Wind Diesel Research Articles

Distributed Renewable Energy Access to Micro-Grid System Random Multi-Objective Economic Dispatch

With the development of distributed generation technology rapidly, a large number of wind, solar and other renewable energy access to access system . Since renewable energy is intermittent and stochastic, which posed economic dispatch system a serious challenge. Consider the system operating costs and sewage expenses, the paper constructs multi-objective micro-grid system economic dispatch model composed by the wind turbine, diesel engine, battery and load. And through MATLAB / Simulink simulation, model is established to verify the correctness and effectiveness.

Energy dispatch strategy for a photovoltaic–wind–diesel–battery hybrid power system

In this paper, an energy dispatch model that satisfies the load demand, taking into account the intermittent nature of the solar and wind energy sources and variations in demand, is presented for a solar photovoltaic–wind–diesel–battery hybrid power supply system. Model predictive control techniques are applied in the management and control of such a power supply system. The emphasis in this work is on the co-ordinated management of energy flow from the battery, wind, photovoltaic and diesel generators when the system is subject to disturbances. The results show that the advantages of the approach become apparent in its capability to attenuate and its robustness against uncertainties and external disturbances. When compared with the open loop model, the closed-loop model is shown to be more superior owing to its ability to predict future system behavior and compute appropriate corrective control actions required to meet variations in demand and radiation. Diesel consumption is generally shown to be more in winter than in summer. This work thus presents a more practical solution to the energy dispatch problem.

Real power and frequency control of a small isolated power system

This paper describes the dynamic analysis of a small isolated power system comprising a wind turbine generator and a diesel generator. The analysis is carried out in time domain considering simplified models of the system components by taking into account the wind turbine pitch controller and the diesel engine speed governor. Wind disturbance model consisting components of gusting of wind, rapid ramp changes and random noise. The wind generator is always operated with its rated power and the additional power required by the load is supplied by the diesel generator. For better dynamic performances of wind–diesel system under wind and load disturbance conditions, two control schemes are used. In the first case, a proportional–integral (P–I) controller and in the second case a proportional–integral–derivative (P–I–D) controller are used. Gain parameters of these controllers are optimized using genetic algorithm (GA) and Particle swarm optimization (PSO) considering two different objective functions and the results are compared. The sensitivity analysis of the wind diesel system is carried out for parameter uncertainties and the stability of the system is analyzed using D-stability criterion. Analysis is also carried out to examine the effect of power injection to a 69 bus radial distribution network by wind–diesel isolated system.

Stability analysis and reactive power compensation issue in a microgrid with a DFIG based WECS

This paper presents a novel methodology for compensating reactive power in a microgrid, having a DFIG based wind–diesel system, to enhance the voltage stability of the hybrid system. UPFC as a FACTS device is proposed in order to improve the control of reactive power mismatch and the stability of the system. A small signal model of the wind–diesel system, DFIG based wind turbine system, UPFC and the controllers are designed for the stability analysis. Further, the voltage variation and reactive power compensation is analysed with the incorporation of proposed ANFIS based UPFC controller. Simulations are performed in MATLAB environment for transient stability analysis in a wind–diesel based microgrid with different wind power input and 2% step increase in load demand. Simulation results illustrate the efficiency and effectiveness of the proposed approach and its impact upon transient behaviour of the microgrid.

Functional Predictive Control for Voltage Stability Improvements of Autonomous Hybrid Wind–Diesel Power System

This study investigates the application of the model predictive control technique for voltage stability of an isolated hybrid wind–diesel power system based on reactive power control. The proposed generation system mainly consists of a synchronous generator for a diesel-generator system and an induction generator for a wind energy conversion system. A static VAR compensator is used to stabilize load voltage through compensating reactive power. Two control paths are used to stabilize load bus voltage based on model predictive control. The first control path is used to adjust the total reactive power of the system by controlling the static VAR compensator firing angle. The second is proposed to control the excitation voltage of the synchronous generator. Model predictive control is used to determine t optimal control actions, including system constraints. To mitigate calculation effort and reduce numerical problems, especially in a large prediction horizon, an exponentially weighted functional model predictive control (F-model predictive control) is applied. The proposed controller was tested through step change in load reactive power plus step increase in input wind power. The performance of the proposed system with the proposed controller was compared with classical model predictive control; moreover, this scheme is tested against parameter variations.

