG, (controllable) loads, and storage in small-scale networks, which can operate in both grid-connected and islanded mode. In this article, the islanded operating condition is considered. As in the conventional networks, a hierarchical control structure can be implemented in islanded microgrids. In recent years, many different concepts for primary, secondary, and tertiary control of microgrids have been investigated. These controllers can be classified as either local or centralized. In this article, the hierarchical control for application in microgrids is discussed, and an overview of the control strategies is given with respect to the reserve provision by the DG units, loads, and storage equipment.

The need for new generation systems has motivated the development of microgrids. This new concept may provide significant benefits such as losses reduction, high degree of efficiency and reliability to the transmission and distribution networks. This paper presents generalities about microgrids, including general structure and different topologies. Also an original methodology for facilitating its design and evaluation is proposed. Finally, the microgrid located at the Parque Tecnológíco de Guatiguará at the Universidad Industrial de Santander, is analyzed and an operation analysis is included for different operations stages of loads and generation, the performance of operation of storage systems, the interaction with the grid and an energy balance for all the system.

Free to download eBook on Practical Solar Tracking Design, following the sun solar tracking system, sun tracking system, sun tracker system, solar tracker system, sun positioning system, and sun path tracking with follow the sun position calculation (azimuth, elevation, zenith), sun trajectory, sun following system, sunrise tracking, sunset tracking, sunlight-phases, dawn, dusk, moon-phase, twilight, moonrise, moonset calculator. Solar Tracking is a key Technology to unlock the full potential of RE in RES.
In harnessing power from the sun through a solar tracker or solar tracking system and following the sun, renewable energy system developers require automatic solar tracking software and solar position algorithms. As a result of the apparent motion of the sun, a sun path on-axis sun tracking system such as the altitude-azimuth dual axis or multi-axis solar tracker systems use a sun tracking algorithm or ray tracing sensors or software to ensure the sun's passage through the sky is traced with high precision in automated solar tracker applications, right through summer solstice, solar equinox and winter solstice using sun positional astronomy.

In general, this book may benefit solar research, sun surveying, sun position applet, solar energy harvesting, solar energy tracker and sun tracking solar panel applications in countries such as Africa, Mediterranean, Italy, Spain, Greece, USA, Mexico, South America, Brazilia, Argentina, Chili, India, Malaysia, Middle East, UAE, Russia, Japan and China. This book on practical automatic Solar-Tracking Sun-Tracking is in .PDF format and can easily be converted to the solar tracking system sun tracking system .EPUB .MOBI .AZW .ePub .FB2 .LIT .LRF .MOBI .PDB .PDF .TCR formats for smartphones and Kindle by using the ebook.online-convert.com facility.

From sun tracing software perspective, the sonnet Tracing The Sun has a literal meaning. Within the context of sun track and trace, this book explains that the sun's daily path across the sky is directed by relatively simple principles, and if grasped/understood, then it is relatively easy to trace the sun with sun following software. Sun Surveyor and Sun Position computer software for tracing the sun are available as open source code, sources that is listed in this book. This book also describes the use of satellite tracking software and mechanisms in solar tracking applications using Sun Microsystems and other processor architecture.
Using solar equations in an electronic circuit for solar tracking is quite simple, even if you are a novice, but mathematical solar equations are over complicated by academic experts and professors in text-books, journal articles and internet websites. In terms of solar hobbies, scholars, students and Hobbyist's looking at solar tracking electronics or PC programs for solar tracking are usually overcome by the sheer volume of scientific material and internet resources, which leaves many developers in frustration when search for simple experimental solar tracking source-code for their on-axis sun-tracking systems. This booklet will simplify the search for the mystical sun tracking formulas for your sun tracker innovation and help you develop your own autonomous solar tracking controller.

By directing the solar collector directly into the sun, a solar harvesting means or device can harness sunlight or thermal heat. This is achieved with the help of sun angle formulas, solar angle formulas or solar tracking procedures for the calculation of sun's position in the sky. Automatic sun tracking system software includes algorithms for solar altitude azimuth angle calculations required in following the sun across the sky. In using the longitude, latitude GPS coordinates of the solar tracker location, these sun tracking software tools supports precision solar tracking by determining the solar altitude-azimuth coordinates for the sun trajectory in altitude-azimuth tracking at the tracker location, using certain sun angle formulas in sun vector calculations. Instead of follow the sun software, a sun tracking sensor such as a sun sensor or camera with vision based sun following image processing software can also be used to determine the position of the sun optically. Such optical feedback devices are commonly used in solar panel tracking systems and dish tracking systems.

