CN203204895U - Moving die bidirectional wind power energy conversion experiment platform based on double-fed generator - Google Patents

Abstract

The utility model provides a moving die bidirectional wind power energy conversion experiment platform based on a double-fed generator. The moving die bidirectional wind power energy conversion experiment platform based on the double-fed generator is characterized in that the experiment platform comprises a PLC control cabinet, an asynchronous motor, the double-fed generator, a full-power converter, a feed cabinet, a back-to-back converter, a power distribution transformer and an electric energy quality measurement instrument. With the experiment platform of the utility model adopted, the deficiencies of existing experiment platforms can be eliminated, and therefore, multi-aspect requirements of teaching can be satisfied. With the technical schemes of the utility model adopted, a multifunctional experiment platform about wind driven power generation can be realized; with the multifunctional experiment platform about wind driven power generation adopted, experiments related to two kinds of power generation modes and two kinds of converter structures can be realized, and one of power generation schemes in a PC can be selected before operation, and the experiment detection range of the experiment platform is from original wind to electric energy quality of generated electricity; and experimenters can understand related principles about wind power generation and related control technology more deeply.

Description

Based on the two-way wind-powered electricity generation energy conversion of the dynamic model of double-fed generator experiment table

Technical field: the utility model belongs to the higher education instrument and equipment field of wind-power electricity generation.Relate in particular to a kind of wind-power electricity generation energy conversion and Power Quality Detection dynamic model experiment platform and experimental technique.

Background technology: in recent years, in today that fossil energy consumed and caused the environment severe exacerbation day by day, wind energy has waited until widely as clean energy resource and has used that it is more and more paid attention to by people, wherein a kind of hairdo of effectively utilizing is exactly wind-power electricity generation, and wind-power electricity generation becomes the research emphasis of various countries.Carry out the research of wind-power electricity generation control technology, optimal method is to carry out field experiment.But be subjected to the condition effect such as bulky of environment, natural cause, weather, equipment, can not at any time wind generator system be tested, field condition is comparatively abominable again, and this brings a lot of difficulties to site test.Therefore the analog platform at laboratory structure wind generating technology just becomes necessary, simulates the operating characteristic of actual wind energy conversion system by analog platform, utilizes the analog feature of wind energy conversion system to carry out the correlative study of wind generating technology.

Along with the fast development of wind-power electricity generation, being connected to the grid of increasing high-power blower makes the electrical network quality of power supply seriously reduce.Thereby make the power quality problem of wind-powered electricity generation and the focus that solution becomes research gradually thereof.To improve the quality of power supply of electrical network, at first will make accurate detection and analysis to the quality of power supply, measure the quality of power supply level of electrical network, and analyze and judge the reason that causes various power quality problems, for the improvement of the quality of power supply provides foundation.So to the detection of the quality of power supply with analyze necessary.

Up to the present, the current experiments platform is unidirectional mostly, can only finish a kind of related experiment of electricity generation system, and economy is bad, and cost performance is not very high, and weak effect.

The utility model content:

The utility model purpose: the utility model provides a kind of two-way wind-powered electricity generation energy conversion experiment table of dynamic model based on double-fed generator and experimental technique, its objective is solve the existing function singleness of former experiments platform, economy is bad, cost performance is low and the problem of weak effect.

Technical scheme: the utility model is achieved through the following technical solutions:

The two-way wind-powered electricity generation energy conversion of a kind of dynamic model based on double-fed generator experiment table, it is characterized in that: this experiment table comprises PLC switch board, asynchronous machine, double-fed generator, full power convertor, feeder cabinet, back-to-back converter, substation transformer and quality of power supply surveying instrument; The PLC switch board is connected to frequency converter, frequency converter is connected to asynchronous machine, asynchronous machine links to each other with the axle of double-fed generator and can reciprocally generate electricity, asynchronous machine is connected to full power convertor, full power convertor is connected to feeder cabinet, feeder cabinet is connected to substation transformer, and substation transformer is connected to frequency converter; Double-fed generator also is connected to feeder cabinet on the one hand, is connected with back-to-back converter on the other hand; The PLC switch board is connected with back-to-back converter with full power convertor respectively; The PLC switch board connects PC.

