| 摘要 |
PURPOSE:To enable distinguishing defective parts automatically for facilitating the after-the-fact action, by conducting a superposed inspection from the point of time when a failure occurs in regular monitoring, and by distinguishing defective parts of an input converter from the results of said inspection. CONSTITUTION:When a monitoring failure or zero-phase voltage monitoring failure occurs in CT circuit and PT circuit for taking in a current quantity and voltage quantity from an electric power system, an inspection input signal is superposed on the secondary side of said CT circuit and PT circuit (Step 105). Then, if a signal passing through an analog input circuit is superposed abnormally, the secondary side of said CT circuit and PT circuit is judged to be defective (Step 113). Also, if said signal is superposed normally, the primary side of the CT circuit and PT circuit is judged to be defective (Step 108). |
