CN101344073A - Variable-speed constant-frequency apparatus of wind generator set - Google Patents

Abstract

The invention discloses a variable speed constant frequency device for a wind power generation unit, which comprises a planetary gear transmission and a rotating speed adjusting device, wherein, the planetary gear transmission is provided with a sun wheel, a planet carrier, and rotatable annular gears which form three concentric rotating shafts; the three concentric rotating shafts are respectively connected with a wind wheel, a generator rotor and the rotating speed adjusting device randomly and correspondingly; the rotating speed adjusting device is a DC motor speed regulating device or an AC motor variable frequency speed regulating device, and the wind wheel is provided with a speeder. The invention is a mechanical device with low manufacturing cost, and can replace the transducer with high price, thus greatly reducing the manufacturing cost of the unit; the invention has the advantages of simple structure, low failure rate, safe and reliable operation, wide speed regulating range, strong adaptive capacity to the wind speed, full utilization of the wind energy, good economical efficiency of the unit, high transmission efficiency and remarkably reduced self energy consumption of the unit; the wind power generation unit adopting the device can use a power frequency synchronous generator without harmonic pollution, leads the unit to obtain the electric power quality the same as that of a conventional heat power station and improves adaptive capacity to the electric fence, and saves the transformer.

Description

Variable-speed constant-frequency apparatus of wind generator set

Technical field

The present invention relates to wind power generating set, relate in particular to its variable-speed constant-frequency apparatus.

Background technique

Wind power generating set generally adopts the variable-speed operation mode, and promptly at wind speed hour, the rotating speed of wind wheel is low, and when wind speed was high, the rotating speed of wind wheel was also high, makes the tip-speed ratio of blade remain at best state, so just utilize wind energy, Economy height the energy fullest.And Large-scale Wind Turbines will be connected with electrical network, to mains supply, just need take special technique, makes blower fan under the variable-speed operation state, and the frequency of output electric energy but is constant, and is the network operation frequency.

The technological means that generally adopts has following two kinds now:

1. doubly-fed variable-speed constant-frequency technology:

Adopt double-fed induction formula generator, generator unit stator is connected with electrical network, and generator amature is connected operation technique with electrical network after the frequency conversion of double-fed frequency variator.The rotor-exciting frequency of Frequency Converter Control generator makes the mechanical rotation frequency of generator amature add that excitation frequency is consistent with electrical network electricity frequency.Therefore can adjust that the rotor-exciting frequency makes the generator amature variable-speed operation and the generator frequency of surfing the Net is a power frequency.This technology is owing to have only the power of rotor portion to pass through frequency variator, and therefore, the capacity of frequency variator can be less.But limited by frequency converter voltage, the slewing range that can realize have only synchronous speed-1/3～1/3 between.In addition, this technology is to the requirement height of generator, and generator amature needs slip ring, and generator amature is operated under the inverter supply pattern, the insulation of rotor winding needs special consideration, and rotor will bear high-frequency pulse voltage and high rotating speed, adapts to the also needs special measure reinforcement of ability of electrical network.

2. full power frequency conversion login technique:

Adopt synchronous generator, be connected operation with electrical network by frequency variator.The rotating speed of generator amature can be realized stepless change operation in the scope of broad, the output electric energy of generator becomes the power frequency online after by the full power frequency variator.The advantage of this technology is to realize the variable-speed operation of blower fan in wideer scope, and it is strong to adapt to electrical network energy force rate double-fed transmission technology, and shortcoming is that the transducer power that needs is big, the cost height.

More than two kinds all be to realize constant frequency by the electromagnetism frequency conversion, the complex structure of electromagnetism converter plant, the cost height, component number is many, probability of failure is big, stability, reliability is relatively poor.

Have again, be subjected to the restriction of frequency converter voltage, all need transformer to be connected, increased the link and the cost of unit with electrical network.And unit can not use conventional power frequency synchronous generator, the electric energy poor quality, and harmonic pollution is big, and it is not enough to adapt to the electrical network ability.

Summary of the invention

The purpose of this invention is to provide a kind of simple in structure, cheap, reliable and stable, slewing range wide, to the electrical network no-harmonic wave pollution, adapt to the variable-speed constant-frequency apparatus of wind generator set that the electrical network ability is strengthened.

