CN106469239A - The moment of torsion of wind generating set pitch control motor determines method, selection method and device - Google Patents

Abstract

The present invention relates to the moment of torsion of wind generating set pitch control motor determines method, selection method and device, belong to technical field of wind power generation.By setting up blower fan phantom, carry out wind power generating set operating mode setting, calculate blade root moments, tilting moment, axial force, resultant radial force, power, rotating speed and pitch variable bearings acceleration；Build mathematical model, determine the frictional force of pitch variable bearings, then solve pitch variable bearings driving torque and braking torque；Pitch motor is finally selected according to pitch motor nominal drive moment of torsion, maximum drive moment and brake torque.Device includes pitch motor torque arithmetic module, pitch motor peak torque and nominal torque computing module and pitch motor type selecting module.The present invention has the advantages that principle is simple, easy to operate, high precision, reasonable selection pitch motor on the premise of ensureing the normal operation of large-scale wind electricity set pitch control system, advantageously reduce pitch-controlled system probability of malfunction and Generator Set manufacturing cost, improve the market competitiveness.

Description

The moment of torsion of wind generating set pitch control motor determines method, selection method and device

Technical field

The invention belongs to technical field of wind power generation is and in particular to a kind of moment of torsion of wind generating set pitch control motor determines Method, pitch motor selection method and device.

Background technology

Develop towards the direction of the big blade of unit Large Copacity with wind generating technology, oar system is especially become to overall design System is put forward higher requirement.Blower variable blade control system is the important component part of wind turbine control system, to machine Group safety and stability has efficiently run highly important effect；But recent pitch-controlled system Frequent Troubles, a certain wind field statistics Result shows that its probability accounts for whole machine institute faulty about 20%, and chife failure models have motor oscillating, overheated, axle fracture etc..Wherein Pitch motor directly determines the reliability of pitch-controlled system work, if blower fan cannot be put away the oars, may lead to down tower, driving etc., Cause severe safety accident, economic loss is huge.

Pitch motor driving torque and braking moment are to choose the foundation of pitch motor, therefore, select accurately to drive Dynamic torque and braking moment computational methods are most important to pitch motor type selecting.Due to the uncertainty of friction between bearings and journals power, its Impact to motor is very big, constantly needs to take into account this calculating pitch motor moment of torsion, but typically passes through at present Bladed software design patterns pitch actuator module (becoming oar executor) directly obtains pitch motor relevant parameter, does not consider Frictional force between bearing, thus wind generating set pitch control Motor torque calculates and is inaccurate, and in turn results in pitch motor type selecting Improper, so that pitch-controlled system is worked unreliable.

Content of the invention

The invention provides the moment of torsion of wind generating set pitch control motor determines method, selection method and device, to solve Existing method can not accurately calculate wind generating set pitch control Motor torque, and it is improper in turn result in pitch motor type selecting, becomes The oar system insecure problem of work.

For solving above-mentioned technical problem, the method for the present invention comprises the steps：

1) according to wind generator set blade, driving-chain, electromotor and tower parameters of operating part, set up phantom；

2) carry out wind power generating set operating mode according to fan design authentication specifications to arrange and submit calculating to, solve wind-force and send out Corresponding blade root moments M of group of motors pitch variable bearings Each point in time_z, tilting moment M_xy, axial force F_z, resultant radial force F_xy、 Power P, rotational speed omega_PWith pitch variable bearings acceleration alpha_P；

3) according to corresponding tilting moment M of Each point in time_xy, axial force F_z, resultant radial force F_xy, power P and rotational speed omega_P, Calculate Each point in time corresponding variable-paddle bearing friction power M_fic；

4) according to calculated variable-paddle bearing friction power M_fic, blade root moments M_z, power P, rotational speed omega_PAnd pitch axis Hold acceleration alpha_P, solve the driving torque M of pitch variable bearings_dtWith braking torque M_bt.

