The solar tracking bracket is the support structure of the photovoltaic module, which rotates through one or two axes to enhance or increase the output of the photovoltaic module.
There are basically two types on the market: balanced drive brackets and mechanical drive brackets.
1. Balance drive bracket
The schematic diagram of the balanced drive bracket is shown in Figure 1.
The balance drive bracket uses the heat of the sun to change the state of the refrigerant, thereby moving the balance point through an axis. As the temperature rises, the density of the refrigerant becomes lighter and rises to the highest point of the system to change the equilibrium state. The balance drive bracket is usually designed with an even number of modules, and some are odd. Use automatic shock absorbers to reduce the influence of wind. In strong wind, they will be adjusted to the state of least wind resistance, and the tilt angle can be adjusted manually. The big advantage of the balanced drive bracket is that its operation does not require an external power source, which means that it has low maintenance costs under normal working conditions and is therefore suitable for remote areas.
Advantages of balanced drive bracket:
(1) No power supply is required.
(2) Low maintenance cost.
(3) Few moving parts
Disadvantages of balanced drive bracket:
(1) There is a risk of leakage of the refrigerant.
(2) High installation requirements (it must be vertical with high accuracy).
(3) Vibration caused by strong wind will shorten the life of components
(4) No user repairable parts
(5) The refrigerant is scarce and difficult to obtain
2 Mechanical drive bracket
The mechanical drive bracket adopts many different forms of design, but there is a common feature. They all use a certain form of motor to drive the array, which is completed by installing a gear box or a linear drive. These two drive sources are generally based on time. Or the micro-processing unit control of the daylight sensor.
1). Linear drive drive unit
The linear drive is a mechanically driven plunger, which pushes the pivot frame to rotate in an arc by changing the length of the plunger. The schematic diagram is shown in Figure 2.
In Figure 2, the sides AC and CB of the triangle ABC are fixed. As the length of AB changes, the angle X changes. The linear drive controls the length of side AB. Due to the simple implementation mechanism, solar tracking devices based on linear drives are the most common form of drive units. In Figure 2, the stability of the tracker is determined by the triangle ABC. When the tracker is almost vertical (to the east or west), the triangle is almost non-existent. Therefore, the solar tracking device is not very stable under the extreme value of the angle, and may be damaged by the wind. In most cases, the solar tracking device manually adjusts the tilt angle and performs well in small wind areas.
Advantages of linear drive drive unit:
(1) There is only one replacement drive unit that comes with it.
(2) Usually the design is compact.
(3) It can be repaired on site.
(4) The installation requirements are not so strict.
Disadvantages of linear drive drive unit:
(1) When the driver also becomes a node (stabilizer), what problems will arise when the straight push establishes a 90″ arc: at the maximum extension range, the driver can be almost parallel to the plane of the pivot structure, which results in the driving The shaft point will generate a large stress, and it may fail prematurely in the windy area
(2) External power supply is required
2). Gearbox drive components
Gearbox drive components are different from other types of trackers in that they are driven by one or two shafts and usually have a stronger structure on the final drive. The gearbox driving part also uses a microprocessor to realize self-control, as shown in Figure 3.
Advantages of gearbox drive components:
(1) It has a high wind load carrying capacity.
(2) High intensity.
(3) Less maintenance.
(4) It can be repaired on site.
Disadvantages of gearbox drive components:
(1) Heavy weight and labor-intensive installation.
(2) External power supply is required