Solar Tracking System
In order to maximise sunlight collection and therefore energy generation and revenue, it is necessary to introduce solar tracking systems into solar power systems. A dual-axis tracker can increase energy generation at peak times in early morning and later afternoon, boosting revenues by up to 50%. There are three common methods that can be used to implement a solar tracking system: time-based control, sunlight intensity comparison and space-time synchronization.
Space-time synchronization method has a high control precision and excellent adaptability, but needs a complicated software system to support the hardware. Therefore the control methods should be selected according to the practical requirements.
According to the mechanisms used to change the facing direction of solar panel, solar tracking systems can be divided into Single-Axis and Dual-Axis systems. Single-axis solar tracking systems can only track the sunlight by rotating around a fixed horizontal axis, while dual-axis solar tracking system can rotate about two axes, i.e. X and Y axes to ensure the sunlight always hits solar panel vertically.
A dual-axis solar tracking system is composed of anemometer, temperature sensor, photoelectric sensors, light intensity sensors, rotary encoder, signal processing circuit (comparators, amplifiers and ADCs), MCU/DSC, isolator, motor drivers and motors, RS485/CAN, human machine interface(keypad and LCD display), power management and RTC.
Anemometer is used to detect wind speed. When wind speed is greater than the preset value, system will carry out a protection mechanism. Temperature sensor is used to detect the weather temperature. Photoelectric sensors monitor if sunlight is hitting solar panel vertically. Sunlight intensity sensors detect the change of sunlight intensity, so that system can determine which control method should be used for current weather condition or season. MCU/DSC is the core of system used to process input signals, implement control algorithms and give control instructions. Step motors, DC motors and servo motors can be used to drive solar panels to always face the sun straightly. RS485/CAN interface is used to communicate between systems and other control centers. Keypad and LCD display are used to build a human machine interface. Power management and RTC provide power and real time clock for system.