Analysis Of Hybrid Systems Research Articles

A Hybrid Systems Approach to Dual-Objective Functional Electrical Stimulation Cycling

Motorized functional electrical stimulation (FES) cycling can serve as a physical rehabilitation strategy for individuals whose lower limbs are affected by neurological injuries. Motorized FES cycling is unique among human-robot interaction tasks because the cycle’s motor and rider’s leg muscles must be simultaneously controlled. In this letter, two tracking objectives are proposed for the combined cycle-rider system. First, the rider’s leg muscles are stimulated to pedal the cycle at a desired cadence, and second, the cycle’s motor is used to regulate the interaction torque between the cycle and rider using an admittance controller. A novel hybrid systems analysis using Lyapunov- and passivity-based techniques is conducted to prove that the cycle’s motor can globally exponentially regulate the admittance error system and prove that the cadence error system is output feedback passive. Experiments conducted on five participants illustrate the efficacy of the controllers with an average admittance error of -0.01±0.70 RPM at an average cadence of 45.51±1.77 RPM for a desired cadence of 50 RPM.

Feasibility Study and Deployment of Solar Photovoltaic System to Enhance Energy Economics of King Abdullah Campus, University of Azad Jammu and Kashmir Muzaffarabad, AJK Pakistan

As non-renewable energy sources become depleted, the world is transitioning toward renewable energy sources (RERs), which entail several significant advantages, including cost savings, large-scale availability, and minimal losses. Pakistan is sixth among the countries most affected by global warming and abrupt climatic changes. Severe floods, catastrophic rains, and wind gusts have created new challenges in the country regarding resilient and reliable power supply. Due to harsh weather conditions, the power shut down, blackouts, and prolonged fault in the transmission systems are common and cause millions of dollars in economic losses annually. The main challenge of providing a reliable power supply while satisfying the climatic conditions to use renewable energy resources has a global significance. This article aims to develop a hybrid power network (PV/Battery/Grid) for King Abdullah Campus, The University of Azad Jammu and Kashmir, Muzaffarabad, Pakistan. The results for the proposed system are compared with the existing system while they are supplying the same power to the load. The cost of energy (COE) from the existing on- grid Hybrid system is Rs.27.32/kWh. It can be seen that energy cost is minimized by up to Rs.0.251/kWh by the effective use of solar energy. Optimization results conclude that the on- grid hybrid (PV/Battery/Convertor/Grid) is more efficient than all other configurations. Therefore, it is concluded that the proposed hybrid power system for grid-connected sites is most efficient, stable, cost-effective, and environmentally friendly. The ultimate goal was to design an economically feasible hybrid power system and analyze the techno-socio impacts of the PV hybrid system for the campus. Data were initially collected for the desired site and then simulated via the HOMER simulation tool, which determined the net load and feasibility of the proposed system. This techno-economic analysis of the PV hybrid system will enhance the utilization of solar power in other educational or commercial facilities in the region may follow the path in the future.

Lyapunov Function computation for Periodic Linear Hybrid Systems via Handelman, Polya and SoS approaches: A comparative study

We propose a method for the stability analysis of linear hybrid systems with periodic jumps. The method relies on the solution to polynomial inequalities based on the Handelman decomposition. Compared to existing approaches, such as sum-of-squares (SoS) and Polya's theorem, the proposed method reduces the computation time to obtain stability certificates.

