基于PLCC的果园轮灌控制系统设计及试验

Application and Test of Round Irrigation Controller in Orchards Based on Low-voltage Power Line Carrier Communication Technology

提出一种二线合一的控制方式,将电力线载波通信技术应用到果园轮灌控制系统。以ST7540载波芯片为基础,设计耦合滤波电路构成电力线载波通信模块;根据均匀传输线理论,建立果园轮灌电力传输线模型;利用此模型在不同传输距离下对电力线载波通信模块的传输可靠性进行测试。测试结果表明,ST7540在直流24 V电压情况下,理论上通信距离可以达到2 000 m,能够满足果园分区轮灌控制系统的传输距离需求。

Abstract： A new scheme that combines the power lines with signal lines together is proposed in the paper, and the low-voltage power line carrier communication technology is applied to round irrigation automatic controller in orchards. The power line carrier module is based on ST power line carrier communication chip ST7540 with coupling filter circuit so as to realize power line carrier communication. Then power transmission line model in round irrigation is established according to the even transmission theory. Finally, the transmission character of the power line carrier module is tested by this model. The results show that the ST7540 model communication operation is reliable and stable in DC power line, and the control distance can reach about 2000 m long theoretically. Hence, it can absolutely meet the performance demand of control system in the partition round irrigation area. Key words： round irrigation in orchards; power line carrier communication; ST7540; transmission line model