Communication Of DC Micro_Grid And It’s Energy Management System

With the more extensive application of DC Micro-grid, its communications technology, become increasingly concerned. This thesis’s design which is based on this described ZigBee communications and Ethernet gateway implementations of DC Micro-grid in detail. This thesis is divided into five chapters, which are the introduction, hardware design of gateway, software design of gateway, monitoring software, and optimal energy management.For the realization of communication between multi-converters in DC micro-network, and then implementing monitoring and energy management. A communication scheme based on Zigbee wireless sensor networks and Ethernet was proposed. The system adopted the JN5139to achieve the Zigbee communication of converter equipments and coordinators; It implements Ethernet communication between coordinators and monitoring end hosts, combining the CP2200Ethernet controller chip. The experiment shows that the scheme is flexible in network construction and easy in maintenance; ZigBee chips and the Ethernet chip were directly connected in the coordinators, So it reduce intermediate links and improve the overall communication effectiveness of the system.Software design is based on the ZigBee protocol stack, and then Ethernet communication and serial communication function are realized. Because CP2200chip is not in the original JN5139program, a low-level driver for it is implemented. And it is focused on the method of finding out the short address though the MAC addresses and two-way communication.In practical application, all kinds interference from natural and human factors often cause system input and output error. To this end, it plays an extremely important role to real-time monitor input/output voltage and current of each generator’s DC-DC devices and analysis and diagnosis for the stable operation of the whole network in DC micro network system. The fault can be monitored by the real-time detection of the voltage and current of each converter through a wireless node. Then parameters of the components will be passed to the coordinator through ZigBee protocol.Finally, these parameters will be sent to the computer through the coordinator to real-time display and process in Visual Studio2010integration development platform by using C#languages programming.On the basis of good communication, novel energy management strategies were put forward, according to several energy supply and demand situations between renewable energy power generation units and loads. In accordance with the equilibrium conditions of the power, the constraint of battery charge and discharge and real-time pricing, the genetic algorithms is applied to achieve the most economical efficient. Due to the limitation of environment and condition, the prediction power of renewable energy generation each time data is given by the forecasting of radiation intensity and wind speed and steady state calculation model of photovoltaic and wind power which is not very accurate and will get further optimization in the later study.