Design Of Controller For Control And Protection Switch Based On Ethernet

Control and Protective Switching Device is a new type of low-voltage electrical products, which can realize the functions of multiple low-voltage electrical appliances on a single electromagnetic mechanism. With the advantages of small size, high reliability and simple operation, the control and protection switch has become an indispensable switch device in low voltage power system. With the rapid development of network communication technology, Ethernet with the advantages of high transmission rate, good openness, support varies of physical media and topology is widely used. Therefore, it is of academic significance and practical value to design of controller for control and protection switch based on Ethernet.Firstly, in this thesis a study on the protection method of the controller is carried, the theoretical basis is provided for the hardware and software design of the following controller.Secondly, based on the research of the protection method of the controller, designed hardware and software of the controller. The hardware circuit is composed of PIC18F4620 core module circuit, peripheral circuit, data acquisition circuit, data processing circuit, output circuit, man-machine interface and the Ethernet communication interface circuit composed of W5500. In software design, according to the modularization design concept, the whole soft design is divided into system initialization, data acquisition, data processing, fault protection, and communication module. The communication module subroutine based on Modbus protocol which in the way of by host "query" slave "response", achieved the function of switch on, switch off, parameter setting, status query, the query parameters.Finally, designed the host computer with Delphi, which has network communication establishment, data receiving and sending, data processing, data storage and other functions. In this thesis introduced the function of each sub interface.Through on-line debugging of the upper and lower machine, verified the feasibility of using Ethernet to realize the communication between host computer and controller, and the application of the interface of the host computer.