CN101581765A - Back electromotive force zero-crossing detection circuit of brushless direct current motor - Google Patents

Back electromotive force zero-crossing detection circuit of brushless direct current motor Download PDF

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Publication number
CN101581765A
CN101581765A CNA2009101475647A CN200910147564A CN101581765A CN 101581765 A CN101581765 A CN 101581765A CN A2009101475647 A CNA2009101475647 A CN A2009101475647A CN 200910147564 A CN200910147564 A CN 200910147564A CN 101581765 A CN101581765 A CN 101581765A
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circuit
output terminal
zero
input
tandem
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CNA2009101475647A
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CN101581765B (en
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薛晓明
时倩
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薛晓明
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Abstract

The invention discloses a back electromotive force zero-crossing detection circuit of a brushless direct current motor, comprising a line voltage difference detection circuit, a PWM modulation noise cancellation circuit, a zero-crossing comparison circuit, and a false zero shielding circuit. When in use, the motor three-phase terminal voltage containing a PWM modulation wave is sent into the line voltage difference detection circuit and the PWM modulation noise cancellation circuit for treatment to output a smooth non-conduction opposite potential signal which is enlarged by four times and does not contain the PWM modulation wave, and then a back electromotive force zero-crossing signal which contains a phase changing moment is obtained by the comparison of the zero-crossing comparison circuit, and finally a precise back electromotive force zero-crossing signal is output after the false zero shielding circuit removes the false zero. Without a filter circuit, the back electromotive force zero-crossing detection circuit of the brushless direct current motor can adapt to various brushless direct current motors which are controlled by PWM modulation technology, and carry out non-phase shift precise detection to the back electromotive force zero-crossing signal within the wide speed range of 0.5 percent to 100 percent of rated rotating speed.

Description

Back electromotive force zero-crossing detection circuit of brushless direct current motor

Technical field

The present invention relates to a kind of back electromotive force zero-crossing detection circuit, particularly relate to a kind of unified accurate testing circuit of brushless direct-current machine counter electromotive zero crossing that can adapt to various PWM modulation strategy controls.

Background technology

Brushless DC motor without position sensor detection rotor position is the simplest, practical method is to determine by detecting back electromotive force zero-crossing, because the back electromotive force of winding is to be difficult to the directly physical quantity of measurement, mainly contain two kinds of methods at present: the one, by detecting the motor terminal voltage signal, obtain the zero crossing of winding back-emf signal after comparing indirectly, the deficiency of this method is: need to filter PWM modulating wave in the terminal voltage with electric capacity in testing circuit, can produce phase shift, and change along with the variation of motor speed, make commutation inaccurate, especially when system's speed adjustable range is very wide, phase shift was excessive when motor operated in high frequency, can not implement correct commutation; The 2nd, in PWM copped wave shutoff or conduction period the terminal voltage of motor is sampled, directly obtain the zero crossing of back-emf signal, though this kind method has overcome the deficiency that first method exists, but need adopt the different method of samplings at different PWM modulation strategies, increased manufacturing cost, be unfavorable for that tissue produces, be subjected to the influence of inverter switching device pipe and diode drop simultaneously, when having limited the motor tick-over to the correct detection of back electromotive force zero-crossing.

Summary of the invention

Technical matters to be solved by this invention is: a kind of filter capacitor that do not need is provided, phase shift does not appear, be not subjected to the influence of inverter switching device pipe and diode drop, the brushless direct-current machine counter electromotive zero crossing that can adapt to various PWM modulation technique controls is unified testing circuit.

The technical solution adopted in the present invention is:

Comprise the line voltage difference detection circuits, the PWM zoop is eliminated circuit, the zero crossing comparator circuit, falseness screened circuit at zero point, line voltage difference detection circuits interface A, B, C is connected with the triple-phase line of brshless DC motor respectively, the PWM zoop is eliminated circuit and is connected with the line voltage difference detection circuits, the zero crossing comparator circuit is eliminated circuit with the PWM zoop and is connected, falseness screened circuit at zero point is connected with the zero crossing comparator circuit, six commutation signal S1 that do not modulate through PWM, S2, S3, S4, S5, S6 eliminates circuit with the PWM zoop respectively and is connected with falseness screened circuit at zero point.

