CN103256188A - Twisting vibration control method and device of wind generating set transmission chain - Google Patents

Abstract

The invention belongs to the technical field of wind power generation system control, and discloses a twisting vibration control method and device of a wind generating set transmission chain. The twisting vibration control method comprises the following steps that step1, a rotation speed omega G of a high-speed shaft of the wind generating set transmission chain and a rotation speed omega W of a low-speed shaft of the wind generating set transmission chain are detected and obtained at the same time; step2, difference calculation is carried out to get a result that omega e=( omega G -Nomega W), wherein N is the transmission ratio of a gear box; step3, the difference omega e is subjected to lowpass filtering to filter detected high-order noises, so that omega e' is obtained, delta 1 is made to be equal to p omega e', and p is an error feedback gain; step4, a generator electromagnetic torque instruction value TG1 is calculated to be equal to TG+ delta 1 omega G, and a torque controller controls the generator to output the electromagnetic torque instruction value TG1. According to the twisting vibration control method and device, damping self-adapting adjustment control is achieved, and moreover power loss caused by changes of damping is eliminated when the wind generating set is in a stable state.

Description

A kind of Torsional Vibration Control method and device of wind power generating set Transmitted chains

Technical field

The invention belongs to the Control Technology of Wind Power Generation System field, particularly a kind of Torsional Vibration Control method and device of wind power generating set Transmitted chains.

Background technique

In wind-power generating system, variable speed drive between wind energy conversion system and the generator (being generally gear-box) is absolutely necessary, it is big flexible that this makes that the wind power generating set Transmitted chains has, and may cause occurring in the system dynamic course problem of Transmitted chains torsional vibration.

Less and cause the problem of Transmitted chains torsional vibration easily at the damping of Transmitted chains, at present the general method that adopts is: the basis at the setting value of original torque increases a very little additional torque opposite with reverse speed Transmitted chains, be used for increasing the damping of Transmitted chains, to suppress the Transmitted chains torsional vibration.But additional torque normally adopts generator speed to pass through the approximate acquisition of a band-pass filter, and frequency filtering and feedback gain directly have influence on the inhibition ability of torsional vibration.

Summary of the invention

The objective of the invention is to propose a kind of method and device that suppresses the torsional vibration of wind power generating set Transmitted chains.The present invention can realize damping adaptive adjusting control, and eliminates the power loss that causes because of damping change when wind power generating set is in stable state.

A kind of Torsional Vibration Control method of wind power generating set Transmitted chains may further comprise the steps:

S1: detect the rotational speed omega that obtains wind power generating set Transmitted chains high speed shaft simultaneously _GRotational speed omega with lower velocity shaft _W,

S2: calculate ω as difference _e=(ω _G-N ω _W), N is the velocity ratio of gear-box;

S3: with difference ω _eBy the high order noise of lower pass-filter filtering detection, thereby can get ω _e', make δ ₁=p ω _e', p is the Error Feedback gain;

S4: calculate generator electromagnetic torque command value T _G1=T _G+ δ ₁ω _G, torque controller control generator output electromagnetic torque command value T _G1

Before step S3 with difference ω _eLower limit set be 0rad/s, the upper limit is set between the 5-10rad/s

Described with difference ω _eCarry out in the process of lower pass-filter, the cutoff frequency of lower pass-filter is greater than 5 times of natural oscillation frequency.

A kind of torsional vibration control device of wind power generating set Transmitted chains comprises:

The wind power generating set Transmitted chains is for the rotational speed omega that high speed shaft is provided _GRotational speed omega with lower velocity shaft _W, with the rotational speed omega of lower velocity shaft _WExport the velocity ratio booster to, with the rotational speed omega of high speed shaft _GTransfer to difference calculator and torque controller respectively;

The velocity ratio booster, for the velocity ratio N that obtains gear-box, and with the N ω that calculates _WExport difference calculator to;

Difference calculator is used for calculating difference ω _e=(ω _G-N ω _W), and with difference ω _eExport low-pass filter to;

Low-pass filter is used for difference ω _eHigh order noise by the lower pass-filter filtering detects draws ω _e', and with ω _e' export the proportional gain device to;

The proportional gain device is used for calculating self adaption feedback factor δ ₁, and with self adaption feedback factor δ ₁Export torque controller to;

Torque controller is used for calculating generator electromagnetic torque command value T _G1=T _G+ δ ₁ω _G, and control generator output electromagnetic torque command value T _G1

The torsional vibration control device of described a kind of wind power generating set Transmitted chains also comprises:

The difference amplitude limiter is used for obtaining the difference ω from difference calculator _e, and with difference ω _eLower limit be defined as 0rad/s, the upper limit is limited between the 5-10rad/s.

