Remote Area Power Supply Systems Research Articles

Improvement of frequency response in remote area power supply systems using ultracapacitor with enhanced inertia support controller

Improvement of frequency response in remote area power supply systems using ultracapacitor with enhanced inertia support controller

Role of a Unitized Regenerative Fuel Cell in Remote Area Power Supply: A Review

This manuscript presents a thorough review of unitized regenerative fuel cells (URFCs) and their importance in Remote Area Power Supply (RAPS). In RAPS systems that utilize solar and hydrogen power, which typically include photovoltaic modules, a proton exchange membrane (PEM) electrolyzer, hydrogen gas storage, and PEM fuel cells, the cost of these systems is currently higher compared to conventional RAPS systems that employ diesel generators or batteries. URFCs offer a potential solution to reduce the expenses of solar hydrogen renewable energy systems in RAPS by combining the functionalities of the electrolyzer and fuel cell into a single unit, thereby eliminating the need to purchase separate and costly electrolyzer and fuel cell units. URFCs are particularly well-suited for RAPS applications because the electrolyzer and fuel cell do not need to operate simultaneously. In electrolyzer mode, URFCs function similarly to stand-alone electrolyzers. However, in fuel cell mode, the performance of URFCs is inferior to that of stand-alone fuel cells. The presented review summarizes the past, present, and future of URFCs with details on the operating modes of URFCs, limitations and technical challenges, and applications. Solar hydrogen renewable energy applications in RAPS and challenges facing solar hydrogen renewable energy in the RAPS is discussed in detail.

Analysis and design of wind energy conversion with storage system

This paper discusses about remote area power supply (RAPS) system for the conversion of power from wind into electrical energy along with supercapacitor and battery storage to supply main load and dump load. Generation of power during varying loads and fluctuating wind is difficult to control. The wind power generating system have difficulty to supply the required amount of reactive power. This is compensated using synchronous condenser. The performance related to the energy storage system is improved using energy management algorithm. The wind power is converted to dc using bridge rectifier and buck boost converter. Voltage controlled converter is designed to convert dc to ac to operate in synchronization with grid voltage. Real power obtained from the wind energy conversion system and the reactive power are controlled separately to provide support for the frequency and voltage control. The system is simulated to show the performance of the developed system.

Tailor-designed vanadium alloys for hydrogen storage in remote area and movable power supply systems

Vanadium-based alloys are potential materials for hydrogen storage applications in Remote Area Power Supply (RAPS) and Movable Power Supply (MPS). In this study, V80Ti8Cr12 alloys are tailor-made to meet the RAPS and MPS working conditions (293–323 K and 0.2–2 MPa). The effects of pulverization methods and particle sizes on the alloy's hydrogen storage properties have been systematically investigated. In addition, a novel Pressure-Composition-Isotherm approach is employed for the first time to accurately evaluate the hydrogen storage capacities. The reduction of particle size enhances the absorption kinetics due to the increased surface area. However, mechanical pulverization causes lattice distortion that decreases the hydrogen absorption capacity and desorption rate. In contrast, hydrogen embrittlement can effectively pulverize the alloys without generating lattice distortion. The results reveal that 5 mm sample, which is simply subjected to hydrogen embrittlement, achieves the largest usable hydrogen storage capacity up to 2.1 wt% and the fastest hydrogen desorption rate of ∼4 sccm/g that is nine times quicker than required for RAPS and MPS applications. After 500 cycles, the 5 mm alloy retains 90 % of its capacity, demonstrating excellent durability. Hence, 5 mm hydrogen-embrittled V80Ti8Cr12 alloy is an ideal hydrogen storage material in RAPS and MPS systems.

