Showing papers on "Prime mover published in 2021"

4E analysis and three-objective optimization for selection of the best prime mover in smart energy systems for residential applications: a comparison of four different scenarios

Abstract: Recently, using integrated energy systems for residential-scale applications has been of great interest to the researchers. The objective of this study is the proposal, techno-economic analysis, and optimization of the best prime mover for the residential scale combined cooling, heating, and power generation system (CCHP). Different prime movers consisting of solid oxide fuel cell (SOFC), internal combustion engine (ICE), microgas turbine (MGT), and hybrid SOFC/GT system for power production are integrated with HRSG and double effect Li/Br refrigeration system for heating and cooling generation, respectively. A parametric study is conducted on the best case to find the key decision variables. Also, a very cutting-edge optimization, which is 3D multi-objective optimization, is carried out for minimizing the unit product cost and emission and maximizing the exergetic efficiency. Results revealed that the hybrid SOFC/GT has higher exergy efficiency of 69.06% and unit product cost of 37.78 $ GJ−1, among other case studies. Also, optimization results indicate a maximum exergy efficiency of 73.15%, and a minimum cost of 25.08 ($ GJ−1) can be reached for the SOFC-/GT-based CCHP system. Moreover, the optimized emission for the best-case scenario becomes 62.52 g MWh−1.

Optimal Allocation and Sizing of Synchronous Condensers in Weak Grids With Increased Penetration of Wind and Solar Farms

Abstract: The increasing number of weak-grid-connected renewable energy resources in power systems has created various challenges in recent years. Some examples include un-damped voltage oscillations in the ERCOT and sub-synchronous resonance in the North-China power grid. Several solutions for these challenges have been proposed, such as Static Compensators and Synchronous Condensers (SynCons). SynCons, being synchronous machines without a prime mover, provide several benefits in weak power systems, such as frequency support, system strength, and voltage regulation. Although SynCons are widely-utilized to mitigate the weak grid integration challenges, their installation /operation costs make them a costly solution. Additionally, their lead-time can be more than a year, which means their initial sizing and allocation must be optimal. In this paper, a method for the optimal allocation and sizing of SynCons is proposed. The main objective of this method is maintaining Short Circuit Ratio (SCR) in the system greater than pre-defined values while the investment and operation costs of SynCons, and voltage deviation in the system are minimized. Three meta-heuristic optimization algorithms are used to implement the proposed method, and its performance is evaluated via Electromagnetic Transient (EMT) time-domain simulation in a modified IEEE 39-bus system. The PSCAD/EMTDC software is used for the time-domain simulation. The simulation results confirm that with optimized allocation and sizing, the SCR of the network in all areas is more than pre-defined values, and also, all renewable energy resources can ride through disturbances and comply with given grid codes.

Solar-based Kalina cycle integrated with PEM fuel cell boosted by thermoelectric generator: Development and thermodynamic analysis

Abstract: The present study deals with the development and thermodynamic assessments of a solar-assisted Kalina cycle with solar energy as the prime mover. Three configurations of the studied systems were su...

A New Grid-Connected Constant Frequency Three-Phase Induction Generator System under Unbalanced-Voltage Conditions

Abstract: This paper presents a new constant frequency, direct grid-connected wind-based induction generator system (IGS). The proposed system includes a six-phase cage rotor with two separate three-phase balanced stator windings and a three-phase SV-PWM inverter which is used as a STATCOM. The first stator winding is connected to the STATCOM and is used to excite the machine. The main frequency of the STATCOM is considered to be constant and equal to the main grid frequency. In the second stator winding, the frequency of the induced emf is equal to the constant frequency, so the generator output frequency is independent of the load power demand and its prime mover speed. The second stator winding is directly connected to the main grid without an intermediate back-to-back converter. In order to regulate the IGS output active and reactive power components, a sliding mode control (SMC) is designed. Assuming unbalanced three-phase voltages for the main grid, a second SMC is developed to remove the machine output’s negative sequence currents. Moreover, a conventional PI controller is used to force the average exchanging active power between the machine and STATCOM to zero. This PI controller generates the reference value of the rotor angular speed. An adjustable speed pitch angle-controlled wind turbine is used as the IGS’s prime mover. The effectiveness and capability of the proposed control scheme have been supported by the simulation results.

