Research on Frequency Response Characteristics and Optimization Methods of Signal Cable Length to High Voltage Divider

In modern high-voltage power systems, high-voltage dividers are used to convert high voltage signals into measurable low voltage signals, ensuring the safety and stability of the system. However, cable length has a significant impact on the frequency response characteristics of high-voltage dividers, which may introduce signal attenuation and phase distortion, thereby affecting measurement accuracy. This paper establishes an electrical model of cable distribution parameters and simulates cables of different lengths (0.1 m to 10 m) in the frequency range of $10^{-3} \mathrm{~Hz}$ to $10^{8} \mathrm{~Hz}$. It is found that cable length has a relatively small effect on the voltage divider ratio at low frequencies $\left(10^{-3} \mathrm{~Hz}\right.$ to $10^{5}$ Hz), while the effect of cable length is significant at high frequencies $\left(10^{5} \mathrm{~Hz}\right.$ to $\left.10^{8} \mathrm{~Hz}\right)$. The voltage divider ratio changes more significantly due to longer cables. The increase in cable length gradually brings the range of high-frequency signals affected closer to the low-frequency region. In addition, in logarithmic coordinates, a linear relationship between cable length and the frequency corresponding to 95% attenuation of the voltage divider ratio is observed, providing a basis for optimizing the frequency response characteristics of high-voltage dividers. To optimize frequency response, the paper proposes a correction method utilizing adaptive digital filtering techniques that integrate inverse filtering and model-based compensation, effectively mitigating high-frequency attenuation and phase distortion. This approach enhances measurement accuracy and stability in power systems, providing critical support for safe operation.