CN202550947U

CN202550947U - Efficient control device for direct-current brushless motor based on phase current cutoff angle

Info

Publication number: CN202550947U
Application number: CN2012201593369U
Authority: CN
Inventors: 寿金乔; 王海兵; 张政毓
Original assignee: HANGZHOU RUIFANG TECHNOLOGY Co Ltd
Current assignee: HANGZHOU RUIFANG TECHNOLOGY Co Ltd
Priority date: 2012-04-16
Filing date: 2012-04-16
Publication date: 2012-11-21
Anticipated expiration: 2022-04-16

Abstract

The utility model relates to an efficient control device for direct-current brushless motor based on a phase current cutoff angle. The device comprises a central processing unit, wherein an output end of the central processing unit is connected with a permanent direct-current brushless motor through upper bridge arm driving and lower bridge arm driving; and an input end of the central processing unit is connected with a speed setting module and the permanent direct-current brushless motor. The efficient control device for the direct-current brushless motor has the advantages that the efficiency of the motor can be further improved by one grade by a control algorithm, and the heat quantity of the motor is reduced. Under the condition of the same output power, because reactive current is reduced along with the reduction of reactive power, the wire diameter of a coil of the motor can be correspondingly reduced, and a good platform for reducing the cost of the motor is provided. Because the efficiency of the motor is improved, the direct benefit for users is that using fee is greatly reduced.

Description

A kind of efficient control device of the dc brushless motor based on the phase current angle of cut-off

Technical field

The utility model relates to dc brushless motor control field, especially a kind of efficient control device of the dc brushless motor based on the phase current angle of cut-off.

Background technology

Non-brush permanent-magnet DC motor is compared with the single-phase asynchronous motor of common capacitor start in small-power section (below the 500W), has special advantages.Particularly convert to aspect the efficient of mechanical energy at electric energy; The operating efficiency of the single-phase asynchronous motor of capacitor start generally all is lower than 60%; And because its inherent characteristic, want to raise the efficiency almost unrealistic, and the operating efficiency of non-brush permanent-magnet DC motor is at least more than 80%.Though aspect the manufacturing cost of motor; Non-brush permanent-magnet DC motor will be higher than 2 to 4 times of the single-phase asynchronous motors of capacitor start; And non-brush permanent-magnet DC motor also must have supporting controller ability operate as normal; But, make non-brush permanent-magnet DC motor have very high controllability, applicable to various operational environment just because of the mechanical property of controller and non-brush permanent-magnet DC motor itself.

The non-brush permanent-magnet DC motor controller adopts the square-wave signal of mutual deviation 120 degree to drive mostly at present, does not add control basically for running current, just is used for doing corresponding protection and uses, for example the overcurrent of non-brush permanent-magnet DC motor, stall, overload or the like.But because the winding in the dc brushless motor all is perception, thus power factor (PF) is reduced, thus cause the increase of reactive power.

Because motor coil all is perceptual; After electric current passes through perceptual device; Will there be deviation in various degree in the phase angle of voltage and the phase angle of electric current, and this phase deviation angle is big more, and reactive power will become big active power and will diminish in the so same apparent power.

Summary of the invention

The utility model will solve the shortcoming of above-mentioned prior art, and a kind of efficient control device based on the dc brushless motor of phase current angle of cut-off that reduces reactive power through the phase angle between Control current and the voltage is provided.

The utility model solves the technical scheme that its technical problem adopts: the efficient control device of this dc brushless motor based on the phase current angle of cut-off; Comprise central processing unit; The output of central processing unit drives with following brachium pontis driving through last brachium pontis and is connected with non-brush permanent-magnet DC motor, and the input of central processing unit is connected with speed setting module and non-brush permanent-magnet DC motor.

As preferably, said central processing unit is 8, and following peripheral hardware is contained in inside: 10 bit A/D converters, 6 tunnel carry the complementary PWM output of dead band function.

As preferably, this device comprises the power module to light current module for power supply all on the control board.

As preferably, central processing unit also is connected with gathers the current amplification circuit that is serially connected in each resistance voltage that goes up mutually, and the output of the electric current comparing unit that comprises in the current amplification circuit is connected with the middle fracture of central processing unit.

The effect that utility model is useful is: the utility model can improve a grade with efficiency of motor again through control algolithm, has reduced the caloric value of motor, and hardware cost does not need to increase.Under same power output, because the reducing of reactive power, reactive current also descends thereupon, so the line of the coil of motor footpath can reduce accordingly, for cost falls in motor a good platform is provided.Owing to improved efficiency of motor, the direct benefit that brings to the user is exactly that cost of use significantly reduces.

Description of drawings

Fig. 1 is the whole principle block diagram of the utility model;

Fig. 2 is the utility model software principle block diagram;

Fig. 3 is a brachium pontis boostrap circuit schematic diagram on the utility model;

Fig. 4 is the utility model software principal function flow chart;

Fig. 5 is that the utility model overcurrent interrupts flow chart;

Fig. 6 is the utility model Hall capture interrupt flow chart;

Description of reference numerals: central processing unit 1, last brachium pontis drives 2, and following brachium pontis drives 3, current amplification circuit 4, non-brush permanent-magnet DC motor 7, speed setting module 8, power module 9.