Active hybrid energy storage management in a wind-dominated standalone system with robust fractional-order controller optimized by Gases Brownian Motion Optimization Algorithm

Accessibility to sustainable and reliable electrical energy for remote area power supply (RAPS) systems under high penetration levels of wind energy requires adopting appropriate technologies and controllers. In recent years, energy storage has gained significant attention for smoothing inherent voltage and power fluctuations of standalone systems. This paper presents a filtration-based fractional-order PI (FOPI) controller optimized by Gases Brownian Motion Optimization (GBMO) algorithm to manage an active battery-supercapacitor hybrid energy storage system (HESS) in a wind-dominated RAPS system. The GBMO algorithm has a high accuracy and convergence rate among optimization algorithms introduced in recent years. Moreover, a fuzzy logic controller (FLC) guarantees the wind turbine generator's maximum power point tracking (MPPT) at any wind condition while mitigating its fluctuating torque. The proposed RAPS system uses the advantages of the FOPI controller, the GBMO optimization algorithm, the FLC-based MPPT algorithm, and a high-pass filter to manage precise coordination between different components of the RAPS system. The high-pass filter decouples high and low-frequency voltage oscillations to modify the HESS performance and relieve battery stress, thereby extending its lifespan. The proposed controller's performance and robustness are verified in comparison with an optimal PI controller based on GBMO under turbulent wind speed and load step changes in a detailed model of the system. The results demonstrate the superiority of the optimal FOPI controller over the optimal PI controller.

Thermal analysis and optimization of stand-alone microgrids with metal hydride based hydrogen storage

Stand-alone microgrids, also known as remote area power supply systems, are crucial towards providing electricity access to off-the-grid locations/buildings and for communities trying to become 100% dependent on renewables. Design and development of efficient energy storage system remains a key challenge for the stand-alone microgrid technology. Metal hydride based hydrogen-energy storage system, offering long term energy storage at near ambient conditions and additional benefits of thermal and green hydrogen output, have attracted researchers and industrialists worldwide. In this work, LaNi5 (Lanthanum Penta-nickel) based hydrogen-energy storage system for stand-alone microgrid application is studied. An optimization study is performed to find the optimal sizes of hybrid (solar + wind) and wind microgrid components for the requirements of typical Indian village/UK community of 50 households located at various geographical locations, having diverse solar and wind resources availability. The study ensures that the microgrid satisfies the required electric load but is not over-designed, which is achieved by limiting the two performance parameters i.e., unmet load fraction and excess electricity fraction, below 10%. The optimization study is done based on an hourly analysis for a year using the simulation software HOMER. A thermal analysis is carried out to quantify the additional benefit of thermal output from the energy storage system. Comparisons between the performance and thermal output of optimized hybrid and wind microgrids are carried out for the selected locations. Also, green hydrogen produced for energy storage and available for use at the end of the year is quantified. Upon comparing hybrid (solar PV + wind turbine) and wind energy based microgrids, it is observed that hydrogen storage requirement decreases by up to 97% while using hybrid energy source depending on the location. Besides serving electrical load, the microgrid delivers thermal outputs of about 1kWh and 5kWh for Indian and UK locations respectively.

Remote area power supply system for oil leakage detection systems and stop valves drives for pipelines

This paper describes problem of electrical power supply of data collection points for leakage detection and stop valve control systems, designed for emergency shutoff of fault parts of oil pipelines in areas without centralized power supply. Autonomous electrical power supply complex, based on thermoelectric generators and photovoltaic panels, was proposed as a solution. Structure and parametric sufficiency of power supply system were established. Computer model for estimation of autonomous power system effectiveness was developed and validated.

Selection of Best Power Supply Source for Telecom Towers in Remote Areas

Installation of telecom towers in remote areas especially in developing countries like India is a major problem for telecom industries because of the unavailability of reliable power supply. The grid supply is not regular in these countries and up to some extent, they are dependent on diesel generators for power supply. But these diesel generators have some major issues such as high operating cost due to high cost of fuel, transportation cost of fuel, high maintenance cost, and these diesel generators also emits pollution to the environment. In presented work, an approach has been proposed for telecom companies for providing power supply to their telecom towers. An economic cost analysis has been proposed by considering various criteria such as cost, air & noise pollution and reliability, etc. Some power supply alternatives including unconventional and hybrid of conventional and unconventional alternatives have been compared to find the solution such as diesel-powered telecom towers, solar powered telecom towers, and their hybrids. The main objective of this work is to provide a reliable, cost effective and environment friendly Remote Area Power Supply (RAPS) system for a particular site in India (Uttar Pradesh). A number of criteria are involved in discussed problem in order to select an effective power supply source. Therefore, the problem has been considered as a Multi Criteria Decision Making (MCDM) problem. To select the best alternative, a Fuzzy AHP and TOPSIS based approach has been proposed. Fuzzy AHP (Analytic Hierarchy process) has been used for calculating the weightage of criteria and the concept of Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) has been applied for ranking the alternatives. The results give assured reliability and sustainability for remote areas using a solar photovoltaic (PV)-diesel generator hybrid energy system.