Dynamic sun tracing is also used in solar surveying and sun surveying systems that build solar radiance, irradiance and DNI models for GIS (geographical information system) and database systems. In such solar resource modelling systems, a pyranometer or solarimeter is used in addition to measure direct and indirect, scattered, dispersed, reflective radiation for a particular geographical location. Sunlight analysis is important in flash photography where photographic lighting are important for photographers. GIS systems are used by architects who add sun shadow applets to study architectural shading or sun shadow analysis, solar flux calculations, optical modelling or to perform weather modelling. Such systems often employ a computer operated telescope type mechanism with ray tracing program software as a solar navigator or sun tracer that determines the solar position and intensity.

Many open-source sun following and tracking algorithms and source-code for solar tracking programs and modules are freely available to download on the internet today. The purpose of this booklet is to assist developers to track and trace suitable source-code and solar tracking algorithms for their application, whether a hobbyist, scientist, technician or engineer. The solar library used by solar position calculators, solar simulation software and solar contour calculators include machine program code for the solar hardware controller which are software programmed into Micro-controllers, Programmable Logic Controllers PLC, programmable gate arrays, Arduino processor or PIC processor. PC based solar tracking is also high in demand using C++, Visual Basic VB, as well as Windows and Mac based software for sun path tables on Matlab, Excel. Some books and internet webpages use other terms, such as: sun angle calculator, sun position calculator or solar angle calculator. As said, such software code calculate the solar azimuth angle, solar altitude angle, solar elevation angle or the solar Zenith angle (Zenith solar angle is simply referenced from vertical plane, the mirror of the elevation angle measured from the horizontal or ground plane level). Similar software code is also used in solar calculator apps or the solar power calculator apps for IOS and Android smartphone devices. Most of these smartphone solar mobile apps show the sun path and sun-angles for any location and date over a 24 hour period. Some smartphones include augmented reality features in which you can physically see and look at the solar path through your cell phone camera or mobile phone camera at your phone's specific GPS location.

Software algorithms predicting position of the sun in the sky are commonly available as Java applets, C++ code, Basic, GBasic and QBasic code, Matlab and Simulink procedures, TRNSYS simulations, Scada system apps, Labview module, mobile and iphone apps, tablet apps, and so forth. At the same time, PLC software code for a range of sun tracking automation technology (mechatronic, electrical, pneumatic, hydraulic drives and motors) can follow the profile of sun in sky for Siemens, HP, Panasonic, ABB, Allan Bradley, OMRON, SEW, Festo, Beckhoff, Rockwell, Schneider, Yokonawa, or Muthibishi platforms. Sun path projection software are also available for a range of processors, including Siemens S7-1200 or Siemens Logo, OMRON PLC, Ercam PLC, AC500plc ABB, National Instruments, PIC processor, Arduino, and so forth. Analogue or digital interfacing ports on these processors allow for tracking orientation angle feedback through one or a combination of angle sensor or angle encoder, shaft encoder, precision encoder, optical encoder, magnetic encoder, direction encoder, rotational encoder, tilt sensor, inclination sensor, or pitch sensor. Note that the tracker's elevation or zenith axis angle may measured with an altitude angle, declination angle, inclination angle, pitch angle, or vertical angle, zenith axis. Similarly the tracker's azimuth axis angle be measured with a azimuth angle sensor, horizontal angle, roll angle sensor.

Many solar tracker applications cover a wide spectrum of solar energy and concentrated solar devices, including solar power generation, solar desalination, solar water purification, solar steam generation, solar electricity generation, solar industrial process heat, solar thermal heat storage, solar food dryers, hydrogen production from methane or producing hydrogen and oxygen from water (HHO). Many patented or non-patented solar apparatus include tracking in solar apparatus for solar electric generator, solar desalinator, solar steam engine, solar ice maker, solar water purifier, solar cooling, solar refrigeration, USB solar charger, solar phone charging, portable solar charging tracker, solar cooking or solar dying means. Your project may be the next breakthrough or patent, but your invention is held back by frustration in search for the sun tracker you require for your solar powered appliance, solar generator, solar tracker robot, solar freezer, solar cooker, solar drier, solar freezer, or solar dryer project. Whether your solar electronic circuit diagram include a simplified solar controller design in a solar electricity project, solar power kit, solar hobby kit, solar steam generator, solar hot water system, solar ice maker, solar desalinator, hobbyist solar panels, hobby robot, or if you are developing professional or hobby electronics for a solar utility or micro scale solar powerplant for your own solar farm or solar farming, this publication may help accelerate the development of your solar tracking innovation.

