傳輸(shu)：電(dian)能(neng)的(de)傳輸(shu)，它(ta)和(he)變電(dian)、配電(dian)、用電(dian)一起，構成電(dian)力系統的(de)整體功能(neng)。通過輸(shu)電(dian)，把相距甚(shen)遠的(de)(可(ke)達數千千米)發(fa)電(dian)廠和(he)負(fu)荷 中心起來(lai)，使電(dian)能(neng)的(de)開發(fa)和(he)利用超越地域的(de)限制(zhi)。和(he)其(qi)他能(neng)源(yuan)的(de)傳輸(shu)(如輸(shu)煤、輸(shu)油(you)等)相比，輸(shu)電(dian)的(de)損耗小、效益(yi)高、靈活方便、易(yi)于(yu)調控(kong)、環境污染少;輸(shu) 電(dian)還可(ke)以將不同地點的(de)發(fa)電(dian)廠連接起來(lai)，實行峰谷調節。輸(shu)電(dian)是(shi)(shi)電(dian)能(neng)利用*性的(de)重要(yao)體現，在現代化社(she)會中，它(ta)是(shi)(shi)重要(yao)的(de)能(neng)源(yuan)動脈。

  輸(shu)(shu)(shu)(shu)電(dian)(dian)線路(lu)按(an)結構(gou) 形式可分為(wei)(wei)架空(kong)輸(shu)(shu)(shu)(shu)電(dian)(dian)線路(lu)和地(di)下(xia)輸(shu)(shu)(shu)(shu)電(dian)(dian)線路(lu)。前者由(you)線路(lu)桿塔、導線、絕(jue)緣子等(deng)構(gou)成，架設在(zai)地(di)面上;后者主要用電(dian)(dian)纜，敷設在(zai)地(di)下(xia)(或水下(xia))。輸(shu)(shu)(shu)(shu)電(dian)(dian)按(an)所送電(dian)(dian)流(liu)(liu)(liu)性質 可分為(wei)(wei)直(zhi)流(liu)(liu)(liu)輸(shu)(shu)(shu)(shu)電(dian)(dian)和交(jiao)(jiao)流(liu)(liu)(liu)輸(shu)(shu)(shu)(shu)電(dian)(dian)。19世紀(ji)80年(nian)代首先成功(gong)地(di)實現了直(zhi)流(liu)(liu)(liu)輸(shu)(shu)(shu)(shu)電(dian)(dian)，后因(yin)受電(dian)(dian)壓提(ti)不高的(de)限制(輸(shu)(shu)(shu)(shu)電(dian)(dian)容量大(da)體與輸(shu)(shu)(shu)(shu)電(dian)(dian)電(dian)(dian)壓的(de)平方成比例)19世紀(ji)末為(wei)(wei)交(jiao)(jiao)流(liu)(liu)(liu) 輸(shu)(shu)(shu)(shu)電(dian)(dian)所取(qu)代。交(jiao)(jiao)流(liu)(liu)(liu)輸(shu)(shu)(shu)(shu)電(dian)(dian)的(de)成功(gong)，迎來了20世紀(ji)電(dian)(dian)氣化時(shi)代。20世紀(ji)60年(nian)代以來，由(you)于電(dian)(dian)力電(dian)(dian)子技術的(de)發(fa)展(zhan)，直(zhi)流(liu)(liu)(liu)輸(shu)(shu)(shu)(shu)電(dian)(dian)又有(you)新發(fa)展(zhan)，與交(jiao)(jiao)流(liu)(liu)(liu)輸(shu)(shu)(shu)(shu)電(dian)(dian)相配合，形成交(jiao)(jiao) 直(zhi)流(liu)(liu)(liu)混合的(de)電(dian)(dian)力系統。

  輸(shu)(shu)(shu)電(dian)(dian)電(dian)(dian)壓(ya)的(de)高(gao)低是(shi)輸(shu)(shu)(shu)電(dian)(dian)技術發展(zhan)水(shui)平的(de)主要標志。到20世(shi)紀90年代，世(shi)界各國常(chang)用輸(shu)(shu)(shu)電(dian)(dian)電(dian)(dian)壓(ya)有220千伏(fu)及以上(shang)的(de)高(gao)壓(ya)輸(shu)(shu)(shu)電(dian)(dian)330～765千伏(fu)的(de)超高(gao)壓(ya)輸(shu)(shu)(shu)電(dian)(dian)，1000千伏(fu)及以上(shang)的(de)特高(gao)壓(ya)輸(shu)(shu)(shu)電(dian)(dian)。

