Control method for brushless direct current motor for automotive air conditioning fan

Abstract

The invention discloses a control method for a brushless direct current motor for a novel automotive air conditioning fan. The method comprises the following steps of: comparing a current instruction serving as a rotation speed control instruction obtained on the basis of fan load characteristics with a current feedback signal acquired on a direct current side of an inverter for the brushless direct current motor; inputting an error signal into a proportional-integral regulator for regulation so as to obtain a duty cycle control signal for regulating the rotation speed of the brushless directcurrent motor; and combining the duty cycle control signal with a reversing signal obtained by detecting the counter potential of the motor and performing PWM control to realize speed regulating operation of the brushless direct current motor. By the method of the invention, the rotation speed of the fan is directly regulated and the current of the brushless direct current motor is controlled by current single-loop control, so that the control delay introduced by simultaneously regulating both rotation speed loop and current loop is avoided, and rapid dynamic response and stable-state speed regulation precision of running of the brushless direct current motor for the automotive fan are improved.

Description

technical field [0001] The invention relates to a control method of a brushless DC motor for an automobile air-conditioning fan. By controlling the amplitude of the DC current, the speed adjustment and current closed-loop control of the brushless DC motor without a position sensor are realized, so as to improve the rapid dynamics of the fan system of this type Response and steady-state speed regulation accuracy. Background technique [0002] At present, the requirements for cooling fans in automotive electrical products are getting higher and higher, especially the fan driving motors are required to have the advantages of high efficiency, energy saving, quietness, and good reliability. At present, permanent magnet DC motors are widely used in automotive air-conditioning fans. Although their structure is simple and low in cost, their inherent brush and commutator structures have brought disadvantages such as low efficiency and poor reliability, and they have been unable to ad...

AI Technical Summary

Problems solved by technology

[0004] It can be seen from the above analysis process that the traditional brushless DC motor control method for air-conditioning fans needs to use two proportional-integral controllers to achieve closed-loop control of speed and current, which will affect the bandwidth of the control system and bring corresponding control delays. For the extremely complex application environment of automobiles, it will cause dynamic tracking control errors and steady-state speed regulation accuracy

At the same time, because the measurement accuracy and service life of Hall sensors are easily affected by ambient temperature and vibration, the traditional control strategy of brushless DC motors for air-conditioning fans is also difficult to apply to automotive air-conditioning systems

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