The U.S. electrical grid, the largest and most complex man-made system in the world, is highly vulnerable to three types of external threats: 1) natural disasters, 2) intentional physical attacks, and 3) cyber-attacks. The technical community has recommended hardening the grid to make it more resilient to attack by using distributed generation and microgrids. Solar photovoltaic (PV) systems are an ideal distributed generation technology to provide power for such microgrids. However, both the deployment velocity and the policy of how to implement such technical solutions have been given far less attention than would be normally considered adequate for a national security risk. To address this threat, this paper reviews the technical and economic viability of utilizing defense contracting for the beginning of a national transition to distributed generation in the U.S. First, the technical scale of electrical demand and the solar PV system necessary is analyzed in detail to meet the first level of strategic importance: the U.S. military. The results found that about 17GW of PV would be needed to fortify the U.S. military domestically. The current domestic geographic deployment of microgrid installations in the critical U.S. defense infrastructure were reviewed and compared to historical grid failures and existing and planned PV installations to mitigate that risk. The results showed a minimal number of military bases have introduced solar PV systems, leaving large parts of the Department of Defense electrical infrastructure vulnerable to attack. To rectify this situation, the technical skills of the top 20 U.S. defense contractors is reviewed and analyzed for a potential contracting transition to grid fortification. Overall the results indicate that a fortified U.S. military grid made up of PV-powered microgrids is technically feasible, within current contractors skill sets and economically viable. Policy recommendations are made to accelerate U.S. military grid fortification.

For the islanded operation of a microgrid, several control strategies have been developed. For example, voltage-based droop control can be implemented for the active power control of the generators and the control of the active loads. One of the main advantages of a microgrid is that it can be implemented as a controllable entity within the electrical network. This requires the ability of the utility grid to control or influence the power exchange with the microgrid by communicating with only one unit. However, little research has been conducted on controlling the power transfer through the point of common coupling (PCC). This paper addresses this issue by introducing the concept of a smart transformer (ST) at the PCC. This unit controls the active power exchange between a microgrid and the utility grid dependent on the state of both networks and other information communicated to the ST. To control the active power, the ST uses its taps that change the microgrid-side voltage at the PCC. This voltage-based control of the ST is compatible with the voltage-based droop control of the units in the microgrid that is used in this paper. Hence, the microgrid units can automatically respond to changes of ST set points and vice versa. Several simulation cases are included in this paper to demonstrate the feasibility of the ST concept.

This paper presents a fault-tolerant secondary and adaptive primary microgrid control scheme using a hybrid multi-agent system, capable of operating based on either semi-centralised or distributed control modes. The proposed scheme includes a droop-based primary control level that operates by taking into consideration the microgrid energy reserves in both production and storage. Since the proposed scheme is designed for microgrids with AC-coupled units, the secondary level is responsible for: a) the coordination of the microgrid units operation, b) voltage and frequency restoration and c) calculation of the droop/ reversed-droop coefficients. The suggested architecture is arranged upon a group of dedicated asset agents and a supervising agent: each microgrid asset-such as PV, energy storage system, load bus-has a preassigned agent that is able to collect local measurements, take decisions independently and finally, collaborate with the rest of the agents in order to achieve more complex control objectives. The multi-agent system is easily scalable, thanks to its build-in "plug-and-play" capability. Further, it can operate in a flexible manner either with or without the supervising agent operational, owing to fast redistribution of the supervising agent tasks. In order to test the proposed hybrid scheme, two separate physical microgrids have been modelled and used on three simulation scenarios. The multi-agent system interacts with simulation models similar to real physical systems. Contingencies and fault scenarios of microgrids are examined. Additionally, a comparison with conventional control methodologies is performed in order to illustrate further the operation of a hybrid approach. Overall, results show that the proposed control framework exhibits unique characteristics regarding reconfigurability and fault-tolerance, while power quality and improved load sharing are ensured even in case of critical component failure.