  變(bian)電(dian)(dian)(dian)(dian)(dian)：電(dian)(dian)(dian)(dian)(dian)力(li)系統中，發電(dian)(dian)(dian)(dian)(dian)廠(chang)將天(tian)然的(de)(de)(de)(de)(de)(de)一次能(neng)源(yuan)轉變(bian)成電(dian)(dian)(dian)(dian)(dian)能(neng)，向遠方的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)力(li)用(yong)戶(hu)送電(dian)(dian)(dian)(dian)(dian)，為(wei)了減小輸電(dian)(dian)(dian)(dian)(dian)線路上的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)能(neng)損耗及線路阻抗(kang)壓(ya)降，需要(yao)(yao)將電(dian)(dian)(dian)(dian)(dian)壓(ya)升(sheng)高;為(wei)了滿足電(dian)(dian)(dian)(dian)(dian)力(li)用(yong) 戶(hu)安全的(de)(de)(de)(de)(de)(de)需要(yao)(yao)，又要(yao)(yao)將電(dian)(dian)(dian)(dian)(dian)壓(ya)降低(di)，并分(fen)配給各個用(yong)戶(hu)，這(zhe)就需要(yao)(yao)能(neng)升(sheng)高和(he)降低(di)電(dian)(dian)(dian)(dian)(dian)壓(ya)，并能(neng)分(fen)配電(dian)(dian)(dian)(dian)(dian)能(neng)的(de)(de)(de)(de)(de)(de)變(bian)電(dian)(dian)(dian)(dian)(dian)所(suo)。所(suo)以(yi)變(bian)電(dian)(dian)(dian)(dian)(dian)所(suo)是電(dian)(dian)(dian)(dian)(dian)力(li)系統中通(tong)過其(qi)變(bian)換電(dian)(dian)(dian)(dian)(dian)壓(ya)、接受和(he)分(fen)配 電(dian)(dian)(dian)(dian)(dian)能(neng)的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)工裝置，它是發電(dian)(dian)(dian)(dian)(dian)廠(chang)和(he)電(dian)(dian)(dian)(dian)(dian)力(li)用(yong)戶(hu)的(de)(de)(de)(de)(de)(de)中間(jian)環節(jie)，同時通(tong)過變(bian)電(dian)(dian)(dian)(dian)(dian)所(suo)將各電(dian)(dian)(dian)(dian)(dian)壓(ya)等級的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)網起來，變(bian)電(dian)(dian)(dian)(dian)(dian)所(suo)的(de)(de)(de)(de)(de)(de)作用(yong)是變(bian)換電(dian)(dian)(dian)(dian)(dian)壓(ya)，傳輸和(he)分(fen)配電(dian)(dian)(dian)(dian)(dian)能(neng)。變(bian)電(dian)(dian)(dian)(dian)(dian)所(suo)由電(dian)(dian)(dian)(dian)(dian) 力(li)變(bian)壓(ya)器、配電(dian)(dian)(dian)(dian)(dian)裝置、二次系統及必(bi)要(yao)(yao)的(de)(de)(de)(de)(de)(de)附屬設(she)備組成。

  變壓器是變電所的中心設備，變壓器利用的是電磁感應原理。
配(pei)電(dian)(dian)裝(zhuang)(zhuang)置是(shi)變電(dian)(dian)所中所有的(de)開關電(dian)(dian)器(qi)、載流導體輔助設備(bei)(bei)連接(jie)在一起的(de)裝(zhuang)(zhuang)置。其作用是(shi)接(jie)受和分(fen)配(pei)電(dian)(dian)能。配(pei)電(dian)(dian)裝(zhuang)(zhuang)置主(zhu)要由母線、高(gao)壓斷(duan)路器(qi)開關、電(dian)(dian)抗器(qi)線圈、互感(gan)器(qi)、電(dian)(dian)力電(dian)(dian)容器(qi)、避雷器(qi)、高(gao)壓熔斷(duan)器(qi)、二次設備(bei)(bei)及必要的(de)其他輔助設備(bei)(bei)所組成。

  二次設備是指一次系統狀態測量、控制、監察和保護的設備裝置。由這些設備構成的回路叫二次回路，總稱二次系統。
  二次系(xi)統(tong)的(de)設備包含測量裝置、控制(zhi)裝置、繼電保護裝置、自動控制(zhi)裝置、直(zhi)流(liu)系(xi)統(tong)及必要的(de)附屬設備。