Showing papers on "Prime mover published in 2018"
TL;DR: In this paper, a thermodynamic analysis for a combined cooling, heating and power (CCHP) system based on proton exchange membrane (PEM) fuel cell as a prime mover is done.
101 citations
TL;DR: In this article, a combined cooling, heating and power (CCHP) system has been designed under an electric charge supply strategy for a residential complex in Iran, where three types of gas engine, diesel engine, and gas turbine as prime movers have been presented and analyzed separately and simultaneously at six different scenarios and the appropriate scenario has been proposed for the CCHP system.
86 citations
TL;DR: In this article, a comprehensive review of cogeneration system, covering the principle operation and types of prime movers available for use in power plant, building and industrial plant, is presented.
Abstract: Several factors such as climate change, increment in fuel cost and digital technology era have lead to transformation of conventional grid into smart grid. Existing microgrid can be integrated with smart grid characteristics by various topologies, including cogeneration system where both electricity and thermal energy from single source of fuel can be produced. Cogeneration system has better efficiency, lower costs and able to reduce greenhouse gas emissions compared to singular conventional methods. This paper presents a comprehensive review of cogeneration system, covering the principle operation and types of prime movers available for use in power plant, building and industrial plant. Prime movers such as gas turbine, steam turbine, micro turbine, reciprocate engine and fuel cell are compared in terms of size (kW), efficiency and principal operation. This review also describes the hierarchical control system for cogeneration system; classified into three types, which are local, centralized and decentralized. This study tries to find the most suitable control strategy for certain cogeneration system by referring to the related standards available. A number of cogeneration applications in commercial buildings, including hospital, airport, shopping complex and hotel, are presented to show the effectiveness of the cogeneration system. Overall, this paper presents comparison between each prime mover technology, factors that influence the selection of prime movers, challenges and prospects of cogeneration system.
83 citations
TL;DR: In this article, the authors proposed a combined cooling; heating and power cycle in microscale to be portable, maintenance free, undetectable, environmentally friendly and can provide the energy demand of a single-family when access to energy suppliers is limited.
51 citations
TL;DR: In this article, the damping torque of the prime mover over the entire oscillation frequency range, and under different turbine parameters, must be greater than a threshold to guarantee robustness and adaptability.
Abstract: Negative damping of prime movers is a major cause of sustained frequency oscillations in power systems. Increasing the damping torque of prime movers by adjusting governor parameters is an effective measure to prevent frequency oscillations. The oscillation frequency is volatile and turbine parameters change under loading conditions. To guarantee robustness and adaptability, the governor parameters should be adjusted to ensure sufficient damping torque over the entire range of oscillation frequency and under different turbine parameters. An optimization model of governor parameters is proposed. A constraint of the model is that the damping torque of the prime mover over the entire oscillation frequency range, and under different turbine parameters, must be greater than the threshold. The composite dynamic performance of primary frequency regulation under different loading conditions is the optimization objective. Test results validate the proposed method. The stability of the frequency oscillation mode under different conditions can be guaranteed.
50 citations
TL;DR: The CCHP system for the tile factory showed the better performance of selling scenario using a gas engine with a capacity of 5000 and 700, however, the nominal capacity of the prime movers in the selling scenario was higher than that in the no-selling strategy.
47 citations
TL;DR: Detailed mathematical formulation for the proposed OOS detection method is provided and the results confirm that the proposed approach can accurately identify OOS conditions, earlier than the rotor angle noticeably increases.
Abstract: This paper introduces a new approach, based on faster-than-real-time (FTRT) analysis, to predict out-of-step (OOS) condition of a turbine-generator (T-G) unit subsequent to a fault scenario. The proposed FTRT analysis is based on 1) solving a state-space model of the T-G electromechanical system and corresponding controllers without the need for online measurements, and 2) an estimated Thevenin equivalent of the rest of the power system. The measurement-free FTRT analysis is carried out after the Thevenin parameters are estimated subsequent to the fault clearance instant. Equal area criterion is applied on the predicated variables to detect OOS condition. A reliable decision can be made based on this approach, since it does not involve simplifying assumptions contrary to the existing approaches. The FTRT approach accurately considers the impacts of the detailed model of the generator, automatic voltage regulator, prime mover, governor system, and the host power system. This paper provides detailed mathematical formulation for the proposed OOS detection method and verifies its feasibility and accuracy based on single machine and large test systems. The proposed approach is also implemented on an industrial platform and evaluated. The results confirm that the proposed approach can accurately identify OOS conditions, earlier than the rotor angle noticeably increases.
