CN104539200A - Rotating speed controller of motor, and rotating speed control method of motor - Google Patents

Abstract

Disclosed in the invention is a rotating speed controller of a motor. The rotating speed controller comprises: a detection module, which is used for detecting a current rotating speed of a motor; a switch component calculation module, which is used for carrying out calculation to obtain a switch component of the rotating speed controller according to the current rotating speed of the motor, the target rotating speed of the motor, and an external disturbance quantity calculated in advance; a continuous component calculation module, which is used for carrying out calculation based on a preset formula to obtain a continuous component of the rotating speed controller; and a torque output module, which is used for calculating a sum of the switch component and the continuous component of the rotating speed controller, and obtaining an electromagnetic reference torque of the motor and outputting the electromagnetic reference torque. In addition, the invention also discloses a rotating speed control method of a motor. Therefore, the rotating speed controller has the wider bandwidth than the traditional variable structure controller and has the high robustness for the parameter or external disturbance.

Description

The rotational speed governor of motor, the method for controlling number of revolution of motor

Technical field

The present invention relates to Motor Control Field, particularly relate to the method for controlling number of revolution of motor speed controller, motor.

Background technology

Especially in SERVO CONTROL occasion in permagnetic synchronous motor controls, require that rotational speed governor has wider bandwidth, to follow the tracks of rotary speed instruction signal quickly and accurately.Under motor exists electric parameter disturbance and random perturbation condition, require that rotating-speed tracking performance is not subject to the impact of above-mentioned disturbance or can recovers quickly under disturbed conditions, namely to disturbance, there is the features such as strong robustness.

In existing rotational speed governor, PI controller based on uneoupled control principle is widely used, as long as because just can meet the demands PI controller bandwidth Design enough greatly, but affect by rotational speed governor saturation effect, rotational speed governor bandwidth is very restricted, thus causes rotating-speed tracking error.In addition, in motor operation course, the mechanical parameter of motor can change with the change of different operating condition condition as moment of inertia and the coefficient of viscosity, load torque, by the impact of above-mentioned factor, adopts traditional PI controller can reduce the control performance of motor.

Summary of the invention

Main purpose of the present invention is the method for controlling number of revolution providing a kind of motor speed controller and motor, is intended to make this rotational speed governor have the bandwidth wider than traditional variable-structure controller, and to parameter or external disturbance strong robustness.

For achieving the above object, the invention provides a kind of rotational speed governor of motor, comprising:

Detection module, for detecting the current rotating speed of motor;

Switching components computing module, for rotating speed, the rotating speed of target of motor, the precalculated external disturbance amount current according to described motor, calculates the switching components obtaining rotational speed governor;

Continuous component computing module, for obtaining the continuous component of rotational speed governor according to the formulae discovery preset;

Torque output module, for calculate the switching components of described rotational speed governor and continuous component and, obtain the electromagnetism torque reference of motor, and export this electromagnetism torque reference.

Preferably, described switching components computing module comprises:

Interference acquiring unit, the motor speed that rotating speed of target and described detection module for obtaining rotational speed governor detect, calculates the error x of described motor speed and rotating speed of target;

Sliding-mode surface obtains unit, for the error x according to described motor speed and rotating speed of target, generates the sliding-mode surface s of rotational speed governor;

Symbol processing unit, for carrying out Symbol processing to described sliding-mode surface s, to add symbol to described sliding-mode surface s;

Gain processing unit, for the sliding-mode surface s after interpolation symbol and precalculated gain being processed, obtains the switching components of rotational speed governor.

Preferably, described precalculated gain k _tefor: k _te=-(| d| _max+ δ), wherein δ is just little constant, and d is the external disturbance amount of rotational speed governor.