Full power convertor and double-fed generator all are connected to feeder cabinet by the switch cubicle that is incorporated into the power networks/drags.

Be connected an identical quality of power supply surveying instrument respectively after back-to-back converter and full power convertor, quality of power supply surveying instrument comprises power quality analyzer, power measurement instruments and waveform recording camera.

The crowbar holding circuit of a protection current transformer in parallel and direct supply between the rotor-side of double-fed wind power generator and back-to-back converter respectively; The full power convertor centre also connects a chopper leadage circuit; A tachometer torquemeter also is housed between asynchronous machine and double-fed generator.

The experimental technique that utilizes the above-mentioned two-way wind-powered electricity generation energy conversion of the dynamic model based on double-fed generator experiment table to implement, it is characterized in that: this method is divided into two kinds of methods arranged side by side, a kind of is to utilize the double-fed generator generating, and another kind is to select the asynchronous machine generating, and concrete steps are as follows:

When selecting the double-fed generator generating, PC is according to the various operating conditions of actual wind field, the unit wind wheel of simulating under the various wind-resources conditions drives situation, go full power convertor to drive asynchronous machine by the PLC switch board then, drag the operation of double-fed wind power generator group by asynchronous machine, when reach and during net spee and phase sequence the double-fed wind power generator group can be generated electricity by way of merging two or more grid systems when consistent, at this moment, quality of power supply surveying instrument begins to gather the operation information of unit and sends control system to and test macro; On the operation interface of PC, can carry out the selection simulation of different operating modes, also can show the wind-resources situation of real-time collection, can carry out the be incorporated into the power networks simulated experiment of control strategy of motor, the process that observe unit synchronization, adjustment of field excitation, is incorporated into the power networks;

When selecting generation mode to be the asynchronous generator generating, the switch cubicle that is incorporated into the power networks in the switch cubicle that is incorporated into the power networks of double-fed generator is connected, give the full power convertor move instruction by the PLC switch board, remove to change the exciting current of double-fed generator rotor again by the control back-to-back converter, thereby change rotor speed, when reach and during net spee and phase sequence the asynchronous generating unit can be generated electricity by way of merging two or more grid systems this moment when consistent, quality of power supply surveying instrument begins to gather the operation information of unit and sends control system to and test macro; On the operation interface of PC, can carry out the selection simulation of different operating modes, also can show the wind-resources situation of real-time collection, can carry out the be incorporated into the power networks simulated experiment of control strategy of motor, the process that observe unit synchronization, adjustment of field excitation, is incorporated into the power networks.

The current transformer control strategy of this experiment table is as follows: what outer shroud control was selected for use is meritorious and idle control, and in addition, the active power outer shroud can be torque or the control of rotating speed outer shroud, and interior ring device processed is current closed-loop control, wherein stator side active power p _s, the stator side reactive power Q _s, electromagnetic torque T _eWith rotor speed ω _rThe numerical value of surveying for testing tool feeds back in the controller, when adopting direct Power Control, the position signalling of the error of instantaneous meritorious, the reactive power by detecting stator output and the magnetic linkage of rotor, meritorious instruction catches principle according to machine unit characteristic by maximal wind-energy and provides, idle instruction is according to the electrical network requirements set, compare according to detected power and given power, error is carried out computing by the PI power governor, the respectively meritorious and idle component instruction of output motor stator current is then with the meritorious idle component current i of the actual rotor of feedback _Rd, i _RqError be converted into voltage instruction by pi regulator, judge the residing sector of voltage vector according to voltage instruction, be to select optimum voltage vector to follow the tracks of institute with the meritorious reactive power of control generator the scale to be given the variation of instructing, wherein stator side active power P from switch _s, the stator side reactive power Q _s, electromagnetic torque T _eWith rotor speed ω _rWith the pass of rotor current be:

T _e＝n _pL ₀(i _qsi _dr-i _dsi _qr)＝L ₀n _pψ _si _qr/L _s＝L ₀n _pU _si _qr/(L _sω ₁) (4)

P _s＝u _dsi _ds+u _qsi _qs＝U _si _qs＝U _sL ₀i _qr/L _s (5)

Q _s＝u _qsi _ds-u _dsi _qs (6)

$J\frac{{\mathrm{d\ω}}_r}{\mathrm{dt}}+B{\mathrm{\ω}}_r=n_p(T_m-\frac{L_0{n}_p{U}_s{i}_{\mathrm{qr}}}{L_s{\mathrm{\ω}}_1})---\left(7\right)$

L _sSelf-induction for stator winding under the dq coordinate system; L ₀Be the equivalent mutual inductance between stator winding under the dq coordinate system and rotor winding.u _DsAnd u _QsBe respectively stator voltage dq axle component, i _DsAnd i _QsBe respectively stator current dq axle component, i _DrAnd i _QrBe respectively rotor current dq axle component, ψ _DsAnd ψ _QsBe respectively stator magnetic linkage dq axle component, J is moment of inertia.

For the purpose of the safety of total system, before the operation of generator auto-parallel, must finish manually and be incorporated into the power networks, auto-parallel could normally start after having only the success of manually being incorporated into the power networks, wherein manually be incorporated into the power networks mainly is whether finish the phase sequence of the condition of being incorporated into the power networks consistent, also comprise whether equally detecting voltage magnitude, voltage is directly measured with voltage table, and phase sequence detecting method has three synchronised synchronizing methods and oscillograph to detect same footwork, for three synchronised synchronizing methods light gradation, light rotary process is arranged; For oscillograph detect with footwork it be by logical 1,2 passages of oscillograph respectively in detection of grid and the generator three-phase voltage magnitude, phase place and the frequency of a corresponding phase judge that the utility model adopts the light gradation of three synchronised synchronizing methods with to adjust phase sequence consistent.

Phase sequence detecting method is as follows: with three direct cross-over connections of bulb in electrical network and double-fed generator stator corresponding mutually between.Combination method is: 1. the size by double-feed current transformer regulator generator rotor excitation current changes the stator terminal induced voltage, and it is identical with amplitude, frequency and the phase place of line voltage that stator-induced electromagnetic is pressed; 2. after voltage is adjusted, if phase sequence unanimity, light should show as light and shade alternately, if not being light and shade, light do not replace, illustrate that then phase sequence is inconsistent, at this moment should adjust the outlet phase sequence (noting: can not adjust the charged danger of grid side phase sequence) of generator, must stop dragging system and wait until that generator speed is zero (because there is remanent magnetism to exist in double-fed generator rotor and the stator winding, as long as the non-vanishing generator unit stator of generator speed just has induced voltage).Adjust rotor phase sequence or the realization of stator phase sequence, strict guarantee phase sequence unanimity after can disconnecting S2 and S3 disconnector.3. according to f ₁=f ₂+ f _m, f wherein ₁The voltage on line side frequency, f ₂The exciting current frequency, f _mThe generator shaft gyro frequency), the frequency of regulator generator rotating speed or adjusting double-feed current transformer exciting current changes the frequency of stator side induced voltage when the light light and shade is alternately very slow, frequency and line voltage frequency that the stator-induced electromagnetic pressure is described are very approaching, at this moment the moment of waiting for the complete deepening of light arrives, and the switch that is incorporated into the power networks can close a floodgate.