Technical solution of the present invention is:

A kind of variable-speed constant-frequency apparatus of wind generator set, this device comprises planetary transmission and speed setting unit; Described planetary transmission has sun gear, planet carrier, ring gear, and this ring gear is rotatable, constitutes three concentric running shafts, three corresponding arbitrarily respectively wind wheel, generator amature, speed setting units of connecting of axle, promptly

Described ring gear connects generator amature, and sun gear connects speed setting unit, and planet carrier connects wind wheel; Or

Described ring gear connects generator amature, and sun gear connects wind wheel, and planet carrier connects speed setting unit; Or

Described sun gear connects generator amature, and planet carrier connects speed setting unit, and ring gear connects wind wheel; Or

Described sun gear connects generator amature, and planet carrier connects wind wheel, and ring gear connects speed setting unit; Or

Described planet carrier connects generator amature, and sun gear connects wind wheel, and ring gear connects speed setting unit; Or

Described planet carrier connects generator amature, and sun gear connects speed setting unit, and ring gear connects wind wheel.

Described speed setting unit comprises torque motor and frequency variator thereof, wind speed round signal transmitting device, signal processor; The output shaft of torque motor connects the running shaft of the planetary transmission of speed setting unit correspondence, the output terminal of wind speed round signal transmitting device connects the input end of signal processor, the output terminal of signal processor connects the input end of frequency variator, the output terminal coupling torque motor of frequency variator.

Described speed setting unit also can comprise DC torque motor and speed regulator thereof, wind speed round signal transmitting device, signal processor; The output shaft of DC torque motor connects the running shaft of the planetary transmission of speed setting unit correspondence, the output terminal of wind speed round signal transmitting device connects the input end of signal processor, the output terminal of signal processor connects the input end of speed regulator, and the output terminal of speed regulator connects DC torque motor.

Described wind wheel is provided with speeder, and the output shaft of this speeder connects planetary transmission.

But described speeder planetary pinion speeder, also ordinary gear speeder.

Useful technique effect of the present invention:

The present invention solve wind power generating set must variable-speed operation and when needing contradiction that constant frequency surfs the Net in order to obtain high power coefficient, three rotatable planetary transmissions of particular design have been adopted, use the power frequency synchronous generator to be connected with electrical network, successfully realized the variable speed constant frequency operation, this planetary transmission is a kind of mechanical device, cheap, substitute expensive frequency variator, reduced the unit cost significantly; This device simple in structure, rate of fault is low, and is safe and reliable to operation; The speed adjustable range of this device is wide, and it is strong to adapt to the wind speed ability, and Wind Power Utilization is abundant, and unit economy is good; The transmission efficiency height of this device, unit significantly reduces from power consumption; Adopt the wind power generating set of this device can use the power frequency synchronous generator, do not had harmonic pollution, make unit can obtain the electric energy quality identical with conventional heat power station, the ability that adapts to electrical network is improved, and can save transformer.

Describe the present invention in detail below in conjunction with embodiment.

Description of drawings

Fig. 1 is the schematic diagram of this variable-speed constant-frequency apparatus of wind generator set

Fig. 2 is the rotating speed, moment of torsion, power of this speed governing axle dimensionless change curve along with input shaft slippage s

Fig. 3 is the structural representation of an example of this variable-speed constant-frequency apparatus of wind generator set

Fig. 4 is the structured flowchart of this speed setting unit

Embodiment

The present invention adopts the speed ratio technology of frequency conversion drive regulating tooth roller box, can make the operation of wind power generating set variable speed constant frequency effectively.The main feature of this technology is to adopt three all rotatable planetary pinion gear stages.As everyone knows: the Gear Planet Transmission level of gear-box generally is that ring gear maintains static, and planet carrier and sun gear rotate gear-box speedup or the deceleration that realizes constant velocity-ratio.

