On-line detection method for change rate of impedance to ground of steel rail of railway wooden sleeper bridge

The invention relates to the technical field of railway catenary power supply and public work, in particular to a railway wooden sleeper bridge steel rail ground impedance change rate on-line detection method which comprises the following steps: S1, in the process that an electric locomotive passes through a railway wooden sleeper bridge, steel rail ground potential and ground leakage current waveforms are collected; s2, performing time-phased FFT (Fast Fourier Transform) on the acquired voltage and current values; s3, performing sliding average value calculation on the specific frequency components of the voltage and the current after the step S2; s4, the voltage amplitude and the current amplitude of the corresponding frequency component in the corresponding time period are used for calculating the rail-to-ground impedance value Zf of the corresponding frequency, and the impedance change rate is dZf/dt. The method has the advantages that the on-line detection of the resistance to ground ...