Fan With External Rotor Permanent Magnet Brushless Dc Motor And Drive System Design

In china, air-pumps consume more electricity than any other industrial equipments and the consumption of the pumps occupy 40% of the entire electric power. The efficiency of our air-pumps is 10% to 30% lower than abroad, so adapting the pumps for energy conservation is an urgent task. It's very meaningful for releasing the contradiction between supply and demand of electricity, improving the construction of modernization and narrowing the gap between our state and developed countries.The small-scale air-pump (l~10kw) have their own properties. Each individual consumes little but the quantities of the pumps are large. So it is useful to reduce the consumption of the small-scale air-pumps. However few of us think much of it in past time.This paper presents a type of permanent magnetic brushless DC motor for driving small-scale air-pumps. Permanent Magnet Brushless DC Motor (PMBDCM) is a kind of new type motor with the development of power electronics and permanent-magnet material, It is widely used as a high-performance driving machine because of its advantages such as simple structure, reliable operation and convenient maintenance which the AC motors have and the inherent advantages as a DC motor of high efficiency, low magnet excitation loss and excellent speed controllability.We moderate the winds of the pumps by regulate the motor's speed and by this way we could meet the target of energy conservation. In this paper, we analysis the motor from material, magnet structure, magnetization, and the coefficient of magnet arcs and we provide the structure, principles and design demands of the motor. A prototype of the permanent magnetic brushless DC motor was made to drive the external rotor pumps, and the driving systems was designed by the demand of speed regulating, system protection and cost saving. This control system of brushless direct current motor is based on special integrated circuit. The design scheme is tested and the sample has been manufactured. The simple and predominant performance is shown by the prototype trials. The control system is used mainly in small power brushless direct current motor control.We use the prototype of the permanent magnetic brushless DC motor to drive the small-scale air-pumps and the measured data show that the motor is more efficient, has lower cost and the advantages for industrialization.