Available online at www.sciencedirect.com Procedia Engineering 3 (0) 994 999 I-SEEC0 The Derivation of Efficiency Equation of the Prototype of Pico Wind Turbine Produces the Electricity S. Jugsujinda a*, P. Jugsujinda b, T. Seetawan a a Thermoelectrics Research Center, Faculty of Science and Technology, Sakon Nakhon Rajabhat University, 680 Nittayo Rd., Sakon Nakhon, 47000, Thailand b Sakonnakhonpattanasuksa School, 7 Itu Rd. Sakon Nakhon, 47000, Thailand Elsevier use only: Received 30 September 0; Revised 0 November 0; Accepted 5 November 0. Abstract This research has purposed to derive efficiency equation of the prototype of pico wind turbine produces the electricity (PPWTPE). By using a ventilating fan of cm diameter as a blower, at rotating speed of,880 rpm. Blower blew the wind to PPWTPE of alternator. The wind turbine of alternator modified from magnet motor of central processing unit fan of computer. Magnet motor composes of the cylindrical magnet 30 mm diameters, magnetic field intensity of 70 mt, 7 propellers of 74 mm diameter. These components were enclosed at the center of wind turbine rotate around copper line no.40 as 4 coils, each coil 550 turns. It shows that, the distance between blower and the pico wind turbine of 8 cm obtained the wind speed 7.4 m/s, the PPWTPE rotated of 855 rpm. The magnet was rotated around the 4 coils and induced the accelerating voltage of 4.9 volts and accelerating current 7.5 ma in 4 coils. The induced accelerating current from 4 coils sent AC signal to bridge rectifier circuit converts AC to DC obtained voltage of 3.60 V and DC current of 4.90 ma, and the 7 LED lamps were bright. By using a derived efficiency equation of the PPWTPE, the PPWTPE has estimate efficiency of 9 %. 00 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of I-SEEC0 Open access under CC BY-NC-ND license. Keywords: derivation of efficiency equation; pico wind turbine; electricity. Introduction At the end of 00, the total wind turbine would generate electrical power worldwide at 3,000 MW []. It was predicted that it would be,00 GWin 00. Wind energy technology development is focused on rated power, rotor diameter, hub height, potential annual and energy yield. The rated power of wind * Corresponding author. Tel.: +6-68-873-6595; fax: +6-604-97-095. E-mail address: suwitju@hotmail.com. 877-7058 0 Published by Elsevier Ltd. doi:0.06/j.proeng.0.0.044 Open access under CC BY-NC-ND license.
S. Jugsujinda et al. / Procedia Engineering 3 (0) 994 999 995 turbine was upgraded from 30 kw to 5 MW in 980 and 005 respectively with bigger rotor diameter and higher hub height. To improve a weak system, the wind turbine using synchronous generators are proposed with both woundfield and permanent magnet rotors, which they can control the output power factor []. The impact of induction wind turbine on voltage stability is mentioned in [3]. It shows that the voltage stability is affected by the capacity of wind turbine when connected to a weak network. Moreover, the power injected from a small wind turbine into a DC bus is presented in [4]. The concept is used for installing small windmills on their own properties to offset the load. Besides, the environmental issues of wind turbine are important when it located close to community [5]. In Thailand, the wind energy is applied typically for water pumping purposes in remote areas. In 983, the wind energy application for electricity generation was experimented by the Electricity Generation Authority of Thailand (EGAT) in Phuket province. Four small wind turbines: 8.5,, and 0.83 kw respectively were installed in a pilot station at Prom Thep Cape [6]. The result achieved indicated that the wind energy generation worked reasonably well. After that, in the early 990, the wind turbines were applied to connect to the grid system. This research will study a new way for create a pico wind turbine obtained generate electricity in easy practical. It is lowest cost by use materials which is easy to modify, finding in the marketplace, installed, and maintenance. To generate knowledge and the ways to improve and develop to increase the higher electrical generation power, increase higher efficiency and can be used as alternative energy sources in the future. Study and analyze technical information about pico wind turbine to generate electricity such as the speed of the wind turbine blade relate to induced current, induced voltage, the generate electrical power at different speed of wind turbine blade.. Materials and Methods Fig.. Pico wind turbine setup comprises (a) blower; (b, e, f) wind turbine and generator; (c, g) bridge rectifier circuit; and (d) lamp Pico wind turbine setup in Fig. comprises (a) blower performs to change electrical energy to wind energy and send the wind to wind turbine blade. (b) Wind turbine and generator performs to change wind energy to mechanical energy use for magnet rotor rotate the fixing copper coil. The rate of change of magnetic field from magnet rotation will generate induced current in fixing copper coil and sent it to bridge rectifier circuit. (c) Bridge rectifier circuit performs to change accelerating current to direct current and sent to LED lamp. (d) LED lamp performs to change electrical energy to light energy. The methodology is following;. Measure AC voltage and AC current are generated from generator at the location 4 cm length of each wind turbine frame that moving away from blower.. Use anemometer and Tachometer measured wind speed and wind turbine rotational rate (rpm) respectively, at 4 cm length of each wind turbine frame that moving away from the blower.
