【作者】 徐方明；

【导师】 葛良全；

【作者基本信息】 成都理工大学 ， 测试计量技术及仪器， 2007， 硕士

【摘要】 励磁系统是电力系统的一个重要组成部分，它在调节发电机机端电压、分配电网无功功率和提高电力系统稳定性等方面都起着重要的作用。励磁系统由励磁调节器和励磁功率单元组成，其中励磁调节器是励磁系统的中枢，负责实现励磁系统的基本控制功能、励磁限制和其他辅助功能。随着发电机单机容量和电网规模的增大，发电机组和电力系统对励磁系统的快速性、可靠性、多功能性等方面提出了更高要求。现代励磁调节器普遍采用微处理器为核心，所以也称为微机励磁调节器，其基本控制过程、励磁限制以及辅助功能均通过软件设计来实现，具有调节迅速、精度高、可靠性高等优点。双通道励磁调节器是指在每个发电机配置两个微机励磁调节器，一个为主机，一个为备机，两个通道之间实现冗余备份，可以极大提高励磁系统的可靠性。本项目是在南京南瑞自动控制有限公司资助下开展的。励磁系统的功率单元采用由可控硅组成的三相全控整流电路，可控硅的控制端由励磁调节器进行软件触发，每个通道的励磁调节器在硬件上采用数字信号处理器(DSP)作为励磁调节器的主控芯片，用可编程控制器(CPLD)完成接口电路的设计，同时设计模拟量处理、开入开出量的处理以及脉冲触发电路。在软件上，主控流程采用改进型的PID控制方法，同时实现各种励磁限制和辅助功能。为了协调两个通道调节器之间的工作，确保同一时刻只有一个通道调节器输出有效，同时为了保证两个通道切换时输出无扰动，设计了两个通道之间的信息交互方式以及脉冲闭锁、脉冲切换控制电路。实验结果表明，双通道励磁调节器在空载和并网条件下，其调节速度、精确度、可靠性和稳定性等方面都满足行业标准的要求。更多还原

【Abstract】 Excitation system is an important part of power system. It has important effectto regulate the voltage of synchronous generator, distribute reactive power andimprove the stabilization of power system. Excitation system is made up of regulatorand power units. The regulator, as the core of excitation system, carries out its basiccontrol functions, excitation limits and other assistant functions.As a single synchronous generator’s electric power becomes higher and thescale of power system becomes bigger, synchronous generator and power system hasmore demand on expeditiousness, reliability and multi function of excitation system.Modern excitation regulator is called microprocessor-based regulator because itis used microprocessor as its central control unit. Its’ basic control functions,excitation limits and other assistant functions are carried out by software programswhich are run in microprocessor. Microprocessor-based excitor has rapid regulatingspeed, high precision, more reliability and other excellences.What Double-channel microprocessor-based excitation regulators mean that onesynchronous generator has two microprocessor-based regulators, one as the main, theother as the backup. It can improve reliability of excitation system.This research program is supported by Nanjing Nari Automation institute.Three-phasic controllable commutating circuit, which is made up of SiliconControlled Rectifier (SCR), is used in excitation system as power unit. The controlport of SCR is controlled by the microprocessor-based regulator. This paper usesDSP as the main control chip of the microprocessor-based regulator and CPLD as itsinterface circuits, designs process circuits of analog signals, logical signals andpulse-open circuit. This paper also uses ameliorated PID arithmetic to carry outregulator’s basic control functions, excitation limits and other assistant functions bysoftware programs. In order to harmonize double microprocessor-based regulators’working, ensure only one regulator’s output in effect and switch between tworegulators without disturbing outputs, the paper designs communication circuits andpulse closedown and control circuits between them.Experiments show that the microprocessor-based excitation regulators meetindustry standards in regulating speed, precision, reliability and stability both on thecondition of generator’s open circuit and in load.更多还原