How to perform step-by-step power supply inspection on the medium frequency induction heating machine?

When installing and debugging the medium frequency induction heating machine, we must not only do a good job of inspection before power supply, but also do a good job of step-by-step power supply inspection and inspection after power supply, because each inspection is related to whether the equipment can Normal use. Today, the editor will tell you how we should conduct a gradual power supply inspection.

(1) Only supply power to the relay operating circuit, and completely cut off other circuits (the fuse of the corresponding circuit can be removed). Then simulate various faults (such as water outage, overcurrent, door opening), and conduct power outage tests to check whether the actions of each protection system and monitoring systems such as signal lights are normal.

(2) Set the action values of the water pressure relay, overcurrent relay, time relay, etc. according to the requirements of the process and equipment itself. When setting the overcurrent relay of the filament circuit, you should consider avoiding the inrush current of cold power transmission. This is important for equipment with graded power transmission, otherwise it will easily cause malfunction.

(3) Measure the power supply voltage of the filament circuit. After confirming that it meets the requirements, you can send the filament voltage according to regulations (don't forget to send cooling water), and conduct the test immediately. If it is found that the filament voltage of the oscillator tube is too high or too low, measures should be taken to deal with it. If a magnetic saturation regulator is used, the voltage regulator should also be used to artificially create power fluctuations to check its voltage stabilization performance. If the voltage stabilization value is incorrect or the voltage stabilization performance is not good, it should be adjusted. When adjusting, it must be carried out under the conditions of rated power supply voltage and rated load. Generally, the method of changing the number of turns of the resonant winding and compensation winding is used. If necessary, the method of changing the core air gap and resonant capacitance can also be considered. For detailed debugging methods, please refer to the voltage regulator factory instructions or relevant technical information.(3) Measure the power supply voltage of the filament circuit. After confirming that it meets the requirements, you can send the filament voltage according to regulations (don't forget to send cooling water), and conduct the test immediately. If it is found that the filament voltage of the oscillator tube is too high or too low, measures should be taken to deal with it. If a magnetic saturation regulator is used, the voltage regulator should also be used to artificially create power fluctuations to check its voltage stabilization performance. If the voltage stabilization value is incorrect or the voltage stabilization performance is not good, it should be adjusted. When adjusting, it must be carried out under the conditions of rated power supply voltage and rated load. Generally, the method of changing the number of turns of the resonant winding and compensation winding is used. If necessary, the method of changing the core air gap and resonant capacitance can also be considered. For detailed debugging methods, please refer to the voltage regulator factory instructions or relevant technical information.

Nowadays, the oscillating tube filaments of some medium-frequency induction heating machines are powered by silicon-controlled AC voltage regulators. At this time, stepless continuous voltage regulation is generally used, and single-phase silicon controlled anti-parallel circuits are often used. The voltage stabilizing performance of this voltage stabilizing circuit is not affected by the load. In order to ensure that the tube is not damaged due to control system failure during debugging, it is best to first replace the load with a bulb of appropriate power (which meets the thyristor maintaining current requirements) for debugging. After adjustment, connect the real load for inspection. During debugging, the unit should be adjusted first and then the system. After the unit is adjusted, phase analysis can be performed with the system in open loop. When analyzing the phase, it is better to use an oscilloscope or a voltmeter for monitoring. First cut off the amplifier or connect a feedback resistor in parallel to the input and output ends of the amplifier to reduce the amplification factor, and then place the setting potentiometer at zero. After power is supplied, the conduction angle of the thyristor should be very small or zero, and the output voltage should also be very small or zero. Otherwise, the trigger pulse should be exchanged or the trigger power supply should be inverted. Then gradually increase the set value. At this time, the conduction angle of the thyristor should gradually expand, and the output voltage will increase. Otherwise, the trigger circuit power supply and the main circuit power supply may not be connected to the same phase, causing the thyristor anode voltage to rise. It is out of phase with its trigger pulse, and this situation needs to be dealt with. After the open-loop voltage regulation is normal, closed-loop debugging can be performed. The main purpose of closed-loop debugging is to select the parameters of the correction link to improve the dynamic quality of the system. Finally, the accuracy of the voltage stabilizing system is measured.

After reading the above description, do you already know how to perform a step-by-step power supply check? For the installation and debugging of medium frequency heating machines, if you have other questions, you can call us. Of course, we can also provide you with on-site installation and debugging equipment services.