CN103414433A

CN103414433A - Hall position sensor fault emergency method

Info

Publication number: CN103414433A
Application number: CN2013103123314A
Authority: CN
Inventors: 相里康; 马瑞卿; 韩伟键; 张震
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2013-07-23
Filing date: 2013-07-23
Publication date: 2013-11-27
Anticipated expiration: 2033-07-23
Also published as: CN103414433B

Abstract

The invention discloses a Hall position sensor fault emergency method. After a Hall position sensor fails, a motor is not directly closed, the motor can continue working on the basis of giving an alarm, the hazard rating of the failure of the Hall position sensor is greatly reduced, and the reliability of a system is increased. The Hall position sensor fault emergency method comprises the steps that during the process when the motor runs, three routes of Hall position sensors can have eight kinds of status at most, wherein the all-zero or all-one status is the fault status, and 0 is respectively assigned to initial values; the time when the motor rotates by two ringsis used as a detection period, and if one status of the Hall position sensors appears, 1 is assigned to a corresponding variable; the value of an array is observed; when the motor fails, which one of the Hall position sensors fails is analyzed and determined by analyzing the 0 status; the failure of the one Hall position sensor is accurately positioned through software, and a user can timely and accurately replace the fault sensor according to the fault information after the system stops working.

Description

A kind of hall position sensor fault emergency method

Technical field

The present invention relates to a kind of fault handling method of brshless DC motor, specifically, relate to a kind of hall position sensor fault emergency method.

Background technology

In recent years, development along with power electronic technology, microelectric technique and novel magnetic material, brshless DC motor, so that its volume is little, lightweight, efficiency is high, moment is large, the characteristics of good speed adjustment features, is applied widely in fields such as Aeronautics and Astronautics, Digit Control Machine Tool, robots.Brshless DC motor basic structure is comprised of motor body, controller, position transducer.The effect of position transducer is to detect the position of main rotor in motion process, the position signalling of rotor magnetic steel magnetic pole is converted to the signal of telecommunication, for logic switching circuit provides correct commutation information, with conducting and the cut-off of controlling them, make electric current in the motor armature winding along with the variation commutation in order of rotor-position, form step-type rotating magnetic field in air gap, drive p-m rotor and continuously rotate.Tradition has brushless motor permanent magnet pole or excitation winding to be positioned on stator, and armature is positioned on rotor, and it carries out commutation by carbon brush and phase changer, without the controller intervention.Brushless DC motor rotor adopts high residual magnetic flux density and large coercitive rare earth permanent-magnetic material, and every pair of magnetic pole accounts for 180 ° of electrical degrees; And armature is positioned on stator, by three-phase alternating current, produce rotating magnetic potential, drive rotor.Owing to having cancelled the phase changer structure, brushless direct current motor controller must be able to be learned the position of current rotor, to control the direction of magnetic potential, thereby makes the motor rotation.

The position transducer kind is a lot, and electromagnetic type, photoelectric type, Mageneto-sensitive type etc. are arranged; They differ from one another, however due to the Mageneto-sensitive type hall position sensor have simple in structure, volume is little, convenient and flexible installation, be easy to the advantages such as electromechanical integration, obtain applying more and more widely.Brshless DC motor adopts three-phase structure usually, and the hall position sensor number equates with number of motor phases, every 120 ° of electrical degrees, be uniformly distributed, so brshless DC motor is equipped with three hall position sensors usually, is used to indicate current rotor-position.The hall position sensor output signal is overturn when pole orientation changes.Due to 120 °, hall position sensor interval electrical degree, and account for 180 ° of electrical degrees every magnetic pole, also namely not there will be three hall position sensors to be positioned at the situation under same magnetic pole, be not the same corresponding to sensor output signal Ye Ji tri-road signals.Therefore, six kinds of " 001 "～" 110 " state only may appear in three road Hall element signal HA, HB, HC, 60 ° of electrical degrees of every kind of Hall state continuance.Electric machine controller is constantly controlled the stator field direction by reading this three-way sensor signal, thus the drive motors rotation.Brshless DC motor adopts the three phase full bridge structure, and conduction mode is " conducting in twos ".Adopting this topological structure, produce different magnetic potentials by different switch combinations, therefore, is that the commutation table just can reliably rotate by drive motors as long as obtain the correct switch relation of sensor signal and switch combination.As the hall position sensor fault, cause the commutation mistake, very likely cause motor rotation blockage, make the motor winding bear very large electric current, cause the even damage of motor of electric machine controller.Position transducer generally is arranged on motor body inside, easily is hit, and is difficult for heat radiation, and easily is subject to the impact of motor high-intensity magnetic field, is one of the weakest link of brshless DC motor.Brshless DC motor is usually used in some occasions that need long-time continuous, stable operation, as fuel pump, electric steering engine etc.; Therefore when breaking down after, the operating state of motor does not allow hard stop, has now just required a kind of first aid mode to make motor continue to move, until change corresponding fault element when allowing to stop.For the present processing mode of hall position sensor fault, be only to occur complete zero or for the moment complete when three road Hall elements being detected, stop immediately machine operation and irrecoverable.This processing mode is too rough, if now motor is key element, such processing mode can make system paralyse immediately, may cause catastrophic consequence.

