Wind direction and wind velocity measuring apparatus for wind turbine, and device and method for controlling yaw angle of wind turbine by using same
A technical object of the present disclosure is to provide an anemometer for a wind turbine which is capable of precisely measuring a wind velocity and a wind direction. To this end, an anemometer for a wind turbine of the present disclosure is an anemometer for a wind turbine which is used for a wind turbine including a plurality of rotating blades and a hub which is equipped at a rotation center of the plurality of rotating blades and has a nosecone and is equipped in the nosecone.
1. An anemometer for a wind turbine which is used for a wind turbine including a plurality of rotating blades and a hub which is equipped at a rotation center of the plurality of rotating blades and has a nosecone,
wherein the anemometer is equipped in the nosecone; and
wherein the anemometer comprises:
a first ultrasonic sensor which oscillates a first ultrasonic wave and receives a second ultrasonic wave;
a second ultrasonic sensor which oscillates the second ultrasonic wave and receives the first ultrasonic wave;
a third ultrasonic sensor which oscillates a third ultrasonic wave in a first direction intersecting the first ultrasonic wave and receives a fourth ultrasonic wave in a second direction opposing to the first direction; and
a fourth ultrasonic sensor which oscillates the fourth ultrasonic wave in the second direction and receives the third ultrasonic wave in the first direction,
wherein the first and second ultrasonic sensors measure a first wind velocity in a same direction as a transmitting direction of the first ultrasonic wave and
the third and fourth ultrasonic sensors measure a second wind velocity in a same direction as a transmitting direction of the third ultrasonic wave.
2. The anemometer according to claim 1 , further comprising:
a support unit which supports the first, second, third, and fourth ultrasonic sensors to the nosecone,
wherein the first, second, third, and fourth ultrasonic sensors, the support unit, and a rotary shaft of the hub are disposed on one plane.
3. The anemometer according to claim 2 , wherein the support unit includes:
a center support shaft which is equipped in the nosecone to be disposed to coincide with an axial direction of the rotary shaft;
a first support member which is branched at a distal end of the center support shaft and supports the first ultrasonic sensor and the fourth ultrasonic sensor; and
a second support member which is branched at a distal end of the center support shaft and supports the second ultrasonic sensor and the third ultrasonic sensor.
4. The anemometer according to claim 3 , wherein the first support member includes:
a first branching unit branched at the center support shaft; and
a first mounting unit which is equipped at a distal end of the first branching unit and supports the first ultrasonic sensor and the fourth ultrasonic sensor at ends of the first mounting unit, and
the second support member includes:
a second branching unit branched at the center support shaft; and
a second mounting unit which is equipped at a distal end of the second branching unit and supports the second ultrasonic sensor and the third ultrasonic sensor at ends of the second mounting unit.
5. The anemometer according to claim 4 , wherein an anti-freezing hot wire is equipped in each of the first and second mounting units.
6. The anemometer according to claim 3 , wherein the transmitting direction of the first ultrasonic wave and the transmitting direction of the third ultrasonic wave are disposed on a same line, as seen from the direction of the rotary shaft.
7. A yaw angle control apparatus of a wind turbine using the anemometer according to claim 1 , comprising:
an arithmetic unit which calculates a velocity of an axial wind blowing in an axial direction of the rotary shaft of the hub and a velocity of a cross wind blowing in a direction which is perpendicular to the rotary shaft and is horizontal with a ground using the first and second wind velocities measured by the anemometer; and
a control unit which controls a yaw angle of the rotary shaft using the velocity of the cross wind calculated by the arithmetic unit.
8. The yaw angle control apparatus according to claim 7 wherein the arithmetic unit calculates the velocity of the axial wind and the velocity of the cross wind using the following Equations 1 and 2,
{right arrow over ( U 1)}= {right arrow over (U)} ×cos θ+( {right arrow over (V)} ×cos ϕ+ {right arrow over (W)} ×sin ϕ)=sin θ
{right arrow over ( U 2)}× {right arrow over (U)} ×cos θ−( {right arrow over (V)} ×cos ϕ+ {right arrow over (W)} ×sin ϕ)=sin θ [Equation 1]
in which {right arrow over (U1)} is the first wind velocity measured by the anemometer, {right arrow over (U2)} is the second wind velocity measured by the anemometer, θ is a half an angle between {right arrow over (U1)} and {right arrow over (U2)}, and ϕ is a rotation angle of the nosecone and when {right arrow over (U1)} and {right arrow over (U2)} are parallel to the ground, ϕ is “zero” degree, and
{right arrow over (U)} =({right arrow over ( U 1)}+{right arrow over ( U 2)})/(2×cos θ)
{right arrow over (V)} =({right arrow over ( U 1)}−{right arrow over ( U 2)})/(2×cos ϕ×sin θ)− {right arrow over (W)} ×tan ϕ [Equation 2]
in which {right arrow over (U)} is the velocity of the axial wind, {right arrow over (V)} is the velocity of the cross wind, and {right arrow over (W)} is a velocity of a vertical wind blowing in a direction perpendicular to the ground.