Described line voltage difference detection circuits comprises resistance R 1A, R2A, R1B, R2B, R1C, R2C, R3A, R3B, R3C, R4A, R4B, R4C, R5A, R5B, R5C, operational amplifier U1A, U1B, U1C, U1D, U1E, U1F, R1A, R1B, the end of R1C respectively with motor triple-phase line A, B, C connects, the end of the other end of R1A and R2A, the end of R3C, the positive terminal of U1A, the end of oppisite phase tandem of U1C, the end of the other end of R1B and R2B, the end of R3A, the positive terminal of U1B, the end of oppisite phase tandem of U1A, the end of the other end of R1C and R2C, the end of R3B, the positive terminal of U1C, the end of oppisite phase tandem of U1B, the end of R4A, the other end of R3A, the tandem of U1A output terminal, the end of R4B, the other end of R3B, the tandem of U1B output terminal, the end of R4C, the other end of R3C, the tandem of U1C output terminal, the other end of R4A, the end of R5A, the end of oppisite phase of U1D, the positive terminal tandem of U1E, the other end of R4B, the end of R5B, the end of oppisite phase of U1E, the positive terminal tandem of U1F, the other end of R4C, the end of R5C, the end of oppisite phase of U1E, the positive terminal tandem of U1D.

Described PWM zoop is eliminated circuit and is comprised operational amplifier U2A, U2B, U2C, U2D, both-end input analog switch U3A, U3B, U3C, or door U4A, U4B, U4C, resistance R 6A, R6B, R6C, R7, the normal phase input end of U2A, U2B, U2C is connected with U1D, the U1E of line voltage difference detection circuits, the output terminal of U1F respectively, also be connected with the input end of U3A, U3B, U3C respectively, the output terminal of U2A, U2B, U2C is connected with separately end of oppisite phase respectively, also is connected with another input end of U3A, U3B, U3C respectively; U3A, U3B, the U3C output terminal respectively with three resistance R 6A, R6B, the end of R6C connects, U3A, U3B, the control end of U3C respectively with U4A, U4B, the output terminal of U4C connects, two input ends of U4A respectively with commutation signal S1, S2 connects, two input ends of U4B respectively with commutation signal S3, S4 connects, two input ends of U4C respectively with commutation signal S5, S6 connects, three resistance R 6A, R6B, the other end of R6C is connected with the normal phase input end of U2D, the inverting input of U2D is connected with output terminal through resistance R 7, the output terminal of U2D, the lower end of diode D1, diode D2 upper end tandem, upper end connection+15V the power supply of diode D1, diode D2 lower end connection-15V power supply.

Described zero crossing comparator circuit operational amplifier U5 positive terminal ground connection, the end of oppisite phase of operational amplifier U5 is connected with the output terminal that the PWM zoop is eliminated circuit computing amplifier U2D.

Described falseness screened circuit at zero point comprises not gate U6, XOR gate U7 and U10, with door U8 and U11, rejection gate U9, d type flip flop U12, resistance R d1 and Rd2, capacitor C d1 and Cd2, the output terminal of zero crossing comparator circuit operational amplifier U5, the end of resistance R d1, the input end of U10, the D end tandem of U12, the other end of Rd1, the end of capacitor C d1, another input end tandem of U10, the output terminal of U10 is connected with the input end of U11, the output terminal of U11 is connected with the clock trigger end C of U12, the output terminal output back electromotive force zero passage square-wave signal of U12, six commutation signal S1 that do not modulate through PWM, S2, S3, S4, S5, corresponding respectively resistance R d2 one end that connects separately of S6, U6 input end separately, input end of U7 separately, the resistance R d2 other end separately, the end of capacitor C d2 separately, another input end tandem of U7 separately, U6 output terminal separately, U7 output terminal separately is connected with the input end of U8 separately, the output terminal of six U8 is connected with six input ends of U9, and the output terminal of U9 is connected with another input end of U11.

The accurate testing circuit of brushless direct-current machine counter electromotive zero crossing of the present invention, the application simulation switch has been eliminated the PWM zoop and has been obtained the level and smooth non-conduction opposite potential signal of quadruplication, use simple digital circuit and eliminated commutation constantly because the false zero crossing that the conducting simultaneously of motor three phase windings occurs, compare the influence that has realized not being subjected to PWM modulation technique and inverter switching device pipe and diode drop with background technology, need not filter capacitor, realize that under lower speed the back electromotive force zero-crossing signal is not had the purpose that phase shift accurately detects.

Description of drawings

Fig. 1 is a block diagram of the present invention.

Fig. 2 is the circuit connection diagram of one embodiment of the present of invention.

Among the figure: 1, line voltage difference detection circuits, 2, the PWM zoop eliminates circuit, 3, the zero crossing comparator circuit, 4, false zero point screened circuit.