Cogeneration Supporting the Energy Transition in the Italian Ceramic Tile Industry

Abstract: Ceramic tile production is an industrial process where energy efficiency management is crucial, given the high amount of energy (electrical and thermal) required by the production cycle. This study presents the preliminary results of a research project aimed at defining the benefits of using combined heat and power (CHP) systems in the ceramic sector. Data collected from ten CHP installations allowed us to outline the average characteristics of prime movers, and to quantify the contribution of CHP thermal energy supporting the dryer process. The electric size of the installed CHP units resulted in being between 3.4 MW and 4.9 MW, with an average value of 4 MW. Data revealed that when the goal is to maximize the generation of electricity for self-consumption, internal combustion engines are the preferred choice due to higher conversion efficiency. In contrast, gas turbines allowed us to minimize the consumption of natural gas input to the spray dryer. Indeed, the fraction of the dryer thermal demand (between 600–950 kcal/kgH2O), covered by CHP discharged heat, is strictly dependent on the type of prime mover installed: lower values, in the range of 30–45%, are characteristic of combustion engines, whereas the use of gas turbines can contribute up to 77% of the process’s total consumption.

Study of a thermoacoustic-Stirling engine connected to a piston-crank-flywheel assembly.

Abstract: This paper deals with the theoretical description of self-sustained oscillations resulting from the coupling of a piston-crank-flywheel assembly with a thermoacoustic-Stirling prime mover. The governing equations of the piston-flywheel motion are coupled to those of the thermoacoustic system, which is described in the time domain through a rational differential operator relating acoustic pressure fluctuations inside the cavity to the piston's velocity. As a result, the complete device is described by means of a fourth-order nonlinear dynamical system and solved numerically. The dynamical behavior of the system is studied as a function of the temperature difference along the thermoacoustic unit, and it is shown that the regime of stable rotations of the flywheel appears through a saddle-node bifurcation above a threshold value of the temperature difference. Moreover, the simulation results show good agreement with experiments.

A Review of Transverse Flux Machines Topologies and Design

Abstract: High torque and power density are unique merits of transverse flux machines (TFMs). TFMs are particularly suitable for use in direct-drive systems, that is, those power systems with no gearbox between the electric machine and the prime mover or load. Variable speed wind turbines and in-wheel traction seem to be great-potential applications for TFMs. Nevertheless, the cogging torque, efficiency, power factor and manufacturing of TFMs should still be improved. In this paper, a comprehensive review of TFMs topologies and design is made, dealing with TFM applications, topologies, operation, design and modeling.

Minimizing Greenhouse Gas Emissions From Ships Using a Pareto Multi-Objective Optimization Approach

Abstract: To confront climate change, decarbonization strategies must change the global economy. According to statements made as part of the European Green Deal, maritime transport should also become drastically less polluting. As a result, the price of transport must reflect the impact it has on the environment and on health. In such a framework, the purpose of this paper is to suggest a novel method for minimizing emissions from ships, based on so-called Pareto multi-objective optimization. For a given voyage by a ship, the problem is to minimize emissions on the one hand and minimize fuel consumption or passage time on the other. Minimizing emissions is considered as the preferred objective. Therefore, the objective of minimizing fuel consumption or passage time needs to be reformulated as a constraint. Solving such a problem consists of finding most favourable path and speed for the ship and satisfyingthe optimization criteria. Relatively new systems such as hybrid diesel–electric systems have the potential to offer significant emissions benefits. A hybrid power supply utilizes the maximum efficiency of the direct mechanical drive and the flexibility of a combination of combustion power from the prime mover and stored power from energy storage from an electrical supply, at part load and overload. A new report by the American Bureau of Shipping suggests that maritime transport is likely to meet the International Maritime Organization’s target by 2030, solely by using current technology and operational measures. However, this would not be enough to attain the target of reducing CO2 emissions by 2050 by at least 50% compared to 2008. New technologies and operational methods must be applied.