The cutoff frequency of lower pass-filter is greater than 5 times of natural oscillation frequency.

Beneficial effect of the present invention is:

1) need not adopt near filtering link (refer in particular to frequency of natural vibration) in speed feedback, can avoid frequency of natural vibration the unknown and the problem that the filtering link is difficult to design occurs.

2) do not need to detect simultaneously the rotating speed of lower velocity shaft and high speed shaft, in the general wind-powered electricity generation unit lower velocity shaft and high speed shaft speed detector are arranged, can not increase cost.

3) the present invention's rotating speed of detecting lower velocity shaft and high speed shaft is respectively done poorly, by lower pass-filter with amplify the back online adjusting is carried out in feedback damping gain, thereby realizes that damping adaptive regulates control.The dynamic float value is bigger, and the damping adaptive regulator makes feedback damping gain become big, and the stable state time difference value is close to 0, and the damping adaptive regulator reduces to feed back the damping gain, namely

And then have

The final power loss that causes because of damping change of eliminating.

Description of drawings

Fig. 1 is two mass block model schematic representation of wind power generating set Transmitted chains Torsional Vibration Control method;

Fig. 2 is wind power generating set Transmitted chains torsional vibration control device first schematic representation;

Fig. 3 is wind power generating set Transmitted chains torsional vibration control device second schematic representation;

Wind power generating set Transmitted chains machine torque response wave shape comparison diagram when Fig. 4 is the step wind speed in the present invention's (torsional vibration control device of wind power generating set Transmitted chains) and the original system (not adopting wind power generating set Transmitted chains torsional vibration control device of the present invention);

Lower velocity shaft rotating speed and high speed shaft speed waveform figure after original system (not adopting wind power generating set Transmitted chains torsional vibration control device of the present invention) was converted when Fig. 5 was the step wind speed;

Lower velocity shaft rotating speed and high speed shaft speed waveform figure after converting in the wind power generating set Transmitted chains torsional vibration control device when Fig. 6 is the step wind speed;

Generator electromagnetic power response wave shape comparison diagram when Fig. 7 is the step wind speed in the present invention's (torsional vibration control device of wind power generating set Transmitted chains) and the original system (not adopting wind power generating set Transmitted chains torsional vibration control device of the present invention);

Wind power generating set Transmitted chains machine torque response wave shape comparison diagram when Fig. 8 is natural wind simulating in the present invention's (torsional vibration control device of wind power generating set Transmitted chains) and the original system (not adopting wind power generating set Transmitted chains torsional vibration control device of the present invention);

Lower velocity shaft rotating speed and high speed shaft speed waveform figure after original system (not adopting wind power generating set Transmitted chains torsional vibration control device of the present invention) was converted when Fig. 9 was natural wind simulating;

Lower velocity shaft rotating speed and high speed shaft speed waveform figure after converting in the wind power generating set Transmitted chains torsional vibration control device when Figure 10 is natural wind simulating;

Generator electromagnetic power response wave shape comparison diagram when Figure 11 is natural wind simulating in the present invention's (torsional vibration control device of wind power generating set Transmitted chains) and the original system (not adopting wind power generating set Transmitted chains torsional vibration control device of the present invention).

