| 摘要 |
PURPOSE:To enable the detection of a DC current or the like by arranging a circuit element formed of diodes and current limiting resistors between the secondary coil of a main current transformer and the primary coil of an auxiliary current transformer, thereby reduce the capacities of the current transformers and insulating them from a high voltage circuit. CONSTITUTION:At least two main saturable reactors are provided in a main current transformer 200, one respective terminals of the seconary coils 37, 38 thereof are connected, at least two auxiliary saturable reactors are provided in an auxiliary current transformer 300, one respective terminals of the primary coils 40, 41 thereof are connected, and an AC power source 39 is connected between the connecting point thereof and the connecting point of the secondary coils. Further, a parallel circuit element of current limiting resistors 55, 56 for limiting a current flowing when iron cores 35, 36 are saturated, and diodes 53, 54 for bypassing the current of the current transformer at the time of unsaturated iron cores from the resistors 55, 56 is provided. Thus, it can eliminate the effect of the shorting current so as to reduce the capacity of the current transformers or the like and to insulate them from a high voltage circuit, thereby detecting the DC current or voltage. |