A new solar-driven power/desalination system based on a liquid metal magnetohydrodynamic unit

Abstract: In comparison with the conventional turbine-based power unit, liquid metal magnetohydrodynamic (LMMHD) power units have simple structure since they have no moving parts, and hence they are highly reliable systems with low maintenance cost. However, a LMMHD power unit needs a high-temperature prime mover which is conventionally provided by fossil fuels. To cover up this shortcoming, the present study aims at proposing a new LMMHD cogeneration plant for power and fresh water supply, using a concentrated solar power (CSP) system. The devised integrated system was designed and evaluated from the first- and second-laws of thermodynamics perspectives. The results indicated that the proposed cogeneration plant can produce total power of 38.3 kW and fresh water of 881.6 L/h, in which in this case the energy utilization factor (EUF) and total exergy efficiency were computed 99.69% and 5.57%, respectively. Considering the LMMHD power unit as the reference system, it is found that when the idea of cogeneration was employed, the energy and exergy efficiencies of the LMMHD power system can be improved by 150.2% and 4.3%, respectively. Among all constituents, the receiver has the highest exergy destruction of 256.9 kW, followed by the heliostat with exergy destruction of 228.2 kW. The results of parametric study indicated that the energy and exergy efficiencies of the proposed cogeneration system can be improved by increasing the humidifier/dehumidifier effectiveness or decreasing the mass flow rate of the second MHD loop.

Experimental Study on Three Phase Permanent Magnet Synchronous Generator for Pico Hydro Isolated Systems

Abstract: Permanent magnet synchronous generators (PMSG) are becoming popular for small-scale isolated energy systems due to many advantages like self-started generator, suitable for variable and constant speed applications, high efficiency, good voltage regulation, brushless arrangement, low losses, etc. This paper presents the design aspects of specially designed three-phase PMSG and performance verification for small- scale isolated/off-grid applications. In this study, a constant speed prime mover is used as the emulation of micro/pico-hydro turbine. The prime mover is controlled through a voltage/frequency (V/F) drive and connected to the shaft of the generator and make it run at synchronous speed throughout the operation for the generation of voltage. The micro/pico-hydro systems are equipped with constant speed/power turbines. The load rating is restricted to the rated capacity of the generation in the off-grid mode of operation. In this paper, by understanding the features of the source of generation and load, the three-phase PMSG is specially designed with the help of an industry and experimentally verified the performance for the dedicated loads and found satisfactory within acceptable power quality range.

Optimization of Piston Grooves, Bridges on Cylinder Head, and Inlet Valve Masking of Home-Fueled Diesel Engine by Response Surface Methodology

Abstract: Naturally replenished biodiesel fuels are more precise in place of diesel engine applications as they have complying thermal properties, which are extensively used by various researchers. However, there is necessity to optimize their utility to meet stringent emission norms as per Bharat Stage VI (BS VI) and Euro 6. From the exhaustive survey on the studies, number of piston grooves (NG), number of grooves-n-bridges on cylinder head (Gr-Br), and inlet valve masking (IVM) using the response surface methodologies (RSM) technique have not been reported on the competence, emissions, and combustion attributes of diesel engines running on Honge oil methyl ester (HOME), hence this is an identified gap in literature. The present simulation work is for optimizing the performance and lessoning exhaust emitted from the diesel prime mover tested on non-conventional and petro fuels. Experimentation was carried out to inquest the competence, combustion, and emittance of a vertical cylinder, overhead valve, water cooling, open or induction swirl diesel engine running on HOME as the injecting fuel. The object of the present effort is to optimize competence of diesel engines via a statistics inquest called designs of experiments (DoE). To curtail the diverse variations to be experimented on, full factorial designs (FFDs) array was employed. The response surface methodologies (RSM)-based nonlinear or quadratic predictors establish the relation between the input parameters and proposed attributes. The RSM-based mathematical predictors are established to prognosticate the distinguished engine output attributes at 95% confidence interval. The response surface assay discovered that a combination of 2B 3G, ‘IVM’ of 90°, and ‘NG’ of six grooves yields highest brake thermal efficiency (BTE), lessoning smoke, carbon monoxide (CO), and hydrocarbon (HC), but nitrogenous oxides (NOx) emissions increased slightly. Additionally, combustion attributes, such as Ignition delay (ID) and combustion duration (CD), were lessoned, but peak pressure (PP) and heat release rate (HRR) had a higher contrast to performance of HOME biodiesel in a conventional CI engine.

