內置PID調節器在恒(heng)壓(ya)變頻供水(shui)設備中的應用

一、引言

      自從通用變頻(pin)(pin)器問世以來，變頻(pin)(pin)調速(su)技術(shu)在各(ge)個(ge)領域(yu)得(de)到了廣泛的(de)(de)(de)應(ying)用。變頻(pin)(pin)調速(su)恒壓供(gong)水設(she)備以其節能(neng)、安(an)全、高品(pin)質的(de)(de)(de)供(gong)水質量(liang)等(deng)優(you)點，在實際應(ying)用中得(de)到了很大的(de)(de)(de)發展(zhan)。隨著電力電子技術(shu)的(de)(de)(de)飛速(su)發展(zhan)，變頻(pin)(pin)器的(de)(de)(de)功能(neng)也越來越強。充(chong)分利用變頻(pin)(pin)器內置的(de)(de)(de)各(ge)種功能(neng)，對合理(li)設(she)計變頻(pin)(pin)調速(su)恒壓供(gong)水設(she)備，降低成(cheng)本(ben)，保證產(chan)品(pin)質量(liang)等(deng)方面有著非常重要的(de)(de)(de)意義。

二、傳(chuan)統的(de)變頻(pin)調速恒壓供(gong)水設備設計(ji)方案(an)

