Research On The Communication Architecture Of The Small Wind Solar Hybrid Power Grid Based On CAN Bus And ZigBee

With the continuous development of the global economy, the demands for electricity also grow rapidly. Meanwhile, the disadvantages of the traditional power system is becoming more and more apparent because of its high cost and operation difficulty, which is unable to meet the requirements of electricity safety and reliability for the users. Therefore, it is imperative to seek and explore a new mode of power generation of electricity.As an important technology of the smart grid, micro grid technology organized distributed power effectively, becoming one of the important means to solve many problems in traditional power system. However, micro grid is difficult to control because it has many types of distributed generation and varieties of load variety. Therefore, the design and realization of an efficient, reliable, flexible and intelligent control system of micro grid is crucial for the development and application of micro grid. Based on this, this thesis designs small wind and photovoltaic complementary micro grid control system based on CAN bus and ZigBee technology. The detailed research includes the following aspects.In the first place, regarding to the problem of increase in types and controlling difficulty and random distribution of distributed generation, this thesis proposes to design and realize the micro grid control system by Multi-agent technology and analyzes the characteristics of the multi-agent system in detail. And base on this, we design a small wind and photovoltaic complementary micro-grid control system which consists of station agent, micro-grid agent and device agent.Secondly, To effectively coordinate and make full use of distributed generation in micro grid and realize effectively control of micro grid, in this thesis we divide the control pattern of the micro-grid into three types:grid connected control pattern, island control pattern and emergency control pattern, and the three operation pattern and their inter conversion conditions are introduced in detail. Based on this, we put forward the control strategies of the three operation modes of the micro grid control system.Put forward the view of three-level threshold control scheme which is divided into grid threshold, the threshold and emergency threshold in turn, according to the characteristics of the micro grid and off-grid, we describe the function of three-level threshold in detail, and propose the micro grid and off-grid control strategies in detail.Again, regarding to the requirements of real-time and reliability of the micro grid system, this thesis propose to use the CAN bus to replace RS485 bus between Micro-grid agents and device agents to realize data acquisition and control commands transmission, at the same time, we design an RS485-CAN converter, and test CAN bus communication in the experiment platform. And the experiment showed that the CAN bus can realize data acquisition task effectively.Last, in order to realize energy mutual dispatch and supply among the micro grid agents in the Micro grid, this thesis adopts the ZigBee wireless communication technology to build ZigBee network between the micro grid agents, and make threshold decision according to the device agent working parameters collecting by the micro grid agent, and realize energy dispatch strategies in the micro network agent through the ZigBee network.