關于變電站直流屏技術的分析研究
2019/6/10 14:30:31??????點擊:
直(zhi)(zhi)(zhi)流(liu)(liu)屏是變電站(zhan)(zhan)正(zheng)常運(yun)行的(de)重(zhong)要組成(cheng),其(qi)能夠持續向變電站(zhan)(zhan)輸(shu)送穩定的(de)直(zhi)(zhi)(zhi)流(liu)(liu)電源(yuan)(yuan),滿足了電力設備操(cao)作運(yun)行的(de)用(yong)電需(xu)求。從實際運(yun)用(yong)情(qing)況來說,變電站(zhan)(zhan)蓄電池直(zhi)(zhi)(zhi)流(liu)(liu)屏在使用(yong)壽命(ming)及(ji)電能供(gong)應方面的(de)性能難(nan)(nan)以(yi)達到標準要求,制約了直(zhi)(zhi)(zhi)流(liu)(liu)電源(yuan)(yuan)操(cao)作系(xi)統(tong)性能的(de)發揮。研究(jiu)發現采(cai)用(yong)超級電容直(zhi)(zhi)(zhi)流(liu)(liu)屏可有效解決(jue)直(zhi)(zhi)(zhi)流(liu)(liu)電源(yuan)(yuan)供(gong)應難(nan)(nan)題,經過改進后(hou)的(de)超級電容直(zhi)(zhi)(zhi)流(liu)(liu)屏在性能、壽命(ming)、穩定等方面都有了很大的(de)改善,其(qi)與蓄電池直(zhi)(zhi)(zhi)流(liu)(liu)屏相比存在明顯的(de)優勢(shi)。
直(zhi)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)源(yuan)操(cao)作系統簡(jian)稱(cheng)“直(zhi)流(liu)(liu)(liu)屏(ping)”,在變(bian)電(dian)(dian)(dian)(dian)(dian)站中向各種(zhong)電(dian)(dian)(dian)(dian)(dian)力(li)(li)設備提(ti)供穩定的(de)(de)(de)直(zhi)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)源(yuan),也是現代變(bian)電(dian)(dian)(dian)(dian)(dian)站核心的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)力(li)(li)操(cao)作電(dian)(dian)(dian)(dian)(dian)源(yuan)。直(zhi)流(liu)(liu)(liu)屏(ping)技術不僅保(bao)護(hu)了(le)電(dian)(dian)(dian)(dian)(dian)力(li)(li)系統的(de)(de)(de)正常運行(xing)(xing)(xing),對于其他元件的(de)(de)(de)穩定操(cao)控也起到很好的(de)(de)(de)保(bao)護(hu)作用(yong)。對變(bian)電(dian)(dian)(dian)(dian)(dian)站直(zhi)流(liu)(liu)(liu)屏(ping)存在的(de)(de)(de)問(wen)題進行(xing)(xing)(xing)深入(ru)分析,可以保(bao)證(zheng)持續性的(de)(de)(de)直(zhi)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)源(yuan)供應,為電(dian)(dian)(dian)(dian)(dian)力(li)(li)設備及相(xiang)關模塊的(de)(de)(de)正常操(cao)控創造有利的(de)(de)(de)條件。電(dian)(dian)(dian)(dian)(dian)力(li)(li)行(xing)(xing)(xing)業積(ji)極引入(ru)直(zhi)流(liu)(liu)(liu)屏(ping)技術可加快變(bian)電(dian)(dian)(dian)(dian)(dian)站的(de)(de)(de)自動化、智能化發展,提(ti)高變(bian)電(dian)(dian)(dian)(dian)(dian)站設備運行(xing)(xing)(xing)的(de)(de)(de)整體效(xiao)率(lv)。
一(yi)、當前變電(dian)站直流(liu)屏存在的問題
國(guo)內變(bian)(bian)電(dian)(dian)站采(cai)用的(de)(de)(de)直(zhi)(zhi)流屏由充(chong)電(dian)(dian)柜(ju)、充(chong)電(dian)(dian)模塊(kuai)、監控模塊(kuai)、電(dian)(dian)池組(zu)、降壓(ya)硅鏈等(deng)結構(gou)組(zu)成,每一(yi)個模塊(kuai)都對直(zhi)(zhi)流電(dian)(dian)源(yuan)供應(ying)發揮重要(yao)的(de)(de)(de)作(zuo)用。從(cong)行(xing)業(ye)發展趨勢分析直(zhi)(zhi)流屏,其(qi)屬于數字(zi)化調(diao)控模式下運行(xing)的(de)(de)(de)直(zhi)(zhi)流系統,對變(bian)(bian)電(dian)(dian)站直(zhi)(zhi)流電(dian)(dian)源(yuan)供應(ying)具(ju)有調(diao)控、保護、管理、監測(ce)等(deng)多方面作(zuo)用。目(mu)前,變(bian)(bian)電(dian)(dian)站采(cai)用直(zhi)(zhi)流屏技術(shu)具(ju)備了遠程監測(ce)、調(diao)控等(deng)高(gao)級功能(neng),方便了值班人員對電(dian)(dian)力系統運行(xing)的(de)(de)(de)調(diao)控。但直(zhi)(zhi)流屏存在的(de)(de)(de)一(yi)些問(wen)題(ti)(ti)也應(ying)該(gai)引起(qi)技術(shu)人員的(de)(de)(de)關注,鎘(ge)鎳蓄(xu)電(dian)(dian)池、密封鉛酸蓄(xu)電(dian)(dian)池是常用的(de)(de)(de)直(zhi)(zhi)流屏,其(qi)主要(yao)問(wen)題(ti)(ti)如下:
(一)鎘鎳蓄電池(chi)直流(liu)屏
1.性能(neng)問題。變(bian)電(dian)(dian)(dian)(dian)站通(tong)過直流(liu)母(mu)線(xian)(xian)輸出電(dian)(dian)(dian)(dian)能(neng)需(xu)要(yao)使用大批蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)模(mo)塊,以此(ci)來(lai)維持正常的(de)(de)(de)直流(liu)電(dian)(dian)(dian)(dian)源操(cao)控(kong)。如:一(yi)般情況(kuang)下,大型(xing)變(bian)電(dian)(dian)(dian)(dian)站直流(liu)母(mu)線(xian)(xian)輸出220V,需(xu)使用200只(zhi)左右的(de)(de)(de)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)組合(he)模(mo)塊。但鎘(ge)鎳(nie)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)在(zai)生(sheng)產(chan)處理期間,廠(chang)家無法(fa)保證每只(zhi)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)充電(dian)(dian)(dian)(dian)、放(fang)電(dian)(dian)(dian)(dian)性能(neng)完(wan)全一(yi)致,200只(zhi)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)組合(he)起來(lai)會產(chan)生(sheng)明(ming)顯的(de)(de)(de)特(te)性差異。鎘(ge)鎳(nie)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)直流(liu)屏在(zai)供應直流(liu)電(dian)(dian)(dian)(dian)源后所連接的(de)(de)(de)充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)源一(yi)致,并且負荷放(fang)電(dian)(dian)(dian)(dian)的(de)(de)(de)對象相同。這種特(te)點導致局(ju)部鎘(ge)鎳(nie)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)性能(neng)減弱,降(jiang)低了整(zheng)個蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)組合(he)模(mo)塊的(de)(de)(de)功能(neng)。