Preferably, the continuous component T in described continuous component computing module _eeqcomputing formula is:

$\begin{array}{c}{T}_{\mathrm{eeq}}=B_{\mathrm{rN}}\mathrm{\ω}+T_{\mathrm{lN}}+J_N\frac{{\mathrm{d\ω}}^{*}}{\mathrm{dt}}-J_N{c}_1{x}_{\mathrm{\ω}}\\ =(B_{\mathrm{rN}}-J_N{c}_1)x_{\mathrm{\ω}}+J_N\frac{{\mathrm{d\ω}}^{*}}{\mathrm{dt}}+B_{\mathrm{rN}}{\mathrm{\ω}}^{*}+T_{\mathrm{lN}}\end{array}$

Wherein, B _rNfor coefficient of viscosity rated value; J _nfor mechanical inertia rated value; T _lNfor load torque rated value; c ₁for the constant preset; ω ^*for rotating speed of target; x _ωfor the error between current rotating speed and rotating speed of target.

In addition, for achieving the above object, present invention also offers a kind of method for controlling number of revolution of motor, comprise the following steps:

Detect the rotating speed that motor is current;

According to rotating speed of target and the precalculated external disturbance amount of the current rotating speed of described motor, motor, calculate the switching components obtaining this rotational speed governor;

The continuous component of rotational speed governor is obtained according to the formulae discovery preset;

Calculate the switching components of described rotational speed governor and continuous component and, obtain motor electromagnetic torque reference, and export this torque reference.

Preferably, the rotating speed of target of the described rotating speed current according to described motor, motor and precalculated external disturbance amount, calculate the switching components obtaining this rotational speed governor and comprise:

The motor speed that the rotating speed of target of acquisition rotational speed governor and described detection module detect, calculates the error x of described motor speed and rotating speed of target;

According to the error x of described motor speed and rotating speed of target, generate the sliding-mode surface s of rotational speed governor;

Symbol processing is carried out to described sliding-mode surface s, to add symbol to described sliding-mode surface s;

Sliding-mode surface s after interpolation symbol and precalculated gain are processed, obtains the switching components of rotational speed governor.

Preferably, described precalculated gain k _tefor: k _te=-(| d| _max+ δ), wherein δ is just little constant, and d is the external disturbance amount of the motor speed controller pre-set.

Preferably, described continuous component T _eeqcomputing formula be:

$\begin{array}{c}{T}_{\mathrm{eeq}}=B_{\mathrm{rN}}\mathrm{\ω}+T_{\mathrm{lN}}+J_N\frac{{\mathrm{d\ω}}^{*}}{\mathrm{dt}}-J_N{c}_1{x}_{\mathrm{\ω}}\\ =(B_{\mathrm{rN}}-J_N{c}_1)x_{\mathrm{\ω}}+J_N\frac{{\mathrm{d\ω}}^{*}}{\mathrm{dt}}+B_{\mathrm{rN}}{\mathrm{\ω}}^{*}+T_{\mathrm{lN}}\end{array}$

Wherein, B _rNfor coefficient of viscosity rated value; J _nfor mechanical inertia rated value; T _lNfor load torque rated value; c ₁for the constant preset; ω ^*for rotating speed of target; x _ωfor the error between current rotating speed and rotating speed of target.

The present invention is by controlling rotational speed governor compute switch component and continuous component respectively, and the random perturbation of switching components and mechanical parameter disturbance, load torque disturbance and system is relevant, continuous component by with electromechanics parameter rated value (such as, moment of inertia, the coefficient of viscosity) and torque at rated load correlation function obtain, thus make this rotational speed governor have the wider bandwidth of traditional variable-structure controller, and to parameter or external disturbance strong robustness.

Accompanying drawing explanation

Fig. 1 is the high-level schematic functional block diagram of the rotational speed governor of motor of the present invention;

Fig. 2 is the switching components computing module of the rotational speed governor of motor in the present invention and the structural representation of continuous component computing module;

Fig. 3 is the schematic flow sheet of the method for controlling number of revolution of motor of the present invention;

Fig. 4 is the refinement schematic flow sheet calculating switching components in the method for controlling number of revolution of motor of the present invention.