Techno-economic analysis of a nuclear-wind hybrid system with hydrogen storage

Climate change and increasing electricity demand have changed the electricity generation structure to include more renewable energy. To keep the global temperature increment within 2 °C, the fraction of renewable energy in the energy mix will continuously increase. High penetration of wind and solar energy challenges the electricity grid as they are not dispatchable. Hybrid energy systems with energy storage have the opportunity to meet the challenge due to their stability and flexibility in energy dispatching. However, their performances and economics remain questionable and quantitative analyzes are needed. In this work, Hybrid Nuclear-Renewable Tool (HyNuRT) code is developed to analyze the technical and economic performance of a hybrid nuclear-wind system with hydrogen storage. In the code, technical models of wind turbines, nuclear units, and hydrogen production and storage units are developed and coupled to economical evaluation models. The economic model considered features of a small modular reactor which is more suitable to couple with renewable energy due to its lower power output and modular fabrication. The novelty of this method is to estimate system performance of typical months of the year with stochastic real-time data and predict system economic value including the construction phase. This method is computational time-saving and makes optimization possible in a relatively short time. The work analyzed the techno-economic performances of conservative and balanced cases to evaluate their performances and economic values by real grid demand data. Results show balanced case can increase the internal return rate by 2.1% with missing only limited peak demand. Comparison of hybrid nuclear-wind systems with and without hydrogen storage show that with assumptions in this work, hydrogen storage shows its advantage on both to meet the grid demand and increase the economic return by 1% while not strongly impacting the cash flow. The results show hybrid system with hydrogen storage can enhance both the system performance and the economic value under proper configuration.

Investigate and analysis the efficiency of photovoltaic system with active cooling based on numerical method

<p style="margin: 0in 0in 10.6pt 0.5pt; text-align: justify; text-indent: -0.5pt;">The aim of this research is to establish a simulation model to examine the performance and working efficiency of a solar cell system by using computational fluid dynamics (CFD). The proposed model consists of a water feed tube and an absorber plate, as well as a convection heat transfer system, the ansys fluent system simulation program was used. The electrical output of the panel and its efficiency have been investigated and the effect of changes in the intensity of solar radiation on the temperature of the liquid and the absorption plate on the performance of the system have been studied. A dynamic analysis of the thermal hybrid system was performed with a circulation pump. Calculations were performed using a detailed mathematical model. The analysis was performed in three cases, the first case when the system has no cooling, in the second case with constant flow, and in the third case when the pump was optimized. Finally, numerical results were compared with the practical reference results. Both results are in good agreement. The results obtained showed that the system with optimization case give a good improvement in efficiency with low reduction of the thermal efficiency compared to a constant flow.</p>

Inverter-based modeling and energy efficiency analysis of off-grid hybrid power system in distributed generation

Distributed Generation systems are made up of different power generation systems, which are wind turbines, solar panels, fuel cells, energy storage units, micro turbines, and combined heat cycle plants. An inverter is one of the most critical components of Distributed Generation systems. This paper focuses on inverter-based modeling and energy efficiency analysis of the off-grid hybrid system in Distributed Generation. The proposed system is created and simulated using MATLAB/Simulink platform. The obtained results show that the efficiency of the inverter varies between 49.671% and 93.794% under different loads. Model results comply with the inverter efficiency curve specified by the European Commission and U.S. Department of Energy procedures. In the model, the inverter energy efficiency of the hybrid system is compared according to temperature, wind speed, solar radiation, and hydrogen pressure. The inverter exhibits superior performance at low hydrogen pressures. Besides, the efficiency of the inverter is analyzed under load changes.

Comparative Analysis of Off-grid Small Hydro-Solar PV-Diesel Hybrid System in South-west, Nigeria

