| 摘要 |
<p>An arrangement includes an A/D converter and a processing circuit. The A/D converter is configured to generate digital samples of voltage and current waveforms in a polyphase electrical system. The processing circuit is operably coupled to receive the digital samples from the A/D converter. The processing circuit configured is to obtain contemporaneous phase current and voltage samples I A , I B , I C and/or I N , and V A , V B , V C . The processing circuit is further configured to determine at least I CB sample values based on three of the current samples of I A , I B , I C , and I N , and determine a VA value based at least in part on I CB . The processing circuit is further configured to provide information representative of the VA calculation to one of a group consisting of a display, a communication circuit, a memory and a billing calculation unit.</p> |