40 citations
TL;DR: In this paper, a residential community MIES is developed by analyzing residential direct energy consumption within a general design procedure, which considers a prime mover, fed by natural gas, with wind power, photovoltaic generation, and two storage devices serving thermal energy and power to satisfy cooling, heating and electricity demands.
Abstract: Based on analysis of construction and operation of micro integrated energy systems (MIES), this paper presents economic optimization for their configuration and sizing. After presenting typical models for MIES, a residential community MIES is developed by analyzing residential direct energy consumption within a general design procedure. Integrating with available current technologies and local resources, the systematic design considers a prime mover, fed by natural gas, with wind power, photovoltaic generation, and two storage devices serving thermal energy and power to satisfy cooling, heating and electricity demands. Control strategies for MIES also are presented in this study. Multi-objective formulas are obtained by analyzing annual cost and dumped renewable energy to achieve optimal coordination of energy supply and demand. According to historical load data and the probability distribution of distributed generation output, clustering methods based on K-means and discretization methods are employed to obtain typical scenarios representative of uncertainties. The modified non-dominated sorting genetic algorithm is applied to find the Pareto frontier of the constructed multi-objective formulas. In addition, aiming to explore the Pareto frontier, the dumped energy cost ratio is defined to check the energy balance in different MIES designs and provide decision support for the investors. Finally, simulations and comparision show the appropriateness of the developed model and the applicability of the adopted optimization algorithm.
31 citations
TL;DR: It is demonstrated how the remaining useful life of a machine can be increased by appropriate controller design without compromising performance.
Abstract: Electric machines (motors and generators) are over actuated systems. In this paper, we show how to exploit this actuation redundancy in order to mitigate machine degradation while simultaneously ensuring that the desired closed loop performance is maintained. We formulate a multiobjective optimization problem with a cost function having terms representing closed loop performance and component degradation for an inverter-fed permanent magnet synchronous motor. Such machines are important as they are widely used as the prime mover of commercial electric vehicles. The resulting optimal control problem is implemented online via a nonlinear model predictive control (NMPC) scheme. The control framework is validated for standard vehicle drive cycles. Results show that the NMPC scheme allows for better closed loop performance and lower degradation than standard industrial controllers, such as the field-oriented control method. Hence, this paper demonstrates how the remaining useful life of a machine can be increased by appropriate controller design without compromising performance.
27 citations
26 citations
TL;DR: In this paper, a conceptual design of a small-scale dual power-desalination system was presented, in which the best operating parameters of the combined systems were found in a multi-objective optimization with the goal of maximization of the generated electricity and fresh water as well as minimizing the product cost, simultaneously.
TL;DR: A two-level method for forced oscillations source location is proposed that has good robustness for the measurement of data quality issue and is able to locate multimode oscillations with multiple disturbances.
Abstract: Forced oscillations (FOs), which are caused by sustained cyclic disturbances, threaten the safe and stable operation of power system. The most effective way to eliminate FOs is to locate the oscillation source and take corresponding measures. In this paper, a two-level method for forced oscillations source location is proposed. First, the energy structure of the generator is analyzed based on Hamiltonian function. The energy injected into generator is divided into two parts, i.e., energy injected by the prime mover system and excitation system. Then, as to the energy injected into power grid, the phasor relation between the variances of branch variables is analyzed to identify the energy flow direction. Based on the former analysis, the proposed method includes two levels. The bus level location of the oscillation source is realized according to the energy flow direction obtained with phasor analysis. Furthermore, the control device level location within the generator is realized according to the injected energy of the prime mover system and excitation system of generator. This method has good robustness for the measurement of data quality issue and is able to locate multimode oscillations with multiple disturbances. The simulation results in four-machine two-area system, East China power grid and the WECC 179-bus system as well as the comparison with classic energy-based method demonstrate the effectiveness and improvement of the proposed method.
TL;DR: In this paper, a thermal electricity storage configuration based on the Air Bottoming Cycle (ABC) concept is proposed and tested and an energy and a cost analyses are carried out to estimate the performance and the system feasibility.
Abstract: The increment of greenhouse gas emissions from human activities have forced the world authorities to ratify stringent environmental protection measurements devoted to the reduction of primary energy consumption and to the spread of Renewable Energy Sources (RES). To reach the fixed targets, governments have established subsidies especially to support the electricity generation from RES like wind and solar. However, the large penetration of variable and intermittent RES is stressing the need of large-scale energy storage able to stabilize the electric grids. But, available large-scale energy storage technologies like Pumped Hydro, Compressed Air Energy Storage or Flow Batteries, suffer of geographical constrains, require fossil fuel streams or are characterized by low cycle life. For this reason, in the present paper, a new Thermal Electricity Storage configuration based on the Air Bottoming Cycle (ABC) concept is proposed and tested. The off-peak power is firstly converted into thermal energy using an electric heater and, then, stored in a high temperature sensible heat storage. When the power demand is high, using a modified ABC the thermal energy is converted back into electricity. Using the plant mathematical model, an energy and a cost analyses are carried out to estimate the performance and the system feasibility.
