| 摘要 |
PURPOSE:To protect an AC filter facility swiftly and accurately by equipping it with a means for detecting the current flowing in a high-pass filter, a diversion ratio correcting means for removing low frequency ingredients, an operating means for operating an valid, and a command means for outputting a breaker command signal. CONSTITUTION:Since the time constant C1R1 of a differentiating circuit 12 is set to meet C1R1=L/R, the differentiating circuit 12 outputs a voltage signal proportioned to the shunt current betanI' to a resistor R, to the n-order harmonics. Performing valid value operation to the output of this differentiating circuit 12, the signal proportioned to the power consumed in the resistor R can be taken out. Seeing that the command output is issued from a comparison disposition circuit 15 on the basis of this signal, the constitution of the relay becomes simple, and the calculation time is shortened. |
