Parallel connection method and device for multi-channel PD signals

摘要

A parallel connection method and a device for multi-channel partial discharge (PD) signals have input sources of pre-processed and amplified signals received by multiple PD sensors. Then isolation and processing are provided to the signals to ensure that each signal is able to be self-triggered and unidirectional transmitted. Finally, processed signals of each channel are outputted. For ultra-high frequency (UHF) PD signal, the delay transmission is realized by a surface acoustic wave (SAW) delay line method. The present invention makes the amplified multi-channel PD signals self-trigger and unidirectional transmit though isolation processing and then realizes parallel connection without interference. The method also decreases signal transmission loss. Meanwhile, all the detected PD signals transmit on one signal bus through parallel connection method, so as to use only one set of acquisition unit to monitor and acquire the signals received by multiple sensors, which obviously lowers the system cost.

主权项

1. A parallel connection method for multi-channel PD signals comprising steps of:
Step 1.1: receiving input signals sensed from multiple sensors, wherein the input signals include UHF (ultra-high frequency) PD (partial discharge) signals, ultrasonic signals, and high frequency current signals; Step 1.2: pre-processing each of the input signals, including amplifying and filtering; Step 1.3: isolating and processing the amplified and filtered signal through a self-triggering switch, for ensuring self-triggering and unidirectional transmitting of the amplified and filtered signal; and Step 1.4: outputting the processed signal of each channel; wherein isolating and processing comprise steps of: Step 1.3.1: dividing the amplified and filtered signal into two sub-signals, numbered as first and second; Step 1.3.2A: if the first sub-signal is an UHF PD signal, delay-transmitting the first sub-signal; wherein in delay transmission, the first sub-signal is broken down into multiple spectrum signal groups; delaying each group and then compounding; finally, amplifying the combined signal and outputting through the self-triggering switch. Demodulation can be applied to process the output signal; if the first sub-signal is a high frequency current signal or an ultrasonic signal, outputting the first sub-signal directly through the self-triggering switch; Step 1.3.2B: comparing the second sub-signal with reference level to realize signal auto-detection; if meeting a requirement of the reference level, transferring the second sub-signal into a driving signal for switch; and Step 1.3.3: processing the driving signal, for controlling the self-triggering switch.