【作者】 刘毅力；

【导师】 张江滨；

【作者基本信息】 西安理工大学 ， 水利水电工程， 2004， 硕士

【摘要】 水轮机微机调速器是水轮机控制系统中的重要设备，近几年PLC在此领域得到广泛的应用。本文在充分论述了水轮机调速器的发展历史、研究现状和发展趋势基础上，对水轮机调速系统结构、控制策略等技术问题进行了分析和研究。应用西门子S7-200 CPU226 PLC实现了水轮机调速器的基本功能，对该系统的硬件和软件进行了详尽的分析和说明。 本文利用S7-200 PLC自身的特点设计了频率测量单元，根据PID调节各个环节的特点，以及调速器动态特性、静态特性对频率测量的实时性和精度要求的不同，利用S7-200 PLC基本单元中内置的高速计数器以及相应的外围放大整形、分频电路，实现了水轮发电机组频率的测量；在软件上，对微机调速器的整个程序框架、并联PID的离散化过程进行了分析，选用改进的PID算法实现了变参数、变结构的PID调节模式；调速器的机械液压随动系统具有步进电机电液转换元件，采用五相反应式步进电机，根据其驱动特性设计了变频调压驱动器，实现PLC与步进电机驱动器之间数字接口。利用PLC主机模块的高速脉冲输出功能，控制脉冲频率的发生、PWM脉宽电压的调节，并通过步进电机驱动器实现对步进电机高效控制。 该调速器充分利用了S7-200PLC内部资源，附加少量的硬件，实现了微机调速器的主要功能，具有结构简单、体积小、可靠性高的优点。由于其编程简单方便、扩展性强，同时兼有较高的性能价格比，可广泛应用于中小型水轮发电机组的调速控制，对于提高我国中小型水电站自动化水平具有重要的实际意义。更多还原

【Abstract】 Microprocessor-based governor is an important device in the hydraulic turbine control system. Recent years, the PLC technology has been widely applied in the field. In the first part of the paper, the principal and characteristics of the hydraulic turbine governor are discussed, then the history, current status and trends of hydraulic turbine governor are described. Then analyzes and discuss some technology of hydraulic turbine governor, including the system structure, regulating laws, control strategy and the technology of hydraulic turbine governor. SIMENS S7-200 PLC CPU226 is used to realize the basic function of turbine governor; the hardware and software of this system are analyzed in detail.By the virtual of the S7-200 PLC, the frequency measurement unit is designed. There is difference frequency measurement requirement for every part of PID regulating, difference between dynamic quality and static quality in response time and accuracy. According to these, it use the interrupt functions and high-speed counter of the SIMENS S7-200 PLC CPU226 basic unit and some peripheral circuit to measure frequency; In software designed, the procedure frame of hydraulic-turbine governor and disperse process of parallel PID are analyzed, An improved PID algorithm is adopted to realize a PID regulation mode with variable structure and parameters; The mechanical liquid-pressure system of the hydraulic-turbine governor is with electric-hydraulic converter unit of step motor . According to the drive character of five phase of response step motor, a variable frequency regulated voltage driver unit is designed in order to realize interface between PLC and driver of step motor. The interface utilizes the high-speed pulse function of PLC basicunit to realize the control frequency of pulse, PWM regulate voltage and to make use of drivers of step motor control step motor.The hydraulic-turbine governor sufficiency use interior function of S7-200 and a few peripheral circuits to realize primary function of microprocessor-based governor, the governor has the advantage of reliable, simple and small size. For simple program, extend easily and high performance but low cost, it will be widely used medium or small hydropower plants governor. It will enhance the automation level of hydropower plants governor.更多还原