Reliable, efficient, and affordable power supply system is a necessary tool for rapid socio-economic development of any country. Power supply in Nigeria is grossly inadequate and inefficient. This work presented a comparison analysis of Off-Grid Small hydro-Solar Photovoltaic-Diesel Generator hybrid system in three selected locations in South-west, Nigeria. The selected locations are Molete (Oyo state), Abeokuta (Ogun state) and Ede (Osun state). The hydro data for the three locations were collected from their respective River Basin Development Authorities, while the solar data were obtained from National Aeronautics and Space Administration’s global satellite database. The hybrid components consisting of Small hydropower (SHP), Solar Photovoltaic (PV), Battery (BB) and Diesel Generator (DG) were modelled and run using Hybrid Optimization Model for Electric Renewable software with the stream flow, the solar radiation, load and the system components costs as inputs. The work also carried out a comparative analysis based on economic parameters-return on investment and simple payback period different from the conventional use of net present cost, cost of energy(COE) and operating cost. The optimal hybrid combinations for these areas were compared with the usage of autonomous DG. The most optimal hybrid combination for Molete and Ede is PV-BB-SHP System with COEs of $0.347/kWh and $0.161/kWh respectively. The most optimal configuration for Abeokuta is PV-DG-BB-SHP with COE of $0.290/kWh. The results obtained (based on economic and technical considerations) showed that the hybrid system is viable for these areas. The outcome of the research will serve as guide for the government and prospective investors in formulating effective policies towards rapid development of renewable energy technologies in these areas.

Comparative Analysis of Off-grid Small Hydro-Solar PV-Diesel Hybrid System in South-west, Nigeria

Reliable, efficient, and affordable power supply system is a necessary tool for rapid socio-economic development of any country. Power supply in Nigeria is grossly inadequate and inefficient. This work presented a comparison analysis of Off-Grid Small hydro-Solar Photovoltaic-Diesel Generator hybrid system in three selected locations in South-west, Nigeria. The selected locations are Molete (Oyo state), Abeokuta (Ogun state) and Ede (Osun state). The hydro data for the three locations were collected from their respective River Basin Development Authorities, while the solar data were obtained from National Aeronautics and Space Administration’s global satellite database. The hybrid components consisting of Small hydropower (SHP), Solar Photovoltaic (PV), Battery (BB) and Diesel Generator (DG) were modelled and run using Hybrid Optimization Model for Electric Renewable software with the stream flow, the solar radiation, load and the system components costs as inputs. The work also carried out a comparative analysis based on economic parameters-return on investment and simple payback period different from the conventional use of net present cost, cost of energy(COE) and operating cost. The optimal hybrid combinations for these areas were compared with the usage of autonomous DG. The most optimal hybrid combination for Molete and Ede is PV-BB-SHP System with COEs of $0.347/kWh and $0.161/kWh respectively. The most optimal configuration for Abeokuta is PV-DG-BB-SHP with COE of $0.290/kWh. The results obtained (based on economic and technical considerations) showed that the hybrid system is viable for these areas. The outcome of the research will serve as guide for the government and prospective investors in formulating effective policies towards rapid development of renewable energy technologies in these areas.

Performance analysis of a concentrated photovoltaic cell-elastocaloric cooler hybrid system for power and cooling cogeneration

A new hybrid system model comprised of a concentrated photovoltaic cell (CPC) and an elastocaloric cooler (ECC) is proposed, where the ECC is driven by the thermal energy from CPC that cannot be converted into electrical energy. Mathematical expression between the exhaust heat of CPC and the operating electric current as well as the time required for one cycle are derived. Mathematical formulas for the power output and efficiency of CPC and proposed system and the cooling rate and efficiency of ECC are specified. Calculations show that maximum energy efficiency (MEE) and maximum power density (MPD) of hybrid system are, respectively, 20.20 % and 767.47 W m−2 larger than that of the CPC alone. A variety of design parameters and operating conditions affecting the hybrid system performance are studied. Numerical calculation results show that the environmental temperature, solar irradiation, concentration ratio and cross-sectional area ratio of CPC as well as length ratio are helpful to improve the hybrid system performance. The results obtained are helpful to optimally design and run such a real CPC/ECC hybrid system.

