外文翻譯-變頻器在恒壓供水中的應(yīng)用Transducer in the water control system application

1、變頻器在供水控制系統(tǒng)的應(yīng)用 目前，在水位控制中有很大一部分水泵電機是不變速拖動系統(tǒng)，不變速電機 的電能大多消耗在適應(yīng)供水量的變化而頻繁的開停水泵中。 這樣不但使電機工作 在低效區(qū)、減短電機的使用壽命，而且電機的頻繁開停使設(shè)備故障率很高，導(dǎo)致 水資源嚴(yán)重浪費，系統(tǒng)的維護(hù)、維修工作量較大。隨著高位生活用水和工業(yè)用水逐漸增多，傳統(tǒng)的控制方法已經(jīng)落后。原先 用人工進(jìn)行水位控制，由于無法每時每刻對水位進(jìn)行準(zhǔn)確的定位監(jiān)測，很難準(zhǔn)確 控制水泵的起停；使用浮標(biāo)或機械等水位控制裝置使供水狀況有了一些改變，但 由于機械裝置的故障多，可靠性差，給維修帶來很大的麻煩。變頻技術(shù)以其在節(jié)能與恒壓方面的優(yōu)越性能可以解決水壓

2、控制系統(tǒng)存在的 以上問題?？紤]選用單片機或 PLC 與變頻器結(jié)合為核心構(gòu)成的系統(tǒng)都能達(dá)到較 好的控制效果。但在軟件設(shè)計上，PLC 比單片機的編程更簡潔、直觀；從硬件接 口考慮，單片機電路稍微復(fù)雜一些；從經(jīng)濟方面考慮，由于 PLC 工藝的日漸成 熟，小型 PLC 的成本與單片機相差無幾，由于要根據(jù)現(xiàn)場情況調(diào)整系統(tǒng)參數(shù)， PLC 的軟件中時間參數(shù)的調(diào)整更簡單，這樣更有利于售后服務(wù)人員掌握?；谝?上原因，選用了 OMRON 的 CPM1 系列 PLC 與 ABB 的變頻器作為控制核心，再 加上 PSW7 調(diào)節(jié)器與 WSP300 壓力變送器，控制效果非常好，軟件設(shè)計簡單， 硬件接口簡易可行、可靠性高

3、，整個系統(tǒng)的性價比非常高。在供水系統(tǒng)中引進(jìn)變頻器結(jié)合小型 PLC 技術(shù)，不僅改變傳統(tǒng)用閥門控制水 量多少，而且在節(jié)能、恒壓控制等方面均有非常好的效果，本文介紹了變頻器 -PLC 調(diào)控技術(shù)在水泵控制中的應(yīng)用?？刂葡到y(tǒng)用一臺變頻器可以帶三臺水泵， 每臺水泵既可以工作在常規(guī)工頻泵 模式， 也可以工作在變頻泵模式。 每臺泵只能處于變頻或工頻其中一種工作模式， 通過兩個繼電器互鎖保證它的安全與可靠。系統(tǒng)的結(jié)構(gòu)如圖一所示，利用安置在 的生活用水中的壓力變送器將水的壓力信號傳輸?shù)秸{(diào)節(jié)器， 根據(jù)與調(diào)節(jié)器的設(shè)定 值和報警上下限比較，送信號給 PLC 與變頻器，系統(tǒng)的起停泵分別由調(diào)節(jié)器的 壓力下限信號和變頻器的頻

4、率下限信號決定，假如壓力低，調(diào)節(jié)器給 PLC 一個 壓力下限信號，PLC 啟動變頻器，并使一號泵處于變頻工作狀態(tài)， 輸出的頻率 逐漸增大，經(jīng)過一段時間的調(diào)節(jié)，如壓力還低，這時，PLC 讓一號泵處于工頻狀 態(tài)工作，使二號泵處于變頻工作狀態(tài)泵，如壓力還低，則讓二號泵處于工頻狀態(tài) 工作， 使三號泵處于變頻工作狀態(tài)， 如此類推。 當(dāng)壓力達(dá)到調(diào)節(jié)器上限報警值時， 調(diào)節(jié)器輸出降低，變頻器頻率降低，低到頻率下限設(shè)定值，這時變頻器給出一個 頻率下限信號給 PLC ，PLC 根據(jù)先啟先停的原則控制泵的運行順序，例如，PLC 收到頻率下限信號時， 系統(tǒng)中泵的狀態(tài)是一號工頻，二號工頻，三號變頻，這 時一號泵最先啟動

