## 3 Information in the Smart Distribution Network  
The information model by taking a typical distribution network with distributed energy as an example is analyzed in this paper. As shown in Figure 1, as the core component of the distribution network automation system, IED completes the functions of data acquisition, control, protection and power management of the primary system [7; 8]. In Figure 1, IED1 represents an intelligent electronic device and IEDn represents the nth intelligent electronic device. Figure 1: Overview of the power communication network; IED\({}_{(1-n)}\): Intelligent electronic device 1–n. Through the analog-to-digital converter, the conventional IED converts the current and voltage sent by the transformer into electrical data in the form of digital quantities. At the same time, it also converts the state of the distribution switch, such as a circuit breaker that is isolated by an optocupler. The IED makes a corresponding judgment after the logic operation (the protection function judges whether the component has a fault; the control function adjusts the component, etc. ), and operates the corresponding component through a circuit such as an optocupler. With more distributed energy access to the distribution network [9], the automatic system in distribution network will need to implement more functions, and the IED will be more complicated and diversified. For example, after a photovoltaic substation is connected to a distribution network, IED may be require mutual conversion between AC and DC power sources. This requires the IED to add PWM (Pulse Width Modulation) and other functions on the software algorithms and hardware devices, making the information system of the distribution network more complicated. At the same time, the more application of the communication network in the distribution network automation system has fundamentally changed the structure of the information system in the distribution network [9]. The traditional information system originally obtained information through the \"hard connection\" of the cable. With the emergence of more diverse forms of information interaction, the systems have gradually transitioned to transmitting information via communication networks in the form of messages. Compared with the transmission network, the communication method of the distribution network is more diversified, including RS485, RS422, power line carrier (PLC), controller area network (CAN) and other fieldbus, Ethernet and various wireless networks. Different communication methods correspond to different network hardware control modes and communication protocols. In addition to the interworking interconnection problems that general heterogeneous communication systems have to face, the distribution network information system also includes a variety of power system's own protocols, which makes information processing more difficult. Therefore, it is actually a multi-source, heterogeneous, multi-protocol complex information system. There are several reasons for the above characteristics. Data from different sources. The data in the IED may be derived from its own secondary device. And it may be external data transmitted by other IEDs through the communication network. Taking current as an example, the current data of the IED device may be measured by the transformer in the secondary device, or it may be transmitted by other IED devices. This variety of data sources and acquisition methods will make distribution network information difficult to handle. Diversification of the protocol. Now the IED in the distribution network has various communication methods such as RS485, RS422, CAN, Ethernet and various types of wireless. Each communication method constitutes its own communication protocol, and also includes a variety of power protocols. Different protocols use different message formats. When the two parties use different forms of messages for communication, if one of the messages is not converted, the two parties cannot communicate normally.