Embodiment

The invention will be further described below in conjunction with accompanying drawing:

With reference to Fig. 1, utilize two mass block models that wind power generating set Transmitted chains torsional vibration inhibition method is studied, be the W mass block with wind energy conversion system and gear-box equivalence, the generator amature equivalence is the G mass block, transmission is flexible equivalent to high speed shaft, thereby sets up two mass block model, wherein J _W, J _GBe respectively the rotary inertia of W mass block and G mass block, δ _W, δ _GBe respectively the damping constant of W mass block and G mass block, T _WBe wind energy conversion system output torque, T _GBe generator electromagnetic torque, θ _W, θ _GBe respectively the corner of wind energy conversion system and generator, ω _W, ω _GBe respectively wind-driven generator lower velocity shaft rotating speed and high speed shaft rotating speed, k is the stiffness coefficient of axle, T _sBe the machine torque that axle transmits, D _sBe the damping of reversing of between centers, after the high speed shaft equivalence, each amount of lower velocity shaft all will be converted accordingly with lower velocity shaft, and the velocity ratio of gear-box is N (parameter of W mass block is converted).

Suppose that wind energy conversion system is with rotational speed omega under a certain wind speed V _W0Rotation, torque is T _W0, generator is with rotational speed omega _G0Rotation, torque is T _G0At this moment, if wind speed changes suddenly, consider that wind energy conversion system and generator moment rotating speed are respectively this moment:

${\mathrm{\ω}}_W={\stackrel{\·}{\mathrm{\θ}}}_W+{\mathrm{\ω}}_{W0}$

${\mathrm{\ω}}_G={\stackrel{\·}{\mathrm{\θ}}}_G+{\mathrm{\ω}}_{G0}---\left(1\right)$

Wherein:

Wind energy conversion system torsional vibration speed,

Generator torsional vibration speed.Because

Changed the rotating speed of wind energy conversion system and generator, wind energy conversion system output torque this moment T _WWith generator electromagnetic torque T _GAll change thereupon.

Make wind energy conversion system output torque T _WVariation delta T _W, generator electromagnetic torque T _GVariation delta T _G, then

T _W=ΔT _W+T _W0

T _G=ΔT _G+T _G0 (2)

Piecewise linear interpolation scheme according to conventional torque control makes rotational speed omega _G0Near generator electromagnetic torque variable quantity is:

${\mathrm{\ΔT}}_G\≈k_0{\stackrel{\·}{\mathrm{\θ}}}_G---\left(3\right)$

In the formula: k ₀Be proportionality constant.According to the dynamic (dynamical) principle of mechanical structure, mechanical drive train is carried out modeling, so can get wind energy conversion system and generator torsional vibration equation is as follows:

$J_W{\stackrel{\·\·}{\mathrm{\θ}}}_W={\mathrm{\ΔT}}_W-T_s-D_s({\stackrel{\·}{\mathrm{\θ}}}_W-{\stackrel{\·}{\mathrm{\θ}}}_G)-{\mathrm{\δ}}_W{\stackrel{\·}{\mathrm{\θ}}}_W---\left(4\right)$

$J_G{\stackrel{\·\·}{\mathrm{\θ}}}_G=T_s+D_s({\stackrel{\·}{\mathrm{\θ}}}_W-{\stackrel{\·}{\mathrm{\θ}}}_G)-{\mathrm{\ΔT}}_G-{\mathrm{\δ}}_G{\stackrel{\·}{\mathrm{\θ}}}_G---\left(5\right)$

k(θ _W-θ _G)=T _s (6)

In the formula:

For wind energy conversion system reverse speed acceleration,

Generator reverse speed acceleration.

By the torsional vibration equation that can get Transmitted chains model high speed shaft and lower velocity shaft after the arrangement of formula (3), (5) and (6):

$J_G{\stackrel{\·\·}{\mathrm{\θ}}}_G+(D_s+{\mathrm{\δ}}_G+k_0){\stackrel{\·}{\mathrm{\θ}}}_G+{\mathrm{k\θ}}_G={\mathrm{k\θ}}_W+D_s{\stackrel{\·}{\mathrm{\θ}}}_W---\left(7\right)$

Suppose θ _WAnd θ _GBe respectively the input of Transmitted chains system model and output, formula (7) carried out Laplace transformation get:

$\frac{{\mathrm{\θ}}_G\left(s\right)}{{\mathrm{\θ}}_W\left(s\right)}=\frac{k(1+\frac{D_s}{k}s)}{J_G{s}^2+(k_o+{\mathrm{\δ}}_G+D_s)s+k}---\left(8\right)$