2.壽(shou)命(ming)(ming)問題。由于鎘(ge)鎳蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)組合材料(liao)的缺陷,直(zhi)流(liu)屏(ping)(ping)(ping)運行(xing)時本質上處于“浮(fu)充(chong)狀態(tai)”,此(ci)(ci)時鎘(ge)鎳蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)直(zhi)流(liu)屏(ping)(ping)(ping)的使用(yong)壽(shou)命(ming)(ming)取(qu)決于充(chong)電(dian)(dian)(dian)(dian)機。按(an)照行(xing)業標準(zhun)里(li)的規(gui)定,廠家對鎘(ge)鎳蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)的保證(zheng)命(ming)(ming)在10年(nian)以上,而具體使用(yong)的記(ji)錄情(qing)況僅有5年(nian)左右(you)的時間。蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)直(zhi)流(liu)屏(ping)(ping)(ping)壽(shou)命(ming)(ming)縮(suo)短的原因(yin)是由94于俯沖電(dian)(dian)(dian)(dian)流(liu)超標會造(zao)成(cheng)電(dian)(dian)(dian)(dian)解液中的水電(dian)(dian)(dian)(dian)解成(cheng)氫(qing)、氧,這(zhe)是造(zao)成(cheng)蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)炸的根本原因(yin),若采用(yong)鎘(ge)鎳蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)直(zhi)流(liu)屏(ping)(ping)(ping)時未做特殊處理(li),則很容(rong)易引起意外事故。因(yin)此(ci)(ci),直(zhi)流(liu)屏(ping)(ping)(ping)的使用(yong)壽(shou)命(ming)(ming)長短會受到其他(ta)方面因(yin)素的限制(zhi)。
3.氧化(hua)問題。變電(dian)(dian)(dian)廠鎘(ge)(ge)鎳(nie)蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)直(zhi)流屏(ping)使用(yong)期(qi)間也會(hui)(hui)出(chu)現氧化(hua)還原反應(ying),使鎘(ge)(ge)鎳(nie)材料發生化(hua)學反應(ying)生成氧化(hua)鎘(ge)(ge),造成極板(ban)的(de)有效面積不斷減(jian)小。為了避免(mian)氧化(hua)還原反應(ying)的(de)發生,變電(dian)(dian)(dian)站(zhan)工作人員會(hui)(hui)定期(qi)對(dui)蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)進行(xing)(xing)“活化(hua)試驗”分析。在活化(hua)試驗里需對(dui)蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)進行(xing)(xing)充(chong)放(fang)電(dian)(dian)(dian)處理,這一(yi)階段的(de)操作會(hui)(hui)發生極性(xing)反轉而導致(zhi)蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)報廢。另外,氧化(hua)還原反應(ying)在破壞(huai)鎘(ge)(ge)鎳(nie)直(zhi)流屏(ping)性(xing)能的(de)同時,對(dui)變電(dian)(dian)(dian)站(zhan)的(de)穩定運(yun)行(xing)(xing)也會(hui)(hui)埋(mai)下安(an)全(quan)隱患(huan),如(ru):若(ruo)把蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)完全(quan)安(an)裝于柜(ju)內,很容(rong)易引起燒毀(hui)、爆(bao)炸等安(an)全(quan)事故。
(二)密封(feng)鉛酸蓄電池直流屏
在(zai)(zai)科(ke)學(xue)技術的(de)(de)推動下,國(guo)內(nei)變(bian)(bian)電(dian)(dian)站直(zhi)(zhi)流(liu)屏技術不斷發展,許多新的(de)(de)蓄電(dian)(dian)池(chi)(chi)產(chan)(chan)品(pin)也在(zai)(zai)變(bian)(bian)電(dian)(dian)站中得到了(le)普遍(bian)運(yun)用(yong)(yong)。基(ji)于(yu)(yu)鎘鎳(nie)蓄電(dian)(dian)池(chi)(chi)直(zhi)(zhi)流(liu)屏存在(zai)(zai)的(de)(de)不足,企業開始采用(yong)(yong)密封(feng)鉛酸(suan)蓄電(dian)(dian)池(chi)(chi),簡稱(cheng)“閥控蓄電(dian)(dian)池(chi)(chi)”。這種產(chan)(chan)品(pin)在(zai)(zai)質量、性能、價格、維(wei)護(hu)(hu)等方(fang)面均優于(yu)(yu)鎘鎳(nie)蓄電(dian)(dian)池(chi)(chi)。如:閥控蓄電(dian)(dian)池(chi)(chi)無需進行(xing)(xing)過多的(de)(de)維(wei)護(hu)(hu)或加(jia)水處理,為變(bian)(bian)電(dian)(dian)站操(cao)(cao)作人員提供了(le)很大的(de)(de)方(fang)便。但該直(zhi)(zhi)流(liu)屏處于(yu)(yu)“全密封(feng)”狀(zhuang)態也引起了(le)諸多問題,尤其是在(zai)(zai)電(dian)(dian)池(chi)(chi)觀測、檢(jian)查等操(cao)(cao)作時(shi),維(wei)護(hu)(hu)人員難(nan)以及時(shi)更新裝置(zhi)。另外,由(you)于(yu)(yu)國(guo)內(nei)閥控蓄電(dian)(dian)池(chi)(chi)技術相對落后,產(chan)(chan)品(pin)運(yun)用(yong)(yong)于(yu)(yu)變(bian)(bian)電(dian)(dian)站時(shi)壽命無保障,并且對于(yu)(yu)閥控蓄電(dian)(dian)池(chi)(chi)直(zhi)(zhi)流(liu)屏的(de)(de)運(yun)行(xing)(xing)條件十分(fen)嚴格,給變(bian)(bian)電(dian)(dian)站的(de)(de)正常生產(chan)(chan)造成了(le)很大的(de)(de)困難(nan)。
二(er)、影響閾控蓄電池壽(shou)命的因素(su)