Comparing the Use of Diesel and Wind Power in Pumping Water in Saudi Arabia

This study compares a diesel only power system with wind only power system for pumping water in some cities of Saudi Arabia. Cost of Energy (COE) is found to be very sensitive with respect to annual mean wind speed. For 10% annual capacity shortage, for example, the COE decreases by 11.5, 21.8, 22.3 and 13.5% at Dhahran, Riyadh, Jeddah, and Guriat, respectively for an increase in annual mean wind speed of only 0.4m/s. On the other hand, COE for zero capacity shortage is found to be 0.224, 0.455, 0.294, 0.334, and 1.379$/kWh at Dhahran, Riyadh, Jeddah, Guriat, and Nejran, respectively. The cost of pumping water from a well of 50 m total dynamic head (TDH) is studied for both the wind energy and diesel only systems. Cost of water when using wind energy system is found to be 5.35, 10.4, 6.94, 7.71, and 30.56US¢/m3 for Dhahran, Riyadh, Jeddah, Guriat and Nejran, respectively. Cost of water when using diesel only system is found to vary from 7 to 16.5US¢/m3 depending on the fuel price. Furthermore, the wind based system becomes more cost effective when the diesel fuel cost is more than 0.4$/L for all sites except for Nejran. Last but not the least, the utilization of wind power for water pumping in Saudi Arabia will result into avoidance of addition of around 24,000 tons of CO2 equivalent greenhouse gases from entering into the local atmosphere annually.

Inclusion of biodiesel and PV modules in a wind diesel hybrid system supplying electrical loads on a small farm

The growing interest in biofuels is a consequence of the need to reduce operating costs of energy systems and the need to reduce emissions of greenhouse gases. The same applies to PV modules, comprising a solution environmentally desirable for power generation. This paper presents a study on the inclusion of biodiesel and PV modules in a system already in operation on a small farm in southern Brazil. The insertion of biodiesel in different blends with diesel reveals that the use of B100 results in a reduction of about 3% in emissions and a reduction of less than 10% in the final cost of energy. A direct comparison between pure diesel, biodiesel produced from waste agricultural industries poultry slaughtering and various blends indicates the use of B40 as the best choice. The inclusion of PV modules requires a cost reduction for at least 30% of the current value.

Optimization of an off-grid hybrid PV–Wind–Diesel system with different battery technologies using genetic algorithm

The power supply of remote sites and applications at minimal cost and with low emissions is an important issue when discussing future energy concepts. This paper presents the modelling and optimization of a stand-alone hybrid energy system. The system consists of photovoltaic (PV) panels and a wind turbine as renewable power sources, a diesel generator for back-up power and batteries to store excess energy and to improve the system reliability.For storage the technologies of lithium-ion, lead-acid, vanadium redox-flow or a combination thereof have been considered. To be able to use different battery technologies at the same time, a battery management system (BMS) is needed. The presented BMS minimizes operation costs while taking into account different battery operating points and ageing mechanisms.The system is modelled and implemented in Matlab/Simulink. As input, the model uses data of the irradiation, wind speed and air temperature measured in 10min intervals for 10years in Aachen – Germany. The load is assumed to be that of a rural UMTS/GSM base station for telecommunication. For a time frame of 20years, the performance is evaluated and the total costs have been determined. Using a genetic algorithm, component sizes and settings have then been varied and the system re-evaluated to minimize the overall costs. The optimization has been also done for a site in Quneitra – Syria which has very good solar radiation that allows for the comparison between two countries, as the weather data in the two countries differ greatly (different weather data).The optimization results show that using batteries in combination with the renewables is economical and ecological. However, the best solution is to combine redox-flow batteries with the renewables. In addition, a power supply system consisting only of batteries, PV and wind generators may be applicable as well to satisfy the power demand.

