CN113346800B

CN113346800B - Rotor position detection method suitable for brushless direct current motor

Info

Publication number: CN113346800B
Application number: CN202110713613.XA
Authority: CN
Inventors: 吴东华; 范恺; 王娇; 胡登军; 蒋慧
Original assignee: Shaanxi Aero Electric Co Ltd
Current assignee: Shaanxi Aero Electric Co Ltd
Priority date: 2021-06-26
Filing date: 2021-06-26
Publication date: 2022-09-23
Anticipated expiration: 2041-06-26
Also published as: CN113346800A

Abstract

The invention provides a rotor position detection method suitable for a brushless direct current motor, which comprises the steps of firstly detecting whether the brushless direct current motor has the defect that main magnetic steel is 2n pairs of poles, and excitation magnetic steel is n pairs of poles; if the Hall effect sensor exists, 3 paths of Hall sensors A +, B + and C + are added on the basis of the original 3 paths of Hall sensors A, B and C; the Hall sensor A, the Hall sensor B and the Hall sensor C are installed at an interval of 120 degrees in pairs, and the Hall sensor A + and the Hall sensor A, the Hall sensor B + and the Hall sensor B, and the Hall sensor C + and the Hall sensor C are installed at an interval of 90 degrees/n; the Hall sensor A +, the Hall sensor B + and the Hall sensor C + are spaced by 120 degrees in pairs; and then carrying out XOR on the corresponding signals, and outputting three paths of comprehensive signals as input signals for motor rotor position detection and rotating speed calculation, thereby realizing the detection of the motor rotor position signals.

Description

Rotor position detection method suitable for brushless direct current motor

Technical Field

The invention belongs to the technical field of control of a brushless direct current motor of an electric drive system, and relates to a rotor position detection method of a brushless direct current motor with defects.

Background

With continuous evolution and development, the brushless direct current motor integrates all the advantages of the alternating current motor and the direct current motor and appears in the visual field of people, the production efficiency is greatly improved, the energy consumption is reduced, and the brushless direct current motor is widely applied and popularized. The brushless direct current motor replaces a plurality of traditional motors, is widely applied in various fields, has all the advantages of the traditional direct current motor, simultaneously removes carbon brushes and slip ring structures, has the advantage of very low speed in the using process, greatly reduces the power consumption, has very large generated power despite of low speed, has the advantages of small volume and light weight, saves the ultra-large load of a speed reducer, and has very high efficiency in the using process.

The two-conduction and two-conduction square wave current driving mode of the brushless direct current motor is widely applied due to the advantages of simple method, stability, reliability, easy realization and the like. To control the operation of a brushless dc motor, it is necessary to determine the exact position information of the motor rotor, and the position of the rotor can be directly obtained by using a hall position sensor. However, due to various reasons, such as design defects or installation defects, the final assembly plant may receive some defective products, for example, the motor is designed with 2n pairs of main magnetic steels and n pairs of exciting magnetic steels, and the rotor position of such a motor cannot be directly obtained by using the hall position sensor, so that the motor cannot be controlled.

The applicant is a main manufacturer of a domestic aviation power supply system, domestic aviation products are rapidly developed, the demand is large, the task generating time is short, and after the motors with the defects are received, if the motors are returned to a factory and maintained, the product delivery time is prolonged, so that a simple method needs to be provided, and the rotor position detection of the motors with the defects is realized.

Disclosure of Invention

The invention provides a rotor position detection method suitable for a brushless direct current motor, aiming at a defective motor product with 2n pairs of main magnetic steel and n pairs of exciting magnetic steel.

The technical scheme of the invention is as follows:

the rotor position detection method suitable for the brushless direct current motor comprises the following steps of:

step 1: detecting whether the brushless direct current motor has the defect that the main magnetic steel is 2n pairs of poles, and the exciting magnetic steel is n pairs of poles, and if the defect does not exist, directly obtaining the position of a rotor by adopting a Hall sensor; if yes, entering step 2;

step 2: 3 paths of Hall sensors A +, B + and C + are added on the basis of the original 3 paths of Hall sensors A, B and C; the Hall sensor A, the Hall sensor B and the Hall sensor C are installed at an interval of 120 degrees in pairs, the Hall sensor A + and the Hall sensor A are installed at an interval of 90 degrees/n, and the Hall sensor B + and the Hall sensor B, and the Hall sensor C + and the Hall sensor C are also installed at an interval of 90 degrees/n; the Hall sensor A +, the Hall sensor B + and the Hall sensor C + are spaced by 120 degrees in pairs;

and step 3: XOR is carried out on the signal of the Hall sensor A + and the signal of the Hall sensor A, and the output signal is an A comprehensive signal; the Hall sensor B + signal and the Hall sensor B signal are subjected to XOR, and the output signal is a B comprehensive signal; XOR is carried out on the Hall sensor C + signal and the Hall sensor C signal, and the output signal is a C comprehensive signal; and A, B, C comprehensive signals are output as final 3-path Hall signals and serve as input signals for motor rotor position detection and rotating speed calculation.

Further, the step 1 of detecting whether the brushless direct current motor has the defect that the main magnetic steel is 2n pairs of poles, and the excitation magnetic steel is n pairs of poles comprises the following steps:

for a brushless direct current motor with 2n pairs of main magnetic steel poles, the motor is forcibly driven to rotate for one circle, three-phase Hall states are collected, if 12n Hall states are collected, the brushless direct current motor is considered to be normal, and if only 6n Hall states are collected, the brushless direct current motor is considered to have the defect that the main magnetic steel poles are 2n pairs of poles, and excitation magnetic steel is n pairs of poles.

