Sm all-scaled wind turbine is converted to mechanical power of windmill to electric power by generator. However almost all studies seems to have overlooked converting relation of mechanical & electric power. It the reason for was very difficult establishing wind turbine system. In this paper, it is define equation of converting relation of mechanical & electric power. And it is verified by experimental methods. Defined equation will be used in developing electric devices such as inverter and controller in wind turbines. In addition this method can be used in the fields that utilize the rotational power into electrical power through generator.
Recently, there has been a dramatic increase in attention amongst advanced countries paid to environment-friendly energy source due to depletion of fossil energy and environ- mental issues. Also, there is an urgent need for studies on photovoltaic power generation and wind power generation upon micro grid activation. Particularly, studies on commercialization of small wind power generator are actively conducted as there was an increase in use due to its simple structure, convenient maintenance, and low installation cost.
This paper defines in Equations the relation in which mechanical energy of windmill is converted into electric energy from wind power generator. Also, the accuracy of defined Equations is verified by measuring mechanical power of windmill and electric power of generator when windmill rotates the power generator through gearbox at certain wind speed in simple wind tunnel experiment.
Small wind power generator in this paper was examined for the application to photovoltaic power generation associated hybrid streetlight illustrated in
Wind power
Although many parameters do exist as main specification of power generator including voltage, power, RPM (number of rotations),
Equations (5) illustrates voltage dip (
When
Mechanical power is defined as torque and RPM (rotation per minute) of Equations (3) and electric power is defined as current and voltage as Equations (7). Therefore, in order convert mechanical power into electric power, torque shall be converted into current and RPM shall be changed into voltage. The relation between RPM and voltage can be defined with Equations (10) with the use of Equations (4) and Equations (6).
However, there is no interaction Equations of torque and current and Equations (10) is also incomplete as current I is included in the expression.
When there is a decrease in
Since current is constant regardless of efficiency based on conservation law of electric charge, electric power
Vertical wind power generator in this paper is in structure where diameter of windmill can be changed accordingly with the placement of wings and power generation is conducted with gearbox generator. Wind power generation experiment device composed of wind power generator and simple wind tunnel is as illustrated in
Mechanical power experiment device can collect data on RPM of windmill and torque at certain wind speed and display mechanical power curve as illustrated in
Mechanical power test and electric power test were conducted with wind power generator applied in this experiment after classification of 4 cases as shown in
It was verified that highly precise inference can be made from experiment result of
This paper has proposed interaction Equations in which mechanical energy of windmill is converted into electric energy of power generator with the use of wind power theory, power generator theory, conservation of energy principle, conservation law of electric charge and the accuracy was examined through wind tunnel experiment. Reliability was verified as power curve by experiment and inference presented the same trend.
Case | Blade position | Generator |
---|---|---|
CASE 1 | Φ1180, | SYG-208-B-100-135 ( |
CASE 2 | Φ1540 | SYG-208-B-100-135 ( |
CASE 3 | Φ1180, | SYG-208-R-200-300 ( |
CASE 4 | Φ1540, | SYG-208-R-200-300 ( |
Voltage (V) | Current (A) | Max. Power (W) | RPM-Power fitting function ( | |||
---|---|---|---|---|---|---|
a | b | c | ||||
1 step | 51.44 | 0.11 | 5.75 | −0.00336 | 0.345636 | −3.13853 |
2 step | 58.59 | 0.17 | 10.01 | −0.00467 | 0.546838 | −6.01018 |
3 step | 71.43 | 0.24 | 17.08 | −0.00447 | 0.638054 | −5.71139 |
4 step | 91.81 | 0.41 | 37.21 | −0.00492 | 0.902811 | −4.23092 |
5 step | 105.1 | 0.54 | 56.67 | −0.00578 | 1.214972 | −7.17861 |
6 step | 105.77 | 0.55 | 58.46 | -0.00564 | 1.192904 | −4.6289 |
Voltage (V) | Current (A) | Max. Power (W) | RPM-Power fitting function ( | |||
---|---|---|---|---|---|---|
a | b | c | ||||
1 step | 52 | 0.13 | 6.82 | −0.0029 | 0.2974 | −0.9153 |
2 step | 59.83 | 0.19 | 11.26 | −0.0033 | 0.3939 | −0.5269 |
3 step | 73.87 | 0.27 | 19.83 | −0.0042 | 0.6178 | −2.9899 |
4 step | 91.06 | 0.44 | 40.05 | −0.0049 | 0.8911 | −0.5184 |
5 step | 104.8 | 0.54 | 56.49 | −0.005 | 1.0433 | 1.8251 |
6 step | 107.2 | 0.57 | 60.69 | −0.0053 | 1.1329 | −0.0287 |
Defined interaction Equations can stipulate the transmission relation of mechanical and electric system. Therefore, it can not only estimate power generating traits for the development of small wind power generation system but also be utilized for development of inverter or controller. Also, it could be applicable for all sectors in which rotation energy is converted into electric energy such as small hydraulic or tidal power generation.
This research was financially supported by Changwon National University in 2016, Korea.
Lee, K.-J., Yang, H.-D., Park, S.-H., Song, S.-D., Kim, B.-S. and Shin, J.-H. (2016) Characteristics of Me- chanical and Electrical Power Transmission for Small-Scaled Wind Turbine. World Jour- nal of Engineering and Technology, 4, 82-90. http://dx.doi.org/10.4236/wjet.2016.43D011