【正文】 Using buoys or mechanical control devices such as water supply situation has made some changes, but because of mechanical failure more devices, poor reliability to maintenance will face great trouble. Frequency conversion technology, with its superiority in the area of energy efficiency and Hengya pressure control system can be solved by the existence of the above problems. Consider selecting Chanpianji or Plc and transducer bination at the core of the system can achieve a better control results. But in software design, Plc programming of more than Shanpianji concise, and visual。 B:運(yùn)行可靠、穩(wěn)定。這樣不但使電機(jī)工作在低效區(qū)、減短電機(jī)的使用壽命，而且電機(jī)的頻繁開停使設(shè)備故障率很高，導(dǎo)致水資源嚴(yán)重浪費(fèi)，系統(tǒng)的維護(hù)、維修工作量較大。 采用變頻器 PLC恒壓供水裝置有以下幾個(gè)優(yōu)點(diǎn)： 陜西科技大學(xué) 2 A:節(jié)電效益 高。預(yù)計(jì) 21世紀(jì)全數(shù)字控制的應(yīng)用 將更加廣泛深入，甚至取代模擬控制。t reduce, the electrical machinery power factor can obtain the enhancement. B:Moves is reliable, is stable. In the system core part frequency conversion velometer itself reliability is very high, in the ordinary circumstances may the longterm usage 100,000/Above h. The system also selects the soft start method, does not have the electrical impact, does not pollute the electrical work, moreover frequency changer bringing owes presses, the pressure, the overflow, the overload, superheat as well as loses speed and so on each kind of protection function. The system adopts damping filter processing to the pipe work fluctuation of pressure, the water supply constant pressure precision is high, usually can control in the scope. C:The structure is simple, the operation is simple. The installment control system uses the integration rate to be high, necessary plan nimble diverse, obtains water pump movement each kind of bination by the programmable controller. The velocity modulation scope is broad, to water volume change adaptiveness. D:The service life is long, the automaticity is high, does not need the human to safeguard, maintains the quantity to be few. Above system the effect is remarkable in the actual application, if brings in PLC and the frequency changer the programmer the function integration, potential bees some specialpurpose frequency changers, such system reliability and the 陜西科技大學(xué) 6 toughness big enhancement, the application is simpler, the system total cost also can drop. May foresee: The future frequency conversion technology will be able to develop to the below direction: (1) high performance Thus including internal leveling circuit, the contravariant electric circuit all use the high frequency PWM electric circuit to cause the input, the output all are sine waves。系統(tǒng)對(duì)管網(wǎng)壓力波動(dòng)采取阻尼濾波處理，供水恒壓精度較