Nanotechnology is utilized well in the development and improvement of the performance in Solid Oxide Fuel Cells (SOFCs). The high operating temperature of SOFCs (700–900 °C) has resulted in serious demerits regarding their overall performance and durability. Therefore, the operating temperature has been reduced to an intermediate temperature range of approximately 400–700 °C which improved performance and, subsequently, commercialized SOFCs as portable power sources. However, at reduced temperature, challenges such as an increase in internal resistance of the fuel cell components arise. Although, this may not be as serious as problems encountered at high temperature, it still significantly affects the performance of SOFCs. This review paper addresses the work of researchers in the application of nanotechnology in fabricating SOFCs through distinct methods. These methods have successfully omitted or at least reduced the internal resistance and showed considerable improvement in power density of the SOFCs at reduced temperatures.

Nanomaterials for solid oxide fuel cells: A review

This paper proposes a method for power flow control between utility and microgrid through back-to-back converters, which facilitates desired real and reactive power flow between utility and microgrid. In the proposed control strategy, the system can run in two different modes depending on the power requirement in the microgrid. In mode-1, specified amount of real and reactive power are shared between the utility and the microgrid through the back-to-back converters. Mode-2 is invoked when the power that can be supplied by the DGs in the microgrid reaches its maximum limit. In such a case, the rest of the power demand of the microgrid has to be supplied by the utility. An arrangement between DGs in the microgrid is proposed to achieve load sharing in both grid connected and islanded modes. The back-to-back converters also provide total frequency isolation between the utility and the microgrid. It is shown that the voltage or frequency fluctuation in the utility side has no impact on voltage or power in microgrid side. Proper relay-breaker operation coordination is proposed during fault along with the blocking of the back-to-back converters for seamless resynchronization. Both impedance and motor type loads are considered to verify the system stability. The impact of dc side voltage fluctuation of the DGs and DG tripping on power sharing is also investigated. The efficacy of the proposed control ar-rangement has been validated through simulation for various operating conditions. The model of the microgrid power system is simulated in PSCAD.

Power management and power flow control with back-to-back converters in a utility connected microgrid

Environmental aspects of fuel cells: A review.

The increasing demands for environmentally friendly grid-scale electric energy storage devices with high energy density and low cost have stimulated the rapid development of various energy storage systems, due to the environmental pollution and energy crisis caused by traditional energy storage technologies. As one of the new and most promising alternative energy storage technologies, zinc-ion rechargeable batteries have recently received much attention owing to their high abundance of zinc in natural resources, intrinsic safety, and cost effectiveness, when compared with the popular, but unsafe and expensive lithium-ion batteries. In particular, the use of mild aqueous electrolytes in zinc-ion batteries (ZIBs) demonstrates high potential for portable electronic applications and large-scale energy storage systems. Moreover, the development of superior electrolyte operating at either high temperature or subzero condition is crucial for practical applications of ZIBs in harsh environments, such as aerospace, airplanes, or submarines. However, there are still many existing challenges that need to be resolved. This paper presents a timely review on recent progresses and challenges in various cathode materials and electrolytes (aqueous, organic, and solid-state electrolytes) in ZIBs. Design and synthesis of zinc-based anode materials and separators are also briefly discussed.

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Recent Progress on Zinc-Ion Rechargeable Batteries

An updated review of energy storage systems: Classification and applications in distributed generation power systems incorporating renewable energy resources

Renewable energy generation is rapidly growing in the power sector industry and widely used for two categories: grid connected and standalone system. This paper gives the insights about fuel cell operation and application of various power electronics systems. The fuel cell voltage decreases bit by bit with expansion in current because of losses associated with fuel cell. It is difficult in handling large rated fuel cell based power system without regulating mechanism. The issue connected with fuel based structural planning and the arrangements are widely investigated for all sorts of utilization. In order to improve the reliability of fuel cell based power system, the integration of energy storage system and advanced research methods are focused in this paper. The control algorithms of power architecture for the couple of well-known applications are discussed. Additionally, the paper addresses the suitable processor utilized as a part of the energy unit application on the premise of fuel cell characteristics. In this paper, the challenges to improve the dynamics of controller in fuel cell based applications are mentioned.

