Viewing Motor Selection from Fan Performance Curve
Fan EC Motor Fan Permanent Magnet Selection Key Part V-Viewing Motor Selection from Fan Performance Curve
The main performance tests of the fan are often carried out in the production enterprises before the fan is developed and delivered from the factory to obtain the performance curves of the fan such as air volume, pressure, shaft power and noise under the experimental conditions, which show the performance of the fan. Next, we will show a performance graph of an axial flow fan for animal husbandry, and specifically analyze the selection priorities of fan motors.
When the performance graph comprehensively reflects the output of this type of fan 17,500 m/h (the figure does not reflect the fan pressure), it can reach the highest efficiency point with the highest efficiency ≈32%. From the efficiency curve, it can be seen that the fan efficiency will decline if the output of the fan air volume is less than 17500 m/h or higher than 17500 m/h. The fan's air output 17,500 m/h impeller power is at the relatively low point of the curve, and the fan motor input and output are also at the relatively low point of the curve.
The fan efficiency curve is subject to the fact that the high efficiency of the three-phase asynchronous motor is always at a certain point, and the premise or lag will reduce the fan efficiency. The change of fan air volume is directly proportional to the first square of the speed ratio, the change of air pressure is directly proportional to the second square of the speed ratio, and the change of power is directly proportional to the third square of the speed ratio. Although we know that fan speed regulation is more energy-saving, three-phase asynchronous motor cannot provide performance support for fan.
We believe that the EC motor can change the current performance checks and balances of the fan and improve the performance of the fan in all directions. Please see the performance curve of the EC motor:
From the test report of EC motor, it can be seen that the efficiency curve (green curve) of EC motor is a kind of trapezoidal wave period, and the basic structure of EC motor is permanent magnet synchronous motor, which improves fan efficiency by ≈ 10%-20% compared with national standard asynchronous motor. Compared with three-phase asynchronous motor, it has a wider high efficiency range. A motor rated at 15.57N.m has a load ranging from 5N.m to 20N.m and can be output with higher efficiency. Not only the rated efficiency of the fan is improved, but also the efficiency of the full load cycle of the fan is improved. The constant torque characteristic of fan EC motor is more suitable for direct drive. Fan EC motor speed control reduces fan operation noise at the same time.
The EC motor of the fan represents a more energy-efficient, stable, quiet and intelligent future for the fan. At present, the fan EC motor is covering high-performance fan fields such as HVAC system fans, air cooling modules, cooling fans, animal husbandry fans, etc. Volcano Electric is one of the enterprises that have been engaged in fan EC motor research and formed series of products earlier in China.