摘 要:随着国民经济的增长的需要，我国电网覆盖面积日益扩大，于此同时，对供电系统的稳定性要求也日益提高， 备自投作为提高稳定性的自动投入装置已成为研究的重要课题。
ABSTRACT:Summary with the growth needs of the national economy,China's power grid covering an area of growing, at the same time, increasing demands on stability of power supply system, win equipment as inputs to improve the stability of automatic devices have become an important research topic.
For this type of problem, this design uses intelligent programmable controller (PLC) as a solution. The case study of pingbian County Kou hydropower station design, intended for such small power plants power automatic bus transfer station design.
The design addresses the purpose, meaning that research problems and solutions encountered during the design process and measures. Which provides a detailed description of Kou hydropower station with power into the overall solution design, focusing on the missing phase detection and application of PLC address AC relay logic control design. Through the design of phase detection scheme, solve the PLC input sampling issues, provide logic for the PLC input, according to the black-white control design of PLC control module. Main results have a three-phase power supply missing phase detection circuit design and equipment selection, design of main circuit diagram in the control module, I/O allocation table, PLC control wiring diagram, and PLC ladder diagram and procedure selection. This good performance, to achieve automatic control design of automatic bus transfer system requirements, flexibility, ease of operation, low failure rate, maintenance is simple and convenient, real time Kou hydropower station with power automatic bus transfer vacancies and control stability requirements are met.
Key words: programmable logic controllers (PLC); automatic bus transfer; automatic control...