電話(hua): 13816858128郵箱: frelaish@163.com
諧波對供(gong)配電的危害(hai)
主(zhu)要表現在以(yi)下幾個(ge)方(fang)面：
對(dui)供配電線(xian)路的危害
影響線路的穩定(ding)運(yun)行
供配電(dian)系(xi)統(tong)中(zhong)的(de)電(dian)力(li)線路與電(dian)力(li)變壓(ya)器一般采用電(dian)磁(ci)式(shi)繼(ji)(ji)電(dian)器、感應式(shi)繼(ji)(ji)電(dian)器或(huo)晶(jing)體管(guan)繼(ji)(ji)電(dian)器予以檢測保護，使得在故(gu)障情況下保證線路與設備的(de)安(an)全。特別對于電(dian)磁(ci)式(shi)繼(ji)(ji)電(dian)器來說，電(dian)力(li)諧波常會引起繼(ji)(ji)電(dian)保護及自動(dong)裝置(zhi)誤(wu)動(dong)或(huo)拒動(dong)，使其動(dong)作失去選擇性，可靠性降低，容易(yi)造(zao)成系(xi)統(tong)事故(gu)，嚴(yan)重(zhong)威脅電(dian)力(li)系(xi)統(tong)的(de)安(an)全運行。
晶體(ti)(ti)管繼電器雖然(ran)具有許多優點，但(dan)由于采(cai)用了整(zheng)流(liu)取樣電路，容易受諧波影響，產生誤動或(huo)拒動。這樣，諧波將嚴重威脅(xie)供配電系統的穩(wen)定與安全運行。
影響電網的質(zhi)量(liang)
電力系(xi)統中的(de)(de)諧(xie)波能使(shi)電網的(de)(de)電壓與電流波形發生畸(ji)變。配電系(xi)統中的(de)(de)中性線，由于(yu)熒光燈、調光燈、計算機等負載，會(hui)產生大(da)量的(de)(de)奇次諧(xie)波，其中3次(ci)諧(xie)波(bo)的(de)含量較(jiao)多，可達(da)40%；三(san)相(xiang)(xiang)配電線路中，相(xiang)(xiang)線上3的(de)整數(shu)倍諧(xie)波(bo)在(zai)中性(xing)線上會疊加(jia)，使(shi)中性(xing)線的(de)電流(liu)值(zhi)可能超過相(xiang)(xiang)線上的(de)電流(liu)。另外，相(xiang)(xiang)同頻率的(de)諧(xie)波(bo)電壓(ya)與(yu)諧(xie)波(bo)電流(liu)要(yao)產生同次(ci)諧(xie)波(bo)的(de)有功(gong)功(gong)率與(yu)無功(gong)功(gong)率，從而(er)降低電網電壓(ya)，浪費電網的(de)容量。
對電力電容器的(de)危害
當電(dian)(dian)網存在諧波時，投入電(dian)(dian)容(rong)器后其端電(dian)(dian)壓增(zeng)大(da)，通過電(dian)(dian)容(rong)器的電(dian)(dian)流增(zeng)加得(de)更多，使電(dian)(dian)容(rong)器損耗功率(lv)增(zeng)加。對于膜紙復合介質(zhi)電(dian)(dian)容(rong)器，雖然允許有諧波時的損耗功率(lv)為無諧波時損耗功率(lv)的1.38倍(bei)(bei)；對于全膜電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器允許有(you)諧(xie)(xie)(xie)(xie)(xie)波時的損耗功(gong)(gong)率(lv)為(wei)無諧(xie)(xie)(xie)(xie)(xie)波時的1.43倍(bei)(bei),但如果諧(xie)(xie)(xie)(xie)(xie)波含量較高,超(chao)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器允許條件,就會使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流和(he)過(guo)負荷,損耗功(gong)(gong)率(lv)超(chao)過(guo)上(shang)述值，使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器異常發熱，在(zai)(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)場和(he)溫(wen)度(du)的作(zuo)用下(xia)絕(jue)緣介質會加速(su)老(lao)化(hua)。