TY - JOUR

T1 - Measurement of load impedance in power cables using wavelet-transform-based time-frequency domain reflectometry

AU - Lee, Sin Ho

AU - Park, Jin Bae

AU - Choi, Yoon Ho

PY - 2013/9

Y1 - 2013/9

N2 - In this paper, wavelet-transform-based time-frequency domain reflectometry (WTFDR) is proposed for load impedance measurement. In order to measure the load impedance, the energy of the measured signal in the time-frequency domain, the phase difference between the reference signal and the reflected signal, the characteristic impedance, and the attenuation factor of the measured cable must all be known. Since the complex wavelet transform is composed of real and imaginary parts, the phase difference is easily obtained using the ratio of the real coefficient to the imaginary coefficient. In addition, the wavelet energy denotes the sum of the square of the modulus of the wavelet transform and describes the energy of the measured signal in the time and frequency domains. To accurately determine the characteristic impedance and attenuation factors, the power cable should be estimated as a coaxial cable. Using WTFDR with the complex mother wavelet and the estimated power cable, the load impedance can be obtained simply and accurately. Finally, real experiments for the evaluation of various load impedances are carried out to confirm the effectiveness and accuracy of the proposed method compared to the conventional time-frequency domain reflectometry.

AB - In this paper, wavelet-transform-based time-frequency domain reflectometry (WTFDR) is proposed for load impedance measurement. In order to measure the load impedance, the energy of the measured signal in the time-frequency domain, the phase difference between the reference signal and the reflected signal, the characteristic impedance, and the attenuation factor of the measured cable must all be known. Since the complex wavelet transform is composed of real and imaginary parts, the phase difference is easily obtained using the ratio of the real coefficient to the imaginary coefficient. In addition, the wavelet energy denotes the sum of the square of the modulus of the wavelet transform and describes the energy of the measured signal in the time and frequency domains. To accurately determine the characteristic impedance and attenuation factors, the power cable should be estimated as a coaxial cable. Using WTFDR with the complex mother wavelet and the estimated power cable, the load impedance can be obtained simply and accurately. Finally, real experiments for the evaluation of various load impedances are carried out to confirm the effectiveness and accuracy of the proposed method compared to the conventional time-frequency domain reflectometry.

UR - http://www.scopus.com/inward/record.url?scp=84883186764&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84883186764&partnerID=8YFLogxK

U2 - 10.1088/0957-0233/24/9/095008

DO - 10.1088/0957-0233/24/9/095008

M3 - Article

AN - SCOPUS:84883186764

SN - 0957-0233

VL - 24

JO - Measurement Science and Technology

JF - Measurement Science and Technology

IS - 9

M1 - 095008

ER -