      變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)(qi)(qi)的(de)(de)(de)作用(yong)(yong)是為(wei)(wei)電(dian)(dian)(dian)機提(ti)供(gong)可(ke)變(bian)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)的(de)(de)(de)電(dian)(dian)(dian)源，實現電(dian)(dian)(dian)機的(de)(de)(de)無級(ji)調(diao)速(su)，從而使(shi)管網水(shui)(shui)(shui)(shui)壓(ya)(ya)連續變(bian)化。傳感(gan)器(qi)(qi)(qi)(qi)(qi)(qi)的(de)(de)(de)任務是檢(jian)測管網水(shui)(shui)(shui)(shui)壓(ya)(ya)，壓(ya)(ya)力(li)(li)(li)設(she)定(ding)(ding)(ding)單元為(wei)(wei)系(xi)統提(ti)供(gong)滿足用(yong)(yong)戶(hu)需要的(de)(de)(de)水(shui)(shui)(shui)(shui)壓(ya)(ya)期望(wang)值(zhi)。壓(ya)(ya)力(li)(li)(li)設(she)定(ding)(ding)(ding)信(xin)(xin)(xin)號(hao)和壓(ya)(ya)力(li)(li)(li)反(fan)饋信(xin)(xin)(xin)號(hao)在(zai)輸(shu)(shu)入(ru)可(ke)編程(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)(qi)(qi)(qi)后，經可(ke)編程(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)(qi)(qi)(qi)內部PID控(kong)(kong)(kong)制(zhi)(zhi)(zhi)程(cheng)(cheng)序的(de)(de)(de)計算，輸(shu)(shu)出(chu)(chu)(chu)(chu)給變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)(qi)(qi)一(yi)(yi)個轉(zhuan)速(su)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)信(xin)(xin)(xin)號(hao)。還有一(yi)(yi)種辦法(fa)是將壓(ya)(ya)力(li)(li)(li)設(she)定(ding)(ding)(ding)信(xin)(xin)(xin)號(hao)和壓(ya)(ya)力(li)(li)(li)反(fan)饋信(xin)(xin)(xin)號(hao)送入(ru)PID回路(lu)(lu)調(diao)節器(qi)(qi)(qi)(qi)(qi)(qi)，由PID回路(lu)(lu)調(diao)節器(qi)(qi)(qi)(qi)(qi)(qi)在(zai)調(diao)節器(qi)(qi)(qi)(qi)(qi)(qi)內部進(jin)行運算后，輸(shu)(shu)出(chu)(chu)(chu)(chu)給變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)(qi)(qi)一(yi)(yi)個轉(zhuan)速(su)調(diao)節信(xin)(xin)(xin)號(hao)，如圖1中虛線所(suo)示。一(yi)(yi)般的(de)(de)(de)供(gong)水(shui)(shui)(shui)(shui)設(she)備(bei)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)1~3臺(tai)(tai)水(shui)(shui)(shui)(shui)泵(beng)(beng)，1~2臺(tai)(tai)工(gong)作，1臺(tai)(tai)備(bei)用(yong)(yong)。在(zai)這些(xie)水(shui)(shui)(shui)(shui)泵(beng)(beng)中，一(yi)(yi)般只有一(yi)(yi)臺(tai)(tai)變(bian)頻(pin)(pin)(pin)(pin)(pin)泵(beng)(beng)。當(dang)供(gong)水(shui)(shui)(shui)(shui)設(she)備(bei)供(gong)電(dian)(dian)(dian)開始工(gong)作時(shi)(shi)，先起動變(bian)頻(pin)(pin)(pin)(pin)(pin)泵(beng)(beng)，管網水(shui)(shui)(shui)(shui)壓(ya)(ya)達(da)到(dao)設(she)定(ding)(ding)(ding)值(zhi)時(shi)(shi)，變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)(qi)(qi)的(de)(de)(de)輸(shu)(shu)出(chu)(chu)(chu)(chu)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)則(ze)穩(wen)定(ding)(ding)(ding)在(zai)一(yi)(yi)定(ding)(ding)(ding)的(de)(de)(de)數值(zhi)上。而當(dang)用(yong)(yong)水(shui)(shui)(shui)(shui)量(liang)(liang)增(zeng)加(jia)，水(shui)(shui)(shui)(shui)壓(ya)(ya)降低時(shi)(shi)，傳感(gan)器(qi)(qi)(qi)(qi)(qi)(qi)將這一(yi)(yi)信(xin)(xin)(xin)號(hao)送入(ru)可(ke)編程(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)(qi)(qi)(qi)或PID回路(lu)(lu)調(diao)節器(qi)(qi)(qi)(qi)(qi)(qi)，可(ke)編程(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)(qi)(qi)(qi)或PID回路(lu)(lu)調(diao)節器(qi)(qi)(qi)(qi)(qi)(qi)則(ze)送出(chu)(chu)(chu)(chu)一(yi)(yi)個較用(yong)(yong)水(shui)(shui)(shui)(shui)量(liang)(liang)增(zeng)加(jia)前大(da)的(de)(de)(de)信(xin)(xin)(xin)號(hao)，使(shi)變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)(qi)(qi)的(de)(de)(de)輸(shu)(shu)出(chu)(chu)(chu)(chu)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)上升，水(shui)(shui)(shui)(shui)泵(beng)(beng)的(de)(de)(de)轉(zhuan)速(su)提(ti)高(gao)，水(shui)(shui)(shui)(shui)壓(ya)(ya)上升。如果(guo)用(yong)(yong)水(shui)(shui)(shui)(shui)量(liang)(liang)增(zeng)加(jia)很多，使(shi)變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)(qi)(qi)的(de)(de)(de)輸(shu)(shu)出(chu)(chu)(chu)(chu)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)達(da)到(dao)最大(da)值(zhi)，仍不能(neng)使(shi)管網水(shui)(shui)(shui)(shui)壓(ya)(ya)達(da)到(dao)設(she)定(ding)(ding)(ding)值(zhi)時(shi)(shi)，可(ke)編程(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)(qi)(qi)(qi)或PID回路(lu)(lu)調(diao)節器(qi)(qi)(qi)(qi)(qi)(qi)就(jiu)發出(chu)(chu)(chu)(chu)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)信(xin)(xin)(xin)號(hao)，起動一(yi)(yi)臺(tai)(tai)工(gong)頻(pin)(pin)(pin)(pin)(pin)泵(beng)(beng)，其(qi)他泵(beng)(beng)依次(ci)類推。反(fan)之，當(dang)用(yong)(yong)水(shui)(shui)(shui)(shui)量(liang)(liang)減(jian)少，變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)(qi)(qi)的(de)(de)(de)輸(shu)(shu)出(chu)(chu)(chu)(chu)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)達(da)到(dao)最小值(zhi)時(shi)(shi)，則(ze)發出(chu)(chu)(chu)(chu)減(jian)少一(yi)(yi)臺(tai)(tai)工(gong)頻(pin)(pin)(pin)(pin)(pin)電(dian)(dian)(dian)機的(de)(de)(de)命令。圖1中M1~M3為(wei)(wei)電(dian)(dian)(dian)機，P1~P3為(wei)(wei)水(shui)(shui)(shui)(shui)泵(beng)(beng)，JC1~JC6為(wei)(wei)電(dian)(dian)(dian)機起、停、互相(xiang)切(qie)換(huan)的(de)(de)(de)交流接觸器(qi)(qi)(qi)(qi)(qi)(qi)。

