Model simplification and optimization of a passive wind turbine generator

In this paper, the design of a "low cost full passive structure" of wind turbine system without active electronic part (power and control) is investigated. The efficiency of such device can be obtained only if the design parameters are mutually adapted through an optimization design approach. For this purpose, sizing and simulating models are developed to characterize the behavior and the efficiency of the wind turbine system. A model simplification approach is presented, allowing the reduction of computational times and the investigation of multiple Pareto-optimal solutions with a multiobjective genetic algorithm. Results show that the optimized wind turbine configurations are capable of matching very closely the behavior of active wind turbine systems which operate at optimal wind powers by using a MPPT control device

Battery sizing for a stand alone passive wind system using statistical techniques

In this paper, an original optimization method to jointly determine a reduced study term and an optimum battery sizing is investigated. This storage device is used to connect a passive wind turbine system with a stand alone network. A Weibull probability density function is used to generate different wind speed data. The passive wind system is composed of a wind turbine, a permanent magnet synchronous generator feeding a diode rectifier associated with a very low voltage DC battery bus. This study is essentially based on a similitude model applied on an 8 kW wind turbine system. Our reference model is taken from a 1.7 kW optimized system. The wind system generated power and the load demand are coupled through a battery sized using a statistical approach

Optimization of a small passive wind turbine generator with multiobjective genetic algorithms

In this paper Multiobjective Genetic Algorithms (MOGAs) are used for the design of a small wind turbine generator (WTG) coupled to a DC bus through a diode bridge. The originality of the considered system resides in the suppression of the Maximum Power Point Tracker (MPPT). The poor efficiency of the corresponding passive structure is considerably improved by optimizing the generator characteristics associated with the wind turbine in relation to the wind cycle. The optimized configurations are capable of matching very closely the behavior of active wind turbine systems which operate at optimal wind powers by using a MPPT control device

Integrated optimal design and sensitivity analysis of a stand alone wind turbine system with storage for rural electrification

In this paper, the authors investigate a robust Integrated Optimal Design (IOD) devoted to a passive wind turbine system with electrochemical storage bank: this stand alone system is dedicated to rural electrification. The aim of the IOD is to find the optimal combination and sizing among a set of system components that fulfils system requirements with the lowest system Total Cost of Ownership (TCO). The passive wind system associated with the storage bank interacts with wind speed and load cycles. A set of passive wind turbines spread on a convenient power range (2 – 16 kW) are obtained through an IOD process at the device level detailed in previous papers. The system cost model is based on data sheets for the wind turbines and related to battery cycles for the storage bank. From the range of wind turbines, a “system level” optimization problem is stated and solved using an exhaustive search. The optimization results are finally exposed and discussed through a sensitivity analysis in order to extract the most robust solution versus environmental data variations among a set of good solutions

Synthesis of a compact wind profile using evolutionary algorithms for wind turbine system with storage

In this paper, the authors investigate two methodologies for synthesizing compact wind speed profiles by means of evolutionary algorithms. Such profile can be considered as input parameter in a prospective design process by optimization of a passive wind system with storage. Compact profiles are obtained by aggregating elementary patterns in order to fulfil some target indicators. The main difference between both methods presented in the paper is related to the choice of these indicators. In the first method, they are related to the storage system features while they only depend on wind features in the second

From an integrated optimal design to a systemic optimization of a stand alone passive wind turbine system with storage

In this paper, the authors report the development of a Systemic Optimization Process (SOP) devoted to a passive wind turbine system with electrochemical storage bank. Aim of the SOP is to find the optimal combination and sizing among sets of system components, that meets the desired system requirements with the lowest system owning cost. The passive wind system associated to the storage bank interacts with wind and load cycles (deterministic data). Sets of passive wind turbines are obtained through an Integrated Optimal Design (IOD) process. The system cost model is inspired from constructor data for the wind turbines and related to the battery cycles for the storage bank. An optimization problem is developed and performed using an exhaustive search. The optimization results are finally exposed and discusse

Synthesis of compact wind profiles using evolutionary algorithms

In this paper, the authors face the problem of wind speed processing as environmental variable of a wind turbine system. Generally, the information on wind speed measurements is processed over long periods of time to be relevant with respect to the site characteristics (average and maximum speeds, statistics). Subsequent large scale profiles of wind speed lead to long processing time for simulation analysis and especially for optimization design that penalizes the search of optimal solutions. An original synthesis approach of a compact and representative wind speed profile using an Evolutionary Algorithm (EA) is proposed. This approach is compared to a purely statistical approach based on random number generators. It allows reducing the actual wind profile duration with compression ratios greater (two months of wind speed measurements are compressed in only 1 hour). Then, the synthesis approach by EA is applied to the sizing of an autonomous hybrid system based on wind turbine with battery storage for stand-alone energy systems. It has proven its effectiveness in reducing 200 days of wind speed measurements in only 10 days, allowing sizing the storage system with a significant gain in terms of computing time in the framework of the optimization process

Optimization of a small passive wind turbine based on mixed Weibull-turbulence statistics of wind

A "low cost full passive structure" of wind turbine system is proposed. The efficiency of such device can be obtained only if the design parameters are mutually adapted through an optimization design approach. An original wind profile generation process mixing Weibull and turbulence statistics is presented. The optimization results are compared with those obtained from a particular but typical time cycle of wind speed

An iterative method for selecting decision variables in analytical optimization problem

In this paper, we present an iterative method to assist the designer in the setting of decision variables in an optimization problem with analytical models. This method is based on the Design Structure Matrix (DSM) which allows a clear representation of interactions between variables. Such a process becomes particularly useful for complex optimal design for which choosing the right decision variables to efficiently solve the problem is not so trivial. This approach is applied to the geometrical model of a High Speed Permanent Magnet Synchronous Machine (HSPMSM

Hardware-in-the-loop simulations and control design for a small vertical axis wind turbine

Control design plays an important role in wind energy conversion systems in achieving high efficiency and performance. In this study, hardware-in-the-loop (HIL) simulations are carried out to design a maximum power point tracking (MPPT) algorithm for small vertical axis wind turbines (VAWTs). Wind torque is calculated and applied to an electrical motor that drives the generator in the HIL simulator, which mimics the dynamics of the rotor. To deal with disturbance torques in the HIL system, a virtual plant is introduced to obtain an error between the speeds in the HIL system and virtual plant. This error is used by a proportional-integral (PI) controller to generate a disturbance torque compensation signal. The MPPT algorithm is tested in the HIL simulator under various wind conditions, and the results are compared with numerical simulations. The HIL simulator successfully mimics the dynamics of the VAWT under various wind conditions and provides a realistic framework for control designs