Summary of the invention

Deficiency for fear of the prior art existence, the present invention proposes a kind of hall position sensor fault emergency method, the method can be on the basis that does not change hardware circuit, only depend on software to realize the first aid of failure system, and can guarantee that brshless DC motor can work on after generation hall position sensor fault, until system allows to stop the moment, method simple practical.

Hall position sensor fault emergency method of the present invention is characterized in comprising the following steps:

Step 1. pair variable carries out initialization; At motor operation course Zhong， tri-road hall position sensors, eight kinds of states may occur at most, wherein a zero or full state is malfunction entirely, uses one-dimension array HALL[8] represent eight kinds of states that hall position sensor may occur, initial value all composes 0;

Step 2. is usingd electric machine rotation two circles as a sense cycle, if a kind of state of hall position sensor occurred, gives corresponding variable HALL[x] (x=0～7) tax 1;

Step 3. is observed array HALL[8] value;

(1) if HALL[1]～HALL[6] be 1, and HALL[0] and HALL[7] value be 0, mean the motor fault-free;

(2) if HALL[1]～HALL[6] part be 0, and HALL[0] and HALL[7] value be 1, mean that motor has fault;

(3) when motor has fault, by analyzing HALL[1]～HALL[6] in be 0 state, which hall position sensor of Analysis deterrmination breaks down;

Step 4., in the brshless DC motor running, detects the on off state of three road hall position sensors, records each road hall position sensor real-time service time;

Step 5. is on the basis of determining fault road hall position sensor, to host computer, pass on malfunction and take real-time service time of other two-way hall position sensor and be benchmark, in the moment that fault road hall position sensor should be opened, a given virtual hall position sensor signal, work on system;

Step 6. array HALL[8] zero clearing, for next sense cycle is prepared.

Beneficial effect

A kind of hall position sensor fault emergency method that the present invention proposes, after hall position sensor breaks down, not directly close the motor of work, but on the basis of reporting to the police, motor is worked on, greatly reduce the hazard rating of hall position sensor fault, increased the reliability of system.First-aid method of the present invention can accurately be located motor hall position sensor fault by software, makes the user after system quits work, and changes timely and accurately fault sensor according to fault message.First-aid method of the present invention, on the basis that does not change hardware circuit, only depends on software to realize that the first aid of failure system can obtain good effect, and Cost optimization is low.

The accompanying drawing explanation

Below in conjunction with drawings and embodiments, a kind of hall position sensor fault emergency of the present invention method is described in further detail.

Fig. 1 is the brushless DC motor structure schematic diagram.

Fig. 2 is the brushless DC motor control system circuit diagram.

Fig. 3-a Hall state is 110 o'clock rotor-positions and magnetic potential direction.

Fig. 3-b Hall state is 010 o'clock rotor-position and magnetic potential direction.

Fig. 3-c Hall state is 011 o'clock rotor-position and magnetic potential direction.

Fig. 3-d Hall state is 001 o'clock rotor-position and magnetic potential direction.

Fig. 3-e Hall state is 101 o'clock rotor-positions and magnetic potential direction.

Fig. 3-f Hall state is 100 o'clock rotor-positions and magnetic potential direction.

Fig. 4 is Hall running status schematic diagram.

Fig. 5 is Hall fault emergency method signal flow graph.