996 S. Jugsujinda et al. / Procedia Engineering 3 (0) 994 999 3. Theoretical analysis 3. Blower The blower sends wind energy to wind turbine blade. We will find wind power by starting from the definition of work. dw F dr d dt dw m dt v dr dt d m dt vvdt mdv v m( dvv) m( v dv dv v ) md ( v v) mdv W v dw m dv 0 0 W T mv () By using d/ dt operator operates upon (), we get wind power from blower act upon wind turbine blade. P W T m v () d d air dt dt air air air Finding m air of wind energy acts upon wind turbine blade from the definition of density. Take (3) in (): [ m ( ) V ( ) Al] d dt air air TC air TC d m m ( ) Av (3) air dt air air TC air ( ) 3 air air Av TC air P (4) The equation (4) is the wind power acts upon wind turbine blade. Find air density at 0 C and T C from m P 3 ( kg / m ) ( where M ) V RT (5) R gas cons tant 87.05 J / kg K, T ( T C73.5) K = absolute temperature Air pressure at 0 C ; P 035 Pa 03.5 mbar 0 Find air density at 0 C 035 Pa 0 ( air ) 0 C (87.05 J / kg K)(0 73.5) K 3.93 kg / m (6) Find air density at T C
S. Jugsujinda et al. / Procedia Engineering 3 (0) 994 999 997 ( ) T air TC 035 Pa 73.5 K (87.05 J / kg K)( T 73.5) K 73.5 K 73.5 ( T 73.5) 0 T Take (8) in (4), we get input as the wind power act upon wind turbine blade. 73.5 0 3 Pair Avair ( T 73.5) (7) (8) (9) 3. Wind turbine and generator The blower will send wind energy to wind turbine blade. The cylindrical magnet which sticks on the blade center will perform as magneto for rotating the cylindrical magnetic field around fixing copper field coil. From Faraday s law, the magnetic field of cylindrical magnet [as shown in Fig. (b)] change in time, induced generating voltage will produced in fixing 4 copper coils [as shown in Fig. (c)]. 3.3 Bridge rectifier circuit Bridge rectifier circuit [as shown in Fig. (c, g)] composes 4 diodes connected in bridge circuit in order to change AC to DC. Capacitor 0 V 000 μf connect parallel with load. 3.4 Lamp Lamp is a load resistance composes 7 LED lamps function to change DC from bridge rectifier circuit to light energy as shown in Fig. (d). Electrical power output from pico wind turbine by measuring AC voltage and AC current when it has load sent to the 7 LED lamps. From the definition of power is PV I and find the wind turbine efficiency from the definition of efficiency is AC AC output Efficiency 00% (0) input ( T 73.5 K) V I 00% () (73.5 K) Av 0 AC AC 3 air
998 S. Jugsujinda et al. / Procedia Engineering 3 (0) 994 999 4. Results and discussions Fig.. (a) The relationship between wind speed and electrical power from wind turbine generator.; (b) The relationship between wind speed, AC current, AC voltage, and the efficiency of wind turbine Put the wind turbine frame at 0 cm from blower. Blower generates wind speed at 8.40 m/s and sent the wind to wind turbine to make rotation at a rate of rotation of 906.76 rpm. In second measurement, move a wind turbine frame away from the blowers 4 cm wind speed value is 7.55 m/s and wind turbine will rotate at a rate 87.46 rpm. The measured relationship between wind speeds of 4 cm length of each wind turbine frame and then moving away from the blower and wind turbine rotational rate of each. Take the wind speed and power that had produced to plot graph as in Fig. (a), we found from the direct inspection that when the wind speed increases electrical generator will increase nearly linear. We summarize that the generation electrical power is directly proportional to wind speed, but when the wind speed value 7.55 m/s and 8.4 m/s electrical power will produced by increasing to 96 and 49 mw, respectively as shown in Fig. 8. The slope of this graph in this interval increased by approximately times of the linear graph in the first period that wind speed is in interval 3.86-7.4 m/s. Take the wind speed, AC voltage, AC current, and the efficiency in electrical generation of wind turbine to plot graph as in Fig. (b). The wind turbine produces electricity has estimate efficiency 9 %. This research is a prototype of pico wind turbine and the beginning to bring a pico wind turbine to produce electricity in Thailand and the development of pico wind turbine for electrical generation in Thailand. 5. Conclusion Pico wind turbine in this research has estimate efficiency 9 % and also work under the influence of wind from the blower that sent the wind speed 3.86 8.40 m/s to wind turbine blade. Wind turbine rotates cylindrical magnetic field around the fixing copper coil which induced electrical voltage 3.8 5.5 V, induced current.6 45.3 ma, and give the induced electrical power 8.6 50 mw at fixing copper coil. Pico wind turbine can produce electricity and sent electrical energy to open the LED lamps for using as alternative energy source, for decreased electricity, respond to the government's policy that economize the using electrical power down.
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