Step 3) in variable-paddle bearing friction power M_ficComputing formula be：

Wherein, D_LRaceway diameter, μ is coefficient of friction, M_preFor raceway pretightning force, T₁For Rule of judgment；Work as ω_P When >=0, T₁=1, otherwise, T₁=-1.

Step 4) in pitch variable bearings driving torque M_dtWith braking torque M_btComputing formula be respectively：

M_dt=(M_z+M_{fic_max}+M_acc)*T₂；M_bt=(M_z+M_{fic_max})*T₃

Wherein, M_{fic_max}For maximum bearing frictional force, M_accFor bearing moment of inertia, M_{fic_min}For minimum bearing friction power, T₂、T₃For Rule of judgment； Change total to pitch axis socket end for pitch variable bearings self inertia and pitch motor Rotary inertia.

As P >=0.1＆ ω_P>=0.01 or P ＜ 0.1＆ ω_PWhen >=0.01, T₂=1, otherwise, T₂=0；

Work as ω_P＜ 0.01＆ { ABS (M_z)≥M_{fic_min}When, T₃=1, otherwise, T₃=0.

Maximum bearing frictional force M_{fic_max}=A*M_fic, the span of A is 1～1.25；Minimum bearing friction power M_{fic_min} =B*M_fic, the span of B is 0.75～1.

The wind generating set pitch control choice of electrical machine method of the present invention is：Driving according to calculated pitch variable bearings is turned round Square M_dtWith braking torque M_bt, solve the maximum drive torque M of pitch motor_{mt_max}, maximum braking torque M_{mb_max}And nominal torque M_{mt_rate}；

According to maximum drive torque M_{mt_max}, maximum braking torque M_{mb_max}And nominal torque M_{mt_rate}Choose Wind turbines Pitch motor.

According to calculated nominal torque M_{mt_rate}, tentatively choose pitch motor；Next, it is determined that the preliminary change oar chosen Whether the maximum drive torque of motor is more than maximum drive torque M_{mt_max}Value of calculation, and judge the preliminary pitch motor chosen Whether maximum braking torque is more than maximum braking torque M_{mt_max}Value of calculation；Choose maximum drive torque and be more than maximum drive torque M_{mt_max}Value of calculation and maximum braking torque are more than maximum braking torque M_{mt_max}The motor of value of calculation becomes oar electricity as Wind turbines Machine, pitch motor type selecting terminates.

The maximum drive torque M of pitch motor_{mt_max}, maximum braking torque M_{mt_max}And nominal torque M_{mt_rate}Calculating public Formula is：

M_{mt_ma}X=M_{dt_max}/(i_teeth*η_teeth*i_gbx*η_gbx)

M_{mb_max}=M_{bt_max}/(i_teeth*η_teeth*i_gbx*η_gbx)

M_{mt_rate}=RMS [M_dt]/(i_teeth*η_teeth*i_gbx*η_gbx)

Wherein, i_teethFor the pitch variable bearings number of teeth or the change oar little tooth number of teeth, η_teethFor pitch variable bearings little tooth transmission efficiency, i_gbx For gear box ratio, η_gbxFor gearbox drive efficiency, RMS [M_dt] it is driving torque M_dtRoot-mean-square value.

The wind generating set pitch control choice of electrical machine device of the present invention includes pitch motor torque arithmetic module, pitch motor Peak torque and nominal torque computing module and pitch motor type selecting module；

Described pitch motor torque arithmetic module, for according to wind power generation unit blade, driving-chain, electromotor and tower part Parameter, sets up phantom；Carry out fan condition according to fan design authentication specifications and arrange and submit to calculating, solve blowing machine and become Corresponding blade root moments M of oar bearing Each point in time_Z, tilting moment M_xy, axial force F_z, resultant radial force F_xy, power P, turn Fast ω_PWith pitch variable bearings acceleration alpha_P, and then calculate Each point in time corresponding variable-paddle bearing friction power M_fic, according to being calculated Variable-paddle bearing friction power M_fic, blade root moments M_Z, power P, rotational speed omega_PWith pitch variable bearings acceleration alpha_P, solve pitch axis The driving torque M holding_dtWith braking torque M_bt；

