Solar tracker having brake function

Abstract

A solar tracker having a brake function is disclosed. The solar tracker according to an embodiment of the present invention relates to a technology having a dual position sensing device provided at a part at which altitude adjustment and horizontal rotation of a solar collector plate respectively end, such that a brake is accurately operated for a driving motor, which is respectively in charge of altitude adjustment and horizontal rotation.

Claims

1. A solar tracker having a brake function, comprising: a horizontal rotation portion which comprises a horizontal driving motor configured to horizontally rotate a solar photovoltaic panel, a horizontal actuator comprising a horizontal rotor coupled with the horizontal driving motor, and a horizontal limit control and position sensing circuit comprising first and second horizontal cut-off switches and first and second horizontal contact switches, the first horizontal cut-off switch and the first horizontal contact switch arranged on a first end of the horizontal rotor, the second horizontal cut-off switch and the second horizontal contact switch arranged on a second end of the horizontal rotor, the horizontal limit control and position sensing circuit configured to sense whether a horizontal moving tab comes into contact with one of the first and second horizontal cut-off switches and the first and second horizontal contact switches as the horizontal moving tab moves along a length of the horizontal rotor, wherein the first and second horizontal contact switches and the first and second horizontal cut-off switches are limits switches; an altitude adjustment portion which comprises an altitude adjustment driving motor configured to adjust an altitude of the solar photovoltaic panel, an altitude adjustment actuator comprising an altitude adjustment rotor coupled with the altitude adjustment driving motor, and an altitude adjustment limit control and position sensing circuit comprising first and second altitude adjustment cut-off switches and first and second altitude adjustment contact switches, the first altitude adjustment cut-off switch and the first altitude adjustment contact switch arranged on a first end of the altitude adjustment rotor, the second altitude adjustment cut-off switch and the second altitude adjustment contact switch arranged on a second end of the altitude adjustment rotor, the altitude adjustment limit control and position sensing circuit configured to sense whether an altitude adjustment moving tab comes into contact with one of the first and second altitude adjustment cut-off switches and the first and second altitude adjustment contact switches as the altitude adjustment moving tab moves along a length of the altitude adjustment rotor, wherein the first and second altitude adjustment contact switches and the first and second altitude adjustment cut-off switches are limits switches; a horizontal rotation driving portion which supplies driving power to the horizontal driving motor; an altitude adjustment driving portion which supplies driving power to the altitude adjustment driving motor; and a controller configured to remove driving power to the horizontal driving motor when one of the first and second horizontal contact switches senses contact of the horizontal moving tab and to remove driving power to the altitude adjustment driving motor when one of the first and second altitude adjustment contact switches senses contact of the altitude adjustment moving tab.

2. The solar tracker of claim 1, wherein the horizontal rotor is configured to rotate due to forward or backward rotational driving of the horizontal driving motor, and wherein the first and second horizontal cut-off switches are arranged closer to respective ends of the horizontal rotor than the first and second horizontal contact switches.

3. The solar tracker of claim 1, wherein the altitude adjustment rotor is configured to rotate due to forward or backward rotational driving of the altitude adjustment driving motor, and wherein the first and second altitude adjustment cut-off switches are arranged closer to respective ends of the altitude adjustment rotor than the first and second altitude adjustment contact switches.

4. The solar tracker of claim 1, wherein the horizontal rotation driving portion comprises a horizontal brake diode used for a brake preventing inertial rotation of the horizontal driving motor, wherein the horizontal brake diode is configured to match voltage levels of both ends of the horizontal driving motor with each other when the horizontal moving tab is sensed at one of the first and second horizontal cut-off switches.

5. The solar tracker of claim 1, wherein the altitude adjustment driving portion comprises an altitude adjustment brake diode used for a brake preventing inertial rotation of the altitude adjustment driving motor, wherein the altitude adjustment brake diode is configured to match voltage levels of both ends of the altitude adjustment driving motor with each other when the altitude adjustment moving tab is sensed at one of the first and second altitude adjustment cut-off switches.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a view illustrating components of a solar tracker having a brake function according to an embodiment of the present invention.