使用壽命(ming)是制(zhi)約閥控蓄(xu)電池(chi)推廣(guang)的(de)重要(yao)因
素(su),各大、中(zhong)、小型變(bian)電(dian)站(zhan)采用這種電(dian)源裝置均會考慮使(shi)用壽命(ming)的年限,以(yi)控(kong)制變(bian)電(dian)站(zhan)的運行成本。經(jing)試驗(yan)數(shu)據(ju)分(fen)析,對閥控(kong)蓄電(dian)池使(shi)用壽命(ming)造成影響(xiang)的因(yin)素(su)集中(zhong)在溫度因(yin)素(su)、放電(dian)因(yin)素(su)、失水因(yin)素(su)、腐蝕因(yin)素(su),等等。
(一(yi))溫度因素
盡(jin)管閥控(kong)蓄(xu)電(dian)(dian)池(chi)(chi)運(yun)(yun)用于變電(dian)(dian)站(zhan)還(huan)存在明顯的不(bu)足,但(dan)與鎘鎳蓄(xu)電(dian)(dian)池(chi)(chi)相比(bi)已經有了(le)很大(da)的改(gai)進,對變電(dian)(dian)站(zhan)直(zhi)流電(dian)(dian)源操作(zuo)系統(tong)的運(yun)(yun)行創造(zao)了(le)更好的條(tiao)件。閥控(kong)蓄(xu)電(dian)(dian)池(chi)(chi)壽命(ming)對溫(wen)度十分敏感(gan),生產廠家要(yao)求電(dian)(dian)池(chi)(chi)運(yun)(yun)行環境溫(wen)為15℃~25℃,當環境溫(wen)度超過(guo)25℃后,每(mei)升高10℃電(dian)(dian)池(chi)(chi)壽命(ming)就要(yao)縮短(duan)一(yi)半。
(二)放電因(yin)素
蓄(xu)電池(chi)(chi)(chi)(chi)被(bei)過(guo)度(du)放電是影響蓄(xu)電池(chi)(chi)(chi)(chi)使(shi)用壽命的(de)(de)(de)另一(yi)重要因素。當蓄(xu)電池(chi)(chi)(chi)(chi)被(bei)過(guo)度(du)放電到輸出電壓為零(ling)時,會(hui)導致(zhi)電池(chi)(chi)(chi)(chi)內部(bu)有大(da)(da)量的(de)(de)(de)硫(liu)酸鉛被(bei)吸付到電池(chi)(chi)(chi)(chi)的(de)(de)(de)陰(yin)(yin)極表面,形成電池(chi)(chi)(chi)(chi)陰(yin)(yin)極的(de)(de)(de)硫(liu)酸鹽化。在陰(yin)(yin)極板上形成的(de)(de)(de)硫(liu)酸鹽越多,電池(chi)(chi)(chi)(chi)的(de)(de)(de)內阻(zu)越大(da)(da),閥控蓄(xu)電池(chi)(chi)(chi)(chi)的(de)(de)(de)使(shi)用壽命會(hui)大(da)(da)大(da)(da)減短。
(三)腐蝕因素
板(ban)柵腐蝕是影響(xiang)蓄電池(chi)使用壽命(ming)的重(zhong)要原因。在開路狀(zhuang)態下,鉛合金(jin)與活性二氧(yang)化(hua)鉛直(zhi)接接觸,而且共同(tong)浸在硫(liu)酸溶液中。在過(guo)充電狀(zhuang)態下,正極(ji)由于析氧(yang)反應,水(shui)被消耗,H增加,從而導致正極(ji)附近酸度(du)增高。電池(chi)的柵板(ban)就會變薄,容(rong)量降低,會縮短使用壽命(ming)。
(四)浮充因素
變電站使用的(de)蓄(xu)電池大(da)(da)多(duo)數都處(chu)于長(chang)期的(de)浮充電狀態下,這(zhe)樣(yang)會造(zao)成蓄(xu)電池的(de)陽極極板(ban)鈍(dun)化,使蓄(xu)電池內阻急劇(ju)增大(da)(da),使蓄(xu)電池的(de)實際(ji)容量(Ah)遠(yuan)遠(yuan)低于其(qi)標準(zhun)容量,從而導致(zhi)蓄(xu)電池所能(neng)提供(gong)(gong)的(de)實際(ji)后備供(gong)(gong)電時(shi)間大(da)(da)大(da)(da)縮短,減少其(qi)使用壽命。
(五(wu))失水因素
蓄電(dian)池(chi)失(shi)水(shui)(shui)也是影響(xiang)其使用壽(shou)(shou)命(ming)的因素之一,蓄電(dian)池(chi)失(shi)水(shui)(shui)會導致電(dian)解液(ye)比重(zhong)增加,電(dian)池(chi)柵板的腐(fu)蝕,使蓄電(dian)池(chi)的活(huo)性物(wu)質減(jian)少,從而(er)使蓄電(dian)池(chi)的容量(liang)(liang)降低而(er)導致其使用壽(shou)(shou)命(ming)減(jian)少。當失(shi)水(shui)(shui)5.5%時,容量(liang)(liang)降到75%;失(shi)水(shui)(shui)達(da)到25%時,容量(liang)(liang)基(ji)本消失(shi)。
三、超(chao)級電容用于直流屏的有(you)關試驗(yan)
為了證明(ming)超級電容用于變(bian)電站直流屏(ping)中的優點,列舉了幾個常見(jian)的試驗(yan)案(an)例,根(gen)據(ju)試驗(yan)結果(guo)分(fen)析(xi)超級電容直流屏(ping)技術的綜合性(xing)能特點。
(一)用超級電容對斷路(lu)器合閘的試(shi)驗
超級電(dian)容標稱容量0.82F,耐壓280V,用超級電(dian)容對斷(duan)路器(qi)合(he)(he)(he)閘(zha)的(de)試(shi)驗。試(shi)驗方(fang)法:斷(duan)開615柜合(he)(he)(he)閘(zha)電(dian)源;將已充(chong)電(dian)的(de)超級電(dian)容兩出(chu)線(xian)端并接在(zai)合(he)(he)(he)閘(zha)接觸(chu)器(qi)觸(chu)頭上;模(mo)擬正常方(fang)式合(he)(he)(he)閘(zha),按(an)下(xia)合(he)(he)(he)閘(zha)接鈕,記錄合(he)(he)(he)閘(zha)次(ci)數和(he)電(dian)容端電(dian)壓。共合(he)(he)(he)閘(zha)15次(ci),每次(ci)都(dou)合(he)(he)(he)閘(zha)成功。結(jie)果:電(dian)容充(chong)電(dian)至10%額(e)定電(dian)壓95時,可(ke)(ke)對CD-Ⅱ型電(dian)磁機構可(ke)(ke)靠(kao)合(he)(he)(he)閘(zha)大(da)于8次(ci),每次(ci)合(he)(he)(he)閘(zha)使(shi)電(dian)容端電(dian)壓下(xia)降5V。
(二(er))超級電容充電時間測(ce)試
超(chao)級電(dian)(dian)(dian)容的初充(chong)(chong)電(dian)(dian)(dian),如不加限流電(dian)(dian)(dian)阻(zu)(zu),相當于發生短路。生產(chan)廠家推(tui)薦使用1000W碘鎢(wu)(wu)燈(deng)作限流電(dian)(dian)(dian)阻(zu)(zu),其冷態電(dian)(dian)(dian)阻(zu)(zu)較熱態電(dian)(dian)(dian)阻(zu)(zu)小(xiao)近10倍,符合電(dian)(dian)(dian)容電(dian)(dian)(dian)壓(ya)上升后宜(yi)減小(xiao)限流電(dian)(dian)(dian)阻(zu)(zu)的要求。以(yi)下(xia)試驗數據(ju)均是串入1000W碘鎢(wu)(wu)燈(deng)實測的數據(ju)。結果:不同(tong)的充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)源(yuan)對(dui)充(chong)(chong)電(dian)(dian)(dian)速度有影(ying)響,但不管什么(me)電(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)容由零伏充(chong)(chong)至額定電(dian)(dian)(dian)壓(ya)時僅需3分(fen)鐘。以(yi)后,長期浮充(chong)(chong)電(dian)(dian)(dian)流在0~10mA變化(hua)。