For the simulation of wind power, wind power can be expressed as:

$P_M=\frac{1}{2}{C}_P(\mathrm{\λ},\mathrm{\β}){\mathrm{\ρAv}}^3---\left(1\right)$

$\mathrm{\λ}=\frac{2\mathrm{\πRn}}{v}=\frac{{\mathrm{\ω}}_{\mathrm{tur}}R}{v}---\left(2\right)$

Formula (1), (2) are the mathematical model of wind energy conversion system.Wherein, ρ is atmospheric density, kg/m ³A is that the flow area that flows through wind wheel amasss m ²V is wind speed, m/s; λ is tip speed ratio; ω _TurBe the mechanical angle speed of wind wheel, rad/s; R is the wind wheel radius, m; P _MBe the mechanical output that blower fan is caught, W; T _MBe the machine torque of wind energy conversion system, Nm; C _P(λ β) is power coefficient, and β is propeller pitch angle, its available following function representation

$\left\{\begin{array}{c}{C}_p(\mathrm{\λ},\mathrm{\β})=0.22(\frac{116}{{\mathrm{\λ}}_i}-0.4\mathrm{\β}-5)e^{-\frac{12.5}{{\mathrm{\λ}}_i}}\\ \frac{1}{{\mathrm{\λ}}_i}=\frac{1}{\mathrm{\λ}-0.08\mathrm{\β}}-\frac{0.035}{{\mathrm{\β}}^3+1}\end{array}\right.---\left(3\right)$

Order Be a fixed value, here we are made as wind speed and are divided into incision wind speed, wind rating, three intervals of cut-out wind speed, and value is respectively 4m/s, 12m/s, 18m/s.Compare with these 3 values respectively according to the air speed value in actual measurement wind speed or the database, before the incision wind speed β being set is 0, on duty the incision and wind rating between the time, follow the trail of principle according to the big wind energy of wind and regulate propeller pitch angle β gradually, when wind speed between specified and cut-out wind speed, regulating propeller pitch angle β is pi/2.

Asynchronous machine adopts cage induction motor, at this moment adopt the vector controlled based on the air-gap field orientation, support the switching of direct Power Control, Direct Torque and rotating speed control as this testing table of control of generator and double feedback electric engine for asynchronous machine, also open a Programmable Logic Controller simultaneously, support to download the control strategy of oneself writing, make things convenient for experimental study: concrete grammar is as follows:

System adopts speed closed loop control, and torque controller is pi regulator, and torque reference value is provided

After conversion, obtain the current component reference value

$T_e=p_n{\mathrm{\ψ}}_m^M\×i_s^M=p_n{L}_m{i}_{\mathrm{mm}}{i}_T---\left(8\right)$

${\mathrm{\ω}}_f=\frac{(1+T_{\mathrm{r\σ}}p)i_T}{T_r{i}_{\mathrm{mm}}-T_{\mathrm{r\σ}}{i}_M}---\left(9\right)$

$i_M=\frac{(1+T_{r}p)i_{\mathrm{mm}}+T_{\mathrm{r\&sigma;}}{\mathrm{\&omega;}}_f{i}_{\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="121129154132.png"\; state="\{\{state\}\}">T</figure-callout>}}}{1+T_{\mathrm{r\&sigma;}}p}---\left(10\right)$

In the formula: p is differentiating operator; T _{R σ}Be the rotor leakage time constant; T _rBe rotor time constant; p _nBe number of pole-pairs, when the cage induction motor in the experiment table during as generator its control strategy the control strategy during as generator is identical with double feedback electric engine, just current transformer is full power convertor.

After being incorporated into the power networks, double-fed generator or asynchronous generator detect with the quality of power supply of electric energy mass measurer device to generating, test item comprises parameters such as electric current, voltage, power, harmonic wave, degree of unbalancedness, flickering, on the detecting instrument interface, can demonstrate the detection index situation of the various qualities of power supply, carry out observation, use of electric energy quality test sensor, instrument and meter etc., finally by the Labview system in the PC to data show, processing, storage etc., obtain every test findings of unit, and in display, demonstrate the device oscillogram

