CN-224231847-U - Rail transit power supply cable high-low traveling wave measurement system

CN224231847UCN 224231847 UCN224231847 UCN 224231847UCN-224231847-U

Abstract

The utility model discloses a high-low traveling wave measurement system for a rail transit power supply cable, and relates to the field of traveling wave measurement. According to the utility model, by configuring the current transformer with two characteristics of high precision and strong saturation resistance, intelligent switching of the measuring channel is realized by combining a multi-way switch, data buffer storage is performed by using the FIFO memory, and real-time threshold judgment is realized by using the parallel comparator. When the impact current is detected, the DSP controller rapidly switches the measuring channel and completes data splicing, so that the problem that a single sensor cannot give consideration to both precision and anti-saturation capacity is effectively solved.

Inventors

TANG YU

Assignees

成都鼎汉轨道装备科技有限公司

Dates

Publication Date: 20260512
Application Date: 20250418

Claims (7)

1. The utility model provides a rail transit power supply cable high-low traveling wave measurement system which characterized in that includes: The signal sampling module comprises a first Rogowski coil electronic current transformer and a second Rogowski coil electronic current transformer, wherein the measurement precision of the first Rogowski coil electronic current transformer is higher than that of the second Rogowski coil electronic current transformer, and the anti-saturation capacity of the second Rogowski coil electronic current transformer is higher than that of the first Rogowski coil electronic current transformer; The multichannel switch module is connected with the output ends of the first Rogowski coil electronic current transformer and the second Rogowski coil electronic current transformer, and receives a channel selection signal of the DSP control module to realize channel switching; the integrating circuit module is used for carrying out integral conversion on the voltage signals output by the multi-path switch module; The A/D conversion module converts the integrated analog signals into digital signals, and the output end of the A/D conversion module is respectively connected with the FIFO storage module and the current comparison module; the current comparison module is used for comparing the data converted by the A/D conversion module with a preset threshold value; The DSP control module can set a preset threshold value, issue a corresponding channel selection signal according to the comparison result of the current comparison module, read, store and splice data in the FIFO storage module, and recover fault current complete information.
2. The rail transit power supply cable high-low traveling wave measurement system of claim 1, wherein the first Rogowski coil electronic current transformer is configured to collect a measurement current signal.
3. The rail transit power supply cable high-low traveling wave measurement system of claim 2, wherein the second Rogowski coil electronic current transformer is configured to collect fault current signals.
4. The system of claim 1, wherein the multi-path switch module uses a multi-path analog switch CD4067 to determine which transformer to switch on the output according to the channel selection signal of the DSP control module.
5. The system of claim 1, wherein the a/D conversion module is configured to provide a clock signal to control the sampling frequency.
6. The system of claim 1, wherein the FIFO memory module is configured to send an interrupt signal to the DSP control module after the FIFO memory module is fully loaded.
7. The system for measuring the traveling wave of the high and low power supply cables of the rail transit according to claim 1, wherein the current comparison module is a 16-bit comparator formed by connecting 5 blocks of 74HC85 four-bit numerical comparators in parallel, and the data converted by the A/D conversion module is compared with a threshold value set by the DSP control module.

Description

Rail transit power supply cable high-low traveling wave measurement system Technical Field The utility model relates to the field of traveling wave measurement, in particular to a high-low traveling wave measurement system for a rail transit power supply cable. Background The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. The existing traveling wave monitoring device generally adopts a threshold triggering type data capturing mechanism in the track traffic power supply cable current signal acquisition. When the transmission line fails, the device starts high-speed sampling and stores failure data after the traveling wave current amplitude reaches a preset trigger threshold. However, this triggering mechanism has inherent drawbacks: In the initial stage of the fault, the traveling wave current amplitude value starts to be in an exponentially rising form from zero, when the trigger threshold value is reached, the device can only record the current waveform above the threshold value, and the transient process information below the threshold value in the initial stage of the fault is completely lost because the transient process information does not enter the sampling storage stage. The data truncation phenomenon causes that the recorded fault waveform lacks key characteristic parameters of the initial traveling wave head, and particularly transient characteristics reflecting fault types such as traveling wave wavefront steepness, initial phase and the like cannot be completely captured. Therefore, under the high-precision fault location requirement of a rail transit power supply system, the waveform data loss formed in the prior art directly affects the calculation precision of the traveling wave speed, so that the fault range error is increased, and the complete fault transient process waveform is difficult to reconstruct through the existing sampling mechanism, so that the fault range error becomes a main bottleneck for restricting the promotion of the traveling wave range technology. Disclosure of utility model The utility model aims to solve the problems in the prior art and provides a high-low traveling wave measurement system for a rail transit power supply cable. The technical scheme of the utility model is as follows: a rail transit power supply cable high-low traveling wave measurement system, comprising: The signal sampling module comprises a first Rogowski coil electronic current transformer and a second Rogowski coil electronic current transformer, wherein the measurement precision of the first Rogowski coil electronic current transformer is higher than that of the second Rogowski coil electronic current transformer, and the anti-saturation capacity of the second Rogowski coil electronic current transformer is higher than that of the first Rogowski coil electronic current transformer; The multichannel switch module is connected with the output ends of the first Rogowski coil electronic current transformer and the second Rogowski coil electronic current transformer, and receives a channel selection signal of the DSP control module to realize channel switching; the integrating circuit module is used for carrying out integral conversion on the voltage signals output by the multi-path switch module; The A/D conversion module converts the integrated analog signals into digital signals, and the output end of the A/D conversion module is respectively connected with the FIFO storage module and the current comparison module; the current comparison module is used for comparing the data converted by the A/D conversion module with a preset threshold value; The DSP control module can set a preset threshold value, issue a corresponding channel selection signal according to the comparison result of the current comparison module, read, store and splice data in the FIFO storage module, and recover fault current complete information. Further, the first Rogowski coil electronic current transformer is used for collecting a current signal for measurement. Further, a second Rogowski coil electronic current transformer is used for collecting fault current signals. Further, the multi-way switch module uses the multi-way analog switch CD4067 to determine which transformer to switch on for output according to the channel selection signal of the DSP control module. Further, the A/D conversion module is provided with a clock signal by the DSP control module to control the sampling frequency. Further, after the FIFO storage module is fully loaded, an interrupt signal is sent to the DSP control module. Further, the current comparison module is a 16-bit comparator formed by connecting 5 blocks of 74HC85 four-bit numerical comparators in parallel, and the data converted by the A/D conversion module is received and compared with a threshold value set by the DSP control module. Further, the workflow of the DSP control module includes: step S1, ini