(三(san))超級(ji)電容自放電測試
將超級(ji)電(dian)容(rong)(rong)充(chong)(chong)至(zhi)242V后,與(yu)負載(zai)完全脫(tuo)離,隔日同一時(shi)間測量電(dian)容(rong)(rong)端電(dian)壓(ya)(ya)。結果:端電(dian)壓(ya)(ya)下降速度(du)與(yu)是(shi)否經過浮充(chong)(chong)有(you)關,未經浮充(chong)(chong)開(kai)(kai)始幾個小時(shi)達(da)2~3V/h,即每(mei)小時(shi)下降2~3V,經過浮充(chong)(chong)半小時(shi)以(yi)后,自放電(dian)速度(du)明(ming)顯變(bian)緩,可能(neng)是(shi)電(dian)容(rong)(rong)內部電(dian)荷來不(bu)及(ji)分布均(jun)勻有(you)關。在(zai)正常運用時(shi),超級(ji)電(dian)容(rong)(rong)處(chu)在(zai)長期浮充(chong)(chong)狀態,完全斷(duan)開(kai)(kai)負載(zai)后可維(wei)持有(you)效電(dian)壓(ya)(ya)達(da)3天(72小時(shi))。
四、超級電容直流屏(ping)與蓄(xu)電池直流屏(ping)的性能對比
根據超(chao)級(ji)電(dian)(dian)容運(yun)用于直(zhi)(zhi)(zhi)流屏的(de)試驗(yan)結果分(fen)析(xi),其不(bu)僅擺脫了傳統蓄(xu)電(dian)(dian)池直(zhi)(zhi)(zhi)流屏存在(zai)的(de)不(bu)足,也顯著提(ti)升了變電(dian)(dian)站電(dian)(dian)力系統運(yun)行(xing)的(de)效率,為(wei)操作(zuo)人員的(de)系統控制與改造提(ti)供了足夠的(de)直(zhi)(zhi)(zhi)流電(dian)(dian)源。為(wei)了驗(yan)證超(chao)級(ji)電(dian)(dian)容直(zhi)(zhi)(zhi)流屏的(de)諸多優(you)勢,本文以使用性能為(wei)重點,從故障、壽(shou)命、維(wei)護(hu)等方面,對(dui)超(chao)級(ji)電(dian)(dian)容直(zhi)(zhi)(zhi)流屏與蓄(xu)電(dian)(dian)池直(zhi)(zhi)(zhi)流屏進行(xing)綜合(he)對(dui)比(bi)。
(一)故障方面對比
變電(dian)(dian)站不管(guan)采(cai)用哪一類蓄(xu)電(dian)(dian)池,其在使用時都需要(yao)配備相(xiang)應的放(fang)電(dian)(dian)裝置(zhi),這(zhe)是保證蓄(xu)電(dian)(dian)池持續供應直(zhi)(zhi)流電(dian)(dian)源的重要(yao)條件。參照試驗結果判斷,傳統蓄(xu)電(dian)(dian)池直(zhi)(zhi)流屏(ping)采(cai)用的放(fang)電(dian)(dian)裝置(zhi)的故障(zhang)發(fa)生率(lv)明顯高于超級電(dian)(dian)容(rong)直(zhi)(zhi)流屏(ping),不利于變電(dian)(dian)站日常操作的穩定運行。而超級電(dian)(dian)容(rong)放(fang)電(dian)(dian)裝置(zhi)在結構(gou)方面更(geng)為(wei)簡化,對其進行改造或放(fang)電(dian)(dian)更(geng)加便(bian)捷。
(二)壽(shou)命方面對(dui)比
當蓄(xu)電(dian)(dian)(dian)池(chi)使(shi)用(yong)(yong)(yong)結束(shu)后需(xu)要進行充(chong)電(dian)(dian)(dian)才能正常使(shi)用(yong)(yong)(yong),長(chang)期(qi)充(chong)電(dian)(dian)(dian)會導致蓄(xu)電(dian)(dian)(dian)池(chi)的使(shi)用(yong)(yong)(yong)壽命(ming)減短(duan),一般要短(duan)于(yu)標準使(shi)用(yong)(yong)(yong)壽命(ming)的5~10年時間(jian),限制了蓄(xu)電(dian)(dian)(dian)池(chi)直(zhi)流屏(ping)作用(yong)(yong)(yong)的穩定發揮。而超級(ji)電(dian)(dian)(dian)容直(zhi)流屏(ping)的使(shi)用(yong)(yong)(yong)壽命(ming)更長(chang),這是由于(yu)其(qi)不存在(zai)(zai)過(guo)充(chong)電(dian)(dian)(dian)、過(guo)放電(dian)(dian)(dian)問題,在(zai)(zai)生產(chan)期(qi)間(jian)限定最高充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓即可滿足維護(hu)需(xu)要,有效避免(mian)了超級(ji)電(dian)(dian)(dian)容使(shi)用(yong)(yong)(yong)壽命(ming)減短(duan)。
(三)維(wei)護方面(mian)對比
從(cong)直流屏維護角度來看,變(bian)電(dian)(dian)(dian)(dian)站(zhan)的(de)(de)日(ri)常維護工作量較大(da)(da),不僅(jin)要(yao)定期(qi)(qi)對(dui)蓄電(dian)(dian)(dian)(dian)池進行檢(jian)(jian)測、更新,還(huan)要(yao)對(dui)電(dian)(dian)(dian)(dian)池內部的(de)(de)線路連(lian)接(jie)綜合監測,給工作人員造成了很大(da)(da)的(de)(de)難度。但(dan)超(chao)(chao)級電(dian)(dian)(dian)(dian)容直流屏用于變(bian)電(dian)(dian)(dian)(dian)站(zhan)無需(xu)過(guo)多(duo)的(de)(de)維護,在安裝(zhuang)初期(qi)(qi)對(dui)直流屏裝(zhuang)置全(quan)面檢(jian)(jian)測達標后即可(ke)長期(qi)(qi)使用。從(cong)性(xing)能(neng)(neng)恢復來說(shuo),蓄電(dian)(dian)(dian)(dian)池放電(dian)(dian)(dian)(dian)后要(yao)經過(guo)幾個小時的(de)(de)恢復才(cai)能(neng)(neng)正常供電(dian)(dian)(dian)(dian),超(chao)(chao)級電(dian)(dian)(dian)(dian)容僅(jin)需(xu)3~5分鐘即可(ke)復原(yuan)電(dian)(dian)(dian)(dian)能(neng)(neng)。保持了變(bian)電(dian)(dian)(dian)(dian)站(zhan)的(de)(de)正常供電(dian)(dian)(dian)(dian)。
五、結論
直(zhi)流(liu)電(dian)(dian)(dian)源操(cao)作(zuo)系統是變(bian)電(dian)(dian)(dian)站(zhan)正常運行(xing)的(de)基本(ben)保證(zheng),其(qi)能夠及時將電(dian)(dian)(dian)流(liu)輸送到各個電(dian)(dian)(dian)力(li)(li)設備中供(gong)應使用。伴隨著社(she)會現代化發展步伐的(de)加快,我國變(bian)電(dian)(dian)(dian)站(zhan)建設面臨(lin)著新的(de)改革優化,各種(zhong)蓄電(dian)(dian)(dian)池直(zhi)流(liu)屏(ping)逐漸(jian)被其(qi)他形式(shi)的(de)裝置所取代,這(zhe)對(dui)于變(bian)電(dian)(dian)(dian)站(zhan)未來的(de)革新發展大有(you)幫助。超級(ji)電(dian)(dian)(dian)容直(zhi)流(liu)屏(ping)是變(bian)電(dian)(dian)(dian)站(zhan)直(zhi)流(liu)屏(ping)的(de)先進(jin)技術(shu),其(qi)在性能、維護、壽命、故(gu)障等方面都明顯(xian)優越于傳統的(de)蓄電(dian)(dian)(dian)池直(zhi)流(liu)屏(ping),在電(dian)(dian)(dian)力(li)(li)行(xing)業中應得(de)到全面推廣使用。