      由(you)于(yu)變(bian)(bian)頻(pin)器(qi)(qi)(qi)的(de)(de)(de)轉(zhuan)速控(kong)(kong)(kong)制(zhi)(zhi)(zhi)信(xin)號(hao)(hao)是由(you)可(ke)(ke)(ke)(ke)編(bian)(bian)(bian)(bian)程(cheng)(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)或PID回路(lu)(lu)調(diao)節器(qi)(qi)(qi)給(gei)出(chu)(chu)的(de)(de)(de)，所(suo)以(yi)(yi)對可(ke)(ke)(ke)(ke)編(bian)(bian)(bian)(bian)程(cheng)(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)來講，既(ji)要有模(mo)(mo)(mo)擬(ni)量(liang)(liang)輸(shu)(shu)(shu)入(ru)(ru)接(jie)口(kou)，又要有模(mo)(mo)(mo)擬(ni)量(liang)(liang)輸(shu)(shu)(shu)出(chu)(chu)接(jie)口(kou)。由(you)于(yu)帶模(mo)(mo)(mo)擬(ni)量(liang)(liang)輸(shu)(shu)(shu)入(ru)(ru)/輸(shu)(shu)(shu)出(chu)(chu)接(jie)口(kou)的(de)(de)(de)可(ke)(ke)(ke)(ke)編(bian)(bian)(bian)(bian)程(cheng)(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)價格很高，這無形中(zhong)就(jiu)增加(jia)了(le)供(gong)水設(she)備(bei)的(de)(de)(de)成本。若采(cai)用帶有模(mo)(mo)(mo)擬(ni)量(liang)(liang)輸(shu)(shu)(shu)入(ru)(ru)/數字量(liang)(liang)輸(shu)(shu)(shu)出(chu)(chu)的(de)(de)(de)可(ke)(ke)(ke)(ke)編(bian)(bian)(bian)(bian)程(cheng)(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)，則要在可(ke)(ke)(ke)(ke)編(bian)(bian)(bian)(bian)程(cheng)(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)的(de)(de)(de)數字量(liang)(liang)輸(shu)(shu)(shu)出(chu)(chu)口(kou)另接(jie)一(yi)塊PWM調(diao)制(zhi)(zhi)(zhi)板，將可(ke)(ke)(ke)(ke)編(bian)(bian)(bian)(bian)程(cheng)(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)輸(shu)(shu)(shu)出(chu)(chu)的(de)(de)(de)數字量(liang)(liang)信(xin)號(hao)(hao)轉(zhuan)變(bian)(bian)為(wei)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)變(bian)(bian)頻(pin)器(qi)(qi)(qi)轉(zhuan)速的(de)(de)(de)模(mo)(mo)(mo)擬(ni)信(xin)號(hao)(hao)，造(zao)成可(ke)(ke)(ke)(ke)編(bian)(bian)(bian)(bian)程(cheng)(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)的(de)(de)(de)成本沒(mei)有降低，還增加(jia)了(le)連線和(he)附(fu)加(jia)設(she)備(bei)，降低了(le)整套(tao)設(she)備(bei)的(de)(de)(de)可(ke)(ke)(ke)(ke)靠性。如果采(cai)用一(yi)個(ge)(ge)開關量(liang)(liang)輸(shu)(shu)(shu)入(ru)(ru)/輸(shu)(shu)(shu)出(chu)(chu)的(de)(de)(de)可(ke)(ke)(ke)(ke)編(bian)(bian)(bian)(bian)程(cheng)(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)和(he)一(yi)個(ge)(ge)PID回路(lu)(lu)調(diao)節器(qi)(qi)(qi)，其成本也(ye)和(he)帶模(mo)(mo)(mo)擬(ni)量(liang)(liang)輸(shu)(shu)(shu)入(ru)(ru)/輸(shu)(shu)(shu)出(chu)(chu)的(de)(de)(de)可(ke)(ke)(ke)(ke)編(bian)(bian)(bian)(bian)程(cheng)(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)差不多。所(suo)以(yi)(yi)，在變(bian)(bian)頻(pin)調(diao)速恒壓給(gei)水控(kong)(kong)(kong)制(zhi)(zhi)(zhi)設(she)備(bei)中(zhong)，PID控(kong)(kong)(kong)制(zhi)(zhi)(zhi)信(xin)號(hao)(hao)的(de)(de)(de)產生(sheng)和(he)輸(shu)(shu)(shu)出(chu)(chu)就(jiu)成為(wei)降低給(gei)水設(she)備(bei)成本的(de)(de)(de)一(yi)個(ge)(ge)關鍵環(huan)節。