5、，所以先停，接著如壓力還高，則停二號泵。系統(tǒng)采用了每次 都進(jìn)行低速啟動，高速運行以提高運行效率。采用變頻器-PLC 恒壓供水裝置有以下幾個優(yōu)點：A:節(jié)電效益高。傳統(tǒng)水泵電機均采用大容量電機，用閥門控制水量恒定，造 成電能浪費。 變頻系統(tǒng)，無論工作參數(shù)如何，電機的效率不會降低，電機的功率因數(shù)會得 到提高。B:運行可靠、穩(wěn)定。系統(tǒng)中的核心部件變頻調(diào)速器本身的可靠性很高，一般 情況下可連續(xù)使用 10 萬/h 以上。系統(tǒng)還采用軟啟動方式，不存在電氣沖擊，不 污染電網(wǎng)，而且變頻器自帶欠壓、過壓、過流、過載、過熱以及失速等各種保護(hù) 功能。系統(tǒng)對管網(wǎng)壓力波動采取阻尼濾波處理，供水恒壓精度較高，通常能控制 在

6、 0.002Mpa 范圍內(nèi)。C:結(jié)構(gòu)簡單，操作簡便。裝置的控制系統(tǒng)采用集成度高，配套方案靈活多樣， 由可編程控制器得到水泵運行的各種組合。調(diào)速范圍廣，對水量變化的適應(yīng)能力 強。D:使用壽命長，自動化程度高，無需人看管，維護(hù)量少。 以上系統(tǒng)在實際的應(yīng)用中效果顯著， 如將 PLC 與變頻器中自帶編程器的功能 集成，可開發(fā)成一些專用的變頻器，這樣系統(tǒng)的可靠性與健壯性大大增強，應(yīng)用 更加簡單，系統(tǒng)的總成本也會下降?？梢灶A(yù)見：未來的變頻技術(shù)會向以下方向發(fā)展：(1 高性能化 包括內(nèi)部的整流電路、逆變電路都采用高頻 PWM 電路從而使輸入、輸出都 是正弦波；對于大容量變頻器采用多重化和多機并聯(lián)；降低變頻器自

7、身損耗，實 現(xiàn)高效率化；實現(xiàn)自動調(diào)諧或自優(yōu)化、遙控和遠(yuǎn)控；更加面向用戶，進(jìn)一步提高 可使用性和維修性：向著小型、輕量發(fā)展，以及降低成本等。(2 智能化 包括兩個方面：盡量減少硬件，實現(xiàn)硬件軟件化；采用智能電力電子器件 和其他智能化部件。集成化是智能化的基礎(chǔ)。(3 全數(shù)字化 近年來，各種現(xiàn)代控制理論、專家系統(tǒng)、模糊控制及神經(jīng)元控制等都是發(fā)展 的熱點，將使電力電子控制技術(shù)發(fā)展到一個嶄新的階段。預(yù)計 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。 (4 系統(tǒng)化 變頻技術(shù)的發(fā)展與其相關(guān)技術(shù)的發(fā)展是分不開的， 21 世紀(jì)變頻技術(shù)的發(fā) 在 展是將電網(wǎng)、整流器、逆變器、電動機、生產(chǎn)機械和控制

8、系統(tǒng)等作為一個整體、 從系統(tǒng)上進(jìn)行考慮的。 Transducer in the water control system applications Currently, the water level control in a large part of the electrical pumps are not towing gear shift system, no gear shift most of the electrical energy consumed in the water supply to the frequent changes in the pumps stopped

9、. This not only makes the electrical work in inefficient zones, cut short the useful life of electrical and electrical equipment for the frequent failure to stop the high rate, leading to serious waste of water resources, system maintenance, repairs larger workload. With high living water and indust

10、rial water gradually increased, the traditional control methods that are outdated. Originally used for artificial water level control, water level due to the lack of accurate positioning hour monitoring, it is difficult to accurately control the pumps have stopped; Using buoys or mechanical control

11、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 Constant Pressure control system can be sol