풍력-디젤-플라이휘일 하이브리드 발전시스템 모델링에 관한 연구

본 논문은 도서지역에서 운용되고 있는 풍력-디젤 하이브리드 발전시스템의 풍속변화 등으로 인한 주파수변동 문제를 해결할 수 있는 플라이휘일 저장장치의 모델링 및 제어기 설계 방법을 제안하였다. 플라이휘일 저장장치는 효율측면에서 유리한 영구자석 동기기형 플라이휘일로 선정하여 모델링하였고, 주파수보상 제어기는 AC/DC/AC 양방향컨버터로 구성하되 동기기측 컨버터는 연계계통의 주파수변동에 대하여 충방전운전을 하도록 하고, 계통측 컨버터는 직류버스전압 일정제어를 통하여 출력을 하도록 설계하였다. 제안된 모델링 및 제어기 설계방법을 풍력-디젤 하이브리드 독립운전계통에 적용한 결과 풍속변화에 따른 주파수변동을 적정범위내로 유지할 수 있었다. 【This paper proposes a modeling and controller design method of Flywheel Energy Storage System(FESS) for solving the unstable operation problem in hybrid generation system with wind turbine and diesel generator applied in island area. FESS is considered as a permanent magnetic synchronous machine connected to flywheel because of its efficiency. The controller of FESS is composed of AC/DC/AC back-to-back converter. The AC/DC converter is designed to charge/discharge according to the frequency variation and the DC/AC converter to operate to keep the DC bus voltage constant. The proposed modeling and controller design method of FESS was applied to hybrid generation system with wind turbine and diesel generator. The unstable operation problem owing to wind variations was solved through simulation results.】

Modeling and seeker optimization based simulation for intelligent reactive power control of an isolated hybrid power system

Seeker optimization algorithm (SOA) is a novel heuristic population-based search algorithm based on the concept of simulating the act of human searching. In SOA, the acts of human searching capability and understanding are exploited for the purpose of optimization. In this algorithm, search direction is based on empirical gradient by evaluating the response to the position changes and the step length is based on uncertainty reasoning by using a simple fuzzy rule. In this paper, effectiveness of the SOA has been tested for optimized reactive power control of an isolated wind–diesel hybrid power system model. In the studied power system model, a diesel engine based synchronous generator (SG) and a wind turbine based induction generator (IG) are used for the purpose of power generation. IG offers many advantages over the SG but it requires reactive power support for its operation. So, there is a gap between reactive power demand and its supply. To minimize this gap between reactive power generation and its demand, a variable source of reactive power such as static VAR compensator (SVC) is used. The SG is equipped with IEEE type-I excitation system and dual input power system stabilizer (PSS) like IEEE-PSS3B. The performance analysis of a Takagi–Sugeno fuzzy logic (TSFL)-based controller for the studied isolated hybrid power system model is also carried out which tracks the degree of reactive power compensation for any sort of input perturbation in real-time. In time-domain simulation of the investigated power system model, the proposed SOA–TSFL yields on-line, off-nominal coordinated optimal SVC and PSS parameters resulting in on-line optimal reactive power control and terminal voltage response. The performance of the proposed controller, with the influence of signal transmission delay, has also been investigated.

Use of Ultracapacitors and Batteries for Efficient Energy Management in Wind–Diesel Hybrid System

The interconnection of the wind generator (WG) and the diesel generator (DG) induces some interactions on the common coupling point. These interactions are studied in this paper with the aim of identifying the system limits in performance and proposing an alternative solution. Due to the fast fluctuations of the WG and the DG slow dynamics, ultracapacitors and batteries are used for improving the hybrid system performances and reducing the fuel consumption. The dc-bus voltage is controlled by the diesel engine while providing a smoothed current. To ensure optimized life cycle cost and performance, a lifetime-estimation-based method is proposed. In this method, a rainflow counting method is applied to size the storage devices by taking into account the actual conditions of the system operation. The experimental test bench is designed in a reduced scale. Some simulations and experimental results are presented and analyzed.

Performance Investigation of Isolated Wind–Diesel Hybrid Power Systems With WECS Having PMIG

This paper presents the automatic reactive power control of isolated wind-diesel hybrid power systems having a permanent-magnet induction generator for a wind energy conversion system and a synchronous generator for a diesel generator set. To minimize the gap between reactive power generation and demand, a variable source of reactive power is used such as a static synchronous compensator. The mathematical model of the system used for simulation is based on small-signal analysis. Three examples of the wind-diesel hybrid power system are considered with different wind power generation capacities to study the effect of the wind power generation on the system performance. This paper also shows the dynamic performance of the hybrid system with and without change in input wind power plus 1% step increase in reactive power load.