Advantage and effect: the utility model provides a kind of two-way wind-powered electricity generation energy conversion experiment table of dynamic model based on double-fed generator and experimental technique, and this experiment table comprises PLC switch board, asynchronous machine, double-fed generator, full power convertor, feeder cabinet, back-to-back converter, substation transformer and quality of power supply surveying instrument; The PLC switch board is connected to frequency converter, frequency converter is connected to asynchronous machine, asynchronous machine links to each other with the axle of double-fed generator and can reciprocally generate electricity, asynchronous machine is connected to full power convertor, full power convertor is connected to feeder cabinet, feeder cabinet is connected to substation transformer, and substation transformer is connected to frequency converter; Double-fed generator also is connected to feeder cabinet on the one hand, is connected with back-to-back converter on the other hand; The PLC switch board is connected with back-to-back converter with full power convertor respectively; The PLC switch board connects PC.

The utility model has been filled up the weak point of existing experiment table, to satisfy multi-faceted teaching demand, realize the multi-function experimental rig about wind-power electricity generation, it can realize the related experiment of two kinds of power generation modes and two kinds of converter structures, can be at PC kind selection a kind of electricity generating plan wherein before operation, its test experience scope comprises the quality of power supply from original wind to send electricity.Allow relative theory and the relevant control technology of the understanding wind-power electricity generation that the experimenter can be more deep.

This experiment table can not only be tested by the simulation wind speed in the PC database but also can gather the anemometer tower measured data, and by the blower fan dynamic model program of writing obtaining data are carried out wind power and simulate, to carry out real-time dynamic similation, experimentize according to these simulated datas then.

The utility model is compared with existing experiment table, the utility model has the advantages that:

1, the utility model practicality is good, and the cost performance height can be finished the experiment of two cover electricity generation systems, be that asynchronous machine links to each other with the armature spindle of double feedback electric engine, reciprocal between them, one is that asynchronous machine drags the double feedback electric engine generating, and one is that double feedback electric engine drags the asynchronous machine generating.

2, this testing table is not only supported in the optional PC database default difference simulation wind speed to test also to support measured data to carry out real time modelling wind power to experimentize.

3, it can simulate feature of wind machine and the wind power under the different wind speed, on-line monitoring and the analysis of control performance, characteristics of output power and the quality of power supply of can also be incorporated into the power networks in real time experiment, rotational speed and torque simulated experiment, unit.

4, test macro adopts international fieldbus, interface and communication network, can carry out secondary development according to demand, has very strong compatibility and extendability.

5, system's design has remote monitoring and data presentation system, has demo function, can understand on-the-spot test situation in real time, satisfies multi-faceted teaching demand.

6, for the control of aerogenerator, this testing table is supported direct Power Control, Direct Torque and rotating speed control, also opens a Programmable Logic Controller simultaneously, supports to download the control strategy of oneself writing, and conveniently carries out the experimental study of control strategy.

The simulation of the attainable wind-force unit of the utility model generating state comprises rotating speed, torque, generated energy and meritorious, idle adjusting.Specific as follows:

1) no-load running experiment

2) be incorporated into the power networks control procedure experiment

3) the continuous running experiment that is incorporated into the power networks

4) wind power simulated experiment

5) torque simulated experiment

6) generated output simulated experiment

7) the aerogenerator Power Quality Detection experiment of generating electricity

8) motor control strategy simulated experiment etc.

The utility model relates to two kinds of wind power generating set pilot systems and test method thereof, can satisfy domestic two big wind power generating set requirement of experiment and teaching requirement at present, can experimentize to complete machine critical component and system.Its design standards height possesses advance and economy, and simultaneously, this utility model can be assisted the education experiment of " aerogenerator and energy conversion " " wind-powered electricity generation unit detection technique " course.

Description of drawings:

Fig. 1 is johning knot composition of the present utility model.

Fig. 2 is two-way wind-powered electricity generation energy flow graph.

Fig. 3 is the workflow diagram when adopting the double-fed generator generating in the utility model.

Fig. 4 is the workflow diagram when adopting the asynchronous generator generating in the utility model.