The realization of the object of the invention, functional characteristics and advantage will in conjunction with the embodiments, are described further with reference to accompanying drawing.

Embodiment

Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.

Core concept of the present invention is: by controlling rotational speed governor output switch component and continuous component respectively, and the random perturbation of switching components and mechanical parameter disturbance, load torque disturbance and system is relevant, continuous component by with electromechanics parameter rated value (such as, moment of inertia, the coefficient of viscosity) and torque at rated load correlation function obtain, thus make this rotational speed governor have the wider bandwidth of traditional variable-structure controller, and to parameter or external disturbance strong robustness.

As shown in Figure 1, the structural representation of rotational speed governor of the present invention is shown.This rotational speed governor comprises detection module 110, switching components computing module 120, continuously component computing module 130 and voltage output module 140.Wherein detection module 110 is for detecting the current rotating speed of motor; Switching components computing module 120, for the rotating speed of target according to the current rotating speed of described motor and motor, calculates the switching components obtaining this rotational speed governor; Continuous component computing module 130 obtains the continuous component of rotational speed governor according to the formulae discovery preset; Described torque output module 140 calculate the switching components of described rotational speed governor and continuous component and, obtain the electromagnetism torque reference of motor, and export this electromagnetism torque reference.The disturbance of the switching components that wherein said switching components computing module 120 calculates and mechanical parameter disturbance, load torque disturbance and outside is relevant, described continuous component computing module 130 formula preset carried out when continuous component calculates is the correlation function with electromechanics parameter rated value (such as, moment of inertia, the coefficient of viscosity) and torque at rated load.

The present invention is by controlling rotational speed governor compute switch component and continuous component respectively, and the random perturbation of switching components and mechanical parameter disturbance, load torque disturbance and system is relevant, continuous component by with electromechanics parameter rated value (such as, moment of inertia, the coefficient of viscosity) and torque at rated load correlation function obtain, thus make this rotational speed governor have the wider bandwidth of traditional variable-structure controller, and to parameter or external disturbance strong robustness.

Due in rotational speed governor, the change along with different operating condition conditions, when being subject to the affecting of the factors such as load, changes by the moment of inertia of motor, the coefficient of viscosity, load torque.Therefore, consider the disturbance of mechanical parameter disturbance, load torque disturbance and outside, the account form of the electromagnetic torque of motor will make corresponding changes, as follows:

$T_e=J_N\frac{\mathrm{d\ω}}{\mathrm{dt}}+B_{\mathrm{rN}}\mathrm{\ω}+T_{\mathrm{lN}}+d$

Wherein, J _nfor mechanical inertia rated value; B _rNfor coefficient of viscosity rated value; T _lNfor load torque rated value; D is disturbance quantity.This disturbance quantity will be obtained by following formulae discovery:

$d=\mathrm{\ΔJ}\frac{\mathrm{d\ω}}{\mathrm{dt}}+\mathrm{\Δ}{B}_r\mathrm{\ω}+\mathrm{\Δ}{T}_{\mathrm{lN}}+\mathrm{\ϵ}$

Wherein, Δ J is moment of inertia disturbance quantity; Δ B _rfor coefficient of viscosity disturbance quantity; Δ T _lNfor load torque disturbance quantity; ε is the disturbance of the non-modeling of motor movement equation.

The following specifically describes the design process of above-mentioned rotational speed governor:

First, definition status variable x _ωtracking error between actual speed and rotating speed of target:

x _ω＝ω-ω ^*

Then, according to this tracking error x _ω, the sliding-mode surface of definition control system:

$s=x_{\mathrm{\ω}}+c_1{\∫}_{-\∞}^t{x}_{\mathrm{\ω}}\mathrm{dt}=0$

Rotational speed governor control objectives be make state variable x _ωin finite time, arrive the sliding-mode surface of control system, and remain on sliding-mode surface and run.

