Real-time communication network solution based on Zigbee and Ethernet for photovoltaic systems

The fast grow of photovoltaic (PV) systems is making more green energy but also creating challenges on how to communicate in a large system with a lot of distribution solar sources when they all connect to the national grid. The communication becomes the important part for data acquisition in order to control the whole system stable and efficiency. To deal with this challenge, this paper presents a solution based on Zigbee and Ethernet communication standard. Zigbee standard was created to be a specification of a high level wireless communication protocol which is not only secure, reliable, simple but also low cost and low power. Zigbee is especially suitable for a large network with thousands of devices. So with Zigbee, we can create a communication network for hundreds to thousands of mini solar sources in a large scale of photovoltaic system. Ethernet is a high speed wired communication technology that is used widely in industrial and automatic applications. Together Zigbee and Ethernet bring to us a real-time communication solution for the system. In the experiment prototype of this paper, we use the CC2530ZNP-Mini Kit to create a simple network includes one coordinate and one end device for the first step. The end device was configured to get current and voltage values from a 3-phase gird-connected solar inverter 800Wpk and then send the values to the coordinate. After the coordinate received data, it would send them to an Ethernet controller board. This board was controlled by the STM32F407 chip which is based on the high-performance ARM®Cortex™-M4 32-bit RISC core operating at a frequency of up to 168 MHz. To display the data through Ethernet, we embedded a web server on the chip. By this way, the data was easy to visualize and supervised by using any web browser.