Responsible Editor: Wan Yuzhong talks about the application of silicon avalanche diode in the improvement of air compressor control circuit of a certain type of EMU Wanjiahua South Car Qingdao Sifang Locomotive & Rolling Stock Co., Ltd. (Shandong Qingdao 266111 type electronic product technology in railway rail transit equipment industry Broad application prospects.
During the design verification process, a certain type of EMU found that the air compressor dryer backflushing solenoid valve was abnormally exhausted after the air compressor stopped working (normally, it should be stopped synchronously after the air compressor stopped working). Knowing that the reason is that the air compressor logic control circuit does not meet the design requirements, that is, when the EMU three-phase 400V (the operating voltage of the air compressor> the circuit has no output, the air compressor stops working, but the air compressor dryer reverse blows The solenoid valve associated circuit still has electricity, which causes the dryer backflushing solenoid valve to still exhaust the air, resulting in an abnormal drop in the wind pressure of the EMU pipe network.
After research and analysis, the improvement scheme of the air compressor control circuit is proposed. The specific scheme is to add a unidirectional control component to the contactor control contact circuit of the air compressor, so that the air compressor dryer backflushing solenoid valve working circuit is in the EMU. The three-phase 400V circuit must not be powered when there is no output. To this end, a common rectifying Schottky diode was selected as the unidirectional control element, and in order to ensure the reliability of the unidirectional control element, the silicon surge was selected in consideration of the abnormal inrush voltage in the EMU high-voltage circuit system. The avalanche diode acts as an overvoltage protection component for a conventional rectified Schottky diode.
Before and after the circuit transformation, the parameters of the working circuit of the air compressor (IF (AV) should be greater than SA, VRRM should be greater than 800V), and the P600M model of American Visa is selected. The VRRM is 1000V and IF (AV) is 6A. Application performance of silicon avalanche diodes in the railway industry, selected silicon avalanche diodes of the type TSAD-1S0. This component has excellent performance with 8 tis /2 (is (wavelength time 8 (is, half-peak time 2 tis) and 10/1000 (wavefront time 10, half-peak time lOOOtis) multi-waveform surge protection, reaction Faster time (lS>, 7mA breakdown voltage is greater than 7SV, making the design idea responsible editor: Wan Yu in the TSAD-150 silicon avalanche diode typical test results with a temperature of -4C ~ 8SC. Through a domestic university electromagnetic compatibility.
After the air compressor control circuit of the EMU is improved, the air compressor action meets the design requirements, and the blowback solenoid valve circuit of the air compressor dryer is synchronized with the air compressor working circuit, and the dryer backflushing solenoid valve is only When the air compressor is working, the electric air is exhausted, which effectively solves the problem that the air pressure of the EMU is abnormally reduced due to the abnormal exhaust of the air blower of the air compressor dryer. At the same time, due to the reliable protection performance of the silicon avalanche diode added in the logic control circuit, the EMU has been used for nearly 2 years, and the silicon avalanche diode and the common rectified Schottky diode added by the circuit improvement have no faults. The press is operating normally. fTTi
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