尤(you)其是電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器投入在(zai)(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)已經畸變的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)網中時，還(huan)可(ke)能使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)網的諧(xie)(xie)(xie)(xie)(xie)波加劇，即產(chan)生諧(xie)(xie)(xie)(xie)(xie)波擴大(da)現象。另外，諧(xie)(xie)(xie)(xie)(xie)波的存在(zai)(zai)(zai)往(wang)往(wang)使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)呈現尖(jian)頂波形，尖(jian)頂電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)波易在(zai)(zai)(zai)介質中誘發局(ju)部(bu)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，且由于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)變化(hua)率(lv)大(da)，局(ju)部(bu)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)強度(du)大(da)，對絕(jue)緣介質更能起到加速(su)老(lao)化(hua)的作(zuo)用，從而縮(suo)短電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器的使用壽(shou)命。一般來說，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)每升高10 %，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器的壽(shou)命就要縮(suo)短1/2左右。再者，在(zai)(zai)(zai)諧(xie)(xie)(xie)(xie)(xie)波嚴重(zhong)的情(qing)況(kuang)下(xia)，還(huan)會使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器鼓肚、擊穿(chuan)或爆炸。
對電力(li)變壓器(qi)的危害
諧(xie)(xie)波(bo)使(shi)變壓(ya)器的(de)(de)(de)銅(tong)耗增(zeng)大，其中(zhong)包(bao)括電阻損(sun)耗、導(dao)體(ti)(ti)中(zhong)的(de)(de)(de)渦流損(sun)耗與導(dao)體(ti)(ti)外(wai)(wai)部因漏(lou)磁通引起的(de)(de)(de)雜散(san)損(sun)耗都要(yao)增(zeng)加(jia)(jia)。諧(xie)(xie)波(bo)還(huan)使(shi)變壓(ya)器的(de)(de)(de)鐵耗增(zeng)大，這主(zhu)要(yao)表現在(zai)鐵芯中(zhong)的(de)(de)(de)磁滯(zhi)損(sun)耗增(zeng)加(jia)(jia)。諧(xie)(xie)波(bo)使(shi)電壓(ya)的(de)(de)(de)波(bo)形變得越差，則磁滯(zhi)損(sun)耗越大。同時(shi)由于(yu)以上(shang)兩方(fang)面的(de)(de)(de)損(sun)耗增(zeng)加(jia)(jia)，因此(ci)要(yao)減少(shao)變壓(ya)器的(de)(de)(de)實際使(shi)用容量，或(huo)者說在(zai)選(xuan)擇變壓(ya)器額(e)定(ding)容量時(shi)，需要(yao)考(kao)慮留出電網中(zhong)的(de)(de)(de)諧(xie)(xie)波(bo)含量。除(chu)此(ci)之外(wai)(wai)，諧(xie)(xie)波(bo)還(huan)導(dao)致變壓(ya)器噪聲(sheng)增(zeng)大，變壓(ya)器的(de)(de)(de)振動噪聲(sheng)主(zhu)要(yao)是由于(yu)鐵芯的(de)(de)(de)磁致伸(shen)縮引起的(de)(de)(de)，隨(sui)著諧(xie)(xie)波(bo)次數(shu)的(de)(de)(de)增(zeng)加(jia)(jia)，振動頻率在(zai)1kHZ左右的成分使混雜噪聲(sheng)增加(jia)，有時還(huan)發出金屬(shu)聲(sheng)。
