cooling system design of inverter
The efficiency of theinverter is generally 97 ~ 98%, which means that about 2 ~ 3% of the electric energy is transformed into heat energy, which is much greater than the heat generated by general switches, AC contactors and other electrical appliances. General distribution cabinets are designed for common switches, AC contactors and other electrical appliances. When this kind of cabinet is used for inverter, the internal components shall be arranged to ensure the rationality of ventilation and heat dissipation.
The failure rate of inverter increases exponentially with the increase of temperature, and the service life decreases exponentially with the increase of temperature. When the ambient temperature increases by 10 degrees, the average service life of theinverter is halved. When the inverter works, the current flowing through is very large, and the heat generated by the inverter is also very large. The influence caused by its heating cannot be ignored.
In the thermal design of inverter, it is based on vertical installation, and the heat dissipation will become worse when installed horizontally. The inverter equipped with cooling fans, but the cooling fans shall still be installed at the air outlet of the control cabinet, and the air inlet shall be equipped with filter screen to prevent dust from entering the control cabinet. At the same time, pay attention to the following design points:
1. The electric control cabinet shall have a forced ventilation circuit. The air flow direction of the ventilation circuit shall be unobstructed and comply with the principle of smooth fluid steering. The fan installed on the electric control cabinet shall be more than 30 ~ 50% larger than the total ventilation of the fan of the inverter itself.
2. Generally, the air path of the electric control cabinet shall have an air inlet with low wind resistance. In the case of dirty environment, the air inlet shall have a filter screen with small wind resistance and prevent blockage.
3. It is necessary to install the air deflector and wind deflector in the electric control cabinet. The function of the wind deflector is to block the direct air and avoid the return of hot air, so as to improve the air flow direction in the cabinet and improve the cooling effect.
4. The finverter shall be installed at a certain distance from the surrounding electrical appliances and box wall, especially to leave up and down space to make the air duct smooth and make the air flow freely. According to different power, at least 120 ~ 300mm space shall be reserved, and the left and right front space shall be at least 50mm.