Optimization Design of Wind/Photovoltaic Hybrid Power Systems Based on Genetic Algorithms

Wind power and solar energy power are clean, abundant and renewable. Wind power and photovoltaic power are important alternative energy in the world, which will contribute to adjusting energy structures and protecting environments. The genetic algorithm has the characteristics of automatic optimization and approaches the simulate stuff illimitably. Also, there has no use for accurate model on questions, which is very suitable in the non-linear system. The wind/photovoltaic hybrid systems consist with wind power generation units, photovoltaic matrix, storage battery, diesel engine and data collection and control. This paper optimized the wind/photovoltaic hybrid system using genetic algorithm. The result showed the efficiency of this algorithm in the design of this kind of non-linear system. On the other hand, this hybrid system is strongly non-linear when is running. Finally, abundant operating expenses and maintains expenses will be saved by using genetic algorithm in its dynamic management according to the change of load, wind power and irradiation.

Feasibility analysis of renewable hybrid energy supply options for Masirah Island

In this paper, the assessment and modelling of alternative renewable energy systems for Masirah Island is considered. The hybrid system that is simulated comprises various combinations of wind turbines and/or photovoltaic (PV) supplemented with diesel generators and short-term battery storage. It was found from the analysis that the PV–wind–diesel hybrid system, with battery unit, has the lowest cost values as compared to solar-only or wind–diesel hybrid systems. Furthermore, the study illustrates that for a given hybrid system the presence of battery storage will reduce diesel consumption. The decrease in carbon emission, the percentage of fuel savings, the cost of energy production and the effect of wind and PV penetration are also addressed in this paper. The PV–wind–diesel hybrid option is techno-economically viable for the electrification of the Masirah Island.

Reverse power management in a wind diesel system with a battery energy storage

The subject of this paper is to present the modeling of a Wind Diesel Hybrid System (WDHS) comprising a Diesel Generator (DG), a Wind Turbine Generator (WTG), the consumer Load, a Ni–Cd Battery based Energy Storage System (BESS) and a Distributed Control System (DCS). All the models of the previously mentioned components are presented and the performance of the WDHS is tested through simulation. Simulation results with graphs for frequency and voltage of the isolated power system, active powers generated/absorbed by the different elements and the battery voltage/current/state of charge are presented for negative load and wind speed steps. The negative load step reduces the load consumed power to a level less than the WTG produced power, so that to balance active powers a negative DG power is needed (DG reverse power). As the DG speed governor cannot control system frequency in a DG reserve power situation, it is shown how the DCS orders the BESS to load artificially the system until the DG power falls in a positive power interval. The negative wind step decreases the WTG produced power, returning the power system to a situation where the needed DG power returns to positive, so that the BESS is not needed to load the system.

Required time response of a variable valve actuator equiping a hybrid pneumatic–combustion engine

This work is a part of a research program that aims to modify a conventional internal combustion engine and turn it into a hybrid pneumatic–combustion engine. The hybrid pneumatic–combustion engine should be able to convert mechanical energy into compressed air and convert compressed air back into mechanical energy. The potential application for the concept is any use of the internal combustion engine where the load oscillates between a negative and a positive value, such as automobiles and hybrid wind diesel systems for remote area power generation. In the first application, during vehicle decelerations, an excess of power occurs, and a negative load could be applied to the engine, whereas during vehicle accelerations, a positive load is applied. In the second application, if the generated wind power is higher than consumption demand, then the load applied to the engine could be negative, and if the generated wind power is lower than consumption demand, then the load is positive. In previous work, we exposed an optimization followed by a fuel-saving evaluation of a new hybrid pneumatic–combustion engine concept that uses a variable valve actuator system. The optimization of the valve actuation was based on ideal thermodynamic cycle modeling, assuming therefore an instant response of the variable valve actuator system. In the present work, a more realistic analysis of the system is provided by taking into consideration the dynamic response of the variable valve actuator system. Variable valve actuators have been widely studied for optimizing performance and fuel consumption of the internal combustion engine, especially in spark-ignition engines. For these engines, it is possible to reduce the pumping losses and to optimize the engine filling by controlling the intake and exhaust valve opening and closing angles, as well as their lifts. However, the variation of valve actuation crank angles required in a conventional internal combustion engine is significantly smaller than the one required in the hybrid pneumatic–combustion engine. This paper describes, through simulation, how the valve time response affects the performance of the hybrid pneumatic–combustion engine and recommends a required valve time response.