Design an adaptive sliding mode controller for an advanced hybrid energy storage system in a wind dominated RAPS system based on PMSG

Abstract Controlling of a standalone wind dominated system under variable load conditions and fluctuating wind is a challenging task. Energy storage systems (ESSs) can play a significant role in stabilizing voltage of such systems. In this paper, a nonlinear controller is designed for a remote area power supply (RAPS) system consisting of the wind turbine based on a permanent magnet synchronous generator (PMSG), a battery supercapacitor hybrid energy storage system (HESS) and variable local load connected to the DC bus. An adaptive sliding mode controller (SMC) as a nonlinear control method is designed to improve the stability and the performance of such standalone systems under high perturbations. Moreover, the battery and supercapacitor performances are modified by embedding a filter in the adaptive SMC and proportional–integral (PI) controller. Also, a robust fuzzy logic controller (FLC) is implemented to the power generation system to track the maximum power point from the wind. The simulation results of the system with adaptive SMC reveal the superiority of the proposed controller compared with PI in the three different ESS schemes.

Eco-efficiency improvement of Western Australian remote area power supply

Hybrid energy systems have been used in remote area power supply (RAPS) systems to assist in the development and deployment of renewable energy. Part of its benefit is the reduction of CO2 emissions from the decreased utilisation of fossil-fuelled electricity generation and the reduction in operation and maintenance cost as fossil fuel consumption is offset. This study uses an eco-efficiency analysis (EEA) framework to explore the environmental and economic performance of the current hybrid RAPS systems in Western Australia. The framework integrates life cycle assessment (LCA), eco-efficiency strategies, life cycle costing (LCC) and eco-efficiency portfolio analysis to propose eco-efficiency improvement of these systems. The results show that improving the load restriction of diesel engines, installing exhaust gas recirculation on diesel engines and installing rooftop solar PV on the residential houses of the RAPS system could potentially reduce life cycle CO2 emissions by 9% and the life cycle cost by 1%. The EEA framework presented in this study is expected to provide relevant information to assist energy planners and policy makers for further development and deployment of renewable energy in Australia.

Enhanced Frequency Regulation Using Multilevel Energy Storage in Remote Area Power Supply Systems

Frequency support from renewable power generators is critical requirement to ensure the frequency stability of remote area power supply (RAPS) systems with high penetration of renewable power generation. However, traditional control strategies and the stochastic nature of wind resource constrain wind energy conversion system (WECS) such as permanent magnet synchronous generator (PMSG) from participating in frequency regulation. This work proposes to integrate hybrid energy storage including ultracapacitors (UCs) and lead-acid batteries (LABs) into a PMSG to provide frequency support. The UCs deal with fast changing frequency by emulating conventional inertial response, whereas the LABs mimic automatic governor response (i.e., primary frequency response). The mechanical power reserved in wind turbine using suboptimal maximum power point tracking strategy is utilized to restore system frequency (i.e., secondary frequency response). Moreover, supplementary control strategies are proposed to enable the UCs and LABs to assist primary frequency response and secondary frequency response, respectively. Simulation study and experimental test are carried out to validate the effectiveness of frequency response provided by the multilevel energy storage. The multilevel energy storage solution can effectively regulate RAPS system frequency while avoiding abrupt and frequent charging/discharging of the LABs and significant mechanical/electromagnetic stress on the WECS.