Patent•
05 Jul 2018
TL;DR: In this article, a system and method to operate a doubly-fed induction generator (DFIG) as a grid-friendly virtual synchronous generator (VSG) is described.
Abstract: This invention discloses a system and method to operate a doubly-fed induction generator (DFIG) as a grid-friendly virtual synchronous generator (VSG). It comprises a DFIG modeled as a virtual differential gear that links a rotor shaft driven by a prime mover, a virtual stator shaft coupled with a virtual synchronous generator G and a virtual slip shaft coupled with a virtual synchronous motor M, and a variable frequency drive that behaves as a virtual synchronous motor-generator set to regulate the speed of the virtual synchronous motor M so that the speed of the virtual stator shaft, i.e., the speed of the virtual synchronous generator G, is within a narrow band around the grid frequency even when the rotor shah: speed changes. As a result, a grid-connected DFIG can be controlled to behave like a virtual synchronous generator without using a PLL.
TL;DR: In this paper, a surface-mounted permanent magnet synchronous motor (SPMSM) drive for constructing the prime mover emulators is presented, which can be arranged to drive the tested generator in a conventional speed control mode or a specific wind turbine torque-speed control mode.
Abstract: This paper presents the development of a surface-mounted permanent-magnet synchronous motor (SPMSM) drive for constructing the prime mover emulators. It draws power from the mains via a single-phase boost type switch mode rectifier (SMR) with good line drawn power quality and well-regulated dc-link voltage. The SPMSM drive control scheme can be arranged to drive the tested generator in a conventional speed control mode or a specific wind turbine torque–speed control mode. For performing the prime mover loading test, an interior permanent-magnet synchronous generator (IPMSG) followed by a three-phase Vienna SMR is established. It receives the mechanical driven power from the prime mover and establishes a 400 V dc-link for a dc microgrid. Various wind turbine torque–speed characteristic curves under different wind speeds can be faithfully emulated by the developed prime mover. And the maximum power point tracking function for the IPMSG followed by Vienna SMR is achieved using the perturb and observation method. The established whole prime mover emulator driven IPMSG system is evaluated experimentally under autonomous and microgrid interconnected operation.
01 Sep 2018
TL;DR: Step by step procedures used to design a permanent magnet synchronous generator (PMSG) for small-scale, low speed applications are demonstrated and validated as a contributed step-by-step simple and reliable design tool for such cluster of PMSGs.
Abstract: This paper is dedicated to demonstrate step by step procedures used to design a permanent magnet synchronous generator (PMSG) for small-scale, low speed applications. The main target of this work is the generator directly connected to the prime mover and in the fractional or few kilowatts range. A linear lumped-element-based model is presented, which is used for basic analysis and design. Then, a proposed complete design procedure - asserted with equations, tables, design limits and practical recommendations - are detailed. Also, a flowchart is developed to be later used as a Matlab M-file code for PMSG design with specific requirements. The design procedures are then validated using different techniques including: a) Finite Element Method (FEM) using Maxwell software, through different case studies, b) results comparison with different available generators from both research work and commercial one, and c) experimental results obtained from actual prototype machine implemented by the authors. Such comparisons have validated the proposed procedures as a contributed step-by-step simple and reliable design tool for such cluster of PMSGs.
TL;DR: In this paper, the effect of percentage of biodiesel blends and injection strategies such as variations in start of injection (SOI) timing and dwell angle on diesel engine performance were investigated.
TL;DR: A set of algebraic formulas for the equivalent specific fuel consumption of on-board power systems equipped with electrical energy storage are proposed, which give a quick estimation of the maximum fuel savings obtainable.
TL;DR: In this article, a multi-parameter analysis of a beta-Stirling engine has been presented, where the authors considered the utilization of helium, hydrogen and air as the working media.
TL;DR: A novel index representing the stresses on the SSSG shaft is applied in the multiobjective goal function and decreases SSSGs loss of life in a μG with overhead lines which has high rate of short circuit faults.
