基于PLC的变频调速系统毕业论文

基于PLC的变频调速系统

摘要

能源工业作为国民经济的基础，对于社会、经济的发展和人民生活水平的提高都极为重要。在高速增长的经济环境下，中国能源工业面临经济增长与环境保护的双重压力。目前，国内变频调速系统的研究非常活跃，但是在产业化方面还不是很理想，市场的大部分还是被国外公司所占据。因此，为了加快国内变频调速系统的发展，就需要对国际变频调速技术的发展趋势和国内的市场需求有一个全面的了解，深入研究变频调速系统的发展。设计出系统稳定，调整精度高，调整时间快的变频调速系统，对现今工业设计和工业生产的发展有很大帮助。

本次设计介绍了一种基于PLC的变频器调速系统。将现在应用最广泛的PLC 和变频器综合起来,主要功能实现了:变压变频调速,电机的正反转，加减速以及快速制动等。该系统必须具备以下三个主体部分：控制运算部分、执行和反馈部分。控制运算主要由PLC和变频器来完成；执行元件为变频器和电机；反馈部分主要为速度反馈。

通过设定交流调速系统的转速传输到PLC，PLC根据设定的转速通过模拟量输出模块，输出模拟信号控制变频器的输出频率，控制交流电机调速控制。变频器的转向由正/反转开关进行控制。交流调速系统的转速由测速发电机转换为相应的转速模拟信号,输入模拟量的输入模块，模拟量输入模块产生的数字信号送入PLC。由开环/闭环开关控制系统在开环或闭环状态下运行。当交流调速系统设定为开环运行时，检测到的转速信号PLC不进行处理，直接进行显示；当交流调速系统设定为闭环运行时，光电编码器将检测到的转速信号一方面由PLC与设定转速信号进行运算处理，处理过的信号送去控制变频器，另一方面将数据实时显示。

关键词：PLC 变频器 PID控制

Abstract

Energy industry as the foundation of the national economy, for the development of society and economy and the improvement of people's living standard is very important. The rapid development of Chinese economy environment, the energy industry faced with economic growth and environmental protection dual pressures. At present, the domestic study of variable frequency speed regulation system is very active, but the industrialization is not very ideal, market much still occupied by foreign companies. Therefore, in order to accelerate the development of domestic variable frequency speed regulation system, they need to international variable-frequency regulating speed technology development tendency and the domestic market demand have a comprehensive understanding of variable frequency speed regulation system, further study of the development. Design the system stability, high precision, adjust time adjust quickly and speed-adjusting system, on the current industrial design and the development of industrial production has very great help.

This design is introduced which is based on PLC speed-regulate system. Will now the most widely used PLC and inverter together, main functions: variable pressure frequency control, motor, the positive &negative deceleration and fast brake etc. This system must meet the following three main parts: control computation section, execution and feedback part. Control operations by PLC and inverter to mainly complete; Actuators for converter and motor; Feedback part mainly for speed feedback.

Through the setting of ac speed adjustment system speed transmission to PLC, according to the set speed through PLC simulation output module, output analog signal control inverter frequency, control the output of induction motor control. Inverter by are/reverse switch to control. The speed of the ac adjustable speed system by tachogenerator converted to speed analog signals, input analog quantities of input module, analogue input module produces digital signals into PLC. By the open loop/closed-loop switch control system in the open loop or loop by mode. When communication speed regulation system Settings for the open loop runtime, detected speed signal processing, PLC not directly display; When communication closed-loop speed system Settings for running, photoelectric encoder will detect speed signal on the one hand by PLC and setting speed signal treatment, the operations of signal sent to