scholarly journals Optimal Control of the Positional Electric Drive and Its Implementation

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 70
Author(s):  
Vladimir Dotsenko ◽  
Roman Prokudin ◽  
Alexander Litvinenko

The article deals with the optimal control of the positional electric drive of the stator element of a segment-type wind turbine. The calculation options charts current in the assumption of the minimum energy consumption and the implementation of line chart current using the phenomenon of capacitor discharge. The analysis of the implementation is expressed in a jump-like change in current and a triangular graph of the speed change. This article deals with small capacity synchronous wind turbine generators with a segment type stator. These units have the possibility of intentionally changing the air gap between the rotor and stator. This allows: (1) Reduce the starting torque on the rotor shaft, which will allow the rotor to pick up at low wind speeds. (2) Equivalent to change of air gap in this case is change of excitation of synchronous generators. Thus, the purpose of the article is to consider a method of excitation of generators in a segmented design, by controlling the gap with the electric drive, while providing control should be carried out with minimal losses.

2020 ◽  
Vol 37 ◽  
pp. 63-71
Author(s):  
Yui-Chuin Shiah ◽  
Chia Hsiang Chang ◽  
Yu-Jen Chen ◽  
Ankam Vinod Kumar Reddy

ABSTRACT Generally, the environmental wind speeds in urban areas are relatively low due to clustered buildings. At low wind speeds, an aerodynamic stall occurs near the blade roots of a horizontal axis wind turbine (HAWT), leading to decay of the power coefficient. The research targets to design canards with optimal parameters for a small-scale HAWT system operated at variable rotational speeds. The design was to enhance the performance by delaying the aerodynamic stall near blade roots of the HAWT to be operated at low wind speeds. For the optimal design of canards, flow fields of the sample blades with and without canards were both simulated and compared with the experimental data. With the verification of our simulations, Taguchi analyses were performed to seek the optimum parameters of canards. This study revealed that the peak performance of the optimized canard system operated at 540 rpm might be improved by ∼35%.


2021 ◽  
Vol 25 (1) ◽  
pp. 41-48
Author(s):  
Stanisław Chudzik

The article presents the results of research into the operation of a model of a wind micropower plant with a variable blade angle. The research was carried out on a miniature model of a measuring stand built for the purpose of carrying out work on pre-developed projects of wind micro power plants. The stand allows to carry out measurements related to the selection of the optimal propeller geometry, as well as the development and testing of algorithms for optimal control of the micropower plant. The physical basics of wind turbine operation and the methods of its optimal control are presented. The results of the performed measurements for the selected propeller blade geometry with the possibility of changing its setting angle are presented. A DC generator with a load with a non-linear characteristic in the form of a Li-Po battery cell was used. The results of operation of a simple MPPT control algorithm are presented. The lack of optimal control systems for the operation of micropower plants is dictated by the general belief that the costs of its production are high in relation to the possible improvement of the efficiency of micropower plants. Moreover, the practical methods of controlling larger wind turbines are not optimal for small and very small turbines. The conducted research focused on determining the possibility of using turbines with variable blade angles depending on its rotational speed. In larger wind farms, changing the blade angle is mainly used to limit the power of the turbine at high wind speeds. In micro wind power plants such solutions are not used for economic reasons. However, the use of a simple mechanism for changing the angle of the blades depending on the rotational speed of the propeller can increase the efficiency of the turbine in a wider range of wind speeds. The small dimensions of the research model allow for quick and cheap development of preliminary prototypes of turbine blades thanks to the possibility of using 3D printing technology.


2020 ◽  
Vol 1 (2) ◽  
pp. 61-67
Author(s):  
Mohammad Rizqi Saputra ◽  
Nur Kholis ◽  
Mohammad Munib Rosadi

Abstract Wind is a renewable mechanical energy source that can be used as an energy source because the energy from the wind can be used to drive wind turbines. Savonius wind turbine type L is a tool to convert wind energy into electricity with a simple construction and can work with low wind speeds. The purpose of this study was to determine the effect of differences in diameter and number of blades on the power produced. The method used is a simulation method with an artificial wind source. With a wind speed of 8 m/s. The data analysis technique used is 2-way ANOVA using the SPSS application. Variations used are 20 cm and 40 cm in diameter and the number of blades 2 and 4 . The result is a wind turbine with a variation of 40 cm and 4 blades capable of producing the best output which produces 350.98 RPM voltage of 11.64 volts current of 0.144 amperes and power of 1,676 watts. As for BHP, torque, and turbine efficiency with a variation of 40 cm and 4 blades capable of producing the best output where the generated BHP is 3.352 watts, torque 0.091 N / m efficiency 2.17. For the results of calculations with SPSS wind turbines with a diameter variation of 40 cm and 4 blades, the biggest power is 1,744 watts and for BHP produces 3.3520 watts and the efficiency reaches 2.17%. Keyword : Diameter, number of blade, Performance Abstrak Angin adalah sumber energi mekanik yang bisa diperbaharui sehingga dapat dimanfaatkan sebagai sumber energi karena dapat digunakan untuk menggerakkan turbin angin. Turbin angin savonius tipe L merupakan alat untuk mengubah energi angin menjadi listrik dengan konstruksi yang sederhana dan dapat bekerja dengan kecepatan angin yang rendah. Tujuan penelitian ini untuk mengetahui pengaruh perbedaan diameter dan jumlah sudu terhadap unjuk kerja yang dihasilkan. Metode yang digunakan adalah metode simulasi dengan sumber angin buatan. Dengan kecepatan angin 8 m/s. Teknik analisis data yang digunakan adalah ANOVA 2 arah dengan menggunakan aplikasi SPSS. Variasi yang digunakan adalah diameter 20 cm dan 40 cm serta jumlah sudu 2 dan 4. Hasilnya turbin angin dengan variasi 40 cm dan 4 sudu mampu menghasilkan output terbaik yang dimana menghasilkan RPM 350,98 tegangan 11,64 volt arus 0,144 ampere dan daya 1,676 watt. Sedangkan untuk BHP, torsi, dan efisensi turbin dengan variasi 40 cm dan 4 sudu mampu menghasilkan output yang terbaik dimana BHP yang dihasilkan adalah 3,352 watt, torsi 0,091 N/m efisisensi 2,17. Untuk hasil perhitungan dengan SPSS turbin angin dengan variasi diameter 40 cm dan 4 sudu menghasilkan daya terbesar yakni 1,744 watt dan untuk BHP menghasilkan 3,3520 watt dan efisiensinya mencapai 2,17 % untuk torsi tertinggi dicapai turbin variasi 40 cm 2 sudu dengan torsi 0,116.   Kata kunci : diameter, jumlah sudu, unjuk kerja