Embodiment

The invention will be further described below in conjunction with drawings and Examples.

As shown in Figure 1, a kind of back electromotive force zero-crossing detection circuit of brushless direct current motor of the present invention, comprise line voltage difference detection circuits (1), the PWM zoop is eliminated circuit (2), zero crossing comparator circuit (3), false screened circuit at zero point (4), line voltage difference detection circuits (1) interface A, B, C is connected with the triple-phase line of brshless DC motor respectively, the PWM zoop is eliminated circuit (2) and is connected with line voltage difference detection circuits (1), zero crossing comparator circuit (3) is eliminated circuit (2) with the PWM zoop and is connected, false screened circuit at zero point (4) is connected with zero crossing comparator circuit (3), six commutation signal S1 that do not modulate through PWM, S2, S3, S4, S5, S6 eliminates circuit (2) with the PWM zoop respectively and is connected with false screened circuit at zero point (4).

As shown in Figure 2, line voltage difference detection circuits (1) comprises resistance R 1A, R2A, R1B, R2B, R1C, R2C, R3A, R3B, R3C, R4A, R4B, R4C, R5A, R5B, R5C, operational amplifier U1A, U1B, U1C, U1D, U1E, U1F, R1A, R1B, the end of R1C respectively with motor triple-phase line A, B, C connects, the end of the other end of R1A and R2A, the end of R3C, the positive terminal of U1A, the end of oppisite phase tandem of U1C, the end of the other end of R1B and R2B, the end of R3A, the positive terminal of U1B, the end of oppisite phase tandem of U1A, the end of the other end of R1C and R2C, the end of R3B, the positive terminal of U1C, the end of oppisite phase tandem of U1B, the end of R4A, the other end of R3A, the tandem of U1A output terminal, the end of R4B, the other end of R3B, the tandem of U1B output terminal, the end of R4C, the other end of R3C, the tandem of U1C output terminal, the other end of R4A, the end of oppisite phase of the end U1D of R5A, the positive terminal tandem of U1E, the other end of R4B, the end of R5B, the end of oppisite phase of U1E, the positive terminal tandem of U1F, the other end of R4C, the end of R5C, the end of oppisite phase of U1E, the positive terminal tandem of U1D; The PWM zoop is eliminated circuit (2) and is comprised operational amplifier U2A, U2B, U2C, U2D, both-end input analog switch U3A, U3B, U3C, or door U4A, U4B, U4C, resistance R 6A, R6B, R6C, R7, the normal phase input end of U2A, U2B, U2C is connected with U1D, the U1E of line voltage difference detection circuits (1), the output terminal of U1F respectively, also be connected with the input end of U3A, U3B, U3C respectively, the output terminal of U2A, U2B, U2C is connected with separately end of oppisite phase respectively, also is connected with another input end of U3A, U3B, U3C respectively; U3A, U3B, the U3C output terminal respectively with three resistance R 6A, R6B, the end of R6C connects, U3A, U3B, the control end of U3C respectively with U4A, U4B, the output terminal of U4C connects, two input ends of U4A respectively with commutation signal S1, S2 connects, two input ends of U4B respectively with commutation signal S3, S4 connects, two input ends of U4C respectively with commutation signal S5, S6 connects, three resistance R 6A, R6B, the other end of R6C is connected with the normal phase input end of U2D, the inverting input of U2D is connected with output terminal through resistance R 7, the output terminal of U2D, the lower end of diode D1, diode D2 upper end tandem, upper end connection+15V the power supply of diode D1, diode D2 lower end connection-15V power supply; Zero crossing comparator circuit (3) operational amplifier U5 positive terminal ground connection, the end of oppisite phase of operational amplifier U5 is connected with the output terminal that the PWM zoop is eliminated circuit (2) operational amplifier U2D; False screened circuit at zero point (4) comprises not gate U6, XOR gate U7 and U10, with door U8 and U11, rejection gate U9, d type flip flop U12, resistance R d1 and Rd2, capacitor C d1 and Cd2, the output terminal of zero crossing comparator circuit (3) operational amplifier U5, the end of resistance R d1, the input end of U10, the D end tandem of U12, the other end of Rd1, the end of capacitor C d1, another input end tandem of U10, the output terminal of U10 is connected with the input end of U11, the output terminal of U11 is connected with the clock trigger end C of U12, the output terminal output back electromotive force zero passage square-wave signal of U12, six commutation signal S1 that do not modulate through PWM, S2, S3, S4, S5, corresponding respectively resistance R d2 one end that connects separately of S6, U6 input end separately, input end of U7 separately, the resistance R d2 other end separately, the end of capacitor C d2 separately, another input end tandem of U7 separately, U6 output terminal separately, U7 output terminal separately is connected with the input end of U8 separately, the output terminal of six U8 is connected with six input ends of U9, and the output terminal of U9 is connected with another input end of U11.

