Browsing by Author "Vaezi, Masoud"

Now showing 1 - 8 of 8
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    Control of a Hydraulic Wind Power Transfer System under Disturbances
    (IEEE, 2015-10) Vaezi, Masoud; Izadian, Afshin; Department of Engineering Technology, IU School of Engineering and Technology
    Hydraulic wind power transfer systems deliver the captured energy by the blades to the generators differently and through an intermediate medium i.e. hydraulic fluid. This paper develops a control system for a nonlinear model of hydraulic wind power transfer systems. To maintain a fixed frequency electrical voltage by the system, the generator should remain at a constant rotational speed. The fluctuating wind speed from the upstream applies considerable disturbances on the system. A controller is designed and implemented to regulate the flow in the proportional valve and as a consequence the generator maintains its constant speed compensating for low wind speed and high wind speed disturbances. The controller is applied to the system by utilizing MATLAB/Simulink.
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    Control of a Hydraulic Wind Power Transfer System under Wind Disturbance
    (Office of the Vice Chancellor for Research, 2014-04-11) Vaezi, Masoud; Izadian, Afshin
    The energy of wind can be transferred to the generator by employing a gearbox or through an intermediate medium such as hydraulic fluids. In this method, a high-pressure hydraulic system is utilized to transfer the energy produced from a wind turbine to a central generator. The speed control of wind driven hydraulic machinery is challenging, since the intermittent nature of wind imposes the fluctuation on the wind power generation and consequently varies the frequency of voltage. On the other hand, as the load of the generators increases, the frequency of the voltage drops. Therefore, hydraulically connected wind turbine and generator need to be controlled to maintain the frequency and compensate for the power demands. This poster introduces a closed loop control technique to maintain a constant frequency at the wind turbine generator. The governing equations of the renewable energy transfer system are derived and used to design the control system. The speed control profile obtained from a PI controller demonstrates a high performance speed regulation. The simulation results demonstrate the effectiveness of both the proposed model and the control technique.
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    Energy Storage Techniques for Hydraulic Wind Power Systems
    (IEEE, 2015-10) Vaezi, Masoud; Izadian, Afshin; Department of Engineering Technology, IU School of Engineering and Technology
    Hydraulic wind power transfer systems allow collecting of energy from multiple wind turbines into one generation unit. They bring the advantage of eliminating the gearbox as a heavy and costly component. The hydraulically connected wind turbines provide variety of energy storing capabilities to mitigate the intermittent nature of wind power. This paper presents an approach to make wind power become a more reliable source on both energy and capacity by using energy storage devices, and investigates methods for wind energy electrical energy storage. The survey elaborates on three different methods named “Battery-based Energy Storage”, Pumped Storage Method, and “Compressed Air Energy Storage (CAES)”.
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    Modeling and control of hydraulic wind power transfer systems
    (2014) Vaezi, Masoud; Izadian, Afshin; Anwar, Sohel; Zhu, Likun
    Hydraulic wind power transfer systems deliver the captured energy by the blades to the generators differently. In the conventional systems this task is carried out by a gearbox or an intermediate medium. New generation of wind power systems transfer the captured energy by means of high-pressure hydraulic fluids. A hydraulic pump is connected to the blades shaft at a high distance from the ground, in nacelle, to pressurize a hydraulic flow down to ground level equipment through hoses. Multiple wind turbines can also pressurize a flow sending to a single hose toward the generator. The pressurized flow carries a large amount of energy which will be transferred to the mechanical energy by a hydraulic motor. Finally, a generator is connected to the hydraulic motor to generate electrical power. This hydraulic system runs under two main disturbances, wind speed fluctuations and load variations. Intermittent nature of the wind applies a fluctuating torque on the hydraulic pump shaft. Also, variations of the consumed electrical power by the grid cause a considerable load disturbance on the system. This thesis studies the hydraulic wind power transfer systems. To get a better understanding, a mathematical model of the system is developed and studied utilizing the governing equations for every single hydraulic component in the system. The mathematical model embodies nonlinearities which are inherited from the hydraulic components such as check valves, proportional valves, pressure relief valves, etc. An experimental prototype of the hydraulic wind power transfer systems is designed and implemented to study the dynamic behavior and operation of the system. The provided nonlinear mathematical model is then validated by experimental result from the prototype. Moreover, this thesis develops a control system for the hydraulic wind power transfer systems. To maintain a fixed frequency electrical voltage by the system, the generator should remain at a constant rotational speed. The fluctuating wind speed from the upstream, and the load variations from the downstream apply considerable disturbances on the system. A controller is designed and implemented to regulate the flow in the proportional valve and as a consequence the generator maintains its constant speed compensating for load and wind turbine disturbances. The control system is applied to the mathematical model as well as the experimental prototype by utilizing MATLAB/Simulink and dSPACE 1104 fast prototyping hardware and the results are compared.
