摘要 |
<p>To detect any abnormal loss of a feedback signal in an electric power system wherein a plurality of feedback signals are respectively derived from various system quantities, such as voltage and current, and are used as inputs to a controller that regulates the output of a controllable source of power, the controller is arranged to estimate the desired value of the system quantity from which a first feedback signal is derived, to compare the estimated desired value with the actual value of the same quantity (as indicated by the first feedback signal), and to signal a malfunction if this comparison reveals that the first feedback signal is faulty.</p> |