Described pitch motor peak torque and nominal torque computing module, for the driving torque M according to pitch variable bearings_dtWith Braking torque M_bt, solve the maximum drive torque M of pitch motor_{mt_max}, maximum braking torque M_{mb_max}And nominal torque MM_{mt_rate}；

Described pitch motor type selecting module, for by pitch motor maximum drive torque, maximum braking torque and specified turn Square and maximum drive torque M_{mt_max}Value of calculation, maximum braking torque M_{mb_max}Value of calculation and nominal torque M_{mt_rate}Value of calculation is respectively Relatively, select the pitch motor of Wind turbines.

The maximum drive torque M of pitch motor_{mt_max}, maximum braking torque M_{mb_max}And nominal torque M_{mt_rate}Calculating public Formula is：

M_{mt_max}=M_{dt_max}/(i_teeth*η_teeth*i_gbx*η_gbx)

M_{mb_max}=M_{bt_max}/(i_teeth*η_teeth*i_gbx*η_gbx)

M_{mt_rate}=RMS [M_dt]/(i_teeth*η_teeth*i_gbx*η_gbx)

Wherein, i_teethFor the pitch variable bearings number of teeth or the change oar little tooth number of teeth, η_teethFor pitch variable bearings little tooth transmission efficiency, i_gbx For gear box ratio, η_gbxFor gearbox drive efficiency, RMS [M_dt] it is driving torque M_dtRoot-mean-square value

Beneficial effects of the present invention：Compared with prior art, the determination Method And Principle letter of the pitch motor moment of torsion of the present invention Single, consider the uncertainty of friction between bearings and journals power during the moment of torsion calculating pitch motor；The method result of calculation is more accurate, Ensure reasonable selection pitch motor on the premise of the normal operation of large-scale wind electricity set pitch control system, advantageously reduce pitch-controlled system event Barrier probability and Generator Set manufacturing cost and maintenance cost, improve the market competitiveness.

Brief description

Fig. 1 is that pitch motor is driven schematic diagram with bearing moment；

Fig. 2 is the calculation flow chart of wind generating set pitch control Motor torque；

In Fig. 1,1 is pitch variable bearings for pitch motor 2.

Specific embodiment

Below in conjunction with the accompanying drawings technical scheme is described in further detail.

A kind of moment of torsion of wind generating set pitch control motor of the present invention determines embodiment of the method

As shown in Fig. 2 the computational methods of the present invention comprise the steps：

1) according to wind generator set blade, driving-chain, electromotor and tower parameters of operating part, set up phantom；

2) carry out wind power generating set operating mode according to fan design authentication specifications to arrange and submit calculating to, solve wind-force and send out Corresponding blade root moments M of group of motors pitch variable bearings Each point in time_Z, tilting moment M_xy, axial force F_z, resultant radial force F_xy、 Power P, rotational speed omega_PWith pitch variable bearings acceleration alpha_P；

3) according to corresponding tilting moment M of Each point in time_xy, axial force F_z, resultant radial force F_xy, power P and rotational speed omega_P, Calculate Each point in time corresponding variable-paddle bearing friction power M_fic；

4) according to calculated variable-paddle bearing friction power M_fic, blade root moments M_z, power P, rotational speed omega_PAnd pitch axis Hold acceleration alpha_P, solve the driving torque M of pitch variable bearings_dtWith braking torque M_bt.

Below above-mentioned steps are described in detail：

For step 1), phantom is set up in Wind turbines simulation software according to Wind turbines relevant parameter, wherein Simulation software preferentially chooses bladed software, it would however also be possible to employ the mode that MATLAB is combined with bladed software is emulated, Or using emulation modes such as finite element analyses.Here relevant parameter includes the parts such as blade, driving-chain, electromotor and tower Parameter, the parameter of blade mainly includes geometry and each section aerofoil profile data of blade.