The present invention also can rotate ring gear, so this Gear Planet Transmission level just has three concentric running shafts, and as shown in Figure 1, in variable-speed constant-frequency apparatus BS, 1 is planet carrier X, and 2 is sun gear T, and 3 is ring gear N, according to its geometrical relationship following relation is arranged:

2R ₁＝R ₂+R ₃

2R ₁ω ₁＝R ₂ω ₂+R ₃ω ₃

$M_1=\frac{{-2R}_1}{R_2}{\mathrm{<figure-callout\; id="2"\; label="M"\; filenames="A20081004565500092.png"\; state="\{\{state\}\}">M</figure-callout>}}_2=\frac{{-2R}_1}{R_3}{M}_3$

In the formula: R is the radius of running shaft; ω is the rotating speed of running shaft; M is the moment of running shaft.

Three running shafts can be distinguished corresponding wind wheel L, the rotor of generator F, the torque motor D of connecting arbitrarily, and this torque motor D is with industrial frequency converter B speed governing.For example, resemble shown in Figure 3, can be with 1 input shaft that connects wind wheel L as gear-box, 2 connect speed governing torque motor D, as the speed governing axle of gear-box, 3 rotors that connect power frequency synchronous generator F are as the output shaft of gear-box.So,, can make 1 rotation speed change by the rotating speed that changes 2 according to the above-mentioned relation formula, and 3 invariablenes turning speed.Its reason and double-fed generator category seemingly are equivalent to 3 and are the stator of generator, and 1 is the rotor of generator, and 2 is the excitation frequency of frequency variator.For the ease of understanding, the spy carries out following computational analysis:

Make ω ₃=0 is that output shaft maintains static, and following relation is then arranged:

$\frac{{\mathrm{\&omega;}}_2}{{\mathrm{\&omega;}}_1}=\frac{{2R}_1}{R_2}=G_3---\left(1\right)$

G ₃Physical significance for not considering the situation lower tooth roller box speed governing axle of output shaft and the speed ratio of input shaft.

In like manner make ω ₁=0 is that input shaft maintains static, and the following relationship formula is arranged

$\frac{{\mathrm{\&omega;}}_2}{{\mathrm{\&omega;}}_3}=\frac{{-R}_3}{R_2}=-G_1---\left(2\right)$

G ₁Physical significance for not consider under the situation of input shaft, the speed governing axle of gear-box and the speed ratio of output shaft.Negative sign is that sense of rotation is opposite.

In like manner make ω ₂=0 is that the speed governing axle maintains static, and the following relationship formula is arranged

$\frac{{\mathrm{\&omega;}}_3}{{\mathrm{\&omega;}}_1}=\frac{{2R}_1}{R_3}=G_2---\left(3\right)$

G ₂Physical significance for not consider under the situation of speed governing axle, the output shaft of gear-box and the speed ratio of input shaft.

In fact, the rotating speed of output shaft is the stack of above-mentioned formula (2), (3) two kinds of situations of formula.

Because 3 is output shaft, ω ₃Being power frequency, is 3000rpm to two pole generators, is 1500rpm to four-pole generator.The same leg speed and the slippage of regulation input shaft are

${\mathrm{\&omega;}}_n=\frac{{\mathrm{\&omega;}}_3}{{\mathrm{<figure-callout\; id="2"\; label="G"\; filenames="A20081004565500092.png"\; state="\{\{state\}\}">G</figure-callout>}}_2}$

$s=\frac{{\mathrm{\&omega;}}_n-{\mathrm{\&omega;}}_1}{{\mathrm{\&omega;}}_n}$

Therefore can use slippage S, input power P ₁, generator power frequency ω ₃Represent rotating speed, moment, the power of 3 of 2 of adjusting axles and output shafts, following relation arranged:

ω ₁＝(1-s)ω _n

$M_1=\frac{P_1}{{\mathrm{\&omega;}}_1}=\frac{P_1{G}_2}{(1-s){\mathrm{\&omega;}}_3}$

ω ₂＝-G ₃sω _n＝-G ₁sω ₃

${\mathrm{<figure-callout\; id="2"\; label="M"\; filenames="A20081004565500092.png"\; state="\{\{state\}\}">M</figure-callout>}}_2=-\frac{R_2}{{2R}_1}{M}_1=-\frac{P_1}{G_1(1-s){\mathrm{\&omega;}}_3}$

