CN100459411C - Motor control device and motor control system - Google Patents

Abstract

The related motor control system comprises: a rectification/filter part, multiple inverters to convert power into ac power to drive motors, and a controller to output some PWM signals with different phase. This invention can reduce drive noise efficiently.

Description

Motor control assembly and electric machine control system

Technical field

The present invention relates to a kind of motor control assembly and electric machine control system, relate in particular to a kind of motor control assembly and electric machine control system that when driving a plurality of motor, reduces noise.

Background technology

Generally, be used for the motor-driven control that applies the inverter of AC power and be extensive use of pulse-width modulation (PWM:Pulse Width Modulation) mode.

Fig. 1 is the schematic diagram that is used to drive the motor control assembly of being made up of three inverters of three motors.

Each PWM generating unit 130a, 130b, 130c receive initial signal (Start), clock signal (Clock) and sinusoidal signal (SIG1, SIG2, SIG3) afterwards with serve as also output pwm signal (M1R, M2R, M3R) of basis generation.At this, initial signal (Start) is the basis that produces the starting point of pwm signal (M1R, M2R, M3R), clock signal (Clock) is used to produce self-generating triangular wave (C1, C2, C3), and this self-generating triangular wave (C1, C2, C3) is used for PWM generating unit 130a, 130b, 130c produce pwm signal (M1R, M2R, M3R).

Fig. 2 be the prior motor control system initial signal (Start), triangular wave (C1, C2, C3), sinusoidal signal (SIG1, SIG2, SIG3) and pwm signal (M1R, M2R, M3R) concern schematic diagram.As shown in the figure, PWM generating unit 130a, 130b, 130c serve as that the basis generation is the triangular wave (C1, C2, C3) of starting point with initial signal (Start) with clock signal (Clock).Then, produce pwm signal (M1R, M2R, M3R) according to the crosspoint between triangular wave (C1, C2, C3) and the sinusoidal signal (SIG1, SIG2, SIG3).

But, this prior motor control system as shown in Figure 2, when controlling each motor, for example when stopping to control with the same terms, have same phase owing to be applied to the pwm signal (M1R, M2R, M3R) of R phase in the input power supply (R, S, T) of motor, thereby bring the big problem of noise.

Therefore, the object of the present invention is to provide a kind of motor control assembly and electric machine control system that makes the noise minimum of generation when driving a plurality of motor.

Summary of the invention

Described purpose can realize according to electric machine control system provided by the present invention, and for the electric machine control system of a plurality of motors of control, it is characterized in that comprising: rectification/filtering portion is used for rectification and filtering AC power; A plurality of inverters, the power supply that receives by described rectification/filtering portion institute's rectification and filtering is transformed to the required AC power of described each motor-driven with it afterwards; Motor control assembly is in order to control the AC power that described each inverter exports and export a plurality of pwm signals with phase place inequality; Wherein, the output starting point of pulse-width signal is delayed time and produce a plurality of pulse-width signals with phase place inequality.

At this, described motor control assembly comprises: phase control division is used to export initial signal, clock signal and sinusoidal signal; A plurality of PWM generating units determine the output starting point of described pwm signal according to described initial signal, and produce described pwm signal based on described clock signal and described sinusoidal signal; Time-delay portion for the described pwm signal that described each PWM generating unit is exported has phase place inequality, delays time at least one the described initial signal that is input in described a plurality of PWM generating unit.

And it is the triangular wave of starting point that described PWM generating unit produces with described initial signal based on described clock signal, and can produce described pwm signal according to described triangular wave and described sinusoidal signal.

And the time difference between the described initial signal that is postponed by described time-delay portion is preferably within the one-period scope of described triangular wave.

In addition, described purpose also can realize according to the motor control assembly that another embodiment of the present invention provided, be used to control the motor control assembly of a plurality of pwm signals of a plurality of motors for generation, comprise: phase control division is used to export initial signal, clock signal and sinusoidal signal; A plurality of PWM generating units determine the output starting point of described pwm signal according to described initial signal, and produce described pwm signal based on described clock signal and described sinusoidal signal; Time-delay portion for the described pwm signal that described each PWM generating unit is exported has phase place inequality, delays time at least one the described initial signal that is input in described a plurality of PWM generating unit.