(2) FIG. 2 is a view illustrating a relation between an altitude adjustment driving portion (or horizontal rotation driving portion) and an altitude adjustment limit control and position sensing circuit (or horizontal limit control and position sensing circuit).

(3) FIG. 3 is a view illustrating detailed components of the altitude adjustment limit control and position sensing circuit (or horizontal limit control and position sensing circuit).

(4) FIGS. 4 and 5 are views illustrating operations of the altitude adjustment limit control and position sensing circuit (or horizontal limit control and position sensing circuit).

(5) FIG. 6 is a flowchart illustrating operations of the solar tracker having the brake function.

DETAILED DESCRIPTION

(6) Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the attached drawings.

(7) FIG. 1 is a view illustrating components of a solar tracker having a brake function according to an embodiment of the present invention.

(8) A solar tracker 100 having a brake function according to an embodiment of the present invention includes a horizontal rotation portion 110 which includes a horizontal driving motor 112, a horizontal actuator including a horizontal rotor having a certain length, coupled with the horizontal rotation motor 112, and rotating due to forward and backward driving of the horizontal driving motor 112 and a horizontal moving tab coupled with the horizontal rotor and linearly moving along the horizontal rotor and horizontally rotating a solar photovoltaic panel when the horizontal rotor rotates, first and second horizontal contact switches arranged on both ends of the horizontal rotor and sensing whether the horizontal moving tab comes into contact with the both ends of the horizontal rotor, and a horizontal limit control and position sensing circuit including first and second horizontal cut-off switches located farther than the both ends of the first and second horizontal contact switches and sensing whether the horizontal moving tab comes into contact therewith, and horizontally rotates the solar photovoltaic panel;

(9) an altitude adjustment portion 120 which includes an altitude adjustment driving motor 122, an altitude adjustment actuator including an altitude adjustment rotor having a certain length, coupled with the altitude adjustment driving motor 122, and rotating due to forward and backward driving of the altitude adjustment driving motor 122 and an altitude adjustment moving tab coupled with the altitude adjustment rotor and linearly moving along the altitude adjustment rotor and adjusting an altitude of the solar photovoltaic panel when the altitude adjustment rotor rotates, first and second altitude adjustment contact switches arranged on both ends of the altitude adjustment rotor and sensing whether the altitude adjustment moving tab comes into contact with the both ends of the altitude adjustment rotor, and an altitude adjustment limit control and position sensing circuit 124 including first and second altitude adjustment cut-off switches located farther than the both ends of the first and second altitude adjustment contact switches and sensing whether the altitude adjustment moving tab comes into contact therewith, and adjusts an altitude of the solar photovoltaic panel;

(10) a horizontal rotation driving portion 130 which supplies driving power to the horizontal driving motor 112 and includes a horizontal brake diode used for a brake preventing inertial rotation of the horizontal driving motor by matching voltage levels of both ends of the horizontal driving motor 112 with each other when the horizontal moving tab is sensed at the first and second horizontal cut-off switches;

(11) an altitude adjustment driving portion 140 which supplies driving power to the altitude adjustment driving motor 122 and includes an altitude adjustment brake diode used for a brake preventing inertial rotation of the altitude adjustment driving motor by matching voltage levels of both ends of the altitude adjustment driving motor 122 with each other when the altitude adjustment moving tab is sensed at the first and second altitude adjustment cut-off switches; and

(12) a controller 150 which removes driving power to the horizontal driving motor 112 when contact of the horizontal moving tab is sensed at the first and second horizontal contact switches and removes driving power to the altitude adjustment driving motor 122 when contact of the altitude adjustment moving tab is sensed at the first and second altitude adjustment contact switches.

(13) The solar tracker 100 having the brake function according to the embodiment of the present invention performs CPU-less control and CPU control.

(14) 1. CPU-Less Control Controlling a direct current (DC) motor through hardware logic instead of CPU control Using a limit switch as a part of a motor driving circuit to be utilized as a switch capable of unconditionally stopping

(15) 2. CPU Control Recognizing a limit switch as a sensor to stop and initialize a position

(16) FIG. 2 is a view illustrating a relation between the altitude adjustment driving portion (or horizontal rotation driving portion) and the altitude adjustment limit control and position sensing circuit (or horizontal limit control and position sensing circuit).

(17) D3, D4, D5, and D6 are diodes for a brake and used for a brake which prevents inertial rotation of a motor by matching voltage levels of both ends of the motor with each other when a limit switch operates.

(18) FIG. 3 is a view illustrating detailed components of the altitude adjustment limit control and position sensing circuit (or horizontal limit control and position sensing circuit).

(19) 1. A motor driver drives a motor.

(20) 2. A rotating shaft of the motor rotates and a moving tab moves forward.

(21) 3. The moving tab operates sensors 124-11 and 124-12 in a forward direction, and CPU recognizes and controls the same as a start point and an end point.

(22) 4. When the moving tab passes the sensors 124-11 and 124-12 and operates due to an error in CPU control, the moving tab is physically stopped when the moving tab comes into contact with ends of limit switches 124-21 and 124-22.

(23) FIGS. 4 and 5 are views illustrating operations of the altitude adjustment limit control and position sensing circuit (or horizontal limit control and position sensing circuit).

(24) 1. In a normal operation, the motor rotates bidirectionally while the limit switches 124-21 and 124-22 are closed.

(25) 2. When the motor rotates backward to operate a reverse limit switch 124-21, the switch changes to an open state and a current is cut off by a diode such that rotation of the motor is stopped.

(26) 3. When the motor is rotated forward while the reverse limit switch 124-21 is opened, the diode of the reverse limit switch 124-21 is operated as forward bias and the motor is normally rotatable.

(27) 4. When the motor rotates forward, a forward limit switch 124-22 operates in the same structure in which the reverse limit switch 124-21 operates.

(28) FIG. 6 is a flowchart illustrating operations of the solar tracker having the brake function.

(29) Referring to FIG. 6, a position of the sun is checked by an illuminance sensor (S200). Afterwards, whether it is a night mode or not is determined (S202), and then it is a night mode, a position of the solar tracker is initialized (S204). Afterwards, whether upper/lower and left/right zero sensors of the solar tracker are triggered is determined (S206). When the upper/lower and left/right zero sensors of the solar tracker are not triggered, zero points of upper/lower and left/right motors are moved (S208), and then whether upper/lower and left/right zero sensors of the solar tracker are triggered is continuously determined. However, when the upper/lower and left/right zero sensors of the solar tracker are triggered, a zero point of the solar tracker is completely set (S210) and then a process of returning to an initial state and checking the position of the sun using the illuminance sensor is repeated.

(30) Meanwhile, whether it is the night mode is determined and then it is not the night mode, the position of the sun is tracked (S212). Afterwards, whether the position of the sun changes is determined (S214). When the position of the sun changes, the upper/lower and left/right motors are driven to move to a measurement position (S216). Afterwards, movement distances of the upper/lower and left/right motors are counted using an encoder (S218) and the initial stage is performed. However, whether the position of the sun changes is determined and when the position of the sun does not change, the process of returning to the initial stage and checking the position of the sun using the illuminance is repeated.

(31) The exemplary embodiments of the present invention have been described above. It is understood by one of ordinary skill in the art that modifications may be made without departing from the scope of the present invention. Therefore, the described embodiments should be considered in a descriptive point of view not in a limitative one. Accordingly, the scope of the present invention is not limited to the above-described embodiments and should be interpreted as including the content stated in the claims and a variety of embodiments within the equivalent scope thereof.

INDUSTRIAL APPLICABILITY

(32) The present invention is a technique related to a solar tracker.