Advantageous effects

The invention provides a rotor position detection method suitable for a brushless direct current motor with defects. The method comprises the steps that firstly, the position detection of a rotor is analyzed, when the main magnetic steel of a motor is 2n pairs of poles, the exciting magnetic steel is n pairs of poles, so that in the process of one rotation of the motor, the rotor positions detected by a Hall sensor are only 6n states, and the rotor positions detected by the Hall sensor of the motor which is normally designed are 12n, so that half position information is lost, and the other half position information needs to be detected by a certain design method; and secondly, aiming at the detected motor with defects, the design of adding 3 paths of Hall sensor position detection signals on the basis of the original 3 paths of Hall sensor position detection signals realizes the detection of the motor rotor position signals under the condition of not changing the existing motor.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a 4 antipodal Hall state diagram;

FIG. 2 is a 2 antipodal Hall state diagram;

FIG. 3 is a block diagram of a 6-way Hall sensor installation;

fig. 4 is a 6-way hall logic state diagram.

Detailed Description

The invention provides a rotor position detection method suitable for a brushless direct current motor with defects, which is mainly realized by the following processes:

1. rotor position detection analysis

The rotor position detection of the brushless direct current motor with the defect is analyzed, for the brushless direct current motor with the defect, half of the rotor position information is lost from the rotor position detected by the hall sensor, and all the position information needs to be detected by a certain design method.

Taking 4 pairs of pole main magnet brushless dc motor as an example, under the condition of correct motor design, the motor rotates for one circle, and the three-phase hall state is shown in fig. 1. The excitation magnetic steel of the motor is designed to rotate for a circle under the condition of 2 pairs of poles, and the three-phase Hall state is shown in figure 2.

As can be easily seen from fig. 1 and 2, in the case of a defect (2 pairs of pole-excited magnetic steels) in a 4-pair main-magnet brushless dc motor, half of the hall state is lost, so that a rotor position detection design is required to detect all position information.

In summary, for a brushless dc motor with 2n pairs of poles and main magnetic steel, the motor is forcibly driven to rotate for one circle, three-phase hall states are collected, if 12n hall states are collected, the brushless dc motor is considered to be normal and free of defects, if only 6n hall states are collected, the brushless dc motor is considered to have the defects that the main magnetic steel has 2n pairs of poles and the exciting magnetic steel has n pairs of poles, and then the following method is adopted for processing.

2. Rotor position detection design

For the motor which is obtained by the analysis and has the defects of 2n pairs of poles of main magnetic steel and n pairs of poles of exciting magnetic steel, the motor is complex in production and processing and long in period, so that the comprehensive detection of the position signal of the motor rotor is realized by adding the design of 3 paths of Hall sensor position detection signals under the condition of not changing the existing motor.

Fig. 3 is a block diagram of a 6-way hall sensor according to the present application, in which 3 ways of hall sensors a +, B +, and C + are added on the basis of the original 3 ways of hall sensors a, B, and C. The Hall sensor A, the Hall sensor B and the Hall sensor C are installed at an interval of 120 degrees in pairs, the Hall sensor A + and the Hall sensor A are installed at an interval of 90 degrees/n, similarly, the Hall sensor B + and the Hall sensor B, the Hall sensor C + and the Hall sensor C are also installed at an interval of 90 degrees/n, in the embodiment, n is 2 in 4 pairs of pole main magnetic steel, and therefore the Hall sensor A + and the Hall sensor A, the Hall sensor B + and the Hall sensor B, and the Hall sensor C + and the Hall sensor C are also installed at an interval of 45 degrees; and the interval between the Hall sensor A +, the Hall sensor B + and the Hall sensor C + is 120 degrees.

Fig. 4 is a 6-way hall logic state diagram, the hall sensor a + signal is xored with the hall sensor a signal, the output signal is an a comprehensive signal, the hall sensor B + signal is xored with the hall sensor B signal, the output signal is a B comprehensive signal, the hall sensor C + signal is xored with the hall sensor C signal, the output signal is a C comprehensive signal, and the A, B, C comprehensive signal is output to the controller as the final 3-way hall signal and is used as the input signal for motor rotor position detection and rotating speed calculation, so that the comprehensive detection of the motor rotor position signal is realized.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention.

Claims

1. A rotor position detection method suitable for a brushless direct current motor is characterized by comprising the following steps: the method comprises the following steps:

step 2: 3 paths of Hall sensors A +, B + and C + are added on the basis of the original 3 paths of Hall sensors A, B and C; the Hall sensor A, the Hall sensor B and the Hall sensor C are arranged at an interval of 120 degrees in pairs, the Hall sensor A + and the Hall sensor A are arranged at an interval of 90 degrees/n, and the Hall sensor B + and the Hall sensor B, and the Hall sensor C + and the Hall sensor C are also arranged at an interval of 90 degrees/n; the Hall sensor A +, the Hall sensor B + and the Hall sensor C + are spaced by 120 degrees in pairs;

2. A rotor position detecting method for a brushless dc motor according to claim 1, wherein:

step 1, detecting whether the brushless direct current motor has the defect that the main magnetic steel is 2n pairs of poles, and the excitation magnetic steel is n pairs of poles, comprises the following steps:

for the brushless direct current motor with 2n pairs of pole main magnet steel, the motor is forcibly driven to rotate for one circle, three-phase Hall states are collected, if 12n Hall states are collected, the brushless direct current motor is considered to be normal, and if only 6n Hall states are collected, the brushless direct current motor is considered to have the defect that the main magnet steel is 2n pairs of poles, and the excitation magnet steel is n pairs of poles.