Description natural oscillation frequency and system damping as can be known according to typical second-order system:

${\mathrm{\ω}}_n=\sqrt{\frac{k}{J_G}}$

$\mathrm{\ξ}=\frac{k_0+{\text{\δ}}_G+D_s}{2\sqrt{J_{G}k}}---\left(9\right)$

According to control theory as can be known, if system damping ξ is less, at θ _GFollow the tracks of θ _WThe time, it is big that system may overshoot occur, and the adjusting time is long, even problem such as vibration occurs.K (θ is arranged again _W-θ _G)=T _s, so θ _GTracking effect directly have influence on wind power generating set Transmitted chains machine torque.By formula (9) as can be known, because torque controller is introduced, the damping of mechanical drive train is improved, can improve the stability of system, but when rated wind speed is above, because torque controller is output as constant, do not increase the effect of mechanical drive train damping, and the damping of mechanical drive train itself is very little, is easy to occur the unit torsional oscillation.

With reference to Fig. 2, a kind of Torsional Vibration Control method of wind power generating set Transmitted chains may further comprise the steps:

S1: detect the rotational speed omega that obtains wind power generating set Transmitted chains high speed shaft simultaneously _GRotational speed omega with lower velocity shaft _W

S2: calculate ω as difference _e=(ω _G-N ω _W), N is the velocity ratio of gear-box.

S3: with difference ω _eBy the high order noise of lower pass-filter filtering detection, thereby can get ω _e', make δ ₁=p ω _e', p is the Error Feedback gain.For avoiding that near the signal the natural oscillation frequency is filtered, the cutoff frequency of lower pass-filter should be greater than 5 times of natural oscillation frequency.

S4: calculate generator electromagnetic torque command value T _G1=T _G+ δ ₁ω _G, torque controller control generator output electromagnetic torque command value T _G1

With reference to Fig. 3, particularly, before step S2 with difference ω _eLower limit set be 0rad/s, the upper limit is set between the 5-10rad/s.

The invention allows for a kind of torsional vibration control device of wind power generating set Transmitted chains, the mode of execution of this control gear is identical with said method embodiment, no longer repeats at this.

The following describes test effect of the present invention:

According to formula (1) to formula (9), the system damping that gets final product newly

$\mathrm{\ξ}=\frac{k_0+{\mathrm{\δ}}_G+D_s+{\mathrm{\δ}}_1}{2\sqrt{J_{G}k}}---\left(11\right)$

After the feedback of a generator speed of stack was gone up in torque controller output, the damping of mechanical drive train had corresponding raising, as long as δ ₁Select suitably can effectively suppress the torque wide fluctuations on the gear-box.

When system's (wind power generating set) when being in stable state, have

That is:

T _G=T _W-δ ₁ω _G

(12)

At this moment,

T then _GBe infinitely close to T _W, the present invention eliminates the power loss under the stable state when reducing the machine torque dynamic oscillation.

Because the wind power generating set Transmitted chains is flexibility, therefore transmission of torque has time-delay when wind speed changes, and this causes the vibration of wind power generating set Transmitted chains machine torque, also makes lower velocity shaft rotating speed and high speed shaft rotating speed have small instantaneous error.It is poor that the rotating speed that the present invention detects lower velocity shaft and high speed shaft is respectively done, and by lower pass-filter with amplify the back online adjusting is carried out in feedback damping gain, thereby realizes that damping adaptive regulates control.

Effect below by comparative illustration control scheme of the present invention.

With reference to Fig. 4, Fig. 5 and Fig. 6, under the step wind speed, the wind power generating set Transmitted chains machine torque response of original system has certain dynamic oscillation, when adopting self-adaptive damping variable control scheme, owing to introduce rotating speed (solid line among corresponding diagram 5 and Fig. 6) transient deviation of lower velocity shaft (dotted line among corresponding diagram 5 and Fig. 6) and high speed shaft as the control target, suppressed the vibration of wind power generating set Transmitted chains machine torque greatly, not vibration during high speed shaft rotating-speed tracking lower velocity shaft rotating speed (conversion back).