直(zhi)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)源(yuan)操(cao)作系統簡(jian)稱(cheng)“直(zhi)流(liu)(liu)(liu)屏(ping)”,在變(bian)電(dian)(dian)(dian)(dian)(dian)站中向各種(zhong)電(dian)(dian)(dian)(dian)(dian)力(li)(li)設備提(ti)供穩定的(de)(de)(de)直(zhi)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)源(yuan),也是現代變(bian)電(dian)(dian)(dian)(dian)(dian)站核心的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)力(li)(li)操(cao)作電(dian)(dian)(dian)(dian)(dian)源(yuan)。直(zhi)流(liu)(liu)(liu)屏(ping)技術不僅保(bao)護(hu)了(le)電(dian)(dian)(dian)(dian)(dian)力(li)(li)系統的(de)(de)(de)正常運行(xing)(xing)(xing),對于其他元件的(de)(de)(de)穩定操(cao)控也起到很好的(de)(de)(de)保(bao)護(hu)作用(yong)。對變(bian)電(dian)(dian)(dian)(dian)(dian)站直(zhi)流(liu)(liu)(liu)屏(ping)存在的(de)(de)(de)問(wen)題進行(xing)(xing)(xing)深入(ru)分析,可以保(bao)證(zheng)持續性的(de)(de)(de)直(zhi)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)源(yuan)供應,為電(dian)(dian)(dian)(dian)(dian)力(li)(li)設備及相(xiang)關模塊的(de)(de)(de)正常操(cao)控創造有利的(de)(de)(de)條件。電(dian)(dian)(dian)(dian)(dian)力(li)(li)行(xing)(xing)(xing)業積(ji)極引入(ru)直(zhi)流(liu)(liu)(liu)屏(ping)技術可加快變(bian)電(dian)(dian)(dian)(dian)(dian)站的(de)(de)(de)自動化、智能化發展,提(ti)高變(bian)電(dian)(dian)(dian)(dian)(dian)站設備運行(xing)(xing)(xing)的(de)(de)(de)整體效(xiao)率(lv)。
一(yi)、當前變電(dian)站直流(liu)屏存在的問題
國(guo)內變(bian)(bian)電(dian)(dian)站采(cai)用的(de)(de)(de)直(zhi)(zhi)流屏由充(chong)電(dian)(dian)柜(ju)、充(chong)電(dian)(dian)模塊(kuai)、監控模塊(kuai)、電(dian)(dian)池組(zu)、降壓(ya)硅鏈等(deng)結構(gou)組(zu)成,每一(yi)個模塊(kuai)都對直(zhi)(zhi)流電(dian)(dian)源(yuan)供應(ying)發揮重要(yao)的(de)(de)(de)作(zuo)用。從(cong)行(xing)業(ye)發展趨勢分析直(zhi)(zhi)流屏,其(qi)屬于數字(zi)化調(diao)控模式下運行(xing)的(de)(de)(de)直(zhi)(zhi)流系統,對變(bian)(bian)電(dian)(dian)站直(zhi)(zhi)流電(dian)(dian)源(yuan)供應(ying)具(ju)有調(diao)控、保護、管理、監測(ce)等(deng)多方面作(zuo)用。目(mu)前,變(bian)(bian)電(dian)(dian)站采(cai)用直(zhi)(zhi)流屏技術(shu)具(ju)備了遠程監測(ce)、調(diao)控等(deng)高(gao)級功能(neng),方便了值班人員對電(dian)(dian)力系統運行(xing)的(de)(de)(de)調(diao)控。但直(zhi)(zhi)流屏存在的(de)(de)(de)一(yi)些問(wen)題(ti)(ti)也應(ying)該(gai)引起(qi)技術(shu)人員的(de)(de)(de)關注,鎘(ge)鎳蓄(xu)電(dian)(dian)池、密封鉛酸蓄(xu)電(dian)(dian)池是常用的(de)(de)(de)直(zhi)(zhi)流屏,其(qi)主要(yao)問(wen)題(ti)(ti)如下:
(一)鎘鎳蓄電池(chi)直流(liu)屏
1.性能(neng)問題。變(bian)電(dian)(dian)(dian)(dian)站通(tong)過直流(liu)母(mu)線(xian)(xian)輸出電(dian)(dian)(dian)(dian)能(neng)需(xu)要(yao)使用大批蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)模(mo)塊,以此(ci)來(lai)維持正常的(de)(de)(de)直流(liu)電(dian)(dian)(dian)(dian)源操(cao)控(kong)。如:一(yi)般情況(kuang)下,大型(xing)變(bian)電(dian)(dian)(dian)(dian)站直流(liu)母(mu)線(xian)(xian)輸出220V,需(xu)使用200只(zhi)左右的(de)(de)(de)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)組合(he)模(mo)塊。但鎘(ge)鎳(nie)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)在(zai)生(sheng)產(chan)處理期間,廠(chang)家無法(fa)保證每只(zhi)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)充電(dian)(dian)(dian)(dian)、放(fang)電(dian)(dian)(dian)(dian)性能(neng)完(wan)全一(yi)致,200只(zhi)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)組合(he)起來(lai)會產(chan)生(sheng)明(ming)顯的(de)(de)(de)特(te)性差異。鎘(ge)鎳(nie)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)直流(liu)屏在(zai)供應直流(liu)電(dian)(dian)(dian)(dian)源后所連接的(de)(de)(de)充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)源一(yi)致,并且負荷放(fang)電(dian)(dian)(dian)(dian)的(de)(de)(de)對象相同。這種特(te)點導致局(ju)部鎘(ge)鎳(nie)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)性能(neng)減弱,降(jiang)低了整(zheng)個蓄(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)組合(he)模(mo)塊的(de)(de)(de)功能(neng)。