As state variable x _ωwhen operating on this sliding-mode surface, its dynamic variation characteristic retrains by following first-order dynamic equation:

$\stackrel{\·}{x}=-c_{1}x$

Wherein, c ₁>0.As from the foregoing, when t is tending towards infinity, rotating-speed tracking error x _ωconverge on zero, c ₁size can affect rotating-speed tracking error x _ωconvergence efficiency.

In order to state of a control variable x _ωtrack operates on system sliding-mode surface defined above, by the torque reference that definition rotational speed governor exports as follows:

$T_e^{*}=T_{\mathrm{eeq}}+k_{\mathrm{Te}}\mathrm{sgn}\left(s\right)$

In order to determine that rotating speed controls to export the T of continuous component _eeqexpression formula and turn off gain k _tespan, employing Lyapunov stability criterion is carried out design speed controller.According to the definition of above-mentioned sliding-mode surface, its Lyapunov equation is as follows:

$V=\frac{1}{2}{s}^2$

Carry out differentiate to above-mentioned Lyapunov equation, the results obtained are as follows:

$\begin{array}{c}\stackrel{\·}{V}=s\stackrel{\·}{s}\\ =s({\stackrel{\·}{x}}_{\mathrm{\ω}}+c_1{x}_{\mathrm{\ω}})\\ =s(\frac{\mathrm{d\ω}}{\mathrm{dt}}-\frac{d\stackrel{*}{\mathrm{\ω}}}{\mathrm{dt}}+c_1{x}_{\mathrm{\ω}})\end{array}$

Computing formula from above-mentioned electromagnetic torque:

$\frac{\mathrm{d\ω}}{\mathrm{dt}}=\frac{1}{J_N}(T_e-B_{\mathrm{rN}}\mathrm{\ω}-T_{\mathrm{lN}}-d)$

This rotating speed is substituted in the differentiate function of Lyapunov equation the result of time differentiate, can obtain:

$\stackrel{\·}{V}=s[\frac{1}{J_N}(T_e-T_{\mathrm{rN}}-B_{\mathrm{rN}}\mathrm{\ω}-d)-\frac{d\stackrel{*}{\mathrm{\ω}}}{\mathrm{dt}}+c_1{x}_{\mathrm{\ω}}]$

And $T_e^{*}=T_{\mathrm{eeq}}+k_{\mathrm{Te}}\mathrm{sgn}\left(s\right)$

Therefore, $\stackrel{\·}{V}=s[\frac{1}{J_N}(T_{\mathrm{eeq}}+k_{\mathrm{Te}}\mathrm{sgn}\left(s\right){-T}_{\mathrm{rN}}-B_{\mathrm{rN}}\mathrm{\ω}-d)-\frac{d\stackrel{*}{\mathrm{\ω}}}{\mathrm{dt}}+c_1{x}_{\mathrm{\ω}}]$

Suppose T _eeqcomputing formula as follows:

$\begin{array}{c}{T}_{\mathrm{eeq}}=B_{\mathrm{rN}}\mathrm{\ω}+T_{\mathrm{lN}}+J_N\frac{{\mathrm{d\ω}}^{*}}{\mathrm{dt}}-J_N{c}_1{x}_{\mathrm{\ω}}\\ =(B_{\mathrm{rN}}-J_N{c}_1)x_{\mathrm{\ω}}+J_N\frac{{\mathrm{d\ω}}^{*}}{\mathrm{dt}}+B_{\mathrm{rN}}{\mathrm{\ω}}^{*}+T_{\mathrm{lN}}\end{array}$

By T _eeqthe above-mentioned Lyapunov equation of substitution differentiate function in, finally obtain:

$\begin{array}{c}\stackrel{\·}{V}=s\stackrel{\·}{s}\\ =\frac{1}{J_N}s(k_{\mathrm{Te}}\mathrm{sgn}\left(s\right)-d)\end{array}$

From this formula, work as k _tewhen meeting the following conditions,

$\left\{\begin{array}{cc}{k}_{\mathrm{Te}}<d,& s>0\\ k_{\mathrm{Te}}<-d,& s<0\end{array}\right.$

Namely meet Lyapunov stability criterion, rotational speed governor has good convergence.