9. The yaw angle control apparatus according to claim 8 , wherein as the velocity {right arrow over (V)} of the cross wind, an average value when ϕ is “0” degree and “180” degrees is used.
10. The yaw angle control apparatus according to claim 7 , wherein the control unit is configured to perform operations including:
determining whether an absolute value of the velocity of the cross wind is smaller than an allowable reference value; and
adjusting the yaw angle when the absolute value of the velocity of the cross wind is equal to or larger than the reference value.
11. The yaw angle control apparatus according to claim 10 , wherein in the adjusting of the yaw angle, the yaw angle of the rotary shaft is controlled such that a magnitude of the velocity of the cross wind is reduced.
12. The yaw angle control apparatus according to claim 10 , wherein the control unit is configured to perform operations further including:
starting adjusting a pitch angle of a blade so as to interwork with the axial wind when the absolute value of the velocity of the cross wind is smaller than the reference value.
13. A yaw angle control method of a wind turbine using the yaw angle control apparatus of a wind turbine according to claim 7 , the method comprising:
measuring the first and second wind velocities;
calculating the velocity of the axial wind and the velocity of the cross wind using the measured first and second wind velocities; and
controlling a yaw angle of the rotary shaft using the calculated velocity of the cross wind.
14. The yaw angle control method according to claim 13 , wherein in the calculating, the velocity of the axial wind and the velocity of the cross wind are calculated using the following Equations 1 and 2,
{right arrow over ( U 1)}= {right arrow over (U)} ×cos θ+( {right arrow over (V)} ×cos ϕ+ {right arrow over (W)} ×sin ϕ)=sin θ
{right arrow over ( U 2)}× {right arrow over (U)} ×cos θ−( {right arrow over (V)} ×cos ϕ+ {right arrow over (W)} ×sin ϕ)=sin θ [Equation 1]
in which {right arrow over (U1)} is the first wind velocity measured by the anemometer, {right arrow over (U2)} is the second wind velocity measured by the anemometer, θ is a half an angle between {right arrow over (U1)} and {right arrow over (U2)}, and ϕ is a rotation angle of the nosecone and when {right arrow over (U1)} and {right arrow over (U2)} are parallel to the ground, ϕ is “zero” degree, and
{right arrow over (U)} =({right arrow over ( U 1)}+{right arrow over ( U 2)})/(2×cos θ)
{right arrow over (V)} =({right arrow over ( U 1)}−{right arrow over ( U 2)})/(2×cos ϕ×sin θ)− {right arrow over (W)} ×tan ϕ [Equation 2]
in which {right arrow over (U)} is the velocity of the axial wind, {right arrow over (V)} is the velocity of the cross wind, and {right arrow over (W)} is a velocity of a vertical wind blowing in a direction perpendicular to the ground.
15. The yaw angle control method according to claim 14 , wherein as the velocity {right arrow over (V)} of the cross wind, an average value when ϕ is “0” degree and “180” degrees is used.
16. The yaw angle control method according to claim 13 , wherein the controlling includes:
determining whether an absolute value of the velocity of the cross wind is smaller than an allowable reference value; and
adjusting the yaw angle when the absolute value of the velocity of the cross wind is equal to or larger than the reference value.
17. The yaw angle control method according to claim 16 , wherein in the adjusting of the yaw angle, the yaw angle of the rotary shaft is controlled such that a magnitude of the velocity of the cross wind is reduced.
18. The yaw angle control method according to claim 16 , wherein the controlling further includes:
starting adjusting a pitch angle of a blade so as to interwork with the axial wind when the absolute value of the velocity of the cross wind is smaller than the reference value.
19. A yaw angle control apparatus of a wind turbine using the anemometer according to claim 2 , comprising:
an arithmetic unit which calculates a velocity of an axial wind blowing in an axial direction of the rotary shaft of the hub and a velocity of a cross wind blowing in a direction which is perpendicular to the rotary shaft and is horizontal with a ground using the first and second wind velocities measured by the anemometer; and
a control unit which controls a yaw angle of the rotary shaft using the velocity of the cross wind calculated by the arithmetic unit.