At this, it is the triangular wave of starting point that described PWM generating unit produces with described initial signal based on described clock signal, and can produce described pwm signal according to described triangular wave and described sinusoidal signal.

And the time difference between the described initial signal that is postponed by described time-delay portion is preferably within the one-period scope of described triangular wave.

Description of drawings

Fig. 1 is the control block diagram of prior motor control device;

Fig. 2 be the prior motor control system initial signal, triangular wave, sinusoidal signal and pwm signal concern schematic diagram;

Fig. 3 is the control block diagram according to electric machine control system provided by the present invention;

Fig. 4 is the control block diagram of the electric machine control system of Fig. 3;

Fig. 5 be the electric machine control system of Fig. 3 initial signal, triangular wave, sinusoidal signal and pwm signal concern schematic diagram;

Fig. 6 is the power spectral density schematic diagram of prior motor control system according to frequency harmonics;

Fig. 7 is according to the power spectral density schematic diagram of electric machine control system provided by the present invention according to frequency harmonics.

Embodiment

Below, describe the present invention in detail with reference to accompanying drawing.

According to electric machine control system 1 provided by the present invention as shown in Figure 3, comprising provides the AC power supplies of AC power supply department 10, rectification/filtering portion 20, a plurality of inverter 30a, 30b, 30c and motor control assembly 40.

Rectification/filtering portion 20 is used for the AC power that rectification and filtering AC power supplies supply department 10 are provided.Rectification/filtering portion 20 may comprise the diode rectification portion 21 that is used for the AC power that rectification AC power supplies supply department 10 provided and be used for the filtering portion 22 that is made up of electric capacity etc. of the power supply of filtering by 21 rectifications of diode rectification portion.

The power supply that each inverter 30a, 30b, 30c receive by rectification/20 rectifications of filtering portion and filtering is transformed to it each motor 50a, 50b, required AC power and the supply of 50c driving afterwards.At this, each inverter 30a, 30b, 30c receive the pwm signal described later (M1R, M2R, M3R) that provided by motor control assembly 40 afterwards, by a plurality of switch elements according to the pwm signal of being imported (M1R, M2R, M3R) and the switch motion of switch will be AC power by the power conversion of rectification/20 rectifications of filtering portion and filtering and output to motor 50a, 50b, 50c.

Motor control assembly 40 comprises phase control division 41, a plurality of PWM generating unit 43a, 43b, 43c and time-delay portion 42 as shown in Figure 4.

Phase control division 41 outputs are applied to initial signal (Start), clock signal (Clock) and the sinusoidal signal (SIG1, SIG2, SIG3) of each PWM generating unit 43a, 43b, 43c.At this, phase control division 41 is made up of a plurality of electrical equipment/electronic components, in order to motor 50a, 50b, the 50c of control except that PWM generating unit 43a, 43b, 43c and time-delay portion 42.For example, phase control division 41 may comprise clock generator (Clock Generator) that is used for clocking (Clock) and the master processor that is used to export initial signal (Start) and control the bit instruction mutually of each motor 50a, 50b, 50c.

Here, clock generator produces the master clock of motor control assembly 40 whole systems, and the clock signal (Clock) that is input to PWM generating unit 43a, 43b, 43c can be used described master clock.And clock generator can also have other loop structure certainly, is input to the clock signal (Clock) of PWM generating unit 43a, 43b, 43c with generation.

Each PWM generating unit 43a, 43b, 43c determine the output starting point of pwm signal (M1R, M2R, M3R) according to the initial signal (Start) of phase control division 41.And each PWM generating unit 43a, 43b, 43c produce pwm signal (M1R, M2R, M3R) according to the clock signal (Clock) and the sinusoidal signal (SIG1, SIG2, SIG3) of phase control division 41.At this, it is the triangular wave of starting point that each PWM generating unit 43a, 43b, 43c produce with initial signal (Start) based on clock signal (Clock).Then, PWM generating unit 43a, 43b, 43c produce pwm signal (M1R, M2R, M3R) according to triangular wave and sinusoidal signal (SIG1, SIG2, SIG3).Below, each PWM generating unit 43a, 43b, 43c are defined as a PWM generating unit 43a, the 2nd PWM generating unit 43b and the 3rd PWM generating unit 43c arbitrarily, and are described.