Review of Tools for Sustainability Assessment of Renewable Energy Technologies for Remote Area Power Supply

This review discusses the tools used in the sustainability assessment of renewable energy technologies in remote area power supply systems. A comprehensive keyword search was conducted to identify widely used tools in assessing the three pillars of sustainability (economics, environmental and social). Results found that environmental life cycle assessment (ELCA), life cycle costing (LCC), social life cycle assessment (SLCA), triple bottom line (TBL) approach and eco-efficiency analysis (EEA) were commonly used worldwide to assess the environmental, economic and social implications of renewable energy technologies. Eco-efficiency analysis is recommended to be applied in the sustainability assessment of power generating technologies for remote area power supply. This tool does not only assess the economic and environmental implication of existing technologies but also assists in the implementation of improvement opportunities for a better eco-efficiency performance.

Impedance Methods for SoC Determination of Lead Acid Battery Cell

Lead acid batteries are widely used type of batteries. In the automotive industry they must provide a high current pulse to start the car, in traction application they undergo periodic deep discharge and charge cycles and in stationary applications they remain in charged state most of their life. They are also used in hybrid electric vehicles and remote area power supply systems. In these applications they are in a partial state of charge (about 50% of charge) during their operation. In all these applications it is useful to monitor battery state of charge (SoC) instead of monitoring only the battery voltage. Impedance method of monitoring SoC seems to be a good choice.

Methods of SoC determination of lead acid battery

Lead acid batteries are typically used in the automotive industry, where they provide a high current pulse to start the vehicle, in traction applications, where they undergo periodic deep discharge and charge, and in stationary applications, where they remain in charged state most of their life. They are used also in hybrid electric vehicles (HEVs) and in remote area power supply systems (RAPS), where they remain in a state of about 50% of charge during their operation. In this state, these batteries can be charged or discharged with high effectivity. In all these applications, it is necessary to monitor and report the battery state of charge (SoC) instead of simply monitoring the battery voltage.

Eco-efficiency analysis for remote area power supply selection in Western Australia

Remote area power supply (RAPS) systems in Western Australia account for more than 56% of total off-grid electricity supply in Australia and utilise carbon emission intensive diesel and gas generating technologies for power supply. Most of these RAPS systems are run by environmentally unfriendly conventional fuel due to economic reasons. An eco-efficiency analysis (EEA) framework was therefore developed to explore the environmental and economic efficiency of the current diesel RAPS systems in Western Australia. ISO 14040:2006 for Life Cycle Assessment and AS/NZS 4536:1000 (R2014) for Life Cycle Costing have been used to estimate the associated environmental impacts and costs of RAPS systems in conducting an EEA. The results show that the integration of solar photovoltaic panels and an energy storage system into existing diesel generating units for power supply could improve the eco-efficiency of the existing system. It was found that a 4% increase in total life cycle costs with the use of a hybrid system could potentially decrease the overall environmental impacts by 16%.

A Comparative Case Study of Remote Area Power Supply Systems Using Photovoltaic-battery vs Thermoelectric-battery Configuration

Abstract The paper presents a comparative study of two types of remote area power supply (RAPS) systems, which are the existing photovoltaic-based (PV) configuration and the proposed thermoelectric-based (TE) configuration. Both RAPS systems are solar-based power generators and sized according to Melbourne weather conditions (latitude 37.5 o S). In this study, the RAPS system designs for both PV and TE have no backup generator and the batteries are the only device for electrical energy storage. Battery storage is used for storing solar energy during the available days for meeting the energy demand as required. The presented RAPS systems for this comparative study are PV/Battery and TE/Battery configurations. Generally, both PV and TE cells are solar-based power generating cells but they have different pre-conversion inputs. For electrical power generation, PV uses sunlight as input energy while the TE uses concentrated solar heat. The results show that the total setup cost for TE/Battery system is 66% higher than PV/Battery system under similar design requirements. Despite having higher setup cost, the TE/Battery system has the potential to harness both electrical and thermal energy for domestic purposes.

