CN102655388B - Method for driving brushless direct current motor in 150-degree conduction mode - Google Patents

Abstract

The invention relates to a method for driving a brushless direct current motor in a 150-degree conduction mode, which is characterized in that a motor magnetic pole signal is subjected to logic operation and is dealt with a PWM (Pulse-Width Modulation) chopping signal to obtain a modulation signal for driving upper and lower tubes of the brushless direct current motor. The method for driving the brushless direct current motor in the 150-degree conduction mode is characterized in that the absolute value of the conversion tendency of non-phase change current is reduced after being increased in the 150-degree conduction mode within one phase change process, and a phase change torque pulsation is increased after being reduced. Compared with the mode of continuously increasing or lowering in the phase change process for the phase change torque pulsation in a 120-degree conduction driving brushless direct current motor, the 150-degree conduction mode is characterized in that the phase change torque pulsation of the motor is under a rising stage within the time that a power tube is conducted for 30 degrees, and the phase change torque pulsation of the motor is under a lowering state when a shut-off power tube begins to be shut off. When the motor operates at a high speed, the phase change torque fluctuation in the process is reduced into a considerable numerical number.

Description

A kind of 150 ° of conduction modes drive the method for brshless DC motor

Technical field

The invention belongs to brshless DC motor driving method, be specifically related to a kind of method of 150 ° of conduction modes driving brshless DC motor.

Background technology

Three-phase brushless dc motor mainly adopts 120 ° of conduction modes between two, i.e. the each cycle commutation of motor 6 times, and arbitrary moment only has two to be conducted, 120 ° of each each power tube conductings, upper and lower bridge arm conducting differs from 60 °.Conducting state is arranged as T1T6, T1T2, T2T3, T3T4, T4T5, T5T6 in chronological order, and each conducting state is 60 °.

The torque of brshless DC motor is directly proportional to the amplitude of motor magnetic flux and electric current.Due to the existence of motor phase inductance, in commutation process, the electric current of motor winding is switched to mutually another by one and produces mutually commutation delay, causes the generation of commutation torque pulsation.Torque pulsation affects control precision and the servo performance of brshless DC motor, causes vibration and the noise of motor.

While adopting 120 ° of conduction mode commutations, three-phase current, respectively in open-minded, turn-offs, non-commutation state, due to the existence of phase inductance, the fall off rate that makes to close broken phase current is different with the climbing speed of opening phase current, non-converting commutating current changes, and causes the generation of Commutation Torque Ripple.At motor low-speed stage, non-converting commutating current absolute value increases, and torque pulsation is for just; At motor high speed stage, non-converting commutating current absolute value reduces, and torque pulsation is for negative.Commutation torque pulsation causes motor vibrating, produces noise, increases harmonic pollution.

Summary of the invention

The technical problem solving

For fear of the deficiencies in the prior art part, the present invention proposes a kind of method of 150 ° of conduction modes driving brshless DC motor, can effectively suppress motor torque pulsation in the time of high speed.

Technical scheme

A driving method for 150 ° of conduction modes of permanent-magnet brushless DC electric machine, is characterized in that: motor pole signal is carried out to logical operation, then with PWM chopping signal phase with, obtain driving brshless DC motor pipe modulation signal up and down, contain successively following steps:

Step 1: to 6 road motor pole signal H1, H2, H3, H4, H5, H6 carries out logical conversion, obtains 6 tunnel control signals $Q1=H4\·\stackrel{\‾}{H1},$ $Q2=H5\·\stackrel{\‾}{H2},$ $Q3=H6\·\stackrel{\‾}{H3},$ $Q4=H1\·\stackrel{\‾}{H4},$ $Q5=H2\·\stackrel{\‾}{H5},$ $Q6=H3\·\stackrel{\‾}{H6};$

Step 2: control signal and PWM chopping signal phase with, obtain the required modulation signal T1=Q1PWM of three phase inverter bridge, T3=Q3PWM, T5=Q5PWM, T2=Q2, T4=Q4, T6=Q6; Wherein: T1, T3, T5 is upper pipe modulation signal, T2, T4, T6 is lower pipe modulation signal, PWM is chopping signal;

Step 3: the modulation signal of three phase inverter bridge is inputed to permanent-magnet brushless DC electric machine three phase inverter bridge, to drive brshless DC motor.

In described step 1, the acquisition of 6 road motor pole signals is: detect and obtain rotor-position signal: Hall1, Hall2, Hall3, Hall4, Hall5 and Hall6 with motor hall position sensor; When 0≤| the Hall|≤0.8 corresponding motor pole signal of output be low level 0,2.4≤| the Hall|≤3.3 corresponding motor pole signal of output is high level 1; Described | the amplitude that Hall| is rotor-position signal.