42 pairs in time-delay portion be input at least one initial signal (Start) in the pwm signal (M1R, M2R, M3R) of each PWM generating unit 43a, 43b, 43c delay time (t1, t2).As shown in Figure 4, time-delay portion 42 can comprise: first 42a of time-delay portion is used for delayed time by phase control division 41 output and the initial signal (Start) that is input to the 2nd PWM generating unit 43b (t1); Second 42b of time-delay portion is used for delayed time by phase control division 41 output and the initial signal (Start) that is input to the 3rd PWM generating unit 43c (t2).At this, and the time that is postponed by first 42a of time-delay portion and second 42b of time-delay portion (t1, t2) different.

The following waveform that the pwm signal (M1R, M2R, M3R) that is produced by each PWM generating unit 43a, 43b, 43c is described with reference to Fig. 5.

At first, be input to initial signal (Start) non-time delay of a PWM generating unit 43a, the initial signal (Start) that is input to the 2nd PWM generating unit 43b and the 3rd PWM generating unit 43c respectively by first 42a of time-delay portion and second 42b of time-delay portion and time of delay (t1, t2).

At this, as shown in Figure 5, each PWM generating unit 43a, 43b, 43c with initial signal (Start) be the triangular wave that produces of starting point the generation starting point difference preferably and the one-period of triangular wave inconsistent.Thus, (t1 t2) produces between these triangular waves on basis as pwm signal (M1R, M2R, M3R) and has mutually different phase place the time-delay by initial signal (Start).

And each PWM generating unit 43a, 43b, 43c are that the difference of generation starting point of the triangular wave that produces of starting point is preferably less than the one-period of triangular wave with initial signal (Start).Promptly, the starting point that the 2nd PWM generating unit 43b and the 3rd PWM generating unit 43c are preferably in the initial output pwm signal of a PWM generating unit 43a (M1R, M2R, M3R) begins, and in the one-period of this pwm signal (M1R, M2R, M3R) output pwm signal (M1R, M2R, M3R).Thus, (t1, that t2) brings influences minimum can to make the time-delay of the pwm signal (M1R, M2R, M3R) of each PWM generating unit 43a, 43b, 43c output.

Secondly, as shown in Figure 5, each PWM generating unit 43a, 43b, 43c produce the triangular wave with different phase place based on the initial signal (Start) that postpones.And each PWM generating unit 43a, 43b, 43c produce pwm signal (M1R, M2R, M3R) according to each triangular wave and the sinusoidal signal (SIG1, SIG2, SIG3) imported.At this since the time-delay of initial signal (Start) (t1, t2), the phase difference between the triangular wave that each PWM generating unit 43a, 43b, 43c are produced shows as the phase difference between the pwm signal (M1R, M2R, M3R) as shown in Figure 5.

Below, describe the pwm signal of being exported owing to each PWM generating unit 43a, 43b, 43c (M1R, M2R, M3R) in detail and have the effect that reduces noise that mutually different phase place obtains.

Generally, signal can be expressed as some harmonic waves of first-harmonic as shown in Equation 1 by Fourier transform (Fourier transform).

Formula 1:

$x\left(t\right)=x_0+\underset{N=1}{\overset{x}{\mathrm{\Σ}}}{A}_N\cos \left({\mathrm{nw}}_{0}t\right)+\underset{N=1}{\overset{\∞}{\mathrm{\Σ}}}{B}_N\sin \left({\mathrm{nw}}_{0}t\right)$

Here, the pwm signal (M1R, M2R, M3R) of each PWM generating unit 43a, 43b, 43c generation also can be expressed as suc as formula 1.

And, if the noise that is produced among each motor 50a, 50b, the 50c is respectively X1, X2, X3, then arbitrarily the noise effect of starting point by stack (Superposition) principle the noise sum that produces among each motor 50a, 50b, the 50c that becomes.At this,, then can ignore decay if the hypothesis noise is transmitted to greatest extent; With respect to the reception and registration speed of signal, (t1, t2) influence of Chan Shenging is very small, so can ignore in time-delay.

Here, if with noise X1, the X2 and the X3 addition that are produced among each motor 50a, 50b, the 50c, then because identical as the triangular wave of the first-harmonic on the pwm signal (M1R, M2R, M3R) of each motor 50a, 50b, 50c basis, thereby sine of formula 1 (sine) and cosine (cosine) item coefficient A _nAnd B _nIncrease.That is, noise increases along with the number of each motor 50a, 50b, 50c, if having the phase place different with X1 respectively according to X2 of the present invention and X3, then X2 and X3 can be expressed as shown in Equation 2.

