What should I do if the main circuit of the inverter fails?

According to the statistical analysis of the frequency and downtime of the specific common faults of the inverter, the repair rate of the main power supply circuit accounts for more than 60%; Improper setting of the main operating parameters, resulting in about 20% of common failures; Common faults of control circuit boards account for 15%; 5% of common failures are caused by incorrect operation and external anomalies. According to the statistical analysis of the level of common faults and the difficulty of solving them, the occurrence of such common faults will inevitably lead to the destruction and damage of electronic equipment. This is a critical part of the cost of AC drive maintenance. What to do when encountering a failure of the main circuit

(1) Damage to the rectifier block The damage of the rectifier tube is also one of the common problems of the inverter. The rectifier block of the inverter manufactured in the early days was mainly a diode rectifier. At this stage, some rectifier blocks use the thyristor rectifier method (variable voltage radio broadcast frequency converter). Generally, the rectifier module of medium and high power inverters is a three-phase full-wave rectifier. The rectifier, which is responsible for all the electromagnetic energy output from the inverter, is prone to overheating and penetration. After damage, the inverter fails to connect, the commercial insurance is interrupted, the three-phase input or output terminals have a low resistance value (when everything is in order, the resistance value is higher than a megohm) or a short circuit fault. When removing and replacing the rectifier block, it is necessary to evenly coat the surface of the radiator with a layer of silicon thermal paste with excellent thermal conductivity, and then tighten the screws. If the same rectifier block is not available, it can be replaced with another type of rectifier block with the same volume. Before installation and wiring, the fixing screw holes must be punched and tapped again. For example, in the mid-to-late 80s of the 20th century, after the inverter (7.5kVA) rectifier module (elliptical type) manufactured by Siemens PLC was penetrated, since there were no similar rectifier block parts, a rectifier block (rectangular frame) of the same volume manufactured by Sanken was chosen for replacement. It has been in operation for many years and is still working at this stage.

(2) The battery charging resistor of the inverter is easily damaged for the following reasons: if the AC contactor of the main control circuit is not closed well, the current-carrying time is too long, and the battery charging resistor is burned out; or the resistance burns out due to excessive current; Or because of the light load start-up, the main control circuit is connected to the power supply, and the RUN data signal is connected separately, so the battery charge resistor can easily be burned out according to the current and the load inverter current. Its damage is usually characterized by damage, blackening of the shell, cracking, and other signs of damage. It is also possible to measure the resistance according to the multimeter (for devices with different capacities, the resistance value is different, you can refer to the resistance value of the same model)