A comparative analysis of the pump controlled, valve controlled and prime mover controlled hydromotor drive to attain constant speed for varying load

Abstract: The article compares the dynamic performances of the pump-controlled, valve-controlled and prime-mover controlled hydromotor drive systems for a wide range of operating conditions. The control strategy adopted for each of them varies the supply flow to the hydromotor that gives the regulated drive speed. In this respect, the Simscape models are developed for the said systems that are validated experimentally. On the basis of response time, overshoot, and steady-state error obtained from the simulation and test results, it is found that the valve controlled hydromotor drive system is more sensitive than the others; whereas, the load-sensing pump control requires more time to settle but has less overshoot.

Speed-Sensorless and Motor Parameters-Free Starting Method for Large-Capacity Synchronous Machines Based on Virtual Synchronous Generator Technology

Abstract: The large-capacity electrically excited synchronous machines are widely applied in modern industrial production, and starting issues have become one of the most concerns of the synchronous motors in practical operation, such as the long starting time, large current shock, and poor adaption to a wide-ranging load. To deal with these starting problems, many starting methods have been proposed in previous studies. Regrettably, high-performance methods depend on specific motor parameters and complex sensorless technology, while simple and low-cost methods are low performance. In this article, a modified back-to-back starting method is proposed for large-capacity synchronous machines based on virtual synchronous generator (VSG) technology, where the cascaded H-bridge converter is controlled as a VSG to replace the prime mover and synchronous generator of the conventional back-to-back starting system. To reduce the current shock, an initial relative-angle regulator is designed. To improve the robustness in the presence of a wide-ranging load, a damping torque branch is adopted. Extra speed sensors are no longer required since the VSG speed is directly applied in the feedback control loop. To validate the effectiveness of the proposed approach, extensive simulation and experimental results are presented. Compared with conventional approaches, the proposed starting method achieves faster response, smaller starting current, and stronger robustness.

Assessment of a District Trigeneration Biomass Powered Double Organic Rankine Cycle as Primed Mover and Supported Cooling

Abstract: This study presents a combined cooling, heating, and power system powered by biogas, suitable for small scale communities in remote locations. To run such a system, in order to obtain the daily life essentials of electricity, hot water, and cooling, municipal waste can be considered as an option. Furthermore, the organic Rankine cycle part of the organic Rankine cycle powered vapor compression chiller can be used in times of need for additional electric production. The system comprises a medium temperature organic Rankine cycle utilizing M-xylene as its working fluid, and the cooling was covered by an Isobutane vapor compression cycle powered by an R245fa employing organic Rankine cycle. The system analyzed was designated to provide 250 kW of electricity. The energetic and exergetic analysis was performed, considering several system design parameters. The impact of the design parameters in the prime mover has a much greater effect on the whole system. The system proposed can deliver cooling values at the rate between 9.19 and 22 kW and heating values ranging from 879 up to 1255 kW, depending on the design parameter. Furthermore, the second law efficiency of the system was found to be approximately 56% at the baseline conditions and can be increased to 64.5%.

Maximizing Energy Extraction from Direct Grid Coupled Permanent Magnet Synchronous Generators

Abstract: Direct Grid Connection of Permanent Magnet Synchronous Generators (PMSG) has well-known disadvantages such as unstable operation and poor energy extraction when the mechanical power from prime mover tends to change. Wind energy systems are the best examples to see these two drawbacks. On the optimistic side, the elimination of the power electronics present certain cost advantages for the installation stage. However, the advantage may disappear due to the lack of a power electronics system for tracking maximum power point in the face of changing wind speed. This paper proposes a novel PMSG design philosophy such that optimizing PMSG design at the initial stage would compensate for the drawback arising due to lack of Maximum Power Tracking (MPPT) algorithm. Pole numbers of PMSGs, which determine the operation speed, have much more impact on annual energy yield in fixed speed systems than variable speed systems. In this study, optimization of slot/pole combination is described for direct grid coupled PMSGs to extract as much energy as possible according to wind data. A new benchmark, adequacy factor is presented to determine the slot/pole combination. Cut-in wind speed equations are derived for both variable and fixed speed applications to calculate mean power properly. An analytical comparison is carried out between fixed and variable speed operations of PMSGs in terms of annual energy yield for MW power levels. Also, an experimental comparison study is performed by using a 5 kW prototype generator. Results have shown that fixed speed wind energy conversion systems with optimized parameters have more annual energy production than variable speed systems.