2.壽(shou)命(ming)(ming)問題。由于鎘(ge)鎳蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)組合材料(liao)的缺陷,直(zhi)流(liu)屏(ping)(ping)(ping)運行(xing)時本質上處于“浮(fu)充(chong)狀態(tai)”,此(ci)(ci)時鎘(ge)鎳蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)直(zhi)流(liu)屏(ping)(ping)(ping)的使用(yong)壽(shou)命(ming)(ming)取(qu)決于充(chong)電(dian)(dian)(dian)(dian)機。按(an)照行(xing)業標準(zhun)里(li)的規(gui)定,廠家對鎘(ge)鎳蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)的保證(zheng)命(ming)(ming)在10年(nian)以上,而具體使用(yong)的記(ji)錄情(qing)況僅有5年(nian)左右(you)的時間。蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)直(zhi)流(liu)屏(ping)(ping)(ping)壽(shou)命(ming)(ming)縮(suo)短的原因(yin)是由94于俯沖電(dian)(dian)(dian)(dian)流(liu)超標會造(zao)成(cheng)電(dian)(dian)(dian)(dian)解液中的水電(dian)(dian)(dian)(dian)解成(cheng)氫(qing)、氧,這(zhe)是造(zao)成(cheng)蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)炸的根本原因(yin),若采用(yong)鎘(ge)鎳蓄(xu)(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)(chi)直(zhi)流(liu)屏(ping)(ping)(ping)時未做特殊處理(li),則很容(rong)易引起意外事故。因(yin)此(ci)(ci),直(zhi)流(liu)屏(ping)(ping)(ping)的使用(yong)壽(shou)命(ming)(ming)長短會受到其他(ta)方面因(yin)素的限制(zhi)。
3.氧化(hua)問題。變電(dian)(dian)(dian)廠鎘(ge)(ge)鎳(nie)蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)直(zhi)流屏(ping)使用(yong)期(qi)間也會(hui)(hui)出(chu)現氧化(hua)還原反應(ying),使鎘(ge)(ge)鎳(nie)材料發生化(hua)學反應(ying)生成氧化(hua)鎘(ge)(ge),造成極板(ban)的(de)有效面積不斷減(jian)小。為了避免(mian)氧化(hua)還原反應(ying)的(de)發生,變電(dian)(dian)(dian)站(zhan)工作人員會(hui)(hui)定期(qi)對(dui)蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)進行(xing)(xing)“活化(hua)試驗”分析。在活化(hua)試驗里需對(dui)蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)進行(xing)(xing)充(chong)放(fang)電(dian)(dian)(dian)處理,這一(yi)階段的(de)操作會(hui)(hui)發生極性(xing)反轉而導致(zhi)蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)報廢。另外,氧化(hua)還原反應(ying)在破壞(huai)鎘(ge)(ge)鎳(nie)直(zhi)流屏(ping)性(xing)能的(de)同時,對(dui)變電(dian)(dian)(dian)站(zhan)的(de)穩定運(yun)行(xing)(xing)也會(hui)(hui)埋(mai)下安(an)全(quan)隱患(huan),如(ru):若(ruo)把蓄(xu)(xu)電(dian)(dian)(dian)池(chi)(chi)完全(quan)安(an)裝于柜(ju)內,很容(rong)易引起燒毀(hui)、爆(bao)炸等安(an)全(quan)事故。
(二)密封(feng)鉛酸蓄電池直流屏
在(zai)(zai)科(ke)學(xue)技術的(de)(de)推動下,國(guo)內(nei)變(bian)(bian)電(dian)(dian)站直(zhi)(zhi)流(liu)屏技術不斷發展,許多新的(de)(de)蓄電(dian)(dian)池(chi)(chi)產(chan)(chan)品(pin)也在(zai)(zai)變(bian)(bian)電(dian)(dian)站中得到了(le)普遍(bian)運(yun)用(yong)(yong)。基(ji)于(yu)(yu)鎘鎳(nie)蓄電(dian)(dian)池(chi)(chi)直(zhi)(zhi)流(liu)屏存在(zai)(zai)的(de)(de)不足,企業開始采用(yong)(yong)密封(feng)鉛酸(suan)蓄電(dian)(dian)池(chi)(chi),簡稱(cheng)“閥控蓄電(dian)(dian)池(chi)(chi)”。這種產(chan)(chan)品(pin)在(zai)(zai)質量、性能、價格、維(wei)護(hu)(hu)等方(fang)面均優于(yu)(yu)鎘鎳(nie)蓄電(dian)(dian)池(chi)(chi)。如:閥控蓄電(dian)(dian)池(chi)(chi)無需進行(xing)(xing)過多的(de)(de)維(wei)護(hu)(hu)或加(jia)水處理,為變(bian)(bian)電(dian)(dian)站操(cao)(cao)作人員提供了(le)很大的(de)(de)方(fang)便。但該直(zhi)(zhi)流(liu)屏處于(yu)(yu)“全密封(feng)”狀(zhuang)態也引起了(le)諸多問題,尤其是在(zai)(zai)電(dian)(dian)池(chi)(chi)觀測、檢(jian)查等操(cao)(cao)作時(shi),維(wei)護(hu)(hu)人員難(nan)以及時(shi)更新裝置(zhi)。另外,由(you)于(yu)(yu)國(guo)內(nei)閥控蓄電(dian)(dian)池(chi)(chi)技術相對落后,產(chan)(chan)品(pin)運(yun)用(yong)(yong)于(yu)(yu)變(bian)(bian)電(dian)(dian)站時(shi)壽命無保障,并且對于(yu)(yu)閥控蓄電(dian)(dian)池(chi)(chi)直(zhi)(zhi)流(liu)屏的(de)(de)運(yun)行(xing)(xing)條件十分(fen)嚴格,給變(bian)(bian)電(dian)(dian)站的(de)(de)正常生產(chan)(chan)造成了(le)很大的(de)(de)困難(nan)。
二(er)、影響閾控蓄電池壽(shou)命的因素(su)
使用壽命(ming)是制(zhi)約閥控蓄(xu)電池(chi)推廣(guang)的(de)重要(yao)因
素(su),各大、中(zhong)、小型變(bian)電(dian)站(zhan)采用這種電(dian)源裝置均會考慮使(shi)用壽命(ming)的年限,以(yi)控(kong)制變(bian)電(dian)站(zhan)的運行成本。經(jing)試驗(yan)數(shu)據(ju)分(fen)析,對閥控(kong)蓄電(dian)池使(shi)用壽命(ming)造成影響(xiang)的因(yin)素(su)集中(zhong)在溫度因(yin)素(su)、放電(dian)因(yin)素(su)、失水因(yin)素(su)、腐蝕因(yin)素(su),等等。
(一(yi))溫度因素