Embodiment

Below in conjunction with accompanying drawing the utility model is described further:

Embodiment: as shown in Figure 1; The efficient control device of this dc brushless motor based on the phase current angle of cut-off; Comprise central processing unit 1, central processing unit 1 is 8, and following peripheral hardware is contained in inside: 10 bit A/D converters, 6 tunnel carry the complementary PWM output of dead band function.Central processing unit 1 includes the output of 6 road digital quantities, the input of 4 tunnel analog quantitys, the input of 4 road digital quantities altogether.6 road digital quantities comprise: go up brachium pontis three road PWM ripples and following brachium pontis three road PWM ripples, outputed to last brachium pontis driving 2 respectively and driven 3 with following brachium pontis; 4 tunnel analog quantitys inputs comprises: the 1 tunnel is used for speed setting, be connected with speed setting module 8, all the other 3 the tunnel be respectively applied for 3 phase currents collection, be connected with current amplification circuit 4; The input of 4 road digital quantities comprises: 1 passes by stream interrupts, and with

current amplification circuit

4,3 road hall signals, is connected with non-brush permanent-magnet DC motor 7.Last brachium pontis drives in 2 circuit and consists predominantly of boostrap circuit, when following brachium pontis conducting, to the boostrap circuit charging, closes at brachium pontis down and to have no progeny, and the driving voltage of last brachium pontis just utilization is stored in the charge generation in the bootstrap capacitor, like Fig. 3.And the effect that following brachium pontis drives 3 circuit is exactly to amplify drive current, makes the shutoff of power tube and opens the time shortening.Comprise power module 9 in the device to light current module for power supply all on the control board.

Said current amplification circuit 4, this circuit is serially connected in the voltage at each resistance two ends of going up mutually through collection, through behind the corresponding signal transmitting, sends into the AD end of convert of central processing unit 1.Also include the electric current comparing unit in this circuit simultaneously, its output is directly connected to the middle fracture of central processing unit 1, and when non-brush permanent-magnet DC motor generation overcurrent, comparator will produce the interruption that a following saltus step goes out to trigger central processing unit 1, like Fig. 5.

This device is according to the back electromotive force of BLDCM and the conducting and the angle of cut-off of phase current, and the trigger angle of the every phase of dynamic adjustments BLDCM realizes the interval control of BLDCM phase current conducting is reached the target of BLDCM high efficiency control.

Traditional bldc controller has adopted the mode of conducting in twos to remove to control six mos pipes, thus drive motors, and the control of electric current aspect relates to seldom.This programme is on the basis of this control mode, increases the phase control to current waveform.

The phase current and the back-emf of controller real-time tracking motor; Calculate the phase difference of electric current and voltage; Utilize this phase difference to go to revise the PWM duty ratio in the one-period, accomplish current waveform and voltage waveform same-phase basically, thereby improve the utilance of motor busbar voltage.

Adopt Hall element to confirm the position of BLDC rotor,, do not detected phase voltage so MCU does not just spend, thereby reduced complexity of hardware, increased the stability of system because the phase place of the counter potential waveform of the waveform of Hall and motor is identical.Phase current adopts the scheme of sampling resistor, amplifies and filtering through corresponding, sends into the AD pin of MCU.Through software algorithm, catch the zero crossing of phase current.Waveform after amplification filtering is intact is sent into analog comparator simultaneously, compares with the current value of hardware setting, and the signal of output is as the interrupt signal of MCU; Under the situation of motor generation overcurrent or stall; Close PWM with the shortest time and export, arrive the purpose of protection motor, like Fig. 6.

Through Hall not only can be real-time the position of acquisition rotor, according to the number of pole-pairs of the magnet steel of rotor, the still real-time rotating speed that calculates rotor is for software is done the value of feedback that closed-loop control provides speed.

The software aspect: like Fig. 2, shown in 5, after powering at first software to self and the initialization of peripheral hardware, call the starting algorithm of non-brush permanent-magnet DC motor after initialization is accomplished, and judge whether motor is in the stall state in start-up course.Behind normal the startup; Time difference when software relatively calculates the zero crossing of rising edge that Hall element comes out or trailing edge and this phase current with regard to real-time passing through; Thereby calculate the phase difference between the phase voltage and phase current in the current cycle, for output phase voltage time of next cycle as a reference.

Except that the foregoing description, the utility model can also have other execution modes.All employings are equal to the technical scheme of replacement or equivalent transformation formation, all drop on the protection range of the utility model requirement.

Claims

1. efficient control device based on the dc brushless motor of phase current angle of cut-off; Comprise central processing unit (1); It is characterized in that: the output of central processing unit (1) drives (3) through last brachium pontis driving (2) with following brachium pontis and is connected with non-brush permanent-magnet DC motor (7), and the input of central processing unit (1) is connected with non-brush permanent-magnet DC motor (7).

2. the efficient control device of the dc brushless motor based on the phase current angle of cut-off according to claim 1; It is characterized in that: said central processing unit (1) is 8, and following peripheral hardware is contained in inside: 10 bit A/D converters, 6 tunnel carry the complementary PWM output of dead band function.

3. the efficient control device of the dc brushless motor based on the phase current angle of cut-off according to claim 1 and 2, it is characterized in that: this device comprises the power module (9) to light current module for power supply all on the control board.

4. the efficient control device of the dc brushless motor based on the phase current angle of cut-off according to claim 1 and 2; It is characterized in that: central processing unit (1) also is connected with gathers the current amplification circuit (4) that is serially connected in each resistance voltage that goes up mutually, and the output of the electric current comparing unit that comprises in the current amplification circuit (4) is connected with the middle fracture of central processing unit (1).

5. the efficient control device of the dc brushless motor based on the phase current angle of cut-off according to claim 1 and 2, it is characterized in that: central processing unit (1) is connected with speed setting module (8).