Impact of battery storage on economics of hybrid wind-diesel power systems in commercial applications in hot regions

SUMMARY Integration of wind machines and battery storage with the diesel plants is pursued widely to reduce dependence on fossil fuels. The aim of this study is to assess the impact of battery storage on the economics of hybrid wind-diesel power systems in commercial applications by analyzing wind-speed data of Dhahran, East-Coast, Kingdom of Saudi Arabia (K.S.A.). The annual load of a typical commercial building is 620,000 kWh. The monthly average wind speeds range from 3.3 to 5.6 m/s. The hybrid systems simulated consist of different combinations of 100-kW commercial wind machines (CWMs) supplemented with battery storage and diesel generators. National Renewable Energy Laboratory's (NREL's) (HOMER Energy's) Hybrid Optimization Model for Electric Renewables (HOMER) software has been employed to perform the economic analysis. The simulation results indicate that for a hybrid system comprising of 100-kW wind capacity together with 175-kW diesel system and a battery storage of 4 h of autonomy (i.e. 4 h of average load), the wind penetration (at 37-m hub height, with 0% annual capacity shortage) is 25%. The cost of generating energy (COE, $/kWh) from this hybrid wind–battery–diesel system has been found to be 0.139 $/kWh (assuming diesel fuel price of 0.1$/L). The investigation examines the effect of wind/battery penetration on: COE, operational hours of diesel gensets. Emphasis has also been placed on un-met load, excess electricity, fuel savings and reduction in carbon emissions (for wind–diesel without battery storage, wind–diesel with storage, as compared to diesel-only situation), cost of wind–battery–diesel systems, COE of different hybrid systems, etc. The study addresses benefits of incorporation of short-term battery storage (in wind–diesel systems) in terms of fuel savings, diesel operation time, carbon emissions, and excess energy. The percentage fuel savings by using above hybrid system is 27% as compared to diesel-only situation Copyright © 2012 John Wiley & Sons, Ltd.

Consequences of Reducing the Cost of PV Modules on a PV Wind Diesel Hybrid System with Limited Sizing Components

The use of renewable resources for power supply in family homes has passed the stage of utopia to became a reality, with limits set by technical and economic parameters. This paper presents the results of a project originated from the initiative of a middle-class family to achieve energy independence at home. The starting point was the concept of home with “zero energy” in which the total energy available is equal to the energy consumed. The solution devised to meet the energy demand of the residence in question is a PV wind diesel hybrid system connected to the grid, with the possibility of energy storage in batteries and in the form of heating water and the environment of the house. As a restriction, the family requested that the system would represent little impact to the lifestyle and landscape. This paper aims to assess the consequences of reductions in the cost of the PV modules on the optimization space, as conceived by the software Homer. The results show that for this system, a 50% reduction in the cost of PV modules allows all viable solutions including PV modules.

A New Procedure in Reliability Assessment of Wind-Diesel Islanded Grids

High penetration of distributed generation in distribution networks makes the islanding operation more realistic. Because of environmental concerns and increasing fuel prices, the use of renewable energies, particularly wind energy, is becoming a popular choice. In this article, a new algorithm using the Monte Carlo technique and adaptive load shedding for assessing the reliability of wind–diesel systems in the islanding mode of operation is proposed. Weibull distribution and maximum likelihood estimation have been implemented to simulate the wind speed. Then, the islanding indices are introduced, and the reliability indices, when islanding operation is allowed and not allowed, are compared. Finally, a sensitivity analysis is performed to investigate the effects of wind and diesel capacity and the maximum wind to load penetration on the reliability and economic indices.

Multi-objective optimization minimizing cost and life cycle emissions of stand-alone PV–wind–diesel systems with batteries storage

This paper describes an application of the Strength Pareto Evolutionary Algorithm to the multi-objective optimization of a stand-alone PV–wind–diesel system with batteries storage. The objectives to be minimized are the levelized cost of energy (LCOE) and the equivalent carbon dioxide (CO 2) life cycle emissions (LCE). Each solution of the Pareto front is a possible solution for the PV–wind–diesel-batteries system, which can supply the load, but each one has a different LCOE and LCE. Some solutions have low LCOE values, but high LCE values, and vice versa. Results show that the photovoltaic (PV) generator is the most important source of electrical energy for stand-alone systems in Spain and Southern Europe, not only environmentally, but also economically. In some cases, PV is almost the only source of energy, as some solutions of the best Pareto front do not include wind turbines and diesel generators run only a few hours during the year.