Time-varying signal sampling method for identifying initial position of non-inductive brushless motor

Abstract

The invention discloses a time-varying signal sampling method for identifying the initial position of a non-inductive brushless motor. The method comprises the steps of 1, selecting a power-up method, setting cycle index and sampling time, setting cumulative sum and conducting zero clearing; 2, powering up the non-inductive brushless motor with the selected power-up method by means of short-time voltage pulses with specified amplitude, conducting high-frequency filtering and amplifying on an output time-varying current sampling signal after power-up, conducting AD sampling at the sampling time, and adding a sampling result to the cumulative sum; 3, deducting 1 from the cycle index, judging whether the cycle index is 0, executing the step 4 if yes, and executing the step 2 if not; 4, extracting the cumulative sum, and outputting an extraction result. According to the method, the sampling result high in interference resistance and resolution digit can be obtained without adding a hardware circuit or increasing the resolution of an AD converter, obvious noise of the motor can not be generated, and rotation or shaking of a rotor of the motor is avoided during identification.

Description

technical field [0001] The invention relates to the technical field of motor drive, in particular to a time-varying signal sampling method for identifying the initial position of a non-inductive brushless motor, wherein the non-inductive brushless motor includes a brushless DC motor and a permanent magnet synchronous motor. Background technique [0002] With the continuous improvement and perfection of permanent magnet materials, power MOS tubes and control chip functions, sensorless brushless motors including brushless DC motors and permanent magnet synchronous motors have been increasingly used in the fields of industrial control, home appliances and new energy. The wider the application. Compared with brushless motors with position sensors, sensorless brushless motors without position sensors have significant advantages such as small size, low cost, less susceptible to interference in the control system, and high reliability. [0003] As we all know, in order for the mot...

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Problems solved by technology

[0006] However, in the actual application process, the rotor initial position identification based on the inductance method has the following disadvantages: A) the applied voltage pulse time is short, so the current sampling signal is small; B) there are power interference, CPU core interference and I / O port Equal interference; C) The difference in the inductance of the motor at different positions is small; D) The resolution of the ADC is limited

Due to the objective existence of the above-mentioned unfavorable factors, it is technically difficult to obtain accurate sampling values ​​when using the traditional inductance method to sample the time-varying signal AD, so that the initial position of the rotor cannot be accurately identified, which makes the method of identifying the initial position of the rotor by the inductance method practical. has not been widely used

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