In order to achieve a coordinated integration of distributed energy resources in the electrical network, an aggregation of these resources is required. Microgrids and virtual power plants (VPPs) address this issue. Opposed to VPPs, microgrids have the functionality of islanding, for which specific control strategies have been developed. These control strategies are classified under the primary control strategies. Microgrid secondary control deals with other aspects such as resource allocation, economic optimization and voltage profile improvements. When focussing on the control-aspects of DER, VPP coordination is similar with the microgrid secondary control strategy, and thus, operates at a slower time frame as compared to the primary control and can take full advantage of the available communication provided by the overlaying smart grid. Therefore, the feasibility of the microgrid secondary control for application in VPPs is discussed in this paper. A hierarchical control structure is presented in which, firstly, smart microgrids deal with local issues in a primary and secondary control. Secondly, these microgrids are aggregated in a VPP that enables the tertiary control, forming the link with the electricity markets and dealing with issues on a larger scale.

This final project work analyses the behaviour of a proposed microgrid during the period of 24
hours, thorugh a series of simulations using the software PowerWorld. The microgrid architecture
allows the evaluation of the network impact, at the consumer level, about the use of microgrids
with distributed energy in different operational conditions: conventional, distributed generation
and distributed generation with peak hour support. The simulations show the demand and cost
behaviour, according to the modeling and simulation based on the valid norms of the energy
dealership COPEL, on the state of Paraná, providing a general vision of the impact on power and
economic sides of the microgrid adoption.

Microgrids can operate either interconnected to the utility grid or disconnected forming an island. The transition between these modes can cause transient overcurrents or power oscillations jeopardizing the equipment safety or the system stability. This paper proposes a local multi agent control method for a seamless transfer between the islanded and interconnected modes of operation with agents implemented into the microgrid central switch (MCS) and into the microsources inverters. The MCS agent supervises the grid status and controls the switch for the transition of the microgrid through the different operation modes, while it communicates locally with the inverter agents of the microsources. The inverter agents undertake the synchronization process in case of reconnecting and change the inverter control mode depending on the grid status. Simulation and experimental results are presented to show the performance and feasibility of the proposed strategy.

This paper deals with the design of advanced control strategies of sliding mode type for microgrids. Each distributed generation unit (DGu), constituting the considered microgrid, can work in both grid-connected operation mode (GCOM) and islanded operation mode (IOM). The DGu is affected by load variations, nonlinearities and unavoidable modelling uncertainties. This makes sliding mode control particularly suitable as a solution methodology for the considered problem. In particular, a second order sliding mode (SOSM) control algorithm, belonging to the class of Suboptimal SOSM control, is proposed for both GCOM and IOM, while a third-order sliding mode (3-SM) algorithm is designed only for IOM, in order to achieve, also in this case, satisfactory chattering alleviation. The microgrid system controlled via the proposed sliding mode control laws exhibits appreciable stability properties, which are formally analyzed in the paper. Simulation results also confirm that the obtained closed-loop performances comply with the IEEE recommendations for power systems.

The present study analyses the design of the power system of a manned lunar base, in Shackleton crater, using well-established terrestrial technologies deriving from DC microgrids with increased fault-tolerance needs. Expected luminance data from 2020 is used in order to select the ideal base location in terms of mean annual solar irradiance, according to which, the sizing of the power generation and storage units is performed. The proposed grid topology is meshed in order to satisfy the high reliability requirements of a manned space mission and, at the same time, to reduce the mass/ volume budgets of the mission. The load profile is constructed using a set of notional loads. Furthermore, a novel solar array configuration is proposed under the scope of maximizing the energy production under the specific irradiance of the base siting. After preliminary sizing is performed, a series of microgrid-related technologies is suggested, covering all levels of grid design, control and protection.

