The active filter acts as an infinite impedance to the external for the fundamental frequency and as a low resistor for harmonic frequencies.

对外电路而言，在基波频率下有源滤波器被控制为无限大阻抗，在谐波频率下被控制为小电阻。

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Simulation results indicate that dual slope algorithm is of high stability during external faults and is very sensitive to high impedance internal faults.

仿真结果表明：双比率算法较单比率算法，具有外部故障高稳定性，而在内部高阻故障时，也有很高的灵敏度。

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They have a simple construction with low power dissipation and low output impedance and can be used as interfacing circuits in VLSI designs to reduce the number of external connections on a chip.

它们有一个低功耗与低输出阻抗的简单结构，可以用作超大规模集成电路设计中的接口电路，以减少基片的外部引线数。

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