With reference to Fig. 7, under the step wind speed, the obtained generator electromagnetic power dynamic performance of control scheme of the present invention is variation to some extent.This shows, suppress the vibration of wind power generating set Transmitted chains machine torque and can exert an influence to the generator power characteristic, need take all factors into consideration.

With reference to Fig. 8, Fig. 9 and Figure 10, under natural wind simulating, the wind power generating set Transmitted chains machine torque response of original system has big dynamic oscillation more than rated wind speed, and dynamic oscillation is less when rated wind speed is following, has verified when rated wind speed is following and above theory analysis to the Transmitted chains model stability.Owing to introduce rotating speed (solid line among corresponding diagram 9 and Figure 10) transient deviation of lower velocity shaft (dotted line among corresponding diagram 9 and Figure 10) and high speed shaft as the control target, suppressed the vibration of wind power generating set Transmitted chains machine torque greatly, not vibration during high speed shaft rotating-speed tracking lower velocity shaft rotating speed (conversion back).

With reference to Figure 11, under natural wind simulating, the obtained generator electromagnetic power dynamic performance of control scheme of the present invention is variation to some extent, but does not influence the quality of output power.

Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, if of the present invention these are revised and modification belongs within the scope of claim of the present invention and equivalent technologies thereof, then the present invention also is intended to comprise these changes and modification interior.

Claims (6)

1. the Torsional Vibration Control method of a wind power generating set Transmitted chains is characterized in that, may further comprise the steps:

S1: detect the rotational speed omega that obtains wind power generating set Transmitted chains high speed shaft simultaneously _GRotational speed omega with lower velocity shaft _W

S2: calculate ω as difference _e=(ω _G-N ω _W), N is the velocity ratio of gear-box;

S3: with difference ω _eBy the high order noise of lower pass-filter filtering detection, thereby can get ω _e', make δ ₁=p ω _e', p is the Error Feedback gain;

S4: calculate generator electromagnetic torque command value T _G1=T _G+ δ ₁ω _G, torque controller control generator output electromagnetic torque command value T _G1

2. the Torsional Vibration Control method of a kind of wind power generating set Transmitted chains as claimed in claim 1 is characterized in that, before step S3 with difference ω _eLower limit set be 0rad/s, the upper limit is set between the 5-10rad/s.

3. the Torsional Vibration Control method of a kind of wind power generating set Transmitted chains as claimed in claim 1 is characterized in that, and is described with difference ω _eCarry out in the process of lower pass-filter, the cutoff frequency of lower pass-filter is greater than 5 times of natural oscillation frequency.

4. the torsional vibration control device of a wind power generating set Transmitted chains is characterized in that, comprising:

The wind power generating set Transmitted chains is for the rotational speed omega that high speed shaft is provided _GRotational speed omega with lower velocity shaft _W, with the rotational speed omega of lower velocity shaft _WExport the velocity ratio booster to, with the rotational speed omega of high speed shaft _GTransfer to difference calculator and torque controller respectively;

The velocity ratio booster, for the velocity ratio N that obtains gear-box, and with the N ω that calculates _WExport difference calculator to;

Difference calculator is used for calculating difference ω _e=(ω _G-N ω _W), and with difference ω _eExport low-pass filter to;

Low-pass filter is used for difference ω _eHigh order noise by the lower pass-filter filtering detects draws ω _e', and with ω _e' export the proportional gain device to;

The proportional gain device is used for calculating self adaption feedback factor δ ₁, and with self adaption feedback factor δ ₁Export torque controller to;

Torque controller is used for calculating generator electromagnetic torque command value T _G1=T _G+ δ ₁ω _G, and control generator output electromagnetic torque command value T _G1

5. the torsional vibration control device of a kind of wind power generating set Transmitted chains as claimed in claim 4 is characterized in that, also comprises:

The difference amplitude limiter is used for obtaining the difference ω from difference calculator _e, and with difference ω _eLower limit be defined as 0rad/s, the upper limit is limited between the 5-10rad/s.

6. the torsional vibration control device of a kind of wind power generating set Transmitted chains as claimed in claim 4 is characterized in that, the cutoff frequency of described low-pass filter is greater than 5 times of natural oscillation frequency.

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