Prinsloo, G.J., Dobson, R.T., Mammoli, A.A. 2016. Model based design of a novel Stirling solar micro-cogeneration system with performance and fuel transition analysis for rural African village locations. Solar Energy 133, p 315-330 doi:10.1016/j.solener.2016.04.014

This paper describes the performance of a hybrid renewable energy system (HRES) integrated with a combined heat and power cogenerative smart microgrid as remote area power supply (RAPS) in deregulated district energy systems. The research focus on 100% renewables follows on from the ideas of the international energy society (ISES) 100% renewable energy drive, the IEEE smart villages initiative, international renewable energy alliance (IREA), the smart electric power alliance (SEPA) and the alliance for rural electrification (ARE). The proposed hybrid biogas based sun tracker concentrated solar hybrid renewable domestic hot water and power generation system. This alternative energy system design is suitable for space heating, household lighting and cooling refrigeration loads in smart villages, eco-estates, game-farms and remote islands. The study highlights the benefits of embedded generation in integrated and interactive smartgrid configurations for decentralised and district energy systems. International development initiatives such as the Alliance for Rural Electrification and the IEEE Smart Village program have been calling on engineers from developing countries to assist in reducing energy poverty through the design and development of custom designed small-scale sustainable renewable energy solutions. This paper describes the thermodynamic and electrical modeling, simulation and synthesis of a novel kit-based concentrating solar power combined heat and power or hybrid solar cogeneration system. It describes the decentralized solar co-generation system based on a combined cycle Stirling micro-CHP system that includes a low maintenance linear free piston Stirling engine with waste heat recovery, ideal for small business, residential or domestic solar home systems. The concentrating solar combined cycle power and energy system has been designed as a cost-effective community shared solar micro-combined heat and power unit to help enable solar energy utilization within the physical and socio-economic reality of isolated rural areas. This modular plug-and-play unit intends to serve as a stand-alone 100% renewable energy solar powerpack in rural microgrid energy distribution network applications where it will deliver around 3 kW of heat and 1 kW of electricity in distributed generation configurations. The focus of this paper is on the model based design approach in which the main components of the proposed solar micro-combined heat and power system have been systematically modeled on the TRNSYS and Matlab Simulink simulation platforms. This discrete digital modeling approach follows the design guide of the National Renewable Energy Laboratory Village Power Program wherein computer models are used to predict system performance. The TRNSYS model application is extended to meet compulsory World Bank and Development Agency funding and humanitarian investment requirements in terms of providing energy reform and fuel transition projections as part of proving the suitability of newly proposed solar technologies for remote area power applications. The proposed computer model applies statistical weather data to explore the performance, feasibility and fuel transition effects for the solar micro-combined heat and power system in terms of electricity and hot-water generation as well as fuel wood replacement at various locations in Southern Africa. The results show the annual power and hot water generation capability of the system for various sites across Southern Africa, and demonstrates a significant potential in reducing fuel wood usage for villages in these areas. This technology and analysis principles would also be valuable in environmental CO2 sequestration analysis, energy sustainability studies, techno-economic analysis as well as cost benefit studies for greenhouse gas (GHG) mitigation and adaptation technologies. Africa is a developing countries situated in one of the most vulnerable continents to climate variability. Climate change threatens food security and water stress from droughts and floods as well as potential extinction of plant and animal species, calling for nature conservation to reverse wood-land degradation, deforestation and erosion.
This universal distributed generation Stirling engine generation system is ideal for decentralized pre-paid energy co-operatives and pay-as-you-go solar home business models towards empowering remote off-grid villages and indigenous communal living in village communities through indigenous local sustainable energy sources. Energy production from thermodynamic micro-CHP system forms the core of a smart energy system infrastructure that makes up the rural energy system able to serve rural village communities-sustainably. It is intended to ensure sustainable rural development by providing sustainable energy that could displace traditional fossil fuels. The system uses indigenous energy resources, and with added photovoltaic PV or wind energy generation to ensure fossil fuel displacement in replacing fuels such as kerosene, paraffin, candles and wood fuel that cause human health issues and illness due to smoke inhalation. Such hybrid biofuel or biogas solar system provide a sustainable green energy solution and household home heating or district heating solution based on zero-net-energy 100% renewables. It is offered as a humanitarian aid technology to help service coalitions in support of entrepreneurial ventures into engineering for change in remote isolated off-grid rural communities at the bottom of the pyramid.
Follow on work describes the cyber-physical system aspects with smartgrid energy management and control modeling for coordination and optimization of the overall village power system. The integrated community solar and community microgrid solutions are novel in the context of thermo-electrical cogeneration, virtual power plants and hierarchical control structures for remote rural islanded village applications. Hybrid photovoltaic PV, eolica wind, small hydro and biogas cogeneration (poly-generation, tri-generation or hybrid-generation) in multi-carrier pico-grid, nano-grid or micro-grid dispatch can be used for power n energy delivery to drive appliances such as direct current DC LED lighting, fridges, radio, satellite TV, entertainment systems, and sanitation in islanded network configurations. This includes a flexible smart energy management in smart-grid architecture, data analytics and smart-meter instrumentation that includes machine-learning and artificial intelligence with mathematical and economic optimization in demand management, automated demand response, demand management and flexible controllable load curtailment. The intelligent energy management system aspects include customer engagement in control automation, intelligent self-learning, predictive optimization, energy profile or load forecasting, solar forecasting and battery energy storage integration in managing energy reserves. With smart-meter dashboard analytics, this will ensure renewable energy integration in dispersed generation with energy storage (battery, fuel-cell, tank) to ensure practical energy management that deals with the uncertainty, variability, flexibility and energy security in small-scale heat and power microgrids.
Highlights include customer engagement and cooperation in community solar energy utilization in physical & socio-economic reality of isolated rural areas; Localized rural electric power solution to ensure self-sufficient prosumer based energy in community smartgrids; Digital numerical modeling of custom designed kit-based concentrated solar tracker Stirling CSP micro-CHP system; Simulation prediction of CSP system performance in isolated rural African contexts to improve resource coordination and energy preservation; Analysis on fuel transition projections & rural energy generation reform; Need for hot water geyser type energy storage and dispatch; Demonstration of the personalized approach to power supply within sociological relevance and sustainability merit of customized community solar technology.
http://www.sciencedirect.com/science/article/pii/S0038092X16300378
https://www.researchgate.net/publication/301659032_Model_based_design_of_a_novel_Stirling_solar_micro-cogeneration_system_with_performance_and_fuel_transition_analysis_for_rural_African_village_locations

