The application of frequency-increasing pulses for defect detection and localization in high-voltage cables effectively overcomes the limitations of traditional time-frequency domain reflectometry, such as incomplete impedance spectra and weak defect characterization, making it a key research focus in recent years. This study investigates the variation patterns of distributed electrical parameters in high-voltage cables with typical defects under frequency-increasing pulse excitation. By integrating simulations and experimental measurements, the influence of cable structural properties, material characteristics, and defect types on frequency-dependent distributed electrical parameters is systematically revealed. First, the effects of dielectric constant, core resistivity, and cross-sectional area on distributed capacitance and resistance are analyzed, demonstrating that variations in distributed capacitance serve as the critical parameter for impedance spectrum-based techniques. Second, seven types of defect samples are fabricated to quantify abrupt changes in distributed parameters under frequency-increasing pulses (100 Hz ~ 50 MHz). Results indicate that low-resistance grounding and open-circuit faults primarily affect distributed conductance, while defects such as joint moisture ingress, foreign object intrusion, and buffer layer dampness increase distributed capacitance, whereas sheath damage reduces it. This research establishes a theoretical foundation for studying the propagation characteristics of frequency-increasing pulses in high-voltage cables. It holds significant implications for advancing defect detection and localization methods based on time-frequency domain features of impedance spectra under frequency-increasing pulses, thereby enhancing the reliability of power grid operations.