Fig. 5 is the control flow chart that is incorporated into the power networks of the present utility model.

Fig. 6 is power measurement process flow diagram in the utility model.

Fig. 7 is Power Quality Detection analysis process figure in the utility model.

Fig. 8 is the current transformer control strategy figure of this experiment table.

Fig. 9 is the motor control strategy figure during as dragging motor for the cage induction motor in this experiment table.

Embodiment: the utility model is done nearly step explanation below in conjunction with accompanying drawing:

As shown in Figure 1, the utility model provides the two-way wind-powered electricity generation energy conversion of a kind of dynamic model based on double-fed generator experiment table, and this experiment table comprises PLC switch board, asynchronous machine, double-fed generator, full power convertor, feeder cabinet, back-to-back converter, substation transformer and quality of power supply surveying instrument; The PLC switch board is connected to frequency converter, frequency converter is connected to asynchronous machine, asynchronous machine links to each other with the axle of double-fed generator and can reciprocally generate electricity, asynchronous machine is connected to full power convertor, full power convertor is connected to feeder cabinet, feeder cabinet is connected to substation transformer, and substation transformer is connected to frequency converter; Double-fed generator also is connected to feeder cabinet on the one hand, is connected with back-to-back converter on the other hand; The PLC switch board is connected with back-to-back converter with full power convertor respectively; The PLC switch board connects PC.PC connects anemometer tower.Anemometer tower and display centre control desk just communicate by Profibus between the PC, communicate by Ethernet protocol between PC and the PLC, communicate by letter by CANopen between PLC switch board and the frequency converter, communicating by letter between PLC switch board and the current transformer is Profibus.

Connect quality of power supply surveying instrument behind back-to-back converter, quality of power supply surveying instrument comprises power quality analyzer, power measurement instruments and waveform recording camera; Also connect identical quality of power supply surveying instrument after the full power convertor.The purpose that connects power quality analyzer, power measurement instruments and waveform recording camera after back-to-back converter and full power convertor respectively is to understand the quality of power supply and the power that corresponding electricity generation system is generated electricity; And the electric current that produces carried out dynamic real-time measurement, simulates and demonstrates waveform.And axle is connected to a rotational speed and torque measuring instrument between asynchronous machine and double feedback electric engine, torque rotary speed is carried out real-time and dynamic to be measured, measurement data all shows by man-machine interface, the measurement of torque to transmission shaft load determine all have great importance with the Intensity Design of control, kinematic train working part and prime mover choice of capacity etc., in addition, torque and power concern T=9550p/n, p-power (kW), T-torque (Nm), n-rotating speed (r/min).By measuring rotational speed and torque to understand the relations such as conversion efficiency of power.TM12 numeral torsion sensor for torque rotary speed sensing instrument employing HBM directly links to each other with system by the fieldbus fieldbus.

A crowbar holding circuit in parallel between the rotor-side of double-fed wind power generator and back-to-back converter; The full power convertor centre also connects a chopper leadage circuit; A tachometer torquemeter also is housed between asynchronous machine and double-fed generator.

The experimental technique that utilizes the above-mentioned two-way wind-powered electricity generation energy conversion of the dynamic model based on double-fed generator experiment table to implement, this experiment table can be realized two cover electricity generation systems, realize the control of corresponding power generation mode simultaneously by two cover control softwares, a kind of is that asynchronous machine drags double feedback electric engine operation generating as dragging motor, the double-fed generator rotor-side connects back-to-back converter, and the electricity that stator sends flows into feeder cabinet through the switch cubicle that is incorporated into the power networks; Another kind be double feedback electric engine as dragging motor, asynchronous machine is as generator for electricity generation, the electricity that stator sends flows into feeder cabinet through full power convertor, concrete steps are as follows:

Here we introduce the detection method that three-phase synchronous generator directly is incorporated into the power networks and allow the student understand synchronized process, prevent that simultaneously direct control is incorporated into the power networks switch damaging current transformer and gen-set, even electrical network is impacted.So before carrying out wind-power electricity generation, check that at first whether phase sequence satisfies the condition that is incorporated into the power networks, for detection method, with three direct cross-over connections of bulb between the corresponding phase of electrical network and double-fed generator stator.Combination method is: 1. the size by double-feed current transformer regulator generator rotor excitation current changes the stator terminal induced voltage, and it is identical with amplitude, frequency and the phase place of line voltage that stator-induced electromagnetic is pressed; 2. after voltage is adjusted, if phase sequence unanimity, light should show as light and shade alternately, if not being light and shade, light do not replace, illustrate that then phase sequence is inconsistent, at this moment should adjust the outlet phase sequence (noting: can not adjust the charged danger of grid side phase sequence) of generator, must stop dragging system and wait until that generator speed is zero (because there is remanent magnetism to exist in double-fed generator rotor and the stator winding, as long as the non-vanishing generator unit stator of generator speed just has induced voltage).Adjust rotor phase sequence or the realization of stator phase sequence, strict guarantee phase sequence unanimity after can disconnecting S2 and S3 disconnector.3. according to f ₁=f ₂+ f _m, f wherein ₁The voltage on line side frequency, f ₂The exciting current frequency, f _mThe generator shaft gyro frequency), the frequency of regulator generator rotating speed or adjusting double-feed current transformer exciting current changes the frequency of stator side induced voltage when the light light and shade is alternately very slow, frequency and line voltage frequency that the stator-induced electromagnetic pressure is described are very approaching, at this moment the moment of waiting for the complete deepening of light arrives, and the switch that is incorporated into the power networks can close a floodgate.

For the simulation of wind power, wind power can be expressed as:

$P_M=\frac{1}{2}{C}_P(\mathrm{\&lambda;},\mathrm{\&beta;}){\mathrm{\&rho;Av}}^3---\left(1\right)$

$\mathrm{\&lambda;}=\frac{2\mathrm{\&pi;Rn}}{v}=\frac{{\mathrm{\&omega;}}_{\mathrm{tur}}R}{v}---\left(2\right)$

Formula (1), (2) are the mathematical model of wind energy conversion system.Wherein, ρ is atmospheric density, kg/m ³A is that the flow area that flows through wind wheel amasss m ²V is wind speed, m/s; λ is tip speed ratio; ω _TurBe the mechanical angle speed of wind wheel, rad/s; R is the wind wheel radius, m; P _MBe the mechanical output that blower fan is caught, W; T _MBe the machine torque of wind energy conversion system, Nm; C _P(λ β) is power coefficient, and β is propeller pitch angle, its available following function representation

$\left\{\begin{array}{c}{C}_p(\mathrm{\&lambda;},\mathrm{\&beta;})=0.22(\frac{116}{{\mathrm{\&lambda;}}_i}-0.4\mathrm{\&beta;}-5)e^{-\frac{12.5}{{\mathrm{\&lambda;}}_i}}\\ \frac{1}{{\mathrm{\&lambda;}}_i}=\frac{1}{\mathrm{\&lambda;}-0.08\mathrm{\&beta;}}-\frac{0.035}{{\mathrm{\&beta;}}^3+1}\end{array}\right.---\left(3\right)$

Order

Be a fixed value, here we are made as wind speed and are divided into incision wind speed, wind rating, three intervals of cut-out wind speed, and value is respectively 4m/s, 12m/s, 18m/s.Compare with these 3 values respectively according to the air speed value in actual measurement wind speed or the database, before the incision wind speed β being set is 0, on duty the incision and wind rating between the time, follow the trail of principle according to the big wind energy of wind and regulate propeller pitch angle β gradually, when wind speed between specified and cut-out wind speed, regulating propeller pitch angle β is pi/2.