In this paper, we propose a robust voltage control scheme for microgrids based on a suitable designed third-order sliding mode (3-SM) controller. The use of 3-SM allows to reject matched disturbances and unmodeled dynamics, due to the presence of a voltage-sourced-converter (VSC) as interface with the main grid. The motivation for using a 3-SM control approach, apart from its property of providing robustness to the scheme in front of a significant class of uncertainties, is also given by its capability of enforcing sliding modes of the controlled system with chattering alleviation. The microgrid system controlled via the proposed 3-SM approach proves to exhibit appreciable stability properties. Specifically, the voltage error with respect to the required reference is steered to zero in a finite time. The comparison with respect to second order sliding mode (SOSM) and PI controllers shows the beneficial effects of the proposed strategy, and simulation results confirm that our control law provides closed-loop performance complying with the IEEE recommendations for power systems.

Islanded microgrids do not have sufficient resources to contribute enough fault current to legacy protection devices to continue operation. Therefore, when a fault happens in an islanded microgrid, relays with high fault current setting will fail to detect and clear the fault. Contemporary adaptive protection schemes rely on communication technologies to adjust the relay settings to adapt to the microgrids' modes of operation; grid-connected or islanded. However, the risk of communication link failures and cyber security threats such as denial-of-service represent major challenges in implementing a reliable adaptive protection scheme. In order to address this issue, this paper proposes an adaptive protection scheme which utilize super capacitive energy storage to enhance resiliency against communication outages. This paper also introduces an autonomous control algorithm developed for the super-capacitor's AC/DC converter. The proposed control is capable of deciding upon charging, discharging of the super-capacitor, and whether or not to feed fault currents in the AC side, based on direct voltage and frequency measurements from its connection point with the microgrid. This eliminates the need for a control command to be sent from the point of common coupling of the microgrid with main grid to adjust the controller's mode of operation and thus reducing the risk of controller failure due to cyber-attacks or other communication issues. Additionally, the paper proposes a solution to avoid installing a larger super-capacitor by temporarily disconnecting the uncritical pulsed load during the fault instant. The proposed protection scheme was investigated through simulation for various fault types and showed successful results using the proposed scheme in eliminating the aforementioned faults when the communication were available or attacked.