Inverter control cabinet design - Solutions - Huaqiang Electronic Network

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The inverter should be installed inside the control cabinet. The control cabinet should pay attention to the following problems when designing.

1) Heat dissipation problem: The heat generated by the inverter is caused by internal losses. The main circuit is mainly used in the loss of each part of the inverter, accounting for 98%, and the control circuit accounts for 2%. In order to ensure the normal and reliable operation of the inverter, the inverter must be dissipated. We usually use the fan to dissipate heat. The built-in fan of the inverter can remove the internal heat dissipation of the inverter. If the fan does not work properly, stop the inverter immediately. The high-power inverter needs to add a fan to the control cabinet. The air duct of the control cabinet should be designed reasonably. All the air inlets should be equipped with a dust-proof net, and the air is ventilated smoothly, avoiding the formation of eddy currents in the cabinet and forming dust accumulation at a fixed position; Select the matching fan according to the ventilation of the inverter manual. The fan installation should pay attention to the anti-vibration problem.

2) Electromagnetic interference problem:

I. In the inverter, due to rectification and frequency conversion, a lot of interference electromagnetic waves are generated around. These high-frequency electromagnetic waves have certain interference to nearby instruments and instruments, and high-order harmonics are generated. This kind of higher harmonics will The power supply circuit enters the entire power supply network, thereby affecting other instruments. If the power of the inverter accounts for more than 25% of the entire system, it is necessary to consider the anti-interference measures of the control power supply.

II. When there are high-frequency impact loads in the system such as electric welder and electroplating power supply, the inverter itself will be protected due to interference, then consider the power quality problem of the whole system.

3) Protection issues need to pay attention to the following points:

I. Waterproof and anti-condensation: If the inverter is placed on site, it is necessary to pay attention to the pipe flange or other leaking points above the inverter cabinet. There should be no splashing water flow near the inverter. In general, the protection level of the on-site cabinet should be IP43. the above.

II. Dust-proof: All air inlets should be equipped with a dust-proof net to block the entry of floc-like debris. The dust-proof net should be designed to be detachable for easy cleaning and maintenance. The grid of the air filter is determined according to the specific conditions of the site, and the joint between the air filter and the control cabinet should be handled strictly.

III. Corrosion-resistant gas: This situation is more common in the chemical industry. In this case, the inverter cabinet can be placed in the control room.