Enhanced Frequency Response Strategy for a PMSG-Based Wind Energy Conversion System Using Ultracapacitor in Remote Area Power Supply Systems

Conventional generators in wind-diesel hybrid remote-area power supply (RAPS) systems are likely to be heavily stressed during frequency disturbances due to poor frequency response of power electronic interfaced wind energy conversion systems (WECSs). Hence, it is imperative for the WECS to provide frequency support during frequency excursions. However, existing frequency control strategies are slow and will also impose severe mechanical/electromagnetic stress on WECSs. In this paper, frequency response strategies for the PMSG-based WECS are explored, and an enhanced frequency response strategy is investigated to regulate the RAPS system frequency jointly with the integrated ultracapacitors. The proposed short-term frequency response strategy utilizes a virtual inertial technique along with the supplementary droop control. Suboptimal power-point-tracking is also implemented at the PMSG to improve the active power reserve. The enhanced frequency response strategy can regulate the RAPS system frequency while alleviating high rate-of-change-of-power, and thus stresses on both the conventional generator and PMSG under frequency disturbances. Proposed control strategies are validated by both simulations and experiments.

Experimental Analysis of Thermoelectric Heat Exchanger for Power Generation from Salinity Gradient Solar Pond Using Low-Grade Heat

Salinity gradient solar ponds act as an integrated thermal solar energy collector and storage system. The temperature difference between the upper convective zone and the lower convective zone of a salinity gradient solar pond can be in the range of 40-60°C. The temperature at the bottom of the pond can reach up to 90°C. Low-grade heat ( < 100°C) from solar ponds is currently converted into electricity by organic Rankine cycle engines. Thermoelectric generators can operate at very low temperature differences and can be a good candidate to replace organic Rankine cycle engines for power generation from salinity gradient solar ponds. The temperature difference in a solar pond can be used to power thermoelectric generators for electricity production. This paper presents an experimental investigation of a thermoelectric generators heat exchanger system designed to be powered by the hot water from the lower convective zone of a solar pond, and cold water from the upper convective zone of a solar pond. The results obtained have indicated significant prospects of such a system to generate power from low-grade heat for remote area power supply systems.

A Suboptimal Power-Point-Tracking-Based Primary Frequency Response Strategy for DFIGs in Hybrid Remote Area Power Supply Systems

Due to the presence of a power electronic converter, the doubly fed induction generator (DFIG)-based wind generators are isolated from grid frequency variations, which will impose significant burden on conventional generators to regulate frequency in a hybrid remote area power supply (RAPS) system. Thus, participation of wind generators in frequency control is increasingly demanded. In this paper, a primary frequency response strategy is proposed for the DFIG to regulate the RAPS system frequency. A droop control loop without conventionally used high-pass filter is integrated to generate the torque reference for the DFIG to provide primary frequency response, and a supplementary control loop is proposed to enhance the primary frequency response with torque feedback control. Furthermore, the suggested suboptimal power point tracking strategy is capable of reserving wind power to improve the frequency response. The proposed strategy enables DFIG to participate in RAPS system frequency regulation while alleviating high rate of change of power and thus stress on the diesel generators under highly variable load demand. The effectiveness of the proposed strategy is validated through simulations.

Remote Area Power Supply System: An Integrated Control Approach Based on Active Power Balance

This article presents a novel control strategy for a high-penetration, wind-based hybrid remote area power supply (RAPS) system. The proposed RAPS system consists of a permanent magnet synchronous generator (PMSG)-based variable-speed wind turbine and a battery energy storage system (ESS) with a dump load for dc bus voltage control and a diesel generator as a backup supply. An integrated control approach based on the active power balance of the proposed RAPS system has been proposed and developed to regulate the voltage and frequency within an acceptable bandwidth. The proposed integrated control algorithm is implemented by developing a controller for the individual system components in the RAPS system, including the wind energy conversion system, the diesel generator, the battery storage system, and the dump load, while coordinating their response to achieve optimal operation. The optimal operation for the proposed RAPS system is realized by operating the wind turbine generator (WTG) at its maximum power extraction mode while restricting the operation of the diesel generating system at low-load conditions. In addition to the detailed model, which mainly comprises nonlinear high-order characteristics of each system component, a linearized model of the RAPS system is presented to compare the active power sharing among the system components. Laboratory-based experimental tests have been conducted to validate the coordinated approach, and the results are presented in this article.