Maintenance of thyristor components of 1 ton steel shell hydraulic intermediate frequency furnace
After replacing the thyristor component , a 1 ton steel shell hydraulic intermediate frequency furnace burns the thyristor .
IF power failure analysis thyristors burned, do not start immediately after the replacement of the thyristor, the first response frequency power supply troubleshooting system checks, in acknowledged without failure frequency power supply,
If it is turned on again, there will be a phenomenon that the thyristor component is burned when it is turned on . Pay attention to pressure equalization when pressing new thyristor components , otherwise it will cause mechanical damage to the internal chip of the thyristor .
The withstand voltage value of the thyristor element is greatly reduced, and the phenomenon that the thyristor element is burned when the power is turned on appears .
After replacing the new thyristor component , the 1 ton steel shell hydraulic intermediate frequency furnace is turned on normally, but the thyristor components are burned for a while .
Analysis of the reasons for this type of failure are:
(1) The thermal characteristics of the electrical components of the control section are not good;
(2) The thyristor component and the heat sink are misplaced;
(3) The radiator is used repeatedly or press-fitted through a small mesa thyristor element , causing the center of the radiator table to be recessed, causing poor contact between the radiator table and the thyristor surface to burn the thyristor element ;
(4) The scale inside the radiator water chamber is too thick and the heat conduction is not good, causing the components to overheat and burn off;
(5) The temperature of the fast thyristor component rises due to poor heat dissipation, and the turn-off time of the thyristor component increases with the increase of temperature, eventually causing the component not to be turned off, causing the inverter to subvert and burn off the thyristor. element;
(6) The operating temperature of the thyristor component is too high, the gate parameter is reduced, the anti-interference ability is reduced, and the thyristor component and the intermediate frequency power supply are easily generated by mistake .
(7) Check if the RC absorption circuit is intact.
5.3 Fault phenomenon After replacing the new thyristor component , the IF power supply still cannot work normally to burn the thyristor component .
After analyzing and processing the IF power supply , the thyristor component is burned and replaced with a new thyristor component . After the static detection of the IF power supply is normal, it still cannot work normally and is stable, and the thyristor component is easily burned . Pay special attention to this time
Whether the pulse transformer, the power transformer, the intermediate frequency transformer, and the intermediate frequency isolation transformer have a poor insulation between the primary coil and the secondary coil, between the coil and the core, and between the turns and the turns.