For step 2), after establishing blower fan phantom, carry out operating mode setting according to blower fan authentication specifications, thus solving Go out pitch variable bearings variable M_z、M_xy、F_z、F_xySequential load and the corresponding power P of Each point in time, propeller pitch angle θ_P, rotational speed omega_PWith Pitch variable bearings acceleration alpha_PEtc. parameter.Wherein, M_zFor blade root moments, M_xyFor tilting moment, F_zFor axial force, F_xyFor radially Make a concerted effort, blower fan authentication specifications preferably employ blower fan GL authentication specifications or IEC specification, operating mode setting includes the conditions such as wind load, gravity.

For step 3), solve each variable M of blower variable-pitch bearing_z、M_xy、F_z、F_xy、P、θ_P、ω_PAnd α_PAfterwards, utilize Each variable above-mentioned builds bearing friction power mathematical model, that is,

Using bladed Software, solves frictional force M of pitch variable bearings_fic.Wherein, D_L- raceway diameter, μ-coefficient of friction, M_xy- tilting moment, F_z- Axial force, F_xy- resultant radial force, M_pre- raceway pretightning force, T₁- Rule of judgment.M_ficComputing formula to be that ball bearing calculates public Formula, roller bearing and other type computing formula need to be determined with reference to bearing shop instruction.

Wherein, T₁The determination method of value is：Work as ω_PWhen >=0, T₁=1, otherwise, T₁=-1.

For step 4), the driving torque M of pitch variable bearings_dtWith braking torque M_btComputing formula be respectively：

M_dt=(M_z+M_{fic_max}+M_acc)*T₂；

M_bt=(M_z-M_{fic_min})*T₃

Wherein, M_{fic_max}For maximum bearing frictional force, M_accFor bearing moment of inertia, M_{fic_min}For minimum bearing friction power, T₂、T₃For Rule of judgment；

It is that pitch variable bearings self inertia and pitch motor are changed and be used to the total rotation of pitch axis socket end Amount

T₂The determination method of value is：As P >=0.1＆ ω_P>=0.01 or P ＜ 0.1＆ ω_PWhen >=0.01, T₂=1, on the contrary T₂= 0.Wherein, work as ω_PVane propeller-changing when >=0.01, otherwise the unchanged oar of blade.And, as P >=0.1＆ ω_PWhen >=0.01, wind-power electricity generation Unit connects electrical network, and electrical network direct drive pitch motor carries out becoming oar, and driving torque now is defined as M_{dt_grid}；P ＜ 0.1＆ ω_PWhen >=0.01, wind power generating set access failure electrical network, drive pitch motor to carry out becoming oar, driving now by stand-by power supply Moment of torsion is defined as M_{dt_backup}.For P and ω_PThe selection of concrete critical value can be according to the actual parameter of Wind turbines Lai really Fixed, the application preferably 0.1 and 0.01.

T₃The determination method of value is：Work as ω_P＜ 0.01＆ { ABS (M_z)≥M_{fic_min}When, T₃=1, otherwise, T₃=0.

As other embodiment, above-mentioned T₂Or T₃Value is when determining, it would however also be possible to employ propeller pitch angle θ_PWith moment of torsion or power etc. The combination condition of alternate manner is judging whether blade becomes oar；

Maximum bearing frictional force M_{fic_max}And minimum bearing friction power M_{fic_min}Calculation be：Because frictional force exists Uncertainty, Motor drive becomes maximum bearing frictional force M that need to overcome during oar_{fic_max}=A*M_fic, A typically takes 1～1.25；Electricity Machine brake stops minimum bearing friction power M that need to adopt during change oar_{fic_min}=B*M_fic, B typically takes 0.75～1.

Calculating M_btWhen, ω_PBlade unchanged oar during ＜ 0.01, as ABS (M_z)≥M_{fic_min}When need to pass through motor brake moment Keep propeller pitch angle constant, otherwise only rely on frictional force between pitch variable bearings.

When modeling for wind power generating set using bladed software, solve M_fic、M_dtUse in bladed software during moment Channel combination module can complete.

