PLC (programmable logic controller) based online monitoring device for partial discharge signals of transformer

Abstract

The invention discloses a PLC (programmable logic controller) based online monitoring device for partial discharge signals of a transformer. The online monitoring device comprises a PLC, a sensor module, a signal processing circuit module, an analog-to-digital converter, a deserializer module, an FIFO (first in first out) storage, a PCI (peripheral component interconnect) bus interface circuit and an upper computer, wherein the sensor module, the signal processing circuit module, the analog-to-digital converter, the deserializer module, the FIFO storage, the PCI bus interface circuit and the upper computer are respectively connected with the PLC. The PLC is used for controlling the signal processing circuit module, the analog-to-digital converter and the FIFO storage, a plurality of electro-acoustic signals generated by partial discharge of the transformer are uploaded to the upper computer for comprehensive analysis and processing through a PCI bus after processing, synchronous A / D (analog-to-digital) sampling and data temporary storage, wideband electro-acoustic signals can be synchronously monitored on line, complete partial discharge signal characteristics can be timely acquired, monitoring accuracy is improved, and the device is high in reliability and interference resistance and stable in operation.

Description

technical field [0001] The invention belongs to monitoring equipment for synchronously sampling signals generated by partial discharge of transformers, and in particular relates to a PLC-based on-line monitoring device for partial discharge signals of transformers. Background technique [0002] Real-time online monitoring of the partial discharge signal of the transformer can detect the insulation aging of the transformer and predict the development trend of the fault in time, so as to prevent the occurrence of malignant accidents; therefore, people have developed some online monitoring devices, such as Chinese patent applications No. 201210279848.3 discloses a dry-type transformer partial discharge on-line monitoring and its positioning method. The first ultrasonic sensor, the second ultrasonic sensor, the third ultrasonic sensor, and the fourth ultrasonic sensor respectively collect ultrasonic signals in partial discharge signals and transmit to the signal processing unit;...

AI Technical Summary

Problems solved by technology

Although the above-mentioned technical solution realizes the monitoring of the partial discharge signal of the transformer to a certain extent, it still has certain difficulties in synchronous real-time signal monitoring of the broadband electro-acoustic signal of the partial discharge.

This is mainly because the frequency range of the pulse current signal and ultrasonic signal of the partial discharge signal of the transformer is very wide (about 10kHz ~ 10MHz), and it is easily affected by electromagnetic interference and mechanical vibration noise at the work site. The speed and data transmission, signal processing and anti-interference requirements of the processor are very high. The partial discharge monitoring device using a microcontroller or DSP as the main controller is limited by the hardware resources of the controller itself. -Synchronous high-speed A / D sampling and complex signal calculations for acoustic signals affect the accuracy and reliability of monitoring, and the use of high-performance data acquisition cards and dedicated partial discharge analysis and positioning software to collect and process partial discharge signals is difficult It increases the cost of the system and is difficult to be popularized and applied on medium and small transformers

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