Abstract: Optimal placement and sizing of distributed energy resources (DERs) can be performed from various points of view. In this paper, a multiobjective function is employed to determine optimal place and size of DERs including combination of photovoltaic resources and a small-scale synchronous generator (SSSG) with an internal combustion engine as its prime mover. As the objective function, not only minimization of investment costs, operation costs, and system losses are used, but also the voltage of microgrid (μG) busses and current of lines are considered as constraints. In addition, this paper shows mechanical stresses can be imposed on the SSSG caused by generator swings after short circuit fault clearing. Furthermore, it may lead to mechanical fatigue in its associated shaft and prime mover. Meanwhile, it is revealed that the mechanical stresses depend on the DERs placement and size. Thus, a novel index representing the stresses on the SSSG shaft is applied in the multiobjective goal function. This decreases SSSG loss of life in a μG with overhead lines which has high rate of short circuit faults. Optimization studies are performed in a six-bus and four-DER μG using time-based simulations.
TL;DR: In this article, a single person portable CCHP system based on a micro-gas turbine and micro-absorption chiller is proposed and its performance is analyzed under different operational conditions.
Patent•
07 Sep 2018TL;DR: In this article, a combined cooling, heating and power supply system is characterized by being formed through treating a SOFC/GT hybrid power generation system as a reference system and introducing CO2 circulation, ORC circulation and a LNG cold energy utilization system.
Abstract: The invention discloses a combined cooling, heating and power supply system. The combined cooling, heating and power supply system is characterized by being formed through treating a SOFC/GT hybrid power generation system as a reference system and introducing CO2 circulation, ORC circulation and a LNG cold energy utilization system. According to the combined cooling, heating and power supply system, a SOFC/GT serves as a prime mover, high-temperature waste heat, medium-temperature waste heat and low-temperature waste heat of a recovery system of the CO2 circulation and the ORC circulation areutilized correspondingly, and an LNG is used as a cold source for the CO2 circulation and the ORC circulation, and therefore, external cooling (air conditioning and refrigeration), external heating, external power supply, external natural gas supply and external supply of ice and dry ice can be achieved; and the low-carbon emission of the system is realized by condensing and separating CO2 in a flue gas, the available energy loss of the combined supply system can be effectively reduced, gradient and efficient utilization of energy is achieved, and the good energy-saving and emission-reducing effects are achieved.
01 Oct 2018
TL;DR: A grid connection process of a converter controlled squirrel-cage induction generator driven by an uncontrolled speed prime mover to decrease an inrush current during a grid connection of an induction generator.
Abstract: The paper presents a grid connection process of a converter controlled squirrel-cage induction generator driven by an uncontrolled speed prime mover. The main goal of the described method is to decrease an inrush current during a grid connection of an induction generator. The converter is used for a build-up process of a generator voltage and afterwards for a synchronization of the generator voltage with the grid voltage. The synchronization process is made by loading the induction generator with the brake-choppers, connected to the DC-link of the NPC converter. When the squirrel-cage induction generator is connected to the grid, the power electronic converter works as a reactive current source to satisfy the reactive power demand of the generator. The tests have been performed in the laboratory setup with a 7.5 kW induction generator and 8.0 kVA power transformer.
TL;DR: This study proposes a new flux-based approach to detect reverse power condition in the synchronous generators that uses the analysis of angular velocity and acceleration data that are calculated from the estimated magnetic flux at the machine stator terminals.
Abstract: Reverse power relays are utilised to trip turbine generators to avoid prime mover damage and directional relay is most widely used as the main protection for these conditions. An intentional time delay is ordinarily utilised to overcome the possible maloperation of these relays. However, the intentional time delay to prevent maloperation is not an ideal solution. As this time delay increases the reverse power relay operation time, which means that the motoring action of the synchronous generator persist for a longer time, making the prime mover more vulnerable to active power drawn by the generator. This study proposes a new flux-based approach to detect reverse power condition in the synchronous generators. The proposed scheme uses the analysis of angular velocity and acceleration data that are calculated from the estimated magnetic flux at the machine stator terminals. The basic idea of the technique stems from the principle that the stator and rotor magnetic fluxes rotate together at synchronous speed and will not be affected by system disturbances for a short interval according to highly inductive characteristics of the synchronous machine. The main advantage of this predictive algorithm is its speed, security and sensitivity to detect the reverse power conditions.
TL;DR: In this paper, a 3-phase linear generator (TPLG) with 2D Finite Element Method Magnetics (FEMM) and MATLAB analysis is presented.