In summary, as shown in Figure 2, above-mentioned rotational speed governor breaker in middle component computing module 120 can comprise:

Interference acquiring unit 121, the motor speed that rotating speed of target and described detection module 110 for obtaining rotational speed governor detect, calculates the error x of described motor speed and rotating speed of target _ω;

Sliding-mode surface obtains unit 122, for the error x according to described motor speed and rotating speed of target _ω, generate the sliding-mode surface s of rotational speed governor;

Symbol processing unit 123, for carrying out Symbol processing to described sliding-mode surface s, to add symbol to described sliding-mode surface s;

Gain processing unit 124, for the sliding-mode surface s after interpolation symbol and precalculated gain being processed, obtains the switching components of rotational speed governor.

Interference acquiring unit 121, for obtaining the rotating speed interference of rotational speed governor inside, namely calculates the error x of described motor speed and rotating speed of target _ω.Sliding-mode surface obtains unit 122 by the error x of motor speed and rotating speed of target _ωsubstitute into this formula in, the sliding-mode surface s obtaining rotational speed governor can be calculated.Then, Symbol processing unit 123 couples of sliding-mode surface s carry out Symbol processing, i.e. sgn (s), as s>0, and sgn (s)=1; As s=0, sgn (s)=0; As s<0, sgn (s)=-1.Gain processing unit 124, by sgn (s) and precalculated gain k process, obtains the switching components of rotational speed governor.This precalculated gain k _tefor: k _te=-(| d| _max+ δ)

Wherein, δ is just little constant, and d is the external disturbance amount of rotational speed governor.

In addition, the computing formula in the continuous component computing module of rotational speed governor is:

$\begin{array}{c}{T}_{\mathrm{eeq}}=B_{\mathrm{rN}}\mathrm{\&omega;}+T_{\mathrm{lN}}+J_N\frac{{\mathrm{d\&omega;}}^{*}}{\mathrm{dt}}-J_N{c}_1{x}_{\mathrm{\&omega;}}\\ =(B_{\mathrm{rN}}-J_N{c}_1)x_{\mathrm{\&omega;}}+J_N\frac{{\mathrm{d\&omega;}}^{*}}{\mathrm{dt}}+B_{\mathrm{rN}}{\mathrm{\&omega;}}^{*}+T_{\mathrm{lN}}\end{array}$

Wherein, B _rNfor coefficient of viscosity rated value; J _nfor mechanical inertia rated value; T _lNfor load torque rated value; c ₁for the constant preset; ω ^*for rotating speed of target; x _ωfor the error between current rotating speed and rotating speed of target.

Accordingly, the invention allows for a kind of method for controlling number of revolution of motor.As shown in Figure 3, the method for controlling number of revolution of the motor of the embodiment of the present invention comprises the following steps:

The rotating speed that step S110, detection motor are current;

Step S120, rotating speed of target according to the current rotating speed of described motor and motor, calculate the switching components obtaining this rotational speed governor;

The formulae discovery that step S130, basis are preset obtains the continuous component of rotational speed governor;

Step S140, calculate described rotational speed governor switching components and continuously component and, obtain motor electromagnetic torque reference, and export this torque reference.

The disturbance of the switching components that wherein said switching components computing module 120 calculates and mechanical parameter disturbance, load torque disturbance and outside is relevant, described continuous component computing module 130 formula preset carried out when continuous component calculates is the correlation function with electromechanics parameter rated value (such as, moment of inertia, the coefficient of viscosity) and torque at rated load.

The present invention is by controlling rotational speed governor compute switch component and continuous component respectively, and the random perturbation of switching components and mechanical parameter disturbance, load torque disturbance and system is relevant, continuous component by with electromechanics parameter rated value (such as, moment of inertia, the coefficient of viscosity) and torque at rated load correlation function obtain, thus make this rotational speed governor have the wider bandwidth of traditional variable-structure controller, and to parameter or external disturbance strong robustness.