三、新型(xing)變頻(pin)調(diao)速供水設備的解(jie)決方案

      針對(dui)傳統的(de)變(bian)(bian)頻(pin)(pin)調(diao)速供水(shui)設(she)備的(de)不足之處，國外不少生(sheng)產(chan)(chan)(chan)廠(chang)家近年來(lai)紛(fen)紛(fen)推出了(le)一系(xi)列(lie)新(xin)(xin)型產(chan)(chan)(chan)品，如(ru)ABB公司(si)(si)的(de)ACS600、ACS400系(xi)列(lie)產(chan)(chan)(chan)品，富士(shi)公司(si)(si)的(de)G11S/P11S系(xi)列(lie)產(chan)(chan)(chan)品,北京(jing)菱科LK600P系(xi)列(lie)。這(zhe)(zhe)(zhe)些產(chan)(chan)(chan)品將PID調(diao)節器以及簡易可(ke)(ke)編程控制器的(de)功(gong)(gong)能都(dou)綜合進變(bian)(bian)頻(pin)(pin)器內，形成了(le)帶有各(ge)種應用(yong)(yong)(yong)宏的(de)新(xin)(xin)型變(bian)(bian)頻(pin)(pin)器。這(zhe)(zhe)(zhe)類變(bian)(bian)頻(pin)(pin)器的(de)價格僅比通(tong)用(yong)(yong)(yong)變(bian)(bian)頻(pin)(pin)器略(lve)微高一點，但功(gong)(gong)能卻強很多，所以我(wo)們(men)在(zai)山東(dong)文(wen)登曲軸廠(chang)新(xin)(xin)建的(de)生(sheng)活(huo)小區中(zhong)就采用(yong)(yong)(yong)了(le)這(zhe)(zhe)(zhe)種新(xin)(xin)型的(de)設(she)計方案。在(zai)這(zhe)(zhe)(zhe)套給水(shui)設(she)備中(zhong)，我(wo)們(men)采用(yong)(yong)(yong)了(le)ABB公司(si)(si)的(de)ACS601-0011-3帶內置PID功(gong)(gong)能的(de)變(bian)(bian)頻(pin)(pin)器，可(ke)(ke)編程控制器選用(yong)(yong)(yong)西門子S7-214-1BC10-0XB0型，具體原理框圖如(ru)圖2所以示。圖2中(zhong)M1~M2為(wei)電(dian)機(ji)，P1~P2為(wei)水(shui)泵，JC1~JC4為(wei)電(dian)機(ji)起(qi)、停、互(hu)相切換的(de)交流接觸器。