Abstract: Sea wave is an alternative renewable energy source that can meet excessive demand for energy throughout the country. The sea waves have high potentials for harvesting wave energy. A three phase linear generator (TPLG) is an electromechanical energy converter driven by a reciprocating prime mover. It has less mechanical interfaces compared to conventional generator and it can be used to convert the sea wave energy into electrical energy. The design of TPLG with 2D Finite Element Method Magnetics (FEMM) and MATLAB analysis represents the core of the paper. TPLG’s geometrical design model has a rating of 61.2 kW output power with 18 slots. Radial permanent magnets are used in the design of TPLG to provide better performance. FEMM software will be used to simulate and verify the result of TPLG. The outputs of the TPLG voltages are 707.5 V, 411.5 V and 355.2 V. Finally, an AC-DC converter is used to stabilize the output voltage of TPLG. Keywords : three phase linear generator; cogging force; finite element method magnetics; AC-DC converter.
08 Aug 2018
TL;DR: An innovative software was developed in order to assist hydro designers and provide a visual aid when choosing between different layouts of the analyzed hydro scheme (e.g., more than one PAT in series/parallel, different shaft speeds), and has been applied to a real case study of energy recovery in a water network.
Abstract: Pumps As Turbines (PATs) are a class of unconventional hydraulic turbines consisting of standard water pumps working in reverse mode as the prime mover. Such devices can be well suited for either in-pipe energy recovery or small-scale hydropower, but their practical application is hampered by the lack of comprehensive guidelines able to assist the designer in the determination of the optimal plant layout and the choice of equipment. In fact, the performances of a PAT will depend on factors such as its construction type, its size and the flow conditions under which the machine is expected to operate. Ultimately, the design of a PAT-based hydro scheme is a matter of trade-offs which are in most cases not trivial. An innovative software was developed in order to assist hydro designers and provide a visual aid when choosing between different layouts of the analyzed hydro scheme (e.g., more than one PAT in series/parallel, different shaft speeds), and has been applied to a real case study of energy recovery in a water network.
01 Oct 2018
TL;DR: The simulation using MATLAB /Simulink environment have been carried out to evaluate the performance of isolated 3-phase SEIG in micro/Pico hydropower plant using different load with Electronic Load Controller technique used to improve the power quality and maintaining voltage and frequency at desired level.
Abstract: This paper presents analysis of 3-phase Self excited induction generator (SEIG) which is most suitable for standalone Pico-hydroelectric power generation with constant input power. The increasing use of non conventional/renewable energy sources such as bio gas, wind, solar and hydro potential because of its low cost generating system, which are capable to operate in the remote rural areas or where supply of power from grid is not possible or not available. Induction generator is a good choice over well developed synchronous generator for alternative sources of energy like wind based turbine or micro/mini hydro generator because of its low price, simplicity, little maintenance, ruggedness, brushless (for squirrel cage), absence of dc source, protection against short circuit and overload. When driven by fixed speed prime mover or fixed head hydro turbine the SEIG faces the poor voltage regulation which is the main drawback of SEIG. In this paper the simulation using MATLAB /Simulink environment have been carried out to evaluate the performance of isolated 3-phase SEIG in micro/Pico hydropower plant using different load with Electronic Load Controller technique used to improve the power quality and maintaining voltage and frequency at desired level.
01 Jan 2018
TL;DR: A control strategy is proposed for the voltage regulation and the shaft speed control of diesel generators on-board of all-electric ships with Direct Current power and propulsion systems using Input-Output Feedback Linearization of the prime mover dynamical model.
Abstract: In this paper, a control strategy is proposed for the voltage regulation and the shaft speed control of diesel generators on-board of all-electric ships with Direct Current (DC) power and propulsion systems. The proposed methodology is based on Input-Output Feedback Linearization (IOFL) of the prime mover dynamical model. First, a model for different components in the system is represented and by merging them, the overall model of the system is obtained in state space format. Then, an IOFL-based control algorithm is applied for stabilization, voltage regulation and shaft speed control of the diesel generator. The performance of the algorithm is assessed using a model of an inland vessel.
TL;DR: A microgrid system model is created to assess transient and steady-state stability during periods of separation from the grid, and a secondary level control, which distributes the power error according to user defined participation factors, is proposed.
Abstract: A microgrid system model is created to assess transient and steady-state stability during periods of separation from the grid. A secondary control is constructed to dispatch energy sources according to user selected setpoints and participation factors. Two sources—an energy storage device and a synchronous generator—are controlled to share active and reactive load burdens. A system load models the difference between solar and wind-powered generation and load. First-order differential equations are written to describe the system, and implemented in Simulink. The model components carry a high level of detail to capture all relevant modes. Systems include an eight-state salient pole synchronous machine, an AC8B regulator, a prime mover, an equivalent $\pi$ cable, an RL microgrid load, an ideal battery, a simple inverter model, and a detailed LCL filter at the inverter output. A detailed model of the inverter primary control is included, and a secondary level control, which distributes the power error according to user defined participation factors, is proposed.