文档介绍：本科生毕业设计说明书(毕业论文)
题目:电厂综合水泵房水泵变频调速控制系统设计
电厂综合水泵房水泵变频调速控制系统设计
摘要
本论文是根据某电厂综合水泵房工艺要求,现拟对中水提升泵和工业补给水泵两套系统进行变频调速改造。
其中中水提升泵系统(一控三),其变频柜控制三台75KW水泵,变频泵定时循环运行,一周自动切换一次,当变频泵不能满足要求时,自动软启动一台工频泵,当变频泵仍然不能满足压力给定值时,再自动软启动第三台水泵。
工业补给水泵系统(一控二),其变频柜只控制两台37KW小泵,水泵不要求定时循环运行,但能够手动切换运行。当变频泵不能满足要求时,自动启动另一台工频小泵。75KW大泵只能工频手动控制,不参与变频自动控制。
两套系统的基本构成均由变频器(含PID)、软启动器、电动机、压力传感器等构成,而且都利用了变频器来控制水泵电机的软启动和转速。压力变送器用来检测水泵房管网中的当前水压,以电信号的方式送入变频器的PID控制器与设定值进行比较后执行PID运算,对变频器的输出频率和电压进行控制,从而改变水泵电机的转速进而改变供水量,最终使管网中的水压稳定在设定值的附近。
关键词:变频器、软启动器、水泵、PID、调速
The Design of Frequency Control System of an Integrated Water Pump House of a Power Plant
Abstract
This paper is based on technical requirements of an integrated water pump house of a power plant. It is intended for water lift pump and industrial water supply pump frequency control two systems transformation.
Where the water lift pump system (one control three), its variable frequency counter control three pumps of 75KW, these pumps need timing loop operation, one week automatically switch once. When one pump can not meet the requirements, automatically starts frequency pump, when two pump still can not meet the pressure setpoint, and then a third pump automatic soft starts.
Industrial supply pump system (one control two), its variable frequency counter only control two small pumps of 37KW, the two pumps do not require timing loop to run, but the system can be run manually, when one pump can not meet the requirements, automatically starts another small pump. 75KW large pump only manual control by power frequency and it does not participate in frequency control.
The basic structure of the two systems by the frequency inverter (including PID), soft starter, motor, pressure sensors, etc. and both two systems have taken advantage of the inverter to control the pump motor soft start and speed. Pressure transmitter used to detect current pipe pressure of pump, in the form of electrical signals sented into the PID controller of inverter pared with the