Solar Tracking System And Research On BLDC Control

With the resources being used continuously, the energy structure based on conventional energy resources will less adaptable to requirement of sustainable development, so accelerating the exploitation and utilization of renewable resources such as solar energy has been our common ideas. Developing solar power not only save conventional energy, but also benefit for environment. It is one of the most efficient methods for improving the energy mix and reducing the environment pollution and directly brings economic, conventional and social effects.On the base of Introducing Research situation of Solar tracking system and comparison of main tracking schemes, this paper design a dual axis solar tracking system based on Sunlight-Angle transducer. Sunlight-Angle transducer can measure the error of sun light and normal of solar energy modules, and the angel error will decrease to zero by DSP and motor drive circuit. Right now electricity generating efficiency is highest because of sun light perpendicular to solar energy panel. BLDC adopted to drive the system can cut costs compared to Step Motor, and it also achieves high precision with the help of the decelerate device. By the experiment, the error of angel is mainly within5°, and the system achieves better effect.BLDC system has the features of high efficiency, high power density and rapid dynamic response. Besides these, it adopts electronic commutation instead of mechanical one, which overcomes a series of disadvantages caused by the brush friction, and it makes the BLDC more suitable for these applications with very strict conditions, Such as weapon systems, vehicle drives, aeroplanes and spacecrafts. The main disadvantage of BLDC is its large torque ripple. Torque smoothness is an essential requirement in a wide range of high-performance motion applications. So the compensation of pulsating torque is very importance for BLDC system, and Researching on reduce torque ripple is very importance.This paper presents a direct power control scheme for reducing torque ripple based on α-β reference frame and Lyapunov function. The proposed method optimizes electromagnetic active power and electromagnetic reactive power by power control. After analyzing the back EMF waveform and relationship between back EMF and Hall position sensor, the way of online calculation is given. The validity of the proposed control scheme is verified through the simulation.