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    Modeling of a Hydraulic Wind Power Transfer Utilizing a Proportional Valve
    (IEEE, 2015-03) Deldar, Majid; Izadian, Afshin; Vaezi, Masoud; Anwar, Sohel; Department of Mechanical Engineering, School of Engineering
    Hydraulic circuits can transfer remarkable amounts of energy in the desired direction without taking large space. To implement this technology for harvesting the energy of wind appropriately, models of the system are required. Hydraulic wind power technology has the benefits of eliminating expensive and bulky variable ratio gearbox and its costly maintenance, while enabling the integration of multiple wind turbines in a single generation unit. In this paper, the dynamics of different hydraulic elements are studied, nonlinearities are taken into account, pressure dynamics in different parts of the system are studied, and the motor load effects are considered. Based on these considerations, a novel nonlinear state-space representation of the system is introduced. Results of the mathematical model and the experimental data are compared to verify the proposed model. The comparison demonstrated that the mathematical model captures all major characteristics of the hydraulic circuit and can model the system behavior under different operating conditions.
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    Nonlinear State Space Model of a Hydraulic Wind Power Transfer
    (Office of the Vice Chancellor for Research, 2013-04-05) Vaezi, Masoud; Deldar, Majid
    Gearless hydraulic wind power systems are considered as nonlinear models because of some discrete elements such as check valves, proportional and directional valves, and leakage factor of hydraulic pumps and motors. These Nonlinearities will result in behavioral change in the system. This poster introduces nonlinear governing equations for the elements in the proposed hydraulic wind power configuration. Nonlinear state space representation of a hydraulic wind energy transfer for a single wind turbine system is presented. Simulation results are in good agreement with the experimental verifications obtained from prototype. The simulation response demonstrates accurate modeling of the system operation and close tracking of the reference for all states, pressure and pelocity profiles.
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    Optimum Adaptive Piecewise Linearization: An Estimation Approach in Wind Power
    (IEEE, 2016-06) Vaezi, Masoud; Khayyer, Pardis; Izadian, Afshin; Electrical and Computer Engineering, School of Engineering and Technology
    This paper introduces an effective piecewise linearization technique to obtain an estimation of nonlinear models when their input-output domains include multidimensional operating points. The algorithm of a forward adaptive approach is introduced to identify the effective operating points for model linearization and adjust their domains for the maximum coverage and the minimum model linearization error. The technique obtains a minimum number of linearized models and the continuity of their domains. The algorithm also yields global minimum model linearization error. The introduced algorithm is formulated for a wind power transfer system for a 2-D set of input domains. The linearization error can be arbitrarily minimized in exchange for a higher number of models. The results demonstrate a significant improvement in the linearization of nonlinear models.
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    Piecewise Affine System Identification of a Hydraulic Wind Power Transfer System
    (IEEE, 2015-11) Vaezi, Masoud; Izadian, Afshin; Department of Engineering Technology, School of Engineering and Technology
    Hydraulic wind power transfer systems exhibit a highly nonlinear dynamic influenced by system actuator hysteresis and disturbances from wind speed and load torque. This paper presents a system identification approach to approximate such a nonlinear dynamic. Piecewise affine (PWA) models are obtained utilizing the averaged nonlinear models of hysteresis in a confined space. State-space representation of PWA models is obtained over the allocated operating point clusters. The experimental results demonstrate a close agreement with that of the simulated. The experimental results and simulation show more than 91% match.