In figure:

1. bearing 2. casing 3. stator 4. rotor 5. position transducer 6. electronic switch circuit 7. motor 8. hall position sensors

Embodiment

The present embodiment is a kind of hall position sensor fault emergency method.

Fig. 1 is the structural representation of brshless DC motor, and as can be seen from the figure position transducer is positioned at motor body inside, easily is subject to the impact of high-intensity magnetic field and concussion, easily breaks down.The control system of brshless DC motor adopts the three phase full bridge structure; As shown in Figure 2, wherein T1～T6 is power switch pipe, and D1～D6 is fly-wheel diode.Adopt this topology, can produce different magnetic potentials by different switch combinations, the drive motors rotation, the Hall switch state of brshless DC motor commutation process and correspondence is as shown in Fig. 3 a～Fig. 3 f, and concrete Hall switch state is as shown in Figure 4.In the present embodiment, adopt TMS320F2812 as main control chip, IR2130 is as driving chip, select three-phase inverter bridge circuit and on cut down the chopping way of not cutting, select the brshless DC motor of three pairs of utmost points of three-phase herein.As shown in Figure 5, application hall position sensor fault emergency method operates, and concrete steps are:

The first step, carry out initialization to variable; Use one-dimension array HALL[8] represent eight kinds of states " 000 "～" 111 " that hall position sensor may occur, wherein, and HALL[0] representative " 000 ", HALL[1] representative " 001 " ..., HALL[7] and represent 111, initial value all composes 0; Use one-dimension array HallTime[3] mean service time of three road hall position sensors, wherein HallTime[0] represent A phase Hall element, HallTime[1] represent B phase Hall element, HallTime[2] representing C phase Hall element, initial value all composes 0; With variable P_cnt, mean Hall state variation number of times, initial value composes 0, and concrete meaning as shown in Figure 4;

Second step, adopt capture interrupt, input is set from the low level to the high level and all triggers interruption during from high level to low level, with the Hall element output signal, trigger and interrupt, if a kind of state of hall position sensor occurred, compose 1 for corresponding variable, if do not occur, retain initial value 0; Record the Hall service time on current each road, and be saved in one-dimension array HallTime[3] in; By variable P_cnt, record Hall state variation number of times, be at least a circle, the number of turns is more, and when from normal condition, being switched to the first aid state, the suffered impact of system is larger, but false alarm rate is lower;

The 3rd step, the P_cnt of take remembers that 36 are a sense cycle, when end cycle is P_cnt while remembering 36, observation variable HALL[8] value, the Hall state is carried out to comprehensive judgement and draws whether fault of motor; Embodiment is as follows:

1. if HALL[1]～HALL[6] be 1 and HALL[0] or HALL[7] value be 0, mean the motor fault-free;

2. if HALL[1]～HALL[6] part be 0 and HALL[0] or HALL[7] value be 1, mean that motor has fault;

The 4th step, if motor generation Hall element fault, by analyzing HALL[1]～HALL[6] in be 0 state, can analyze which hall position sensor and break down; Concrete grammar is: if Hall element breaks down, three HALL[x are arranged] (x=1～6) be 0, is always 0 or 1 the Hall element broken down that is in three kinds of corresponding Hall states;

The 5th step, troubleshooting; On the basis of clear failure road hall position sensor, to host computer, pass on malfunction and take real-time service time of other two-way hall position sensor and be benchmark, in the moment that fault road hall position sensor should be opened, a given virtual hall position sensor signal, work on system; For example open circuit fault appears in B phase hall position sensor, namely only there will be as Fig. 3-d to tri-kinds of states of Fig. 3-f, and not there will be as Fig. 3-a to these three kinds of states of Fig. 3-c, now according to Hall running status shown in Figure 4, according to A phase Hall element running status HA and C phase Hall element running status HC, fictionalize the running status HB of B phase Hall element, the state so that virtual HB replaces actual detected B phase Hall element, work on system;

The 6th step, array HALL[8] and variable P_cnt zero clearing, for next sense cycle is prepared.

Claims

1. hall position sensor fault emergency method is characterized in that comprising the following steps:

Step 3. is observed array HALL[8] value;

Step 6. array HALL[8] zero clearing, for next sense cycle is prepared.