盡(jin)管閥控(kong)蓄(xu)電(dian)(dian)池(chi)(chi)運(yun)(yun)用于變電(dian)(dian)站(zhan)還(huan)存在明顯的不(bu)足,但(dan)與鎘鎳蓄(xu)電(dian)(dian)池(chi)(chi)相比(bi)已經有了(le)很大(da)的改(gai)進,對變電(dian)(dian)站(zhan)直(zhi)流電(dian)(dian)源操作(zuo)系統(tong)的運(yun)(yun)行創造(zao)了(le)更好的條(tiao)件。閥控(kong)蓄(xu)電(dian)(dian)池(chi)(chi)壽命(ming)對溫(wen)度十分敏感(gan),生產廠家要(yao)求電(dian)(dian)池(chi)(chi)運(yun)(yun)行環境溫(wen)為15℃~25℃,當環境溫(wen)度超過(guo)25℃后,每(mei)升高10℃電(dian)(dian)池(chi)(chi)壽命(ming)就要(yao)縮短(duan)一(yi)半。
(二)放電因(yin)素
蓄(xu)電池(chi)(chi)(chi)(chi)被(bei)過(guo)度(du)放電是影響蓄(xu)電池(chi)(chi)(chi)(chi)使(shi)用壽命的(de)(de)(de)另一(yi)重要因素。當蓄(xu)電池(chi)(chi)(chi)(chi)被(bei)過(guo)度(du)放電到輸出電壓為零(ling)時,會(hui)導致(zhi)電池(chi)(chi)(chi)(chi)內部(bu)有大(da)(da)量的(de)(de)(de)硫(liu)酸鉛被(bei)吸付到電池(chi)(chi)(chi)(chi)的(de)(de)(de)陰(yin)(yin)極表面,形成電池(chi)(chi)(chi)(chi)陰(yin)(yin)極的(de)(de)(de)硫(liu)酸鹽化。在陰(yin)(yin)極板上形成的(de)(de)(de)硫(liu)酸鹽越多,電池(chi)(chi)(chi)(chi)的(de)(de)(de)內阻(zu)越大(da)(da),閥控蓄(xu)電池(chi)(chi)(chi)(chi)的(de)(de)(de)使(shi)用壽命會(hui)大(da)(da)大(da)(da)減短。
(三)腐蝕因素
板(ban)柵腐蝕是影響(xiang)蓄電池(chi)使用壽命(ming)的重(zhong)要原因。在開路狀(zhuang)態下,鉛合金(jin)與活性二氧(yang)化(hua)鉛直(zhi)接接觸,而且共同(tong)浸在硫(liu)酸溶液中。在過(guo)充電狀(zhuang)態下,正極(ji)由于析氧(yang)反應,水(shui)被消耗,H增加,從而導致正極(ji)附近酸度(du)增高。電池(chi)的柵板(ban)就會變薄,容(rong)量降低,會縮短使用壽命(ming)。
(四)浮充因素
變電站使用的(de)蓄(xu)電池大(da)(da)多(duo)數都處(chu)于長(chang)期的(de)浮充電狀態下,這(zhe)樣(yang)會造(zao)成蓄(xu)電池的(de)陽極極板(ban)鈍(dun)化,使蓄(xu)電池內阻急劇(ju)增大(da)(da),使蓄(xu)電池的(de)實際(ji)容量(Ah)遠(yuan)遠(yuan)低于其(qi)標準(zhun)容量,從而導致(zhi)蓄(xu)電池所能(neng)提供(gong)(gong)的(de)實際(ji)后備供(gong)(gong)電時(shi)間大(da)(da)大(da)(da)縮短,減少其(qi)使用壽命。
(五(wu))失水因素
蓄電(dian)池(chi)失(shi)水(shui)(shui)也是影響(xiang)其使用壽(shou)(shou)命(ming)的因素之一,蓄電(dian)池(chi)失(shi)水(shui)(shui)會導致電(dian)解液(ye)比重(zhong)增加,電(dian)池(chi)柵板的腐(fu)蝕,使蓄電(dian)池(chi)的活(huo)性物(wu)質減(jian)少,從而(er)使蓄電(dian)池(chi)的容量(liang)(liang)降低而(er)導致其使用壽(shou)(shou)命(ming)減(jian)少。當失(shi)水(shui)(shui)5.5%時,容量(liang)(liang)降到75%;失(shi)水(shui)(shui)達(da)到25%時,容量(liang)(liang)基(ji)本消失(shi)。
三、超(chao)級電容用于直流屏的有(you)關試驗(yan)
為了證明(ming)超級電容用于變(bian)電站直流屏(ping)中的優點,列舉了幾個常見(jian)的試驗(yan)案(an)例,根(gen)據(ju)試驗(yan)結果(guo)分(fen)析(xi)超級電容直流屏(ping)技術的綜合性(xing)能特點。
(一)用超級電容對斷路(lu)器合閘的試(shi)驗
超級電(dian)容標稱容量0.82F,耐壓280V,用超級電(dian)容對斷(duan)路器(qi)合(he)(he)(he)閘(zha)的(de)試(shi)驗。試(shi)驗方(fang)法:斷(duan)開615柜合(he)(he)(he)閘(zha)電(dian)源;將已充(chong)電(dian)的(de)超級電(dian)容兩出(chu)線(xian)端并接在(zai)合(he)(he)(he)閘(zha)接觸(chu)器(qi)觸(chu)頭上;模(mo)擬正常方(fang)式合(he)(he)(he)閘(zha),按(an)下(xia)合(he)(he)(he)閘(zha)接鈕,記錄合(he)(he)(he)閘(zha)次(ci)數和(he)電(dian)容端電(dian)壓。共合(he)(he)(he)閘(zha)15次(ci),每次(ci)都(dou)合(he)(he)(he)閘(zha)成功。結(jie)果:電(dian)容充(chong)電(dian)至10%額(e)定電(dian)壓95時,可(ke)(ke)對CD-Ⅱ型電(dian)磁機構可(ke)(ke)靠(kao)合(he)(he)(he)閘(zha)大(da)于8次(ci),每次(ci)合(he)(he)(he)閘(zha)使(shi)電(dian)容端電(dian)壓下(xia)降5V。
(二(er))超級電容充電時間測(ce)試
超(chao)級電(dian)(dian)(dian)容的初充(chong)(chong)電(dian)(dian)(dian),如不加限流電(dian)(dian)(dian)阻(zu)(zu),相當于發生短路。生產(chan)廠家推(tui)薦使用1000W碘鎢(wu)(wu)燈(deng)作限流電(dian)(dian)(dian)阻(zu)(zu),其冷態電(dian)(dian)(dian)阻(zu)(zu)較熱態電(dian)(dian)(dian)阻(zu)(zu)小(xiao)近10倍,符合電(dian)(dian)(dian)容電(dian)(dian)(dian)壓(ya)上升后宜(yi)減小(xiao)限流電(dian)(dian)(dian)阻(zu)(zu)的要求。以(yi)下(xia)試驗數據(ju)均是串入1000W碘鎢(wu)(wu)燈(deng)實測的數據(ju)。結果:不同(tong)的充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)源(yuan)對(dui)充(chong)(chong)電(dian)(dian)(dian)速度有影(ying)響,但不管什么(me)電(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)容由零伏充(chong)(chong)至額定電(dian)(dian)(dian)壓(ya)時僅需3分(fen)鐘。以(yi)后,長期浮充(chong)(chong)電(dian)(dian)(dian)流在0~10mA變化(hua)。
(三(san))超級(ji)電容自放電測試
