| Popis: |
An impedance measurement using transient voltage and current waveforms with Fourier transforms is a practical method especially for a power system because steady-state measuring using a variable frequency source is difficult to apply. Since the transient method is an indirect measuring method, its accuracy depends on the measuring condition. This paper investigates the effect of the measurement system on the measured results. A capacitive circuit, which represents the impedance between electrodes implanted into a piece of wood, is used as a circuit under test (CUT). Three variables affecting the measured result are identified: a stray capacitance between CUT and ground, a capacitance of a voltage probe, and a sheath surge impedance of a current injected cable. These parameters are investigated and solved by theoretical calculation. Finally, the capacitance obtained from measured result is confirmed by a theoretical calculation. |