${\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="A20081004565500092.png"\; state="\{\{state\}\}">P</figure-callout>}}_2={\mathrm{<figure-callout\; id="2"\; label="M"\; filenames="A20081004565500092.png"\; state="\{\{state\}\}">M</figure-callout>}}_2{\mathrm{\&omega;}}_2=\frac{s}{1-s}{P}_1$

$M_3=\frac{-M_1}{{\mathrm{<figure-callout\; id="2"\; label="G"\; filenames="A20081004565500092.png"\; state="\{\{state\}\}">G</figure-callout>}}_2}=-\frac{P_1}{(1-s){\mathrm{\&omega;}}_3}$

$P_3=M_3{\mathrm{\&omega;}}_3=-\frac{P_1}{(1-s)}$

If set revolutional slip S 1～0～-1 interval the variation, promptly the input shaft rotating speed is at 0～2* ω _nBetween change.The rotating speed that the speed governing axle is then arranged is along with the S linearity reduces 0, and when S becomes negative value by 0, the speed governing axle oppositely accelerate rotation gradually;

The moment of wind wheel generally is and square being directly proportional of rotating speed that power is directly proportional with the cube of rotating speed.Can set following relationship:

ω ₁＝(1-s)ω _n

$M_1={\mathrm{A\&omega;}}_1^2=A{(1-s)}^2{\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="A20081004565500092.png"\; state="\{\{state\}\}">n</figure-callout>}}^2={(1-s)}^2{M}_n$

ω ₂＝-G ₃sω _n

${\mathrm{<figure-callout\; id="2"\; label="M"\; filenames="A20081004565500092.png"\; state="\{\{state\}\}">M</figure-callout>}}_2=-\frac{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="A20081004565500092.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}{{2R}_1}{M}_1=-\frac{{(1-s)}^2{M}_n}{G_3}$

P ₂＝M ₂ω ₂＝s(1-s) ²P _n

Therefore the direction of the moment of speed governing axle does not change, along with s reduce form quadratic relation and increase.When S is-1, the moment maximum.

The power of speed governing axle changes along with the positive and negative of S, and when S was reduced to 0 by 1, power was reduced to 0 again by 0 to 4/27Pn; When S changed by 0 to-1, the flow direction of power had changed, and becomes by the speed governing axle to export a part of power.

Fig. 2 is the rotating speed of speed governing axle, moment, the power dimensionless change curve along with input shaft slippage S.

Series 1 is ω among Fig. 2 ₂/ (G ₃* ω n) dimensionless factor is along with the dimensionless change curve of slippage S.

Series 2 is (M among Fig. 2 ₂* G ₃)/Mn dimensionless factor is along with the dimensionless change curve of slippage S.

Series 3 is P among Fig. 2 ₃/ Pn dimensionless factor is along with the dimensionless change curve of slippage s.

Series 4 is ω among Fig. 2 ₁/ ω n dimensionless factor is along with the nondimensional change curve of slippage s.

The present invention adopts the charged motivation D of industrial frequency transformer B to drive the speed governing axle.Therefore slippage S is always for just.The design parameter of suitably adjusting gear-box can make the power of frequency converter B be about unit rated power 1/10.

The present invention must make three axles of planetary stage all can select commentaries on classics.One of them axle is an input shaft, and another axle is an output shaft, and the 3rd axle is the speed governing axle, and the speed governing axle adopts the charged motivation D of frequency converter B to drive.Frequency converter B, motor D all can select conventional industrial products for use, and be simple in structure, reliable, can adjust rotating speed and the power of wind wheel L by frequency converter B.