A kind of wind generating set pitch control choice of electrical machine embodiment of the method for the present invention

The present embodiment is to carry out becoming oar according to the nominal torque of pitch motor, maximum drive torque and maximum braking torque Choice of electrical machine.And nominal torque, maximum drive torque and maximum braking torque are moments of torsion according to pitch motor to calculate Arrive, therefore, the determination method of the moment of torsion of this pitch motor relating to.The present embodiment is determining the moment of torsion of pitch motor When, it is to determine that the method described in embodiment of the method to determine Motor torque using the moment of torsion of above-mentioned wind generating set pitch control motor , therefore, this determines that method can refer to above-described embodiment, just no longer elaborates here.

Determine the moment of torsion of pitch motor according to the method described above, that is, be calculated the driving torque M of pitch variable bearings_dtAnd braking Moment of torsion M_btAfterwards, the maximum drive torque M of pitch motor is calculated according to below equation_{mt_max}, maximum braking torque M_{mb_max}And it is specified Torque M_{mt_rate}：

M_{mt_max}=M_{dt_max}/(i_teeth*η_teeth*i_gbx*η_gbx)

M_{mb_ma}X=M_{bt_max}/(i_teeth*η_teeth*i_gbx*η_gbx)

M_{mt_rate}=RMS [M_dt]/(i_teeth*η_teeth*i_gbx*η_gbx)

Wherein, i_teethFor the pitch variable bearings number of teeth or the change oar little tooth number of teeth, η_teethFor pitch variable bearings little tooth transmission efficiency, i_gbx For gear box ratio, η_gbxFor gearbox drive efficiency, RMS [M_dt] it is driving torque M_dtRoot-mean-square value.

As other embodiment, determining nominal torque M_{mt_rate}When it is also possible to by meansigma methodss and other mathematics system Meter mode obtains.

According to calculated nominal torque M_{mt_rate}, tentatively choose pitch motor；Next, it is determined that the preliminary change oar chosen Whether the maximum drive torque of motor is more than maximum drive torque M_{mt_max}Value of calculation, and judge the preliminary pitch motor chosen Whether maximum braking torque is more than maximum braking torque M_{mb_max}Value of calculation；Choose maximum drive torque and be more than maximum drive torque M_{mt_max}Value of calculation and maximum braking torque are more than maximum braking torque M_{mb_max}The motor of value of calculation becomes oar electricity as Wind turbines Machine, pitch motor type selecting terminates.

A kind of wind generating set pitch control choice of electrical machine device embodiment of the present invention

This device includes pitch motor torque arithmetic module, pitch motor peak torque and nominal torque computing module and change Oar choice of electrical machine module.

Pitch motor torque arithmetic module, for joining according to wind power generation unit blade, driving-chain, electromotor and tower part Number, sets up phantom；Carry out fan condition according to fan design authentication specifications to arrange and submit calculating to, solve blower variable-pitch Corresponding blade root moments M of bearing Each point in time_Z, tilting moment M_xy, axial force F_z, resultant radial force F_xy, power P, rotating speed ω_PWith pitch variable bearings acceleration alpha_P, and then calculate Each point in time corresponding variable-paddle bearing friction power M_fic, according to calculated Variable-paddle bearing friction power M_fic, blade root moments M_Z, power P, rotational speed omega_PWith pitch variable bearings acceleration alpha_P, solve pitch variable bearings Driving torque M_dtWith braking torque M_bt.

Pitch motor peak torque and nominal torque computing module, for the driving torque M according to pitch variable bearings_dtAnd braking Moment of torsion M_bt, solve the maximum drive torque M of pitch motor_{mt_max}, maximum braking torque M_{mb_max}And nominal torque M_{mt_rate}.

Pitch motor type selecting module, for by pitch motor maximum drive torque, maximum braking torque and nominal torque with Maximum drive torque M_{mt_max}Value of calculation, maximum braking torque M_{mb_max}Value of calculation and nominal torque M_{mt_rate}Value of calculation respectively than Relatively, select the pitch motor of Wind turbines.