對電力(li)電纜的危害
由于諧波次(ci)數高頻率(lv)上(shang)升，再(zai)加之電纜導(dao)體(ti)截面積越大趨膚效應越明顯，從而導致(zhi)導體的(de)交流(liu)(liu)電(dian)(dian)阻增大，使得電(dian)(dian)纜(lan)(lan)的(de)允許通過電(dian)(dian)流(liu)(liu)減小。另外，電(dian)(dian)纜(lan)(lan)的(de)電(dian)(dian)阻、系統(tong)(tong)母線(xian)(xian)側及(ji)線(xian)(xian)路(lu)感抗(kang)與系統(tong)(tong)串(chuan)聯(lian)，提高功率因數用的(de)電(dian)(dian)容器及(ji)線(xian)(xian)路(lu)的(de)容抗(kang)與系統(tong)(tong)并聯(lian)，在一(yi)定數值(zhi)的(de)電(dian)(dian)感與電(dian)(dian)容下可能發生諧振(zhen)。
對用電設(she)備(bei)的危害
對電動(dong)機的危害(hai)
諧波(bo)對異步(bu)電(dian)(dian)(dian)動(dong)機(ji)(ji)的(de)(de)影響，主要是增加電(dian)(dian)(dian)動(dong)機(ji)(ji)的(de)(de)附(fu)加損耗，降低(di)效率(lv)，嚴重(zhong)時(shi)使電(dian)(dian)(dian)動(dong)機(ji)(ji)過(guo)熱(re)。尤其是負序(xu)(xu)諧波(bo)在(zai)電(dian)(dian)(dian)動(dong)機(ji)(ji)中產生負序(xu)(xu)旋轉(zhuan)磁場，形(xing)成與電(dian)(dian)(dian)動(dong)機(ji)(ji)旋轉(zhuan)方向(xiang)相反(fan)的(de)(de)轉(zhuan)矩，起制(zhi)動(dong)作(zuo)用(yong)，從而(er)減少電(dian)(dian)(dian)動(dong)機(ji)(ji)的(de)(de)出力。另外電(dian)(dian)(dian)動(dong)機(ji)(ji)中的(de)(de)諧波(bo)電(dian)(dian)(dian)流，當頻率(lv)接(jie)近某零件的(de)(de)固有頻率(lv)時(shi)，還會使電(dian)(dian)(dian)動(dong)機(ji)(ji)產生機(ji)(ji)械(xie)振動(dong)，發(fa)出很大的(de)(de)噪聲。
對低壓開關設備(bei)的危害(hai)
對于配(pei)電(dian)(dian)用斷(duan)(duan)(duan)路(lu)器(qi)來說，全電(dian)(dian)磁型(xing)的(de)斷(duan)(duan)(duan)路(lu)器(qi)易受諧(xie)(xie)波(bo)電(dian)(dian)流(liu)的(de)影(ying)(ying)響(xiang)(xiang)(xiang)，使(shi)鐵耗增(zeng)大而發熱(re)，同時由于對電(dian)(dian)磁鐵的(de)影(ying)(ying)響(xiang)(xiang)(xiang)與渦流(liu)影(ying)(ying)響(xiang)(xiang)(xiang)，使(shi)脫扣困難，且諧(xie)(xie)波(bo)次數越(yue)高影(ying)(ying)響(xiang)(xiang)(xiang)越(yue)大；熱(re)磁型(xing)的(de)斷(duan)(duan)(duan)路(lu)器(qi)，由于導體(ti)的(de)集(ji)膚效應與鐵耗增(zeng)加而引起發熱(re)，使(shi)得(de)額(e)定(ding)電(dian)(dian)流(liu)降(jiang)(jiang)低(di)與脫扣電