Development of detailed engine model for evaluation ship performance in waves by a self-propulsion model test

Abstract: The analysis and understanding of the complex behaviour of a ship propulsion plant are of great importance for novel system design, control system synthesis/optimization and to sustain the safety of ship operation in harsh sea conditions. The convenient way to evaluate the design and propulsion performance of a ship in waves is by simulation combining the experimentally obtained characteristics of hull and propeller with the dynamic model of the prime mover. However, the propeller and engine compose a strongly coupled system, in which fluctuating inflow velocity into the propeller due to the wave and hull motions causes propeller torque and rotating speed fluctuations. The latter affects the response of the propulsion engine and vice versa; however, considering the propulsion system response in waves by a full-scale test is hardly possible. Thus, in the past, the authors have developed the experimental methodology of the self-propelled ship model test in which an intelligent propeller drive is controlled by a Marine Diesel Engine Simulator (MDES) providing the response of the engine model in real time, based on the measured propeller torque and speed. This paper introduces further development of MDES in which a full-state dynamic cycle-mean value engine model was introduced providing deep insight into propulsion engine responses in a real-like condition of the actual sea. The similarity of the engine responses at the ship model scale is ensured by the original method of equations transformation developed by the authors. The newly developed MDES was introduced into the self-propulsion model, and a test series in regular waves was performed. The obtained responses were compared with the results of numerical simulation of the full-scale model confirming the validity of the new development and the importance of intrinsic engine characteristics on propulsion system response in waves.

Performance evaluation of different structures of power system stabilizers

Abstract: The electric power from the system should be reliable and economical for consumer’s equipment satisfaction. An electric power system consists of many generators, transformers, transmission lines, loads, etc. For the power system network, dynamic performance and stability are important. The system is lost its stability by some disturbances i.e., load variations, generator failure, prime mover failure, transmission line outage, etc. Whenever load variations in the system, generator rotor speed will vary, means oscillations in the rotor speed, which is deviating from rated speed. The excitation system will control the generator rated line voltage. When fault occurs at any equipment in the system, the system will unstable. If fault occurs at generator, the generator oscillates. To reduce the oscillations and to make the system stable used power system stabilizers (PSS’s). Here, three types of PSS’s are used i.e., PSS1B, PSS2B, PSS4B. Comparisons of three PSS’s are on the multi machine system under some disturbance. From the observations, concluding that PSS4B is quickly control the oscillations in the physical parameters of machine in the system than other power system stabilizers.

Method for performing tasks in a pattern planted

Abstract: An agricultural machine system for performing agricultural tasks in a in a field on which plants (36) are one of planted and to be planted in a pattern, the system comprising:a prime mover;a tool bar (20) connected to the prime mover;a plurality of units (22) attached to the tool bar (20), the units (22) configured to perform at least one agricultural tasks and wherein at least two of the units (22) are disposed in an offset relationship from each other with respect to a forward direction of travel of the agricultural machine about the tool bar (20);and a control unit (24) in communication with the prime mover, the control unit (24) configured to activate the units (22) automatically, as the agricultural machine system travels along a plurality of rows defined by the pattern, to perform the at least one agricultural task selectively at locations determined by the pattern.

Development and Control of a Photovoltaic Fed Flywheel Energy Storage System for Power Conditioning

Abstract: The concept of newer energy storage and power conditioning using suitable controllers in a solar photovoltaic fed flywheel energy storage system (FESS) is presented in this work. The power from a solar photovoltaic arrangement is harvested using a Sinusoidal Pulse Width Modulated (SPWM) DC-DC converter to provide a controlled, efficient and regulated output to drive the Flywheel Energy Storage System. The FESS is designed with the BLDC motor as prime mover that drives a flywheel of cylindrical mass of suitable material and radius. The alternator connected in the same shaft of the prime mover and flywheel powers an electrical load of 1kW. The dynamic stability of the system is taken care by the flywheel, while reliability is ensured using a well designed controller unit. The solar PV arrangement with its controller was simulated using MATLAB, while the flywheel energy storage system was simulated using ANSYS. Based on the simulation results, a working model was fabricated, installed and tested for the required operation. Test results were compared; graphical representations are given to substantiate the working of the flywheel energy storage system.