Issn 305-9397. Ғылым және білім. 2022. №1-1 (66) issn 2305-9397
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228 can start the unit both from the remote control 8, which is located in the immediate vicinity of the unit, and remotely. Research results. The power supply circuit of the microwave installation is shown in figure 2. The frequency converters ПЧ1, ПЧ2 are connected to the phases of the network through the ЭMC filter to control the electric motors M1, M2 of the conveyor drives and the ventilation system, as well as the rectifier B, which forms a DC link, from which magnetron generators MG1...MG6 receive power. Figure 2 – Scheme of the power supply of the microwave installation Magnetron generators are made according to the circuit (fig. 3) containing an inverter И, which is connected to the DC link through a pulse voltage converter ИПН and a smoothing filter СФ. The inverter generates an increased frequency voltage (about 20 kHz), due to which the TA transformer has a significantly smaller weight and dimensions than a transformer operating at a frequency of 50 Hz. Figure 3 – Scheme of the magnetron generator The voltage on the secondary winding of the transformer TA is rectified by a high-voltage diode bridge VD1...VD4 and is fed to the anode-cathode gap of the magnetron VL. The pulse voltage converter makes it possible to maintain a given power level of the microwave generator during mains voltage fluctuations and corresponding changes in the DC link voltage. The cathode is heated by a voltage regulator RN, which provides the necessary path of the heating current in the process of heating the cathode and the output of the magnetron VL to the operating mode. To control the power of the microwave installation at a certain point on the conveyor belt, the power of one of the six magnetrons is changed. This is realized by controlling the PSI and the corresponding voltage change at the magnetron anode relative to the cathode. If the power of the magnetrons is not enough, or some of them are out of order, it is possible to adjust the power in another way. Heating sensors installed at the outlet of each chamber and giving temperature readings on the surface of the processed material transmit readings to the control panel of the installation. Further, the operator makes changes to the speed of rotation of the conveyor belt drive, thus adjusting the processing time of the raw material with microwave energy during its passage through the chambers. The studies carried out in [9] showed that the power supply circuit with a thyristor controller does not ensure stable operation of the microwave installation even when an alternating current |