12、ved by the existence of the above problems. Consider selecting Single Chip Micro controller or PLC and transducer combination at the core of the system can achieve a better control results. But in software design, PLC programming of more than Single Chip Micro controller concise, and visual; From th

13、e hardware interface considerations, Single Chip Micro controller circuit slightly complex; From the economic considerations, the PLC processes are mature, cost and small PLC Single Chip Micro controller a little, because the system parameters to be adjusted in accordance with the situation on the g

14、round, PLC software, the time parameters adjustments simpler, so more conducive to after-sale personnel. For the above reasons, the selection of the Omron PLC CPM1 series with the transducer as ABB control core, coupled with PSW7 conditioners and WSP300 Biansongqi pressure, the effect was very good

15、control, software design simple hardware interface simple and feasible, reliable, the entire system Xingjiebi very high. Transducer in the water system in conjunction with the introduction of small PLC technology not only change the traditional use of water control valves, and in energy conservation

16、, Constant Pressure control, are very good results, the paper introduced a transducer -PLC control technology in the pump control applications.Control system using one Taiwan transducer can bring three pumps, pumps can work at the frequency pump in the conventional model can work in the frequency co

17、nversion pump model. At the pump only in frequency conversion or one of the working frequency mode through two relays efficient ensure its security and reliability. System structure as figure 1 shows, the use of placement in the life of water pressure Biansongqi water pressure signal transmission to

18、 the regulator, in accordance with the regulator to set the value and warning of lower compared 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 press

19、ure 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,

20、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 freq

21、uency 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, 2nd-frequency, 3rd frequency conversion, the first time 1st pumps activated, the first stop,

22、 then as the pressure was high, then stopped on the 2nd pumps. Each system is used for slow start, high-speed 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 wate

23、r volume how many, moreover in aspects and so on energyconservation, constant pressure control had the extremely good effect, this article introduced the frequency changer-PLC regulation technology in water pump control application. The control system may bring three water pumps with a frequency cha

24、nger, 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

25、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 compare, delivers a letter the number fo

26、r PLC and the frequency changer, the system stops the pump separately decided by the regulator low pressure limit signal and the frequency changer lower frequency limit signal, if the pressure is low, the regulator for a PLC low pressure limit signal, the PLC start frequency changer, and causes the

27、first pump to be at the frequency conversion active status, the output frequency increases gradually, passes through a period of time adjustment, if the pressure is also low, by now, PLC let the first pump be at the power frequency condition The work, causes the second pump to be at the frequency co

28、nversion active status pump, if the pressure is also low, then lets the second pump be at the power frequency condition work, causes the third pump to be at the frequency conversion active status, so analogizes. When the pressure achieved when the regulator upper limit reported to the police the val

29、ue, the regulator outputs reduces, the frequency changer frequency reduces, lowers to the lower frequency limit setting value, by now the frequency changer gave a lower frequency limit signal the principle which opened first for the PLC, PLC basis stops first to control the pump the movement order,

30、when for example, PLC received the lower frequency limit signal, in the system the pump condition was a power frequency, two power frequencies, three frequency conversion, the first pump first started by now, therefore stopped first, like the pressure also was then high then stopped the second pump.

31、 The system used all has each time carried on the low speed to start, the high speed movement enhanced the operating efficiency. Uses the frequency changer - PLC constant pressure water supply installment to have following several merits: A:The electricity saving benefit is high. The traditional wat

32、er pump electrical machinery uses the large capacity electrical machinery, is constant with the valve control water volume, creates the electrical energy waste.Frequency conversion system, regardless of the operational parameter how, the electrical machinery efficiency can't reduce, the electric

33、al 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 long-term usage 100,000/Above h. The system also selects the soft start method, does no

34、t have the electrical impact, does not pollute the electrical network, 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 netw

35、ork fluctuation of pressure, the water supply constant pressure precision is high, usually can control in the 0.002Mpa 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 mov

36、ement each kind of combination 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 remarkab

37、le in the actual application, if brings in PLC and the frequency changer the programmer the function integration, potential becomes some special-purpose frequency changers, such system reliability and the toughness big enhancement, the application is simpler, the system total cost also can drop.May

38、foresee: The future frequency conversion technology will be able to develop to the below direction:(1 high performanceThus 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; Uses the multi-densification regarding the large capacity frequency changer and many machine is parallel; Reduces frequency changer own loss, the realization h