Recent advances and challenges of fuel cell based power system architectures and control – A review

PV systems are widely operated in grid-connected and a stand-alone mode of operations. Power fluctuation is the nature phenomena in the solar PV based energy generation system. When solar PV system operates in off-grid to meet remote load demand alternate energy sources can be identified, such as hybrid grid-tied or battery storage system for stable power supply. In the grid-connected condition when solar radiation is insufficient and unable to meet load demand, the energy is accessed from grid via net meter which makes more reliability in the consumer ends. Power quality is a major concern, while injecting PV to the grid and mitigating the effects of load harmonics and reactive power in the distribution system is the challenging area. Off-grid solar PV system is independent of the grid and provides freedom from power quality issues and electricity billing. The excess energy can be accumulated in the battery storage units through superior control. The main research challenges in off-grid are to provide support to load when sudden changes happened in a closed network of the load. This chapter deals with the operational behavior of solar PV system in grid-tied and off-grid system. It includes the issues and research challenges during power unbalancing and environmental (solar irradiation) and load conditions, etc. This chapter contains the control strategies of sliding mode control for grid-tied and off-grid system. The simulations have been performed for solar PV fed multilevel inverters for grid-tied and off the grid in islanding regions. Furthermore, the simulations are carried out for load compensation by mitigating the effects of load harmonics and reactive power in the distribution. The results are also presented to provide better insight to reader for understanding grid-connected and off-grid solar PV system.

Grid-Connected and Off-Grid Solar Photovoltaic System

In island countries, microgrid systems have the ability to provide reliable and improved power quality especially in the vast country with low population density in remote regions. There are two major types of smart grid design in the absence of central grid, namely DC microgrid and AC microgrid. When microgrids are enabled with renewable energy sources, energy storage units increase the reliability in power supply for the load demand on consumer end. The optimized means of extracting power from renewable energy resources like wind, solar, and fuel cell is difficult in islanding mode of operation. Due to occurrence of power imbalance, energy storage units are required which support the energy requirement when power generation cannot meet the load demand. A microgrid is controlled by a supervisory controller that decides which energy storage units are connected to satisfy the load demand. Though the task is simple, appropriate control strategies are required by the microgrid to cope up with disturbances such as sudden changes in environmental and load conditions. An energy storage unit should be designed to fulfill the requirement of fast and dynamic transition of power consumed by loads connected with microgrid. In AC microgrid, the presence of local energy sources and the ability to regulate voltage and frequency can alleviate the burden for conventional generating unit. In DC microgrid, such a problem does not exist; however, the issue of voltage handling is needed to be dealt with. This chapter deals with the integration of energy storage system (ESS) with DC and/or AC microgrid and related energy management control algorithms. It also addresses the research challenges and solutions towards smooth operational behavior of ESS by integrating microgrid enabled with renewable energy sources. The detailed design specifications of ESS for 500 kW microgrid enabled with solar-wind hybrid renewable energy system (RES) is discussed. Validation through simulation studies is performed to understand the operation of effective and efficient integration of ESS with microgrid operating under islanded conditions.

Energy Storage Systems in Solar-Wind Hybrid Renewable Systems

Energy management and economic analysis of multiple energy storage systems in solar PV/PEMFC hybrid power systems

This chapter proposes a non-dominated sorting genetic algorithm (NSGAII) for the multi-objective optimal operation management (MOOM) for distributed microgrid. The main objective of the MOOM is to maximize the safe instantaneous system load, and minimizing the pollutant emission produced by the generating sources. Particle swarm optimization (PSO), genetic algorithm (GA) and NSGAII artificial intelligence techniques are studied and optimized for microgrid. The NSGAII control algorithm projected to maintain the grid voltage and angle stability within the IEEE standards while increased penetration. To construct the microgrid structure, the renewable energy sources such as wind energy, solid oxide fuel cells (SOFC) and solar photo-voltaic (SPV) are considered. The robust NSGAII based optimization algorithm continuously monitors the grid conditions and regulates grid parameters for maximizing the instantaneous safe bus loading. Power system stability indices such as fast voltage stability indices (FVSI), line stability indices (LSI) and line stability factor (LQP).

Vipin Das

Papers

Recent advances and challenges of fuel cell based power system architectures and control – A review

Grid-Connected and Off-Grid Solar Photovoltaic System

Energy Storage Systems in Solar-Wind Hybrid Renewable Systems

Energy management and economic analysis of multiple energy storage systems in solar PV/PEMFC hybrid power systems

Energy Grid Management, Optimization and Economic Analysis of Microgrid