      該(gai)變頻調速恒壓給水(shui)設備采(cai)(cai)用(yong)(yong)2臺(tai)水泵(beng)(beng)，一用(yong)(yong)一備，由可(ke)(ke)(ke)編(bian)程控(kong)制(zhi)器(qi)(qi)(qi)(qi)(qi)定時(shi)切換。若用(yong)(yong)水量大，變(bian)頻(pin)(pin)器(qi)(qi)(qi)(qi)(qi)也可(ke)(ke)(ke)以通(tong)過可(ke)(ke)(ke)編(bian)程接(jie)口向可(ke)(ke)(ke)編(bian)程控(kong)制(zhi)器(qi)(qi)(qi)(qi)(qi)發出信(xin)號(hao)，由可(ke)(ke)(ke)編(bian)程控(kong)制(zhi)器(qi)(qi)(qi)(qi)(qi)控(kong)制(zhi)兩(liang)臺(tai)泵(beng)(beng)同時(shi)工作(zuo)，一臺(tai)變(bian)頻(pin)(pin)運行，一臺(tai)工頻(pin)(pin)運行。圖2中傳感(gan)器(qi)(qi)(qi)(qi)(qi)反饋的(de)水壓信(xin)號(hao)直(zhi)接(jie)送入變(bian)頻(pin)(pin)器(qi)(qi)(qi)(qi)(qi)自帶(dai)的(de)PID調(diao)節器(qi)(qi)(qi)(qi)(qi)輸入口AI2+、AI2-，而(er)壓力設定既可(ke)(ke)(ke)以使用(yong)(yong)變(bian)頻(pin)(pin)器(qi)(qi)(qi)(qi)(qi)的(de)鍵盤(pan)以數字(zi)量的(de)形(xing)式設定，也可(ke)(ke)(ke)以采(cai)(cai)用(yong)(yong)一只電位(wei)器(qi)(qi)(qi)(qi)(qi)以模擬量的(de)形(xing)式送入AI1+、AI1-。這樣通(tong)過變(bian)頻(pin)(pin)器(qi)(qi)(qi)(qi)(qi)的(de)控(kong)制(zhi)面板，在變(bian)頻(pin)(pin)器(qi)(qi)(qi)(qi)(qi)的(de)PID選(xuan)項中選(xuan)擇合適(shi)的(de)PID參數，并經過現場調(diao)試校正，設備就可(ke)(ke)(ke)以正常(chang)運行了(le)。 

      由于PID運算在(zai)變(bian)頻器(qi)(qi)(qi)內部(bu)，這就省(sheng)去了對(dui)(dui)可編(bian)程控制器(qi)(qi)(qi)存貯容量的(de)要(yao)求和(he)對(dui)(dui)PID算法的(de)編(bian)程，而且(qie)PID參(can)數(shu)的(de)在(zai)線調(diao)試非(fei)常(chang)容易，這不僅(jin)降低(di)了生產成本，而且(qie)大大提高了生產效率。由于變(bian)頻器(qi)(qi)(qi)內部(bu)自帶的(de)PID調(diao)節(jie)器(qi)(qi)(qi)采用(yong)了優化算法，所以使水(shui)壓的(de)調(diao)節(jie)十(shi)分平滑，穩定(ding)。同(tong)時，為了保(bao)證(zheng)水(shui)壓反饋(kui)信號值的(de)準確、不失值，可對(dui)(dui)該信號設(she)置濾(lv)波時間常(chang)數(shu)，同(tong)時還可對(dui)(dui)反饋(kui)信號進行換算，使系統的(de)調(diao)試非(fei)常(chang)簡單(dan)、方便。該設(she)備(bei)自1997年10月(yue)在(zai)該生活小區運行以來，一(yi)直保(bao)持良好(hao)的(de)運行狀(zhuang)態，管網(wang)水(shui)壓非(fei)常(chang)穩定(ding)，受到了小區用(yong)戶(hu)的(de)一(yi)致(zhi)好(hao)評(ping)。