2021 ◽  
pp. 66-71
Author(s):  
NIKOLAY V. TSUGLENOK ◽  

The authors have determined the conditions for the eff ective use of modern electrifi ed circular sprinklers in the central part of Russia. Their designs are chosen depending on the agrotechnical requirements for irrigation, including the change in the diameter of the water distribution pipeline. However, when the diameter of the pipeline changes, the load on the electric drive of the support trolleys of the sprinkler changes too, which leads to a corresponding change in energy consumption. In turn, this also changes the load of the water supply pump. The paper sets the task of determining the optimal change in the diameter of pipelines according to the criterion of minimum energy consumption, taking into account a number of assumptions. The authors have analyzed the relationship between the change in the load on the electric drive of the sprinkler support trolley and the change in the diameter of one sprinkler section pipeline. It has been found that a decrease in the diameter by 27% (for example, the transition of the diameter of 219 mm to the diameter of 159 mm) leads to a decrease in the load on the electric drive by 38%. However, this also leads to an increase in the head loss in the water supply pump motor and, respectively, to an increase in the load and energy consumption by 0.8…3.8%. The eff ect is initially obvious, but the power of the electric motor of the water supply pump is 10…25 times higher than that of the electric motor of the sprinkler support trolley. Based on the similarity coeffi cients of the irrigation components (water supply and water distribution), the relationship beteween the total energy consumption and the change in the diameter of the water distribution pipeline has been obtained. By diff erentiating the obtained function, the dependence of the value of the optimal diameter for specifi c operating conditions is also obtained. Graphs of the relationship between energy consumption and the change in diameter have been determined, taking into account some restrictions: pump supply, static pressure, and the number of the sprinkler sections.


2021 ◽  
Vol 104 ◽  
pp. 83-88
Author(s):  
Rahmat Wahyudi ◽  
Diniar Mungil Kurniawati ◽  
Alfian Djafar

The potential of wind energy is very abundant but its utilization is still low. The effort to utilize wind energy is to utilize wind energy into electrical energy using wind turbines. Savonius wind turbines have a very simple shape and construction, are inexpensive, and can be used at low wind speeds. This research aims to determine the effect of the slot angle on the slotted blades configuration on the performance produced by Savonius wind turbines. Slot angle variations used are 5o ,10o , and 15o with slotted blades 30% at wind speeds of 2,23 m/s to 4,7 m/s using wind tunnel. The result showed that a small slot angle variation of 5o produced better wind turbine performance compared to a standard blade at low wind speeds and a low tip speed ratio.


2016 ◽  
Vol 84 (4) ◽  
pp. 2435-2445 ◽  
Author(s):  
Abderrahmen Mechter ◽  
Karim Kemih ◽  
Malek Ghanes

Author(s):  
Sivamani Seralathan ◽  
Micha Premkumar Thomai ◽  
Rian Leevinson Jayakumar ◽  
Basireddy Venkata Lokesh Reddy ◽  
Hariram Venkatesan

Abstract Due to increase in energy demand along with environmental awareness, the attention is shifting towards renewable energy sources. A wind turbine developed from Banki water turbine is used in this study as it starts at low-wind speeds and has high starting torque. Experimental investigations are carried out on a test rig equipped with open jet wind tunnel with wind velocity varying from 7 to 11 m/s. Later, 3D steady-state numerical analyses are performed using ANSYS CFX for better understanding of the flow physics of cross flow VAWT. The experimental investigations revealed that cross flow VAWT has a good self-starting ability at relatively low-wind speeds. A peak power coefficient (Cp, max) value of 0.059 is observed for the tip speed ratio (λ) of 0.30. As the tip speed ratio is raised further, the Cp value is observed to decrease gradually. The numerical simulations reveal the reason for the drop in Cp value. This is due to lessening of positive interaction between the flow and cross flow VAWT blades at higher λ due to vortex formation. The torque coefficient is found to decrease almost linearly from a peak value of around 0.49 at λ = 0 to a value of 0 around λ = 0.60. Polar plot between angle and torque shows that torque output of the turbine is nearly same in all directions which reinforce the potency of cross flow VAWT to be omni-directional as it produces the same performance regardless of wind directions.


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