摘要 |
<p>The impedance of a power system adapted for operation at a predetermined line frequency is measured by providing a test signal of frequency different from the predetermined line frequency by an increment significantly less than the predetermined line frequency to provide an impedance measurement signal representative of the impedance of the power system at the test frequency. The impedance measurement signal is processed to provide a line impedance signal representative of the power system impedance at the predetermined line frequency. <IMAGE></p> |