Analysis of Hybrid and Plug-In Hybrid Alternative Propulsion Systems for Regional Diesel-Electric Multiple Unit Trains

This paper presents a simulation-based analysis of hybrid and plug-in hybrid propulsion system concepts for diesel-electric multiple unit regional railway vehicles. These alternative concepts primarily aim to remove emissions in terminal stops with longer stabling periods, with additional benefits reflected in the reduction of overall fuel consumption, produced emissions, and monetary costs. The alternative systems behavior is modeled using a backward-looking quasi-static simulation approach, with the implemented energy management strategy based on a finite state machine control. A comparative assessment of alternative propulsion systems is carried out in a case study of a selected regional railway line operated by Arriva, the largest regional railway undertaking in the Netherlands. The conversion of a standard diesel-electric multiple unit vehicle, currently operating on the network, demonstrated a potential GHG reduction of 9.43–56.92% and an energy cost reduction of 9.69–55.46%, depending on the type of service (express or stopping), energy storage technology selection (lithium-ion battery or double-layer capacitor), electricity production (green or grey electricity), and charging facilities configuration (charging in terminal stations with or without additional charging possibility during short intermediate stops) used. As part of a bigger project aiming to identify optimal transitional solutions towards emissions-free trains, the outcomes of this study will help in the future fleet planning.

Optimal technology for a hybrid biomass/solar system for electricity generation and desalination in Brazil

In this study, an energy and economic analysis of a novel hybrid system based on a biomass/solar system equipped with a multi-effect desalination unit is carried out. Part of the steam was directed into a heat exchanger to supply the required energy for the multi-effect desalination unit. The capacity of the system was 100 MWe. The proposed system is compared with a photovoltaic power plant, a solar dish/Stirling power plant, a biomass power plant, and a linear Fresnel Reflector solar power plant. The results demonstrate that a solar thermal collector can be considered a promising solution to prevail the problem of the increasing boiler temperature. It reduces the amount of fuel consumption throughout the year, resulting in reducing the levelized cost of energy. Increasing the solar irradiance augments the energy efficiency gains of a hybrid system. The comparison of the power plants showed that the proposed hybrid system had the minimum levelized cost of energy by 7.865 cents of dollar/kWh but has only slightly higher capital investment cost. Additionally, of the solar power plants studied, a photovoltaic system is more efficient for the study region, Natal-RN Brazil, by a levelized cost of energy of 10.45 cents of dollar/kWh.

Energetic and exergetic analysis of solar photovoltaicthermoelectric generator hybrid system

The objective of present study is to determine the energy and exergy performance of the developedSolar Photovoltaic- Thermoelectric generator hybrid system. The experimental setup was examined under Udaipur climatic conditions (24°352 73 N; 73°422 453 E). The hybrid systems convert sunlight into electric power by the PV module and then utilize the rest thermal energy by the TEG module. Based on the first law of thermodynamics, the energy analysis is used to evaluate the output performance of the hybrid system. And the output electric power of the hybrid system is calculated. Moreover, the second law of thermodynamics is applied to the exergy analysis of the hybrid system. The exergy losses caused by the irreversible process of solar radiation converted into electric power and thermal energy are evaluated. The calculation results demonstrate that exergy of system follows the incident solar radiation and most of the input exergy has been lost at output with maximum losses occur when solar radiations are converted into heat.

Analysis of a multi-objective hybrid system to generate power in different environmental conditions based on improved the Barnacles Mating Optimizer Algorithm

Industrial development, increased demand for energy, limited fossil fuels, and the prevention of environmental damage have led to the use of renewable energy to produce power. The combined system includes renewable wind and solar energy systems or other renewable energy. The hybrid system has been widely used in recent decades to provide energy. In this research, an optimal integrated system has been used to generate electricity. The proposed system includes wind, hydropower, and photovoltaic systems. to estimate the maximum power generation and reduce fluctuations in electricity generation, three proposed algorithms have been used and three common solutions have been applied to solve the optimization problem. The performance of the combined system in different weather conditions has also been assessed. The results showed that among the three proposed algorithms, the model improved the Barnacles Mating Optimizer Algorithm (IBMO) has the best distribution and convergence. Among the three common solutions, a common solution has the most logical solution to the optimization problem. And among the different hydrological conditions, the highest electricity generation is related to the wet season. the most important role in the hybrid system related the hydropower so that despite the reduction of electricity produced in the wind and photovoltaic power plants, the hydropower plant compensates for the drop in production of these systems and causes the production flow to continue.