(dian)(dian)流(liu)降(jiang)(jiang)低(di)；電(dian)(dian)子型(xing)的(de)斷(duan)(duan)(duan)路(lu)器(qi)，諧(xie)(xie)波(bo)也會使(shi)其額(e)定(ding)電(dian)(dian)流(liu)降(jiang)(jiang)低(di)，尤其是檢(jian)測(ce)峰值的(de)電(dian)(dian)子斷(duan)(duan)(duan)路(lu)器(qi)，額(e)定(ding)電(dian)(dian)流(liu)降(jiang)(jiang)低(di)得(de)更(geng)多(duo)。由此(ci)可(ke)知，上述三種配(pei)電(dian)(dian)斷(duan)(duan)(duan)路(lu)器(qi)都(dou)可(ke)能因諧(xie)(xie)波(bo)產(chan)生誤動作。
對漏電(dian)斷路器的危害(hai)
對于(yu)漏電(dian)(dian)斷(duan)路(lu)器(qi)來(lai)說(shuo)，由(you)于(yu)諧(xie)波匯漏電(dian)(dian)流(liu)(liu)(liu)的作(zuo)用，可能使(shi)斷(duan)路(lu)器(qi)異常發熱，出現誤動(dong)作(zuo)或不(bu)動(dong)作(zuo)。對于(yu)電(dian)(dian)磁接(jie)角(jiao)器(qi)來(lai)說(shuo)，諧(xie)波電(dian)(dian)流(liu)(liu)(liu)使(shi)磁體部件溫升增大，影響(xiang)接(jie)點，線圈溫度(du)升高(gao)使(shi)額(e)定電(dian)(dian)流(liu)(liu)(liu)降低(di)。對于(yu)熱繼電(dian)(dian)器(qi)來(lai)說(shuo)，因受諧(xie)波電(dian)(dian)流(liu)(liu)(liu)的影響(xiang)也要使(shi)額(e)定電(dian)(dian)流(liu)(liu)(liu)降低(di)。在工(gong)作(zuo)中它們都有可能造(zao)成誤動(dong)作(zuo)。
對弱電(dian)系統設備(bei)的干擾
電(dian)(dian)力(li)(li)線(xian)路上流(liu)(liu)過的(de)幅(fu)值較大(da)的(de)奇次低(di)頻諧波(bo)電(dian)(dian)流(liu)(liu)，通過電(dian)(dian)磁感(gan)應(ying)、靜電(dian)(dian)感(gan)應(ying)與(yu)傳(chuan)導方式(shi)耦合時，會在(zai)鄰近電(dian)(dian)力(li)(li)線(xian)的(de)通信線(xian)路中產生(sheng)干(gan)擾電(dian)(dian)壓，其(qi)中電(dian)(dian)感(gan)應(ying)與(yu)靜電(dian)(dian)感(gan)應(ying)的(de)耦合強度與(yu)干(gan)擾頻率成正比，傳(chuan)導則通過公共(gong)接地耦合，有(you)(you)大(da)量不平(ping)衡電(dian)(dian)流(liu)(liu)流(liu)(liu)入接地極，從而干(gan)擾計算機網絡、通信、有(you)(you)線(xian)電(dian)(dian)視、報警與(yu)樓宇自動化等弱電(dian)(dian)設備(bei)。
影(ying)響電(dian)力(li)測(ce)量的準確性
目前采(cai)用(yong)的電(dian)力測量儀(yi)表(biao)中有磁電(dian)型(xing)(xing)和感應(ying)型(xing)(xing)，它們受諧(xie)波的影(ying)響較大。特(te)別是電(dian)能表(biao)（多采(cai)用(yong)感應(ying)型(xing)(xing)），當諧(xie)波較大時，將(jiang)產生計量混亂，測量不(bu)準確。
諧波對人體有影(ying)響
從人體生理學來說，人體細(xi)胞在受到(dao)刺激(ji)興奮時，會(hui)在細(xi)胞膜靜息電位基礎上發生快速(su)電波(bo)動或可逆翻轉(zhuan)，其(qi)頻率(lv)如果與諧(xie)波(bo)頻率(lv)相(xiang)接(jie)近，電網諧(xie)波(bo)的(de)電磁輻射(she)就會(hui)直接(jie)影響人的(de)腦(nao)磁場與心磁場。