Wherein, pitch motor torque determination module, pitch motor peak torque and nominal torque computing module and change oar electricity The concrete operating principle of machine type selecting module can also with reference to above wind generating set pitch control choice of electrical machine embodiment of the method and The moment of torsion of wind generating set pitch control motor determines embodiment of the method, no longer introduces one by one here.

Claims (10)

1. a kind of moment of torsion of wind generating set pitch control motor determines method it is characterised in that the method comprises the steps：

1) according to wind generator set blade, driving-chain, electromotor and tower parameters of operating part, set up phantom；

2) carry out wind power generating set operating mode according to fan design authentication specifications to arrange and submit calculating to, solve wind-driven generator Group corresponding blade root moments M of pitch variable bearings Each point in time_z, tilting moment M_xy, axial force F_z, resultant radial force F_xy, power P, rotational speed omega_PWith pitch variable bearings acceleration alpha_P；

3) according to corresponding tilting moment M of Each point in time_xy, axial force F_z, resultant radial force F_xy, power P and rotational speed omega_P, calculate Each point in time corresponding variable-paddle bearing friction power M_fic；

4) according to calculated variable-paddle bearing friction power M_fic, blade root moments M_z, power P, rotational speed omega_PWith pitch variable bearings plus Speed alpha_P, solve the driving torque M of pitch variable bearings_dtWith braking torque M_bt.

2. the moment of torsion of wind generating set pitch control motor determines method it is characterised in that step 3 according to claim 1) in Variable-paddle bearing friction power M_ficComputing formula be：

$M_{fic}=\left(\frac{\mathrm{\μ}}{2}\right(4.4*M_{xy}+D_L*\left|F_z\right|+2.2*F_{xy}*D_L*1.73)+M_{pre})*T_1$

Wherein, D_LRaceway diameter, μ is coefficient of friction, M_preFor raceway pretightning force, T₁For Rule of judgment；Work as ω_P≥0 When, T₁=1, otherwise, T₁=-1.

3. the moment of torsion of wind generating set pitch control motor determines method it is characterised in that step 4 according to claim 2) in The driving torque M of pitch variable bearings_dtWith braking torque M_btComputing formula be respectively：

M_dt=(M_z+M_{fic_max}+M_acc)*T₂；M_bt=(M_z-M_{fic_min})*T₃

Wherein, M_{fic_max}For maximum bearing frictional force, M_accFor bearing moment of inertia, M_{fic_min}For minimum bearing friction power, T₂、T₃ For Rule of judgment； It is that pitch variable bearings self inertia and pitch motor are changed to total the turning of pitch axis socket end Dynamic inertia.

4. according to claim 3 the moment of torsion of wind generating set pitch control motor determine method it is characterised in that when P >= 0.1&ω_P>=0.01 or P ＜ 0.1＆ ω_PWhen >=0.01, T₂=1, otherwise, T₂=0；

Work as ω_P＜ 0.01＆ { ABS (M_z)≥M_{fic_min}When, T₃=1, otherwise, T₃=0.

5. the moment of torsion of wind generating set pitch control motor determines method it is characterised in that maximum bearing according to claim 3 Frictional force M_{fic_max}=A*M_fic, the span of A is 1～1.25；Minimum bearing friction power M_{fic_min}=B*M_fic, the value model of B Enclose for 0.75～1.

6. a kind of wind generating set pitch control choice of electrical machine method determining method using the arbitrary described moment of torsion of claim 1-5, It is characterized in that, according to the driving torque M of calculated pitch variable bearings_dtWith braking torque M_bt, solve the maximum of pitch motor Driving torque M_{mt_max}, maximum braking torque M_{mb_max}And nominal torque M_{mt_rate}；

According to maximum drive torque M_{mt_max}, maximum braking torque M_{mb_max}And nominal torque M_{mt_rate}Choose the change oar of Wind turbines Motor.