Performance analysis of a new hybrid system composed of a concentrated photovoltaic cell and a two-stage thermoelectric generator

A new cogeneration system model that integrates a concentrated photovoltaic cell (CPV) and a two-stage thermoelectric generator (TTEG) considering the Peltier, Seebeck and Thomson effects is proposed, where the CPV converts the inlet solar energy into electricity and heat, and the TTEG further harvests the heat for additional electricity production. Mathematical relation of the operating electric currents between TTEG and CPV is determined. Mathematical formulas for the power output and efficiency of the proposed system are specified under different operation conditions. The maximum power density (MPD) and maximum energy efficiency (MEE) of the proposed hybrid system are about 8% greater than that of the stand-alone CPV, respectively. Furthermore, the impacts of the operating temperature of CPV, solar irradiance, concentration ratio, thermocouple number ratio between top-stage and bottom-stage, total number of thermocouple and different thermoelectric materials on the hybrid system performance are revealed. The results may provide some new insights into designing such an efficient solar-to-electricity hybrid system.

Techno-Economic Analysis of a Stand-Alone Hybrid System: Application in Donoussa Island, Greece

Hybrid Renewable Energy Systems (HRES) are an attractive solution for the supply of electricity in remote areas like islands and communities where grid extension is difficult. Hybrid systems combine renewable energy sources with conventional units and battery storage in order to provide energy in an off-grid or on-grid system. The purpose of this study is to examine the techno-economical feasibility and viability of a hybrid system in Donoussa island, Greece, in different scenarios. A techno-economic analysis was conducted for a hybrid renewable energy system in three scenarios with different percentages of adoption rate (20%, 50% and 100%)and with different system configurations. Using HOMER Pro software the optimal system configuration between the feasible configurations of each scenario was selected, based on lowest Net Present Cost (NPC), minimum Excess Electricity percentage, and Levelized Cost of Energy (LCoE). The results obtained by the simulation could offer some operational references for a practical hybrid system in Donoussa island. The simulation results confirm the application of a hybrid system with 0% of Excess Electricity, reasonable NPC and LCoE and a decent amount of renewable integration.

Hybrid System Analysis and Control of a Soft Robotic Gripper with Embedded Proprioceptive Sensing for Enhanced Gripping Performance

Soft Grippers In article number 2000061, Yong-Lae Park and co-workers present a method of controlling a soft robotic gripper for grasping unidentified objects using a hybrid system analysis approach, which enables the system to detect the size of the object and to determine the optimal position of the gripper for successful grasping based on the proprioceptive feedback from an embedded soft strain sensor.

Exergoeconomic Analysis of a Novel Hybrid System by Integrating the Kalina and Heat Pump Cycles with a Nitrogen Closed Brayton System

In recent years, attentions are focused on the application of cutting-edge reactors to utilize the remarkable virtues such as safety and also higher thermal efficiency. Sodium-cooled fast reactors (SFRs) are midst the promising types of fourth generation reactors for their non-reacting behavior and packed configurations, which are considered as heat source of various thermodynamic systems. Accordingly, nitrogen Brayton cycle could be devised as power conversion system (PCS) of the mentioned sodium cooled reactors, due to its simple arrangement. In present study, proposing the topping system of nitrogen Brayton cycle as a power generation system which is driven by the sodium reactor system, Kalina and heat pump cycles, as bottoming cycles, were designed to increase the performance of the overall system by integration with topping system. Subsequently, energy, exergy and exergoeconomic analyses were carried out to examine the reliability of the proposed system. The results displayed that under operating conditions, thermal efficiency, exergetic efficiency of the proposed system are 34% and 62%, respectively. Furthermore, using the exergy point of view, it was revealed that steam generator heat exchanger, SGHX, is the foremost cause of exergy destruction. Also, in order to attain an inclusive insight over the system, a parametric analysis was conducted. Therefore, investigating the influence of alterations in key features of the overall cycle, several optimum working conditions, such as optimal basic concentration of ammonia in Kalina cycle, optimal turbines (I&II) expansion ratio and low-pressure compressor pressure ratio etc., were derived.