U1A of the present invention, U1B, U1C, U1D, U1E, U1F adopt a slice integrated chip NJM2116M, U2A, U2B, U2C, U2D adopt a slice integrated chip LM324, U3A, U3B, U3C adopt three integrated chip MAX4669, U4A, U4B, U4C adopt a slice integrated chip CD4001, and U5 adopts a slice integrated chip NJM2406F.

Engineering process of the present invention is:

As shown in Figure 3, the brshless DC motor three phase terminals voltage that contains the PWM modulating wave is eliminated the level and smooth non-conduction opposite potential signal V that output quadruplication after the processing of circuit does not contain the PWM modulating wave through line voltage difference detection circuits and PWM zoop ABC, V ABCObtain containing the commutation back electromotive force zero-crossing signal Z at constantly false zero point after relatively through amplitude limiter circuit amplitude limit, zero crossing comparator circuit ABC, Z ABCThe square-wave signal Z that has only back electromotive force zero-crossing through the false output at zero point of false screened circuit removal at zero point ABCO

Above-mentioned embodiment is used for explaining the present invention, rather than limits the invention, and in the protection domain of spirit of the present invention and claim, any modification and change to the present invention makes all fall within the scope of protection of the present invention.

Claims (6)

1, back electromotive force zero-crossing detection circuit of brushless direct current motor, it is characterized in that: comprise line voltage difference detection circuits (1), the PWM zoop is eliminated circuit (2), zero crossing comparator circuit (3), false screened circuit at zero point (4), line voltage difference detection circuits (1) interface A, B, C is connected with the triple-phase line of brshless DC motor respectively, the PWM zoop is eliminated circuit (2) and is connected with line voltage difference detection circuits (1), zero crossing comparator circuit (3) is eliminated circuit (2) with the PWM zoop and is connected, false screened circuit at zero point (4) is connected with zero crossing comparator circuit (3), six commutation signal S1 that do not modulate through PWM, S2, S3, S4, S5, S6 eliminates circuit (2) with the PWM zoop respectively and is connected with false screened circuit at zero point (4).
2, back electromotive force zero-crossing detection circuit of brushless direct current motor according to claim 1, it is characterized in that: described line voltage difference detection circuits (1) comprises resistance R 1A, R2A, R1B, R2B, R1C, R2C, R3A, R3B, R3C, R4A, R4B, R4C, R5A, R5B, R5C, operational amplifier U1A, U1B, U1C, U1D, U1E, U1F, R1A, R1B, the end of R1C respectively with motor triple-phase line A, B, C connects, the end of the other end of R1A and R2A, the end of R3C, the positive terminal of U1A, the end of oppisite phase tandem of U1C, the end of the other end of R1B and R2B, the end of R3A, the positive terminal of U1B, the end of oppisite phase tandem of U1A, the end of the other end of R1C and R2C, the end of R3B, the positive terminal of U1C, the end of oppisite phase tandem of U1B, the end of R4A, the other end of R3A, the tandem of U1A output terminal, the end of R4B, the other end of R3B, the tandem of U1B output terminal, the end of R4C, the other end of R3C, the tandem of U1C output terminal, the other end of R4A, the end of R5A, the end of oppisite phase of U1D, the positive terminal tandem of U1E, the other end of R4B, the end of R5B, the end of oppisite phase of U1E, the positive terminal tandem of U1F, the other end of R4C, the end of R5C, the end of oppisite phase of U1E, the positive terminal tandem of U1D.
3, back electromotive force zero-crossing detection circuit of brushless direct current motor according to claim 1, it is characterized in that: described PWM zoop is eliminated circuit (2) and is comprised operational amplifier U2A, U2B, U2C, U2D, both-end input analog switch U3A, U3B, U3C, or door U4A, U4B, U4C, resistance R 6A, R6B, R6C, R7, U2A, U2B, the normal phase input end of U2C respectively with the U1D of line voltage difference detection circuits (1), U1E, the output terminal of U1F is connected, also respectively with U3A, U3B, the input end of U3C connects, U2A, U2B, the output terminal of U2C is connected with separately end of oppisite phase respectively, also respectively with U3A, U3B, another input end of U3C connects; U3A, U3B, the U3C output terminal respectively with three resistance R 6A, R6B, the end of R6C connects, U3A, U3B, the control end of U3C respectively with U4A, U4B, the output terminal of U4C connects, two input ends of U4A respectively with commutation signal S1, S2 connects, two input ends of U4B respectively with commutation signal S3, S4 connects, two input ends of U4C respectively with commutation signal S5, S6 connects, three resistance R 6A, R6B, the other end of R6C is connected with the normal phase input end of U2D, the inverting input of U2D is connected with output terminal through resistance R 7, the output terminal of U2D, the lower end of diode D1, diode D2 upper end tandem, upper end connection+15V the power supply of diode D1, diode D2 lower end connection-15V power supply.