When selecting the double-fed generator generating, PC is according to the various operating conditions of actual wind field, the unit wind wheel of simulating under the various wind-resources conditions drives situation, remove to control frequency converter by the PLC switch board then and drive asynchronous machine, drag the operation of double-fed wind power generator group by asynchronous machine, when reach and during net spee and phase sequence the double-fed wind power generator group can be generated electricity by way of merging two or more grid systems when consistent, at this moment, quality of power supply surveying instrument begins to gather the operation information of unit and sends control system to and test macro; On the operation interface of PC, can carry out the selection simulation of different operating modes, also can show the wind-resources situation of real-time collection, can carry out the be incorporated into the power networks simulated experiment of control strategy of motor, the process that observe unit synchronization, adjustment of field excitation, is incorporated into the power networks;

When selecting generation mode to be the asynchronous generator generating, the switch cubicle that is incorporated into the power networks in the switch cubicle that is incorporated into the power networks of double-fed generator is connected, give the full power convertor move instruction by the PLC switch board, remove to change the exciting current of double-fed generator rotor again by the control back-to-back converter, thereby change rotor speed, when reach and during net spee and phase sequence the asynchronous generating unit can be generated electricity by way of merging two or more grid systems this moment when consistent, quality of power supply surveying instrument begins to gather the operation information of unit and sends control system to and test macro; On the operation interface of PC, can carry out the selection simulation of different operating modes, also can show the wind-resources situation of real-time collection, can carry out the be incorporated into the power networks simulated experiment of control strategy of motor, the process that observe unit synchronization, adjustment of field excitation, is incorporated into the power networks.

After being incorporated into the power networks, double-fed generator or asynchronous generator detect with the quality of power supply of electric energy mass measurer device to generating, test item comprises parameters such as electric current, voltage, power, harmonic wave, degree of unbalancedness, flickering, on the detecting instrument interface, can demonstrate the detection index situation of the various qualities of power supply, carry out observation, use of electric energy quality test sensor, instrument and meter etc., finally by the Labview system in the PC to data show, processing, storage etc., obtain every test findings of unit, and in display, demonstrate the device oscillogram.

Adopt the vector controlled based on the air-gap field orientation during as dragging motor for cage induction motor, adopt the switching of direct Power Control, Direct Torque Control and rotating speed control as the control of generator and double feedback electric engine for asynchronous machine, also open a Programmable Logic Controller simultaneously, support to download the control strategy of oneself writing, make things convenient for the experimental study of wind-power electricity generation control strategy.Can select a kind of control method wherein to experimentize, when adopting direct Power Control.The position signalling of the error of concrete instantaneous meritorious, reactive power by detecting stator output and the magnetic linkage of rotor, meritorious instruction catches principle according to machine unit characteristic by maximal wind-energy and provides, idle instruction sets up on their own according to demand, according to comparing with detected power and given power, error is carried out computing by the PI power governor, the respectively meritorious and idle component instruction of output motor stator current is then with the meritorious idle component current i of the actual rotor of feedback _Rd, i _RqError be converted into voltage instruction by pi regulator, judge the residing sector of voltage vector according to voltage instruction, be to select optimum voltage vector to follow the tracks of institute with the meritorious reactive power of control generator the scale to be given the variation of instructing from switch.

Experiment table of the present utility model can not only be tested by the simulation wind speed in the PC database but also can take the anemometer tower measured data, by the software that has the blower fan dynamic model obtaining measured data is carried out the wind power prediction simulation, experimentize according to these simulated datas then, can certain understanding be arranged and assess the wind energy quality according to these predicted data, these wind power prediction data deposit the wind power prediction database on the one hand in and show by man-machine interface; Remove to control frequency converter according to the wind power prediction data on the one hand, thereby control drags asynchronous machine, wherein said frequency converter is selected the ABB frequency converter for use.

Characteristics of the present utility model are to carry out two-way generating, and experimental implementation person can select a kind of scheme according to corresponding needs in operation interface.Ultimate principle is to substitute wind wheel by powerful prime mover to go the drawing generator operation, the anemometer tower measured data is carried out simulation and forecast or directly adopt the air speed data simulation wind that presