監測前端提供工業系統實時功率檢查

　　電力線完整性已成為工業和醫療設備設計的一個重要方面。許多過程現在依賴于傳感器的輸入，容易受到噪聲和干擾的實時監測。電瞬變很容易擾亂精密測量。如果這些條件沒有得到補償，不正確的讀數可能會導致閉環控制回路遭受像差或系統丟失重要的安全相關的信號。

　　其結果是，某些形式的交流線路監測已成為一個重要的額外的傳感器輸入，以確保瞬變和其他電力線扭曲不影響設備。電力線監測可以用來確保其他高功率設備使用的電源轉換器正常工作，不注入不必要的諧波或呈現不平衡負載到電網，這可能會破壞電力輸送。用戶還可以使用數據來確定進程是否需要優化，以減少整個工廠的功耗使用熱點跟蹤整個能源消耗。

　　Most AC line monitor designs use one or more analog-to-digital converters （ADCs） to convert power line signals into a digital format and then apply digital signal processing using a local processor to derive useful operating parameters such as peak and average power output， power factor angle， harmonic voltage amplitude and line frequency.

　　The key question over designing an AC line monitoring subsystem is to determine which types of measurement are important as these will influence the choice of ADC used to sample the inputs， as well as the number of input channels. For example， a three-phase monitor used to determine harmonic distortion will need to sample both voltage and current for a total of four phases， resulting in a requirement for eight ADC input channels. The fourth phase that needs to be sampled is the neutral line： this will show current flowing if the main phases are unbalanced.