4, back electromotive force zero-crossing detection circuit of brushless direct current motor according to claim 1, it is characterized in that: described zero crossing comparator circuit (3) operational amplifier U5 positive terminal ground connection, the end of oppisite phase of operational amplifier U5 is connected with the output terminal that the PWM zoop is eliminated circuit (2) operational amplifier U2D.
5, back electromotive force zero-crossing detection circuit of brushless direct current motor according to claim 1, it is characterized in that: false screened circuit at zero point (4) comprises not gate U6, XOR gate U7 and U10, with door U8 and U11, rejection gate U9, d type flip flop U12, resistance R d1 and Rd2, capacitor C d1 and Cd2, the output terminal of zero crossing comparator circuit (3) operational amplifier U5, the end of resistance R d1, the input end of U10, the D end tandem of U12, the other end of Rd1, the end of capacitor C d1, another input end tandem of U10, the output terminal of U10 is connected with the input end of U11, the output terminal of U11 is connected with the clock trigger end C of U12, the output terminal output back electromotive force zero passage square-wave signal of U12, six commutation signal S1 that do not modulate through PWM, S2, S3, S4, S5, corresponding respectively resistance R d2 one end that connects separately of S6, U6 input end separately, input end of U7 separately, the resistance R d2 other end separately, the end of capacitor C d2 separately, another input end tandem of U7 separately, U6 output terminal separately, U7 output terminal separately is connected with the input end of U8 separately, the output terminal of six U8 is connected with six input ends of U9, and the output terminal of U9 is connected with another input end of U11.
6, back electromotive force zero-crossing detection circuit of brushless direct current motor according to claim 1, it is characterized in that: U1A, U1B, U1C, U1D, U1E, U1F adopt a slice integrated chip NJM2116M, U2A, U2B, U2C, U2D adopt a slice integrated chip LM324, U3A, U3B, U3C adopt three integrated chip MAX4669, U4A, U4B, U4C adopt a slice integrated chip CD4001, and U5 adopts a slice integrated chip NJM2406F.
CN2009101475647A 2009-06-15 2009-06-15 Back electromotive force zero-crossing detection circuit of brushless direct current motor CN101581765B (en)

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CN2009101475647A CN101581765B (en) 2009-06-15 2009-06-15 Back electromotive force zero-crossing detection circuit of brushless direct current motor

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CN2009101475647A CN101581765B (en) 2009-06-15 2009-06-15 Back electromotive force zero-crossing detection circuit of brushless direct current motor

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103018541A (en) * 2012-11-06 2013-04-03 中南林业科技大学 Counter-potential zero-crossing detection circuit and counter-potential zero-crossing detection method for brushless direct-current motor
CN105137351A (en) * 2015-07-27 2015-12-09 深圳市安进汽车电子有限公司 Method of measuring output stability of instrument stepping motor

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1980044A (en) * 2005-12-05 2007-06-13 乐金电子(天津)电器有限公司 Counterelectro motive detection circuit of dc. brush-free motor
CN201413356Y (en) * 2009-06-15 2010-02-24 薛晓明 Back electromotive force zero-crossing detector of brushless DC motor

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103018541A (en) * 2012-11-06 2013-04-03 中南林业科技大学 Counter-potential zero-crossing detection circuit and counter-potential zero-crossing detection method for brushless direct-current motor
CN103018541B (en) * 2012-11-06 2016-05-11 中南林业科技大学 Brshless DC motor back-emf zero cross detection circuit and detection method
CN105137351A (en) * 2015-07-27 2015-12-09 深圳市安进汽车电子有限公司 Method of measuring output stability of instrument stepping motor

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