CN1728532A - Dual drive single chip control device with external A/D converter for brushless DC motor - Google Patents

Abstract

Belonging to application of single chip technique, the invention includes single chip with A/D converter and signals of sensors at three positions of rotor magnetic steel for back electromotive force of stator winding. Through detecting the back electromotive forces of two sets of stator winding in time-sharing controls phase change and speed of brushless DC motor. Through controlling output level of operational amplification circuit realizes restriction for starting current. Through controlling output voltage of external D/A converter realizes control of speed. Comparing with external A/D converter with Hall sensor and dedicated controller in IC, the disclosed device possesses advantages: low cost, good compatibility, expandable interfaces and functions.

Description

The brushless DC machine double-drive single-chip microcomputer control device of external A/D converter

Technical field the invention belongs to singlechip technology in the DC MOTOR CONTROL Application for Field.

Before background technology the invention applying date, externally arranged D/A converter band Hall element and application-specific integrated circuit (ASIC) are adopted in the control of attached brushless DC motor of electric vehicle, but the defective that exists cost highly compatible difference and function to expand.

Certainly the brushless DC machine double-drive single-chip microcomputer control device that provides a kind of external A/D converter of summary of the invention the invention.

The invention solves the technical scheme that its technical problem adopts: comprise the single-chip microcomputer of being with A/D converter and take from three rotor magnetic steel position sensor signals of the back electromotive force of motor stator winding; Detect the measurement of the back electromotive force of two groups of motor stator windings by timesharing, the commutation speed governing of control brshless DC motor by the output level of control discharge circuit, realizes the restriction of starting current; By controlling the output voltage of external D/A, realize the control of rotating speed.Three rotor magnetic steel position sensor signals taking from the back electromotive force of two groups of motor stator windings are connected with the single-chip processor i/o input respectively; The single-chip processor i/o output is connected with discharge circuit with two reverse swing door circuit respectively, and the output of two reverse swing door circuit is connected with the control end of two groups of 6 power respectively, and external A/D converter is connected with the operational amplifier input.To take from the state of three rotor magnetic steel position sensor signals of back electromotive force of two groups of motor stator windings and the relation between two groups of 6 power tube conductings leaves among the EPROM of single-chip microcomputer with form.

The beneficial effect of the invention is: the position transducer Hall element is removed in the invention from, makes electric machine structure more reasonable, saves simultaneously and controls cost.Realization is to the control of two driving brshless DC motors and leave a plurality of interfaces for the function expansion, has overcome the defective that external A/D converter, Hall element and application-specific integrated circuit (ASIC) controller cost height, poor compatibility, function can't be expanded.

Appended drawings 1 is the electrical schematic diagram of the invention.

Embodiment is consulted Fig. 1.The invention single-chip microcomputer adopts U.S. MICROCHIP company 8-bit microcontroller, and present embodiment adopts single-chip microcomputer PIC16C67.Delivery outlet P ₁Comprise I/O (1), I/O (2), I/O (3), I/O (4), I/O (5), I/O (6), the input with 7406 reverse swing door circuit is connected respectively.7406 output is six MOSFET power tube VF respectively ₁, VF ₂, VF ₃, VF ₄, VF ₅, VF ₆Control end be connected; Delivery outlet P ₂Comprise that I/O (7), I/O (8), I/O (9), I/O (10), I/O (11), I/O (12) are connected with the input of another 7406 reverse swing door circuit respectively.7406 output is six MOSFET power tube VF respectively ₁, VF ₂, VF ₃, VF ₄, VF ₅, VF ₆Control end be connected; Input port P ₀Comprise I/O (13), I/O (14), I/O (15), I/O (16), I/O (17), I/O (18), respectively with three rotor magnetic steel position sensor signal H of the back electromotive force of taking from two groups of motor stator windings ₁, H ₂, H ₃, H ₄, H ₅, H ₆Be connected.Delivery outlet P ₃Comprise that I/O (19) I/O (20), I/O (21), I/O (22), I/O (23), I/O (24), I/O (25), I/O (26) are connected with external A/D converter AD558 input respectively, external A/D converter AD558 output is connected with an input of LM324 operational amplifier by resistance.An input of LM324 operational amplifier passes through grounding through resistance.The invention detects three rotor magnetic steel position sensor signal H of the back electromotive force of two groups of motor stator windings by timesharing ₁, H ₂, H ₃, H ₄, H ₅, H ₆, and by i.e. three the rotor magnetic steel position sensor signal H of the commutation table among the EPROM that leaves single-chip microcomputer with form in ₁, H ₂, H ₃, H ₄, H ₅, H ₆State and 6 power tube VF ₁, VF ₂, VF ₃, VF ₄, VF ₅, VF ₆Relation between the conducting, by the control word that delivery outlet is sent, difference conducting VF ₁, VF ₂VF ₂, VF ₃VF ₃, VF ₄VF ₄, VF ₅VF ₅, VF ₆VF ₆, VF ₁Promptly realize the commutation of brshless DC motor.In the process of the normal operation of brshless DC motor, by controlling the output voltage of external D/A, i.e. the electric current of may command brshless DC motor, and then control rotating speed of motor.Single-chip microcomputer calculates rotating speed of motor by taking from the cycle of two groups of motor stator winding back-emf signals, and it with given rotating speed relatively, as be higher than given rotating speed, and then reduce output numerical value, reduce the electric current of motor, reduce its rotating speed to reach.

Claims (3)

1, a kind of brushless DC machine double-drive single-chip microcomputer control device of external A/D converter comprises the single-chip microcomputer of being with A/D converter and takes from three rotor magnetic steel position sensor signals of the back electromotive force of motor stator winding; It is characterized in that detecting by timesharing the measurement of the back electromotive force of two groups of motor stator windings, the commutation speed governing of control brshless DC motor by the output level of control discharge circuit, realizes the restriction of starting current; By controlling the output voltage of external D/A, realize the control of rotating speed.

2, the brushless DC machine double-drive single-chip microcomputer control device of external A/D converter according to claim 1, three rotor magnetic steel position sensor signals that it is characterized in that taking from the back electromotive force of two groups of motor stator windings are connected with the single-chip processor i/o input respectively; The single-chip processor i/o output is connected with discharge circuit with two reverse swing door circuit respectively, and the output of two reverse swing door circuit is connected with the control end of two groups of 6 power respectively, and external A/D converter is connected with the operational amplifier input.

3, the brushless DC machine double-drive single-chip microcomputer control device of external A/D converter according to claim 1 is characterized in that leaving among the EPROM of single-chip microcomputer with form taking from the state of three rotor magnetic steel position sensor signals of back electromotive force of two groups of motor stator windings and the relation between two groups of 6 power tube conductings.

Images