Transformer maintenance of butt welding machine

       It is used in many industrial equipment. In these equipment, the inverter is often a very important component. In order to ensure the equipment can work stably for a long time, it is necessary to pay attention to the correct use and normal maintenance of the inverter.

      If you want to use the inverter correctly, you must correctly understand the working principle of the inverter and seriously consider the heat dissipation of the inverter. The failure rate of the inverter increases exponentially with the increase in temperature. The service life decreases exponentially with increasing temperature. When the ambient temperature rises by 10 degrees, the service life of the inverter is halved. Therefore, we must pay attention to the heat dissipation problem! When the inverter is working, the current flowing through the inverter is very large, and the heat generated by the inverter is also very large, so the influence of the heat cannot be ignored.

        Usually, the frequency converter is installed in the control cabinet. We need to know the approximate heat generation of an inverter, which can be estimated with the following formula: Approximate heat generation = inverter capacity (KW) × 55 [W] Here, if the inverter capacity is based on constant torque load Quasi (overcurrent capacity 150% * 60s) If the inverter has a DC reactor or an AC reactor, and it is also in the cabinet, the heat will be greater at this time. It is better to install the reactor on the side of the inverter or above the test. At this time, you can use an estimate: Inverter capacity (KW)×60 [W] Because the hardware of each inverter manufacturer is similar, the above formula can be used for products of various brands. Note: If there is a braking resistor, it is because of the braking resistor The heat dissipation capacity is very large, so the best installation location should be isolated from the inverter, such as on or next to the cabinet. So, how to reduce the heating value in the control cabinet? When the inverter is installed in the control cabinet, the heating value of the inverter should be considered. According to the increase in the value of heat generated in the cabinet, the size of the cabinet should be appropriately increased. Therefore, in order to reduce the size of the control cabinet as much as possible, it is necessary to reduce the heat value generated in the cabinet as much as possible. If the radiator of the inverter is placed outside the control cabinet when the inverter is installed, 70% of the heat generated by the inverter will be released to the outside of the control cabinet. Since the large-capacity inverter has a large heat generation, it is more effective for the large-capacity inverter. The main body and the radiator can also be separated by an isolation plate, so that the heat dissipation of the radiator does not affect the main body of the inverter. This effect is also very good. The heat dissipation design of the inverter is based on the vertical installation, and the heat dissipation will be worse if placed horizontally! Regarding the cooling fan, the inverter with a slightly higher power generally has a cooling fan. At the same time, it is also recommended to install a cooling fan on the air outlet of the control cabinet. A filter should be added to the air inlet to prevent dust from entering the control cabinet. Note that the fans on the control cabinet and the inverter are required, and no one can replace the other.

　　 In addition, the following two issues should be paid attention to the heat dissipation of the inverter:

　　 (1) In places where the altitude is higher than 1000m, because the air density is reduced, the cooling air volume of the cabinet should be increased to improve the cooling effect. In theory, the inverter should also consider derating, which is -5% per 1000m. However, because the load capacity and heat dissipation capacity of the designed up-converter are generally larger than those actually used, it depends on the specific application. For example, in a place of 1500m, but for periodic loads, such as elevators, derating is not necessary. 

　　 (2) Switching frequency: The heating of the inverter mainly comes from the IGBT, and the heating of the IGBT is concentrated at the moment of opening and closing. Therefore, when the switching frequency is high, the heat generated by the natural frequency converter becomes larger. Some manufacturers claim that reducing the switching frequency can expand the capacity, which is the reason.