Further, as shown in Figure 4, above-mentioned steps S120 comprises:

The motor speed that step S121, the rotating speed of target obtaining rotational speed governor and described detection module detect, calculates the error x of described motor speed and rotating speed of target _ω;

Step S122, error x according to described motor speed and rotating speed of target _ω, generate the sliding-mode surface s of rotational speed governor;

Step S123, Symbol processing is carried out to described sliding-mode surface s, to add symbol to described sliding-mode surface s;

Step S124, to process adding the sliding-mode surface s after symbol with precalculated gain, the switching components of acquisition rotational speed governor.

First, obtain the rotating speed interference of rotational speed governor inside, namely calculate the error x of described motor speed and rotating speed of target _ω, by the error x of motor speed and rotating speed of target _ωsubstitute into this formula in, the sliding-mode surface s obtaining rotational speed governor can be calculated.Then, Symbol processing is carried out to sliding-mode surface s, i.e. sgn (s), as s>0, sgn (s)=1; As s=0, sgn (s)=0; As s<0, sgn (s)=-1.Finally, by sgn (s) and precalculated gain k process, obtain the switching components of rotational speed governor.This precalculated gain k _dfor: k _d=-(| f _d| _max+ δ)

Wherein, δ is just little constant, and d is the external disturbance amount of rotational speed governor.

Further, the continuous component T of described rotational speed governor _eeqcomputing formula is:

$\begin{array}{c}{T}_{\mathrm{eeq}}=B_{\mathrm{rN}}\mathrm{\&omega;}+T_{\mathrm{lN}}+J_N\frac{{\mathrm{d\&omega;}}^{*}}{\mathrm{dt}}-J_N{c}_1{x}_{\mathrm{\&omega;}}\\ =(B_{\mathrm{rN}}-J_N{c}_1)x_{\mathrm{\&omega;}}+J_N\frac{{\mathrm{d\&omega;}}^{*}}{\mathrm{dt}}+B_{\mathrm{rN}}{\mathrm{\&omega;}}^{*}+T_{\mathrm{lN}}\end{array}$

Wherein, B _rNfor coefficient of viscosity rated value; J _nfor mechanical inertia rated value; T _lNfor load torque rated value; c ₁for the constant preset; ω ^*for rotating speed of target; x _ωfor the error between current rotating speed and rotating speed of target.

These are only the preferred embodiments of the present invention; not thereby the scope of the claims of the present invention is limited; every utilize specification of the present invention and accompanying drawing content to do equivalent structure or equivalent flow process conversion; or be directly or indirectly used in other relevant technical fields, be all in like manner included in scope of patent protection of the present invention.

Claims (8)

1. a rotational speed governor for motor, is characterized in that, the rotational speed governor of described motor comprises:

Detection module, for detecting the current rotating speed of motor;

Switching components computing module, for rotating speed, the rotating speed of target of motor, the precalculated external disturbance amount current according to described motor, calculates the switching components obtaining rotational speed governor;

Continuous component computing module, for obtaining the continuous component of rotational speed governor according to the formulae discovery preset;

Torque output module, for calculate the switching components of described rotational speed governor and continuous component and, obtain the electromagnetism torque reference of motor, and export this electromagnetism torque reference.

2. the rotational speed governor of motor as claimed in claim 1, it is characterized in that, described switching components computing module comprises:

Interference acquiring unit, the motor speed that rotating speed of target and described detection module for obtaining rotational speed governor detect, calculates the error x of described motor speed and rotating speed of target;

Sliding-mode surface obtains unit, for the error x according to described motor speed and rotating speed of target, generates the sliding-mode surface s of rotational speed governor;

Symbol processing unit, for carrying out Symbol processing to described sliding-mode surface s, to add symbol to described sliding-mode surface s;

Gain processing unit, for the sliding-mode surface s after interpolation symbol and precalculated gain being processed, obtains the switching components of rotational speed governor.