In addition,, be about about 10～20rpm, need elder generation, dwindle speed discrepancy as far as possible with generator amature with its speedup because the rotating speed of wind wheel L is generally lower.Therefore, the present invention is provided with speed increaser ZS to wind wheel L, and this speed increaser ZS has three grades, and preceding two-stage is conventional Gear Planet Transmission level, and its ring gear is fixed, and the third level is the horizontal gear gear stage, realizes that speed increaser ZS is connected with the transition of variable-speed constant-frequency apparatus BS.Wind wheel L connects the primary planet carrier of speed increaser ZS, as input shaft, after three grades of speedups, drives the planet carrier X of variable-speed constant-frequency apparatus BS, and transmission ring gear N, ring gear N drive the rotor of power frequency synchronous generator F by coupling.Speed increaser ZS and variable-speed constant-frequency apparatus BS can be arranged in the same casing, make compact structure.The output shaft of torque motor D penetrates in the middle of the horizontal gear of conventional speed increaser ZS, is connected with the sun gear T of variable-speed constant-frequency apparatus BS, as the speed governing axle.Torque motor D carries out speed governing by industrial frequency transformer B powered operation, realizes the synchronous generator rotor constant-speed operation, and its frequency is a power frequency.

Certainly, speed increaser ZS also can all adopt common horizontal gear speedup.Speedup progression is flexible design according to actual needs also.

Referring to Fig. 4: speed governing constant frequency process is by regulating system control automatically, S becomes electrical signal with the wind speed round signal conversion by the signal transmitting device, sending into signal processor C handles, signal processor C exports control signal to frequency converter B, frequency converter B changes power supply frequency, thereby changes the rotating speed of torque motor D.

Certainly, arrangements for speed regulation also can adopt direct current motor and corresponding speed regulator thereof, to the speed governing of speed governing axle.

It below only is an example of the present invention.In fact, according to the structural design of gear-box and unit, input shaft, output shaft, speed governing axle can be selected any among planet carrier X, sun gear T, the ring gear N, and its principle all is the same, can both realize the constant-speed operation of output shaft.

Claims (7)

1. variable-speed constant-frequency apparatus of wind generator set, it is characterized in that: this device comprises planetary transmission and speed setting unit; Described planetary transmission has sun gear, planet carrier, ring gear, and this ring gear is rotatable, constitutes three concentric running shafts, three corresponding arbitrarily respectively wind wheel, generator amature, speed setting units of connecting of axle, promptly

Described ring gear connects generator amature, and sun gear connects speed setting unit, and planet carrier connects wind wheel; Or

Described ring gear connects generator amature, and sun gear connects wind wheel, and planet carrier connects speed setting unit; Or

Described sun gear connects generator amature, and planet carrier connects speed setting unit, and ring gear connects wind wheel; Or

Described sun gear connects generator amature, and planet carrier connects wind wheel, and ring gear connects speed setting unit; Or

Described planet carrier connects generator amature, and sun gear connects wind wheel, and ring gear connects speed setting unit; Or

Described planet carrier connects generator amature, and sun gear connects speed setting unit, and ring gear connects wind wheel.

2. variable-speed constant-frequency apparatus of wind generator set according to claim 1 is characterized in that: described speed setting unit comprises torque motor and frequency variator thereof, wind speed round signal transmitting device, signal processor; The output shaft of torque motor connects the running shaft of the planetary transmission of speed setting unit correspondence, the output terminal of wind speed round signal transmitting device connects the input end of signal processor, the output terminal of signal processor connects the input end of frequency variator, the output terminal coupling torque motor of frequency variator.

3. variable-speed constant-frequency apparatus of wind generator set according to claim 1 is characterized in that: described speed setting unit comprises DC torque motor and speed regulator thereof, wind speed round signal transmitting device, signal processor; The output shaft of DC torque motor connects the running shaft of the planetary transmission of speed setting unit correspondence, the output terminal of wind speed round signal transmitting device connects the input end of signal processor, the output terminal of signal processor connects the input end of speed regulator, and the output terminal of speed regulator connects DC torque motor.

4. variable-speed constant-frequency apparatus of wind generator set according to claim 1 is characterized in that: described wind wheel is provided with speeder, and the output shaft of this speeder connects planetary transmission.

5. variable-speed constant-frequency apparatus of wind generator set according to claim 4 is characterized in that: described speeder is the planetary pinion speeder.

6. variable-speed constant-frequency apparatus of wind generator set according to claim 4 is characterized in that: described speeder is the ordinary gear speeder.

7. variable-speed constant-frequency apparatus of wind generator set according to claim 4 is characterized in that: described speeder and speed setting unit are with box structure or divide box structure.

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