Sensorless starting method for automobile air conditioner

Abstract

The invention relates to a sensorless starting method for an automobile air conditioner. The sensorless starting method comprises the following steps: determining the initial rotor position of a motor; turning a rotor to an aligning angle in a moving direction; introducing a three-phase current on a stator of the motor, and controlling the generated torque vector angle and aligning angle to be 90 degrees so as to guarantee maximum torque starting; accelerating an open loop at a switching speed; and then switching to closed loop operation to complete the starting process of a compressor. By using the method disclosed by the invention, after the initial rotor position of + / -30-degree electrical angle error is obtained, an aligning strategy is used, the rotor is pulled onto the aligning angle in the moving direction of the compressor, and then the processes of open loop acceleration and closed loop cutting are entered. Compared with a pure inductance method starting manner, the maximum starting torque can be obtained; and compared with a traditional aligning manner, the aligning current and aligning time are reduced, and aligning failures are avoided. Practice shows that the starting success rate can be strengthened and the collision and noise during starting are reduced by using the novel sensorless starting method.

Description

technical field [0001] The invention relates to a sensorless starting method for an automobile air conditioner, which belongs to the field of automobile automation. Background technique [0002] With the continuous development of the new energy automobile industry, the current supporting automobile electric air-conditioning compressors have also been developed. Most automotive electric air-conditioning compressors are driven by brushless DC motors (BLDC), and their algorithms mainly include sensorless 6-step square wave drive and field-oriented control. No matter which algorithm is used, its startup belongs to the sensorless startup of the brushless DC motor. [0003] We all know that for the sensorless application of brushless DC motors, the most difficult part is starting; the traditional sensorless starting method is three-stage starting, namely alignment, open-loop acceleration and closed-loop operation. Since the mechanical structure of the electric air conditioner co...

AI Technical Summary

Problems solved by technology

Since the position of the rotor is estimated to have an electrical angle error of plus or minus 30 degrees, it is assumed that the rotor is located in the middle of one of the six zones, so that the actual starting angle may be 60 degrees or 120 degrees, so it cannot Guaranteed maximum starting torque

In addition, the inductance method may still have low resolution, and it is necessary to use the ordinary alignment method for double insurance

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