多通道采樣鍵準(zhǔn)確的電力線路監(jiān)測(cè)

　　準(zhǔn)確的電力線監(jiān)測(cè)已成為一個(gè)重要的要求，不僅集中在電網(wǎng)本身，而且在其邊緣。對(duì)于電網(wǎng)并列的能量收集發(fā)電系統(tǒng)，甚至終端設(shè)備，持續(xù)的電能質(zhì)量特性的分析，有助于確保電網(wǎng)和附加系統(tǒng)的健康。在電力監(jiān)控系統(tǒng)的心臟，模擬數(shù)字轉(zhuǎn)換器（ADC）在測(cè)量線電壓和電流在一個(gè)水平的精度適合每個(gè)應(yīng)用起著關(guān)鍵性的作用。工程師可以滿足一系列的要求從實(shí)用級(jí)系統(tǒng)的精度需要收入的目的基本電力監(jiān)控線路故障，利用高性能ADC檢測(cè)和相關(guān)部件制造商包括模擬設(shè)備，科寶電子，Intersil，線性技術(shù)，集成，芯片技術(shù)，半導(dǎo)體，脈沖電子、德克薩斯文書。

　　在最基本的層面上，電力監(jiān)控系統(tǒng)依賴于測(cè)量瞬時(shí)電壓和電流用電流互感器（CTS）和電壓互感器（稱為PT，電壓互感器）輸出轉(zhuǎn)換的高速ADCs（圖1）。反過來，處理器使用的瞬時(shí)電流和電壓測(cè)量計(jì)算的關(guān)鍵特性，包括有功功率，無功功率，視在功率和功率因數(shù)，甚至更復(fù)雜的計(jì)算，如諧波，這可能會(huì)導(dǎo)致設(shè)備損壞。

　　Figure 1： A typical power-monitoring system samples line current and voltage， using high-speed analog-digital converters （ADCs） to provide high-resolution data to the host processor for calculation of power parameters. （Courtesy of Texas Instruments）

　　Performing these power calculations depends foremost on accurately measured voltage and current. Standards such as ANSI C12.20 for North America and IEC 62053 dictate specific accuracy levels such as Class 0.2， which requires ± 0.2 percent accuracy. In practice， power-measurement systems are typically designed to surpass standard accuracy specifications—relying on high-sample rates and high-resolution converters to capture high-speed transients and to ensure reliable calculation of more complex characteristics such as multiple harmonics.