Architecture, Advancement and Assessment of a Bladeless Wind Solar Hybrid System in Comparison to a Traditional Hybrid Solar System

The use of alternative energy sources is becoming appealing due to its multiple benefits. One such paper describes the development of a new affordable bladeless standalone hybrid system (BSHS) that uses wind and solar energy. The newly Presented affordable bladeless standalone hybrid solution incorporates a bladeless wind turbine (BWT) as well as a solar panel. This article presents a mathematical analysis of a bladeless hybrid system (BHS), a solar panel, and a comparative analysis of a BHS with just an established solar wind hybrid model, with a comparative study executed in form of voltage, current, and power produced by both hybrid systems. The BHS has intended, the BHS is designed and all the results are verified using MATLAB Simulink

Performance Analysis of Multi-Energy Hybrid System Based on Molten Salt Energy Storage

This paper briefly summarizes the current status of typical solar thermal power plant system, including system composition, thermal energy storage medium and performance. The thermo-physical properties of the storage medium are some of the most important factors that affect overall efficiency of the system, because some renewable energy sources such as solar and wind are unpredictable. A thermal storage system is therefore necessary to store energy for continuous usage. Based on the form of storage or the mode of system connection, heat exchangers of a thermal storage system can produce different temperature ranges of heat transfer fluid to realize energy cascade utilization. Founded upon the review, a small hybrid energy system with a molten-salt energy storage system is proposed to solve the problems of heating, cooling, and electricity consumption of a 1000 m² training hall at school. The system uses molten-salt storage tank, water tank and steam generator to change the temperature of heat transfer fluid, in order to realize thermal energy cascade utilization. Compared to the existing heating and cooling system, the proposed system needs more renewable energy and less municipal energy to achieve the same results according to simulation analysis. Furthermore, by improving the original heating and cooling system, PMV has been improved. The comprehensive efficiency of solar energy utilization has been increased to 83%.

Investigative Study on Emissions Level and Cost Analysis of Diesel Powered and Solar PV-Diesel Hybrid Systems

In this work, a comparative study on emissions and cost implications of diesel powered and solar photovoltaic-diesel hybrid systems was carried out for three commercial banks. With the aid of HOMER Pro software, meteorological data, energy demand, system component data, capital and operating costs were used for analysis of the two systems. The results showed that in Bank A, the diesel generator alone releases 111,618 kg/yr of Carbon dioxide while the hybrid system releases 41,618 kg/yr of Carbon dioxide. For Bank B the quantity of carbon dioxide emissions released from the diesel generator in Bank B is 53,830 kg/yr, while the carbon dioxide released from the hybrid energy system is 24,082 kg/yr. For Bank C, the diesel generator alone released 177,799 kg/yr of Carbon dioxide and 129,060 kg/yr of carbon dioxide was released from the hybrid system. This suggests that the diesel generator alone releases more emissions when compared with the hybrid system in all the three banks. The Net present cost of energy and levelized cost of energy were used to find out the cost effectiveness of hybrid systems. The results showed that the levelized cost of energy for the generator alone and hybrid system, respectively in Bank A is $0.713 and $0.343. While for Bank B, it is $0.568 and $0.2553. Finally for Bank C, it was $0.731 and $0.556. Therefore, solar-diesel hybrid system has a comparatively low emission and can be considered as a more economical option for electricity generation.