7. according to claim 6 wind generating set pitch control choice of electrical machine method it is characterised in that according to calculated Nominal torque M_{mt_rate}, tentatively choose pitch motor；Next, it is determined that whether the maximum drive torque of the preliminary pitch motor chosen More than maximum drive torque M_{mt_max}Value of calculation, and judge the maximum braking torque of the preliminary pitch motor chosen whether more than Big braking torque M_{mb_max}Value of calculation；Choose maximum drive torque and be more than maximum drive torque M_{mt_max}Value of calculation and maximum braking torsion Square is more than maximum braking torque M_{mb_max}The motor of value of calculation terminates as Wind turbines pitch motor, pitch motor type selecting.

8. according to claim 6 wind generating set pitch control choice of electrical machine method it is characterised in that the maximum of pitch motor Driving torque M_{mt_max}, maximum braking torque M_{mb_max}And nominal torque M_{mt_rate}Computing formula be：

M_{mt_max}=M_{dt_max}/(i_teeth*η_teeth*i_gbx*η_gbx)

M_{mb_max}=M_{bt_max}/(i_teeth*η_teeth*i_gbx*η_gbx)

M_{mt_rate}=RMS [M_dt]/(i_teeth*η_teeth*i_gbx*η_gbx)

Wherein, i_teethFor the pitch variable bearings number of teeth or the change oar little tooth number of teeth, η_teethFor pitch variable bearings little tooth transmission efficiency, i_gbxFor tooth Roller box gear ratio, η_gbxFor gearbox drive efficiency, RMS [M_dt] it is driving torque M_dtRoot-mean-square value.

9. a kind of wind generating set pitch control choice of electrical machine device is it is characterised in that this device includes pitch motor torque arithmetic Module, pitch motor peak torque and nominal torque computing module and pitch motor type selecting module；

Described pitch motor torque arithmetic module, for joining according to wind power generation unit blade, driving-chain, electromotor and tower part Number, sets up phantom；Carry out fan condition according to fan design authentication specifications to arrange and submit calculating to, solve blower variable-pitch Corresponding blade root moments M of bearing Each point in time_z, tilting moment M_xy, axial force F_z, resultant radial force F_xy, power P, rotating speed ω_PWith pitch variable bearings acceleration alpha_P, and then calculate Each point in time corresponding variable-paddle bearing friction power M_fic, according to calculated Variable-paddle bearing friction power M_fic, blade root moments M_z, power P, rotational speed omega_PWith pitch variable bearings acceleration alpha_P, solve pitch variable bearings Driving torque M_dtWith braking torque M_bt；

Described pitch motor peak torque and nominal torque computing module, for the driving torque M according to pitch variable bearings_dtAnd braking Moment of torsion M_bt, solve the maximum drive torque M of pitch motor_{mt_max}, maximum braking torque M_{mb_max}And nominal torque M_{mt_rate}；

Described pitch motor type selecting module, for by pitch motor maximum drive torque, maximum braking torque and nominal torque with Maximum drive torque M_{mt_max}Value of calculation, maximum braking torque M_{mb_max}Value of calculation and nominal torque M_{mt_rate}Value of calculation respectively than Relatively, select the pitch motor of Wind turbines.

10. according to claim 9 wind generating set pitch control choice of electrical machine device it is characterised in that pitch motor Big driving torque M_{mb_max}, maximum braking torque M_{mb_max}And nominal torque M_{mt_rate}Computing formula be：

M_{mt_max}=M_{dt_max}/(i_teeth*η_teeth*i_gbx*η_gbx)

M_{mb_max}=M_{bt_max}/(i_teeth*η_teeth*i_gbx*η_gbx)

M_{mt_rate}=RMS [M_dt]/(i_teeth*η_teeth*i_gbx*η_gbx)

Wherein, i_teethFor the pitch variable bearings number of teeth or the change oar little tooth number of teeth, η_teethFor pitch variable bearings little tooth transmission efficiency, i_gbxFor tooth Roller box gear ratio, η_gbxFor gearbox drive efficiency, RMS [M_dt] it is driving torque M_dtRoot-mean-square value.