Why Can't General Motors Be Used in Plateau Areas?

Altitude has adverse effects on motor temperature rise, motor corona (high voltage motor) and commutation of DC motor. The following three aspects should be paid attention to: (1) The higher the altitude, the higher the temperature rise of the motor, the lower the output power. However, when the temperature decreases with the increase of altitude enough to compensate for the influence of altitude on the temperature rise, the rated output power of the motor can remain unchanged; (2) anti-corona measures should be taken when the high-voltage motor is used in the plateau; (3) the altitude It is not good for the commutation of the DC motor, so pay attention to the selection of carbon brush materials. Plateau motors are used for motors with an altitude higher than 1000 meters. Refers to the national industry standard: JB/T7573-94 General technical conditions for electrical products under plateau environmental conditions. Plateau motors are divided into many levels: they are no more than 2000 meters, 3000 meters, 4000 meters, and 5000 meters. The main features of the plateau area are: 1. Low air pressure or air density. 2. The air temperature is low and the temperature changes greatly. 3. The absolute humidity of the air is small. 3. The solar radiation illuminance is high. 5. Less precipitation. 6. There are many windy days every year. 7. The soil temperature is low and the freezing period is long.

Due to the above reasons, it will bring the following adverse effects on the operation of the motor. Therefore, corresponding measures should be taken in the design and manufacture: 1. The dielectric strength will be reduced: for every 1000 meters, the dielectric strength will be reduced by 8-15%. 2. The breakdown voltage of the clearance decreases, so the clearance should be increased accordingly according to the altitude. 3. The corona initial voltage is reduced, and anti-corona measures should be strengthened. 4. The cooling effect of the air medium decreases, the heat dissipation capacity decreases, and the temperature rise increases. For every 1000M increase, the temperature rise will increase by 3-10%, so the temperature rise limit should be corrected. The oxygen content of the air at 5000m is only 53% of the oxygen content of the air at sea level.

Plateau motors operate at high altitudes, due to low air pressure, poor heat dissipation conditions, and increased losses, reducing operating efficiency. Therefore, in the same way, the rated electromagnetic load and heat dissipation design of motors operating at different altitudes are different. Motors that are not high-altitude specifications are best run with appropriate load reduction. Otherwise, the life and performance of the motor will be affected, and even burn out in a short time.