3. the rotational speed governor of motor as claimed in claim 2, is characterized in that, described precalculated gain k _tefor: k _te=-(| d| _max+ δ), wherein δ is just little constant, and d is the external disturbance amount of rotational speed governor.

4. the rotational speed governor of motor as claimed in claim 1, is characterized in that, the continuous component T in described continuous component computing module _eeqcomputing formula is:

$\begin{array}{c}{T}_{\mathrm{eeq}}=B_{\mathrm{rN}}\mathrm{\&omega;}+Y_{\mathrm{lN}}+J_N\frac{{\mathrm{d\&omega;}}^{*}}{\mathrm{dt}}-J_N{c}_1{x}_{\mathrm{\&omega;}}\\ =(B_{\mathrm{rN}}-J_N{c}_1)x_{\mathrm{\&omega;}}+J_N\frac{{\mathrm{d\&omega;}}^{*}}{\mathrm{dt}}+B_{\mathrm{rN}}{\mathrm{\&omega;}}^{*}+T_{\mathrm{lN}}\end{array}$

Wherein, B _rNfor coefficient of viscosity rated value; J _nfor mechanical inertia rated value; T _lNfor load torque rated value; c ₁for the constant preset; ω ^*for rotating speed of target; x _ωfor the error between current rotating speed and rotating speed of target.

5. a method for controlling number of revolution for motor, is characterized in that, the method for controlling number of revolution of described motor comprises the following steps:

Detect the rotating speed that motor is current;

According to rotating speed of target and the precalculated external disturbance amount of the current rotating speed of described motor, motor, calculate the switching components obtaining this rotational speed governor;

The continuous component of rotational speed governor is obtained according to the formulae discovery preset;

Calculate the switching components of described rotational speed governor and continuous component and, obtain motor electromagnetic torque reference, and export this torque reference.

6. the method for controlling number of revolution of motor as claimed in claim 5, is characterized in that, the rotating speed of target of the described rotating speed current according to described motor, motor and precalculated external disturbance amount, calculates the switching components obtaining this rotational speed governor and comprises:

The motor speed that the rotating speed of target of acquisition rotational speed governor and described detection module detect, calculates the error x of described motor speed and rotating speed of target;

According to the error x of described motor speed and rotating speed of target, generate the sliding-mode surface s of rotational speed governor;

Symbol processing is carried out to described sliding-mode surface s, to add symbol to described sliding-mode surface s;

Sliding-mode surface s after interpolation symbol and precalculated gain are processed, obtains the switching components of rotational speed governor.

7. the method for controlling number of revolution of motor as claimed in claim 6, is characterized in that, described precalculated gain k _tefor: k _te=-(| d| _max+ δ), wherein δ is just little constant, and d is the external disturbance amount of the motor speed controller pre-set.

8. the method for controlling number of revolution of motor as claimed in claim 5, is characterized in that, described continuous component T _eeqcomputing formula be:

$\begin{array}{c}{T}_{\mathrm{eeq}}=B_{\mathrm{rN}}\mathrm{\&omega;}+Y_{\mathrm{lN}}+J_N\frac{{\mathrm{d\&omega;}}^{*}}{\mathrm{dt}}-J_N{c}_1{x}_{\mathrm{\&omega;}}\\ =(B_{\mathrm{rN}}-J_N{c}_1)x_{\mathrm{\&omega;}}+J_N\frac{{\mathrm{d\&omega;}}^{*}}{\mathrm{dt}}+B_{\mathrm{rN}}{\mathrm{\&omega;}}^{*}+T_{\mathrm{lN}}\end{array}$

Wherein, B _rNfor coefficient of viscosity rated value; J _nfor mechanical inertia rated value; T _lNfor load torque rated value; c ₁for the constant preset; ω ^*for rotating speed of target; x _ωfor the error between current rotating speed and rotating speed of target.