Formula 2:

Here, if with the formula addition that phase place (phase) postpones that has in the formula 2, coefficient ratio then sinusoidal and cosine term does not have the coefficient of phase delay to reduce, if phase delay is the half-wavelength of frequency, then its coefficient is zero.

Here, as mentioned above, general signal shows as some harmonic waves of first-harmonic, thereby has the high frequency waves of first-harmonic multiple, as mentioned above, the phase difference between each pwm signal (M1R, M2R, M3R) along with some harmonic waves near high frequency waves more near the half-wavelength of some harmonic frequencies.Therefore, more little near the high frequency waves noise more.

Fig. 6 and Fig. 7 are to use motor control assembly 40 provided by the present invention before according to the power spectral density (Power Spectral Density) of frequency harmonics and the power spectral density according to frequency harmonics (the Power Spectral Density) schematic diagram of use motor control assembly 40 provided by the present invention.As shown in the figure, can know and use before the motor control assembly 40 provided by the present invention, big according to the power spectral density (Power Spectral Density) of frequency harmonics.On the contrary, bigger when 200KHz when using motor control assembly 40 provided by the present invention, be about 3.5, but after frequency harmonics in as can be seen power spectral density (Power Spectral Density) significantly reduce.

Although illustrate and represented that several embodiments of the present invention, the technical staff with common knowledge of the technical field of the invention should be appreciated that, without departing from the principles and spirit of the present invention, can change present embodiment.And scope of the present invention is according to appended claim and the decision of its equivalent.

As mentioned above, the invention provides motor control assembly and the electric machine control system that reduces the noise that produced when driving a plurality of motor to greatest extent.

Claims (7)

1, a kind of electric machine control system that is used to control a plurality of motors is characterized in that comprising:

Rectification/filtering portion is used for rectification and filtering AC power;

A plurality of inverters are used for the power conversion by described rectification/filtering portion institute's rectification and filtering is the required AC power of described each motor of driving;

Motor control assembly is used to be output as a plurality of pulse-width signals with phase place inequality of the AC power that described each inverter of control exports;

Wherein, the output starting point of pulse-width signal is delayed time and produce a plurality of pulse-width signals with phase place inequality.

2, electric machine control system according to claim 1 is characterized in that described motor control assembly comprises:

Phase control division is used to export initial signal, clock signal and sinusoidal signal;

A plurality of pulse-width modulation generating units are used for determining according to described initial signal the output starting point of described pulse-width signal, and produce described pulse-width signal based on described clock signal and described sinusoidal signal;

Time-delay portion is used to the described pulse-width signal that described each pulse-width modulation generating unit is exported to have phase place inequality, and the described initial signal that at least one pulse-width modulation generating unit in described a plurality of pulse-width modulation generating units is imported is delayed time.

3, electric machine control system according to claim 2, it is characterized in that it is the triangular wave of starting point that described pulse-width modulation generating unit produces with described initial signal based on described clock signal, and produce described pulse-width signal according to described triangular wave and described sinusoidal signal.

4, electric machine control system according to claim 3, the time difference between the described initial signal that it is characterized in that being postponed by described time-delay portion is within the one-period scope of described triangular wave.

5, a kind of generation is used to control the motor control assembly of a plurality of pulse-width signals of a plurality of motors, it is characterized in that comprising:

Phase control division is used to export initial signal, clock signal and sinusoidal signal;

A plurality of pulse-width modulation generating units are used for determining according to described initial signal the output starting point of described pulse-width signal, and produce described pulse-width signal based on described clock signal and described sinusoidal signal;

Time-delay portion is used to the described pulse-width signal that described each pulse-width modulation generating unit is exported to have phase place inequality, and the described initial signal that at least one pulse-width modulation generating unit in described a plurality of pulse-width modulation generating units is imported is delayed time.

6, motor control assembly according to claim 5, it is characterized in that it is the triangular wave of starting point that described pulse-width modulation generating unit produces with described initial signal based on described clock signal, and produce described pulse-width signal according to described triangular wave and described sinusoidal signal.

7, electric machine control system according to claim 6, the time difference between the described initial signal that it is characterized in that being postponed by described time-delay portion is within the one-period scope of described triangular wave.

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