將超級(ji)電(dian)容(rong)(rong)充(chong)(chong)至(zhi)242V后,與(yu)負載(zai)完全脫(tuo)離,隔日同一時(shi)間測量電(dian)容(rong)(rong)端電(dian)壓(ya)(ya)。結果:端電(dian)壓(ya)(ya)下降速度(du)與(yu)是(shi)否經過浮充(chong)(chong)有(you)關,未經浮充(chong)(chong)開(kai)(kai)始幾個小時(shi)達(da)2~3V/h,即每(mei)小時(shi)下降2~3V,經過浮充(chong)(chong)半小時(shi)以(yi)后,自放電(dian)速度(du)明(ming)顯變(bian)緩,可能(neng)是(shi)電(dian)容(rong)(rong)內部電(dian)荷來不(bu)及(ji)分布均(jun)勻有(you)關。在(zai)正常運用時(shi),超級(ji)電(dian)容(rong)(rong)處(chu)在(zai)長期浮充(chong)(chong)狀態,完全斷(duan)開(kai)(kai)負載(zai)后可維(wei)持有(you)效電(dian)壓(ya)(ya)達(da)3天(72小時(shi))。
四、超級電容直流屏(ping)與蓄(xu)電池直流屏(ping)的性能對比
根據超(chao)級(ji)電(dian)(dian)容運(yun)用于直(zhi)(zhi)(zhi)流屏的(de)試驗(yan)結果分(fen)析(xi),其不(bu)僅擺脫了傳統蓄(xu)電(dian)(dian)池直(zhi)(zhi)(zhi)流屏存在(zai)的(de)不(bu)足,也顯著提(ti)升了變電(dian)(dian)站電(dian)(dian)力系統運(yun)行(xing)的(de)效率,為(wei)操作(zuo)人員的(de)系統控制與改造提(ti)供了足夠的(de)直(zhi)(zhi)(zhi)流電(dian)(dian)源。為(wei)了驗(yan)證超(chao)級(ji)電(dian)(dian)容直(zhi)(zhi)(zhi)流屏的(de)諸多優(you)勢,本文以使用性能為(wei)重點,從故障、壽(shou)命、維(wei)護(hu)等方面,對(dui)超(chao)級(ji)電(dian)(dian)容直(zhi)(zhi)(zhi)流屏與蓄(xu)電(dian)(dian)池直(zhi)(zhi)(zhi)流屏進行(xing)綜合(he)對(dui)比(bi)。
(一)故障方面對比
變電(dian)(dian)站不管(guan)采(cai)用哪一類蓄(xu)電(dian)(dian)池,其在使用時都需要(yao)配備相(xiang)應的放(fang)電(dian)(dian)裝置(zhi),這(zhe)是保證蓄(xu)電(dian)(dian)池持續供應直(zhi)(zhi)流電(dian)(dian)源的重要(yao)條件。參照試驗結果判斷,傳統蓄(xu)電(dian)(dian)池直(zhi)(zhi)流屏(ping)采(cai)用的放(fang)電(dian)(dian)裝置(zhi)的故障(zhang)發(fa)生率(lv)明顯高于超級電(dian)(dian)容(rong)直(zhi)(zhi)流屏(ping),不利于變電(dian)(dian)站日常操作的穩定運行。而超級電(dian)(dian)容(rong)放(fang)電(dian)(dian)裝置(zhi)在結構(gou)方面更(geng)為(wei)簡化,對其進行改造或放(fang)電(dian)(dian)更(geng)加便(bian)捷。
(二)壽(shou)命方面對(dui)比
當蓄(xu)電(dian)(dian)(dian)池(chi)使(shi)用(yong)(yong)(yong)結束(shu)后需(xu)要進行充(chong)電(dian)(dian)(dian)才能正常使(shi)用(yong)(yong)(yong),長(chang)期(qi)充(chong)電(dian)(dian)(dian)會導致蓄(xu)電(dian)(dian)(dian)池(chi)的使(shi)用(yong)(yong)(yong)壽命(ming)減短(duan),一般要短(duan)于(yu)標準使(shi)用(yong)(yong)(yong)壽命(ming)的5~10年時間(jian),限制了蓄(xu)電(dian)(dian)(dian)池(chi)直(zhi)流屏(ping)作用(yong)(yong)(yong)的穩定發揮。而超級(ji)電(dian)(dian)(dian)容直(zhi)流屏(ping)的使(shi)用(yong)(yong)(yong)壽命(ming)更長(chang),這是由于(yu)其(qi)不存在(zai)(zai)過(guo)充(chong)電(dian)(dian)(dian)、過(guo)放電(dian)(dian)(dian)問題,在(zai)(zai)生產(chan)期(qi)間(jian)限定最高充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓即可滿足維護(hu)需(xu)要,有效避免(mian)了超級(ji)電(dian)(dian)(dian)容使(shi)用(yong)(yong)(yong)壽命(ming)減短(duan)。
(三)維(wei)護方面(mian)對比
從(cong)直流屏維護角度來看,變(bian)電(dian)(dian)(dian)(dian)站(zhan)的(de)(de)日(ri)常維護工作量較大(da)(da),不僅(jin)要(yao)定期(qi)(qi)對(dui)蓄電(dian)(dian)(dian)(dian)池進行檢(jian)(jian)測、更新,還(huan)要(yao)對(dui)電(dian)(dian)(dian)(dian)池內部的(de)(de)線路連(lian)接(jie)綜合監測,給工作人員造成了很大(da)(da)的(de)(de)難度。但(dan)超(chao)(chao)級電(dian)(dian)(dian)(dian)容直流屏用于變(bian)電(dian)(dian)(dian)(dian)站(zhan)無需(xu)過(guo)多(duo)的(de)(de)維護,在安裝(zhuang)初期(qi)(qi)對(dui)直流屏裝(zhuang)置全(quan)面檢(jian)(jian)測達標后即可(ke)長期(qi)(qi)使用。從(cong)性(xing)能(neng)(neng)恢復來說(shuo),蓄電(dian)(dian)(dian)(dian)池放電(dian)(dian)(dian)(dian)后要(yao)經過(guo)幾個小時的(de)(de)恢復才(cai)能(neng)(neng)正常供電(dian)(dian)(dian)(dian),超(chao)(chao)級電(dian)(dian)(dian)(dian)容僅(jin)需(xu)3~5分鐘即可(ke)復原(yuan)電(dian)(dian)(dian)(dian)能(neng)(neng)。保持了變(bian)電(dian)(dian)(dian)(dian)站(zhan)的(de)(de)正常供電(dian)(dian)(dian)(dian)。
五、結論
直(zhi)流(liu)電(dian)(dian)(dian)源操(cao)作(zuo)系統是變(bian)電(dian)(dian)(dian)站(zhan)正常運行(xing)的(de)基本(ben)保證(zheng),其(qi)能夠及時將電(dian)(dian)(dian)流(liu)輸送到各個電(dian)(dian)(dian)力(li)(li)設備中供(gong)應使用。伴隨著社(she)會現代化發展步伐的(de)加快,我國變(bian)電(dian)(dian)(dian)站(zhan)建設面臨(lin)著新的(de)改革優化,各種(zhong)蓄電(dian)(dian)(dian)池直(zhi)流(liu)屏(ping)逐漸(jian)被其(qi)他形式(shi)的(de)裝置所取代,這(zhe)對(dui)于變(bian)電(dian)(dian)(dian)站(zhan)未來的(de)革新發展大有(you)幫助。超級(ji)電(dian)(dian)(dian)容直(zhi)流(liu)屏(ping)是變(bian)電(dian)(dian)(dian)站(zhan)直(zhi)流(liu)屏(ping)的(de)先進(jin)技術(shu),其(qi)在性能、維護、壽命、故(gu)障等方面都明顯(xian)優越于傳統的(de)蓄電(dian)(dian)(dian)池直(zhi)流(liu)屏(ping),在電(dian)(dian)(dian)力(li)(li)行(xing)業中應得(de)到全面推廣使用。
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