In described step 2, PWM chopping signal is obtained by following steps:

Step (1): according to the speed reference ω setting ^*carry out PI adjusting with the speed feedback value ω of electric machine controller output, obtain with reference to copped wave amplitude, L=K _pe _ω+ K _i∫ e _ωdt, K _pfor proportional gain, K _p>0, K _ifor storage gain K _i>0, wherein: e _ω=ω ^*-ω; The speed feedback value of described electric machine controller output p is motor number of pole-pairs, t>0; T is that motor pole signal H1=1 is 1 time to H1 next time;

Step (2): with the amplitude with reference to copped wave amplitude L and periodic sequence signal F | F| does poor, Δ δ=L-|F|, Δ δ >=0 PWM=0, PWM=1 of Δ δ <0; F is that frequency is the triangular wave of f, f > 0.

Beneficial effect

A kind of 150 ° of conduction modes that the present invention proposes drive the method for brshless DC motor, and under 150 ° of conduction modes, in a commutation process, the conversion trend of non-converting commutating current is absolute value first increases and then decreases, and commutation torque pulsation is fallen after rising.Compared with during with 120 ° of conduction mode drive motors of employing, commutation torque pulsation continues to rise or decline in commutation process, under 150 ° of conduction modes, the commutation torque pulsation of motor within the time of 30 ° of power tube conductings in ascent stage, in the time that starting to turn-off, rises in the decline stage switch-off power pipe, in the high speed operation of motor stage, the fluctuation of this process commutation torque is reduced to a considerable numerical value.

The method that the present invention proposes, under 150 ° of conduction modes can be to motor fast state, causing electric current by factors such as inductance is that the situation of imperfect square wave compensates, thereby reaches the object of torque ripple reduction.

Brief description of the drawings

Fig. 1: brushless DC motor structure;

(a) motor pole and winding position; (b) motor Hall element position;

Fig. 2: three-phase brushless dc motor equivalent circuit diagram;

Fig. 3: 150 ° of conduction mode commutation schematic diagrams;

Fig. 4: electromagnetic torque (T=2Nm) under 120 ° of conduction modes;

Fig. 5: electromagnetic torque (T=2Nm) under 150 ° of conduction modes.

Embodiment

Now in conjunction with the embodiments, the invention will be further described for accompanying drawing:

Certain three-phase permanent brshless DC motor technical indicator rated power P=1.5kW, nominal torque T=2Nm, number of pole-pairs p=1.Three-phase brushless dc motor equivalent circuit diagram is referring to Fig. 2.Equivalent circuit diagram comprises controller inverter circuit power bridge and brshless DC motor body two parts.Controller inverter circuit power bridge is made up of six power tubes (T1～T6) and six fly-wheel diodes (D1～D6), wherein the brachium pontis of T1, T4 composition is connected with motor A phase winding, the brachium pontis of T3, T6 composition is connected with motor B phase winding, and the brachium pontis of T5, T2 composition is connected with motor C phase winding.Brshless DC motor body is as Fig. 1, six Hall elements as shown in Fig. 1 (b), H1 and H2, H3 and H4, differ from 30 ° between H5 and H6; H2 and H3, H4 and H5, differ from 90 ° between H6 and H1.

Its implementation process is as follows:

Period demand signal F is that frequency is the triangular wave of f, f=10kHZ

1) when rotor-position as shown in Figure 1, motor hall position sensor detection rotor position signalling, | Hall1|=0, | Hall2|=3.3, | Hall3|=3.3, | Hall4|=3.3, | Hall5|=0, | Hall6|=0, now 6 road motor pole signal H1=0, H2=1, H3=1, H4=1, H5=0, H6=0.To 6 road motor pole signal H1, H2, H3, H4, H5, H6 carries out logical conversion, obtains 6 tunnel control signals $Q1=H4\&CenterDot;\stackrel{\&OverBar;}{H1}=1,$ $Q2=H5\&CenterDot;\stackrel{\&OverBar;}{H2}=0,$ $Q3=H6\&CenterDot;\stackrel{\&OverBar;}{H3}=0,$ $Q4=H1\&CenterDot;\stackrel{\&OverBar;}{H4}=0,$ $Q5=H2\&CenterDot;\stackrel{\&OverBar;}{H5}=1,$ $Q6=H3\&CenterDot;\stackrel{\&OverBar;}{H6}=1;$

2) according to the speed reference ω setting ^*carry out PI adjusting with the speed feedback value ω of electric machine controller output, obtain with reference to copped wave amplitude, L=K _pe _ω+ K _i∫ e _ωdt, motor does not start, ω=0, wherein e _ω=ω ^*-ω=ω ^*, L=K _pe _ω+ K _i∫ e _ωdt=K _pω ^*+ K _i∫ ω ^*dt;

3) with reference to the amplitude of copped wave amplitude L and periodic sequence signal F | F| does poor: Δ δ=L-|F|=K _pω ^*+ K _i∫ ω ^*dt-|F| $\left\{\begin{array}{c}{K}_p\&CenterDot;{\mathrm{\&omega;}}^{*}+K_i{\&Integral;\mathrm{\&omega;}}^{*}\mathrm{dt}\&GreaterEqual;\left|F\right|,\mathrm{PWM}=1\\ K_p\&CenterDot;{\mathrm{\&omega;}}^{*}+K_i{\&Integral;\mathrm{\&omega;}}^{*}\mathrm{dt}\&le;\left|F\right|,\mathrm{PWM}=0\end{array}\right.;$

4) control signal and PWM chopping signal phase with, obtain the required modulation signal T1=Q1PWM=PWM of three phase inverter bridge, T3=Q3PWM=0, T5=Q5PWM=PWM, T2=Q2=0, T4=Q4=0, T6=Q6=1.Power tube T1T5T6 is open-minded, A phase winding, B phase winding, the energising of C phase winding, and winding current flows to mutually from A phase C respectively, flows out mutually from B, and motor stator and rotor excitation field interacts, dragging motor rotor;

5) when rotor rare-earth permanent magnet turns over 30 °, motor hall position sensor detection rotor position signalling Hall1, Hall2, Hall3, Hall4, Hall5, Hall6, calculates 6 road motor pole signal H1, H2, H3, H4, H5, H6, carries out logical conversion to it, obtains 6 tunnel control signals $Q1=H4\&CenterDot;\stackrel{\&OverBar;}{H1},$ $Q2=H5\&CenterDot;\stackrel{\&OverBar;}{H2},$ $Q3=H6\&CenterDot;\stackrel{\&OverBar;}{H3},$ $Q4=H1\&CenterDot;\stackrel{\&OverBar;}{H4},$ $Q5=H2\&CenterDot;\stackrel{\&OverBar;}{H5},$ $Q6=H3\&CenterDot;\stackrel{\&OverBar;}{H6};$

6) repeating step 2)-4), power tube T1T6 is open-minded, A phase winding, the energising of B phase winding, and winding current A phase, flows out mutually from B, and motor stator and rotor excitation field interacts, dragging motor rotor

7) repeating step 5)-6), the motor power tube that rotates a circle is opened order for T5T6T1, T1T6, T1T6T2, T1T2, T1T2T3, T2T3, T2T3T4, T3T4, T3T4T5, T4T5, T4T5T6, T5T6, circulation according to this, electric motor starting completes, and enters the speed governing stage;

8) read motor pole signal and carry out logical conversion $Q1=H4\&CenterDot;\stackrel{\&OverBar;}{H1},$ $Q2=H5\&CenterDot;\stackrel{\&OverBar;}{H2},$ $Q3=H6\&CenterDot;\stackrel{\&OverBar;}{H3},$ $Q4=H1\&CenterDot;\stackrel{\&OverBar;}{H4},$ $Q5=H2\&CenterDot;\stackrel{\&OverBar;}{H5},$ $Q6=H3\&CenterDot;\stackrel{\&OverBar;}{H6};$ Calculate motor speed: the time that to read H1=1 be 1 to H1 is next time t, the speed feedback value that electric machine controller is exported

9) according to the speed reference ω setting ^*carry out PI adjusting with the speed feedback value ω of electric machine controller output, obtain with reference to copped wave amplitude, L=K _pe _ω+ K _i∫ e _ωdt, wherein ? $L=K_p\&CenterDot;e_{\mathrm{\&omega;}}+K_i\&Integral;e_{\mathrm{\&omega;}}\mathrm{dt}=K_p\&CenterDot;({\mathrm{\&omega;}}^{*}-\frac{1}{t})+K_i\&Integral;({\mathrm{\&omega;}}^{*}-\frac{1}{t})\mathrm{dt};$

10) with reference to the amplitude of copped wave amplitude L and periodic sequence signal F | F| does poor:

$\mathrm{\&Delta;\&delta;L}-\left|F\right|=K_p\&CenterDot;({\mathrm{\&omega;}}^{*}-\frac{1}{t})+K_i\&Integral;({\mathrm{\&omega;}}^{*}-\frac{1}{t})\mathrm{dt}-\left|F\right|$

? $\left\{\begin{array}{c}{K}_p\&CenterDot;({\mathrm{\&omega;}}^{*}-\frac{1}{t})+K_i\&Integral;({\mathrm{\&omega;}}^{*}-\frac{1}{t})\mathrm{dt}\&GreaterEqual;\left|F\right|,\mathrm{PWM}=1\\ K_p\&CenterDot;({\mathrm{\&omega;}}^{*}-\frac{1}{t})+K_i\&Integral;({\mathrm{\&omega;}}^{*}-\frac{1}{t})\mathrm{dt}\&le;\left|F\right|,\mathrm{PWM}=0\end{array}\right.;$

11) control signal and PWM chopping signal phase with, obtain the required modulation signal T1=Q1PWM of three phase inverter bridge, T3=Q3PWM, T5=Q5PWM, T2=Q2, T4=Q4, T6=Q6, the conducting of corresponding power pipe, motor rotation, repeating step 8)-11) complete the driving of motor.

150 ° of conduction mode commutation principles of this brshless DC motor are referring to Fig. 3.Motor opposite potential waveform is 120 ° of trapezoidal waves, and phase current is 150 ° of square waves.Brshless DC motor is under 150 ° of conduction modes when commutation, and when opening phase current and rising, other biphase current remains unchanged, and the power tube of opening is opened after 30 °, and switch-off power pipe turn-offs.Non-converting commutating current absolute value rises to some extent with opening alive rising, then declines to some extent with the decline of closing broken phase current, after 30 ° of electrical degrees, enters next commutation process.

Adopt respectively 120 ° of conduction modes and 150 ° of conduction modes under band nominal load condition, to carry out emulation to this brshless DC motor, simulation result is: under 120 ° of conduction modes, the torque pulsation of motor stable state is 0.6Nm, referring to Fig. 4; Under 150 ° of conduction modes, the torque pulsation of motor stable state is 0.5Nm, referring to Fig. 5.When result shows to adopt 150 ° of conduction modes to make this torque pulsation of brushless DC motor than 120 ° of conduction modes of employing, torque pulsation reduces 17%.

Claims (3)

1. a driving method for 150 ° of conduction modes of permanent-magnet brushless DC electric machine, is characterized in that: motor pole signal is carried out to logical operation, then with PWM chopping signal phase with, obtain driving brshless DC motor pipe modulation signal up and down, contain successively following steps:

Step 1: to 6 road motor pole signal H1, H2, H3, H4, H5, H6 carries out logical conversion, obtains 6 tunnel control signals $Q1=H4\&CenterDot;\stackrel{\&OverBar;}{H1},Q2=H5\&CenterDot;\stackrel{\&OverBar;}{H2},Q3=H6\&CenterDot;\stackrel{\&OverBar;}{H3},Q4=H1\&CenterDot;\stackrel{\&OverBar;}{H4},Q5=H2\&CenterDot;\stackrel{\&OverBar;}{H5},$ wherein H1 and H2, H3 and H4, differ from 30 ° between H5 and H6, H2 and H3, H4 and H5, differ from 90 ° between H6 and H1;

Step 2: control signal and PWM chopping signal phase with, obtain the required modulation signal T1=Q1PWM of three phase inverter bridge, T3=Q3PWM, T5=Q5PWM, T2=Q2, T4=Q4, T6=Q6; Wherein: T1, T3, T5 is upper pipe modulation signal, T2, T4, T6 is lower pipe modulation signal, PWM is chopping signal;

Step 3: the modulation signal of three phase inverter bridge is inputed to permanent-magnet brushless DC electric machine three phase inverter bridge, to drive brshless DC motor.

2. the driving method of 150 ° of conduction modes of permanent-magnet brushless DC electric machine according to claim 1, it is characterized in that: in described step 1, the acquisition of 6 road motor pole signals is: detect and obtain rotor-position signal: Hall1 with motor hall position sensor, Hall2, Hall3, Hall4, Hall5 and Hall6; When 0≤| the Hall|≤0.8 corresponding motor pole signal of output be low level 0,2.4≤| the Hall|≤3.3 corresponding motor pole signal of output is high level 1; Described | the amplitude that Hall| is rotor-position signal.

3. the driving method of 150 ° of conduction modes of permanent-magnet brushless DC electric machine according to claim 1, is characterized in that: in described step 2, PWM chopping signal is obtained by following steps:

Step (1): according to the speed reference ω setting ^*carry out PI adjusting with the speed feedback value ω of electric machine controller output, obtain with reference to copped wave amplitude, L=K _pe _ω+ K _i∫ e _ωdt, K _pfor proportional gain, K _p> 0, K _ifor storage gain K _i> 0, wherein: e _ω=ω ^*-ω; The speed feedback value of described electric machine controller output p is motor number of pole-pairs, t>0; T is that motor pole signal H1=1 is 1 time to H1 next time;

Step (2): with the amplitude with reference to copped wave amplitude L and periodic sequence signal F | F| does poor, Δ δ=L-|F|, Δ δ >=0 PWM=0, PWM=1 of Δ δ <0; F is that frequency is the triangular wave of f, f>0.