外文文献翻译--变频器在供水控制系统的应用(编辑修改稿)

外文文献翻译--变频器在供水控制系统的应用(编辑修改稿)内容摘要：

fe of water pressure 陕西科技大学 4 Biansongqi water pressure signal transmission to the regulator, in accordance with the regulator to set the value and warning of lower pared to send signals to the Plc and the transducer, the system has stopped pumping from regulator pressure level signals and transducer frequency range signal, if the low pressure, regulator to the Plc a pressure lower signal Plc activation transducer, and a frequency conversion 1st pumps work state, and the output frequency gradually increasing, after a period of adjustment, such as pressure is low, then, Plc for 1st pumps in the frequency of work, 2nd pump frequency conversion work at the state pumps, such as pressure is low, 2 pumps at the frequency for the state and make the state 3rd pumps in frequency conversion work, and so on. When the pressure regulator to limit the police on duty, regulator output reduction, transducer frequency reduced to the low frequency range set value at a given frequency transducer signals to the lower PLC,PLC According to Kai principle pause control pump operation sequence, for example, Plc received lower frequency signals, the system pumps state is the frequency 1st, 2ndfrequency, 3rd frequency conversion, the first time 1st pumps activated, the first stop, then as the pressure was high, then stopped on the 2nd pumps. Each system is used for slow start, highspeed operation in order to enhance operational efficiency. Introduces the frequency changer union small PLC technology in the water supply system, not only change tradition with valve control water volume how many, moreover in aspects and so on energy conservation, constant pressure control had the extremely good effect, this article introduced the frequency changerPLC regulation technology in water pump control application. The control system may bring three water pumps with a frequency changer, each water pump already may work in the conventional power frequency pump pattern, also may work in the frequency conversion pump pattern. Each pump only can be in the frequency conversion or the power frequency one kind of working pattern, guarantees its safety and the unreliability mutually through two relay locks. System structure as shown in Figure one, the use places in the domestic water pressure transmitting instrument the water pressure signaling regulator, and reports to the police the bound according to and the regulator setting value to pare, delivers a letter the number for PLC and the frequency changer, the system stops the pump separately decided by the regulator low pressure limit signal and the frequency。