TECHNICAL FIELD
[1]
The present disclosure relates to a solar-tracking solar panel unit, particularly to measures to reduce power consumption of the solar panel unit.
BACKGROUND ART
[2]
Solar-tracking solar panel units have been known. For example, Patent Document 1 discloses a solar panel unit including solar panels, and a driver having an electric motor. The solar panels of the solar panel unit rotate to receive the sunlight incident at a right angle on the solar panels. This can increase the sunlight received by the solar panels, and can increase power generated by the solar panels.
CITATION LIST PATENT DOCUMENT
[3]
[Patent Document 1] Japanese Unexamined Patent Publication No. 2003-324210 JP2003324210A
SUMMARY OF THE INVENTION TECHNICAL PROBLEM
[4]
In the known solar-tracking solar panel unit, an angle of the solar panel may be misaligned from an intended angle when a large external force is exerted on the solar panel, e.g., by strong wind. Thus, when the angle of the solar panel is misaligned, the electric motor is immediately driven to reset the angle of the solar panel.
[5]
In the known control, however, power is constantly supplied to the electric motor to operate the electric motor while the strong wind is blowing. This increases power consumption.
[6]
In view of the foregoing, the present disclosure has been achieved to reduce the power required for controlling the solar panels of the solar panel unit.
SOLUTION TO THE PROBLEM
[7]
A first aspect of the present disclosure relates to a solar panel unit including: a rotatably supported solar panel (20); an actuator (41) which is connected to the solar panel (20) to rotate the solar panel (20); an angle detector (60) which detects an angle of the solar panel (20); and a control unit (73) which operates the actuator (41) such that the angle of the solar panel (20) detected by the angle detector (60) coincides with a command angle. The command angle is an angle of the solar panel (20) determined in accordance with a direction of the sun. The solar panel unit further includes a command angle setting unit (72) which sets the command angle every first predetermined time. The control unit (73) performs tracking control by operating the actuator (41) such that the detected angle coincides with the command angle every time the command angle setting unit (72) sets the command angle, and performs reset control by starting operation of the actuator (41) after second predetermined time has passed since the detected angle was misaligned from the command angle in a period between the tracking controls to reset the angle of the solar panel (20).
[8]
According to the first aspect of the present disclosure, the reset control is performed when the angle of the solar panel (20) is misaligned from the command angle due to strong wind. In the reset control, the operation of the actuator (41) is started after the predetermined time (the second predetermined time) has passed since the angle of the solar panel (20) was misaligned. Thus, when time until the strong wind stops is set as the predetermined time (the second predetermined time), the operation of the actuator (41) can be started to reset the angle of the solar panel (20) after the strong wind has stopped. As a result, the actuator (41) is not wastefully operated while the strong wind is blowing, and operating time of the actuator (41) can be reduced.
[9]
In a second aspect of the present disclosure related to the first aspect, the actuator (41) rotates the solar panel (20) by air pressure.
[10]
According to the second aspect of the present disclosure, when the solar panel (20) rotates due to the strong wind, the pneumatic actuator (41) shrinks (or expands). The air pressure in the actuator (41) increases when the actuator (41) shrinks, while the air pressure in the actuator (41) decreases when the actuator (41) expands. Thus, the actuator (41) generates a restoring force in a direction of resetting the angle of the solar panel (20).
[11]
According to the second aspect of the present disclosure, when the angle of the solar panel (20) misaligned from the command angle due to the strong wind is reset by the restoring force of the pneumatic actuator (41) until the predetermined time (the second predetermined time) has passed since the angle of the solar panel (20) was misaligned from the command angle. Thereafter, the operation of the actuator (41) is started to continue the resetting of the angle of the solar panel. Thus, the operating time of the actuator (41) can further be reduced.
[12]
In a third aspect of the present disclosure related to the second aspect, the solar panel unit further includes: an air pressure supplier (42) which supplies the air pressure to the actuator (41); and a supply passage (44) connecting the air pressure supplier (42) and the actuator (41), wherein a relief valve (43) is provided in the supply passage (44) to discharge air outside.
[13]
According to the third aspect of the present disclosure, when the solar panel (20) rotates in the direction of shrinkage of the actuator (41) due to the strong wind, the air in the actuator (41) may be compressed to abnormally increase the air pressure. However, according to the third aspect of the present disclosure, the air is discharged outside through the relief valve (43) provided between the air pressure supplier (42) and the actuator (41). This can reduce the abnormal increase in air pressure in the actuator (41).
ADVANTAGES OF THE INVENTION
[14]
According to the first aspect of the present disclosure, the reset control is performed to reset the angle of the solar panel (20) misaligned due to the strong wind. In the reset control, the actuator (41) is not operated until the predetermined time (the second predetermined time) has passed since the angle of the solar panel (20) was misaligned to wait for the strong wind to stop, and then the actuator (41) is operated after the lapse of the predetermined time (the second predetermined time) to reset the angle of the solar panel (20). In this way, the actuator (41) is not wastefully operated while the strong wind is blowing, and the operating time of the actuator (41) can be reduced as compared with the conventional case where the electric motor is constantly operated while the strong wind is blowing. This can reduce the power consumption.
[15]
According to the second aspect of the present disclosure, the pneumatic actuator is used as the actuator (41). Thus, the restoring force of the actuator (41) can reset the angle of the solar panel (20) until the predetermined time (the second predetermined time) has passed since the angle of the solar panel (20) was misaligned due to the strong wind. When the angle of the solar panel (20) is not completely reset in the predetermined time (the second predetermined time), the operation of the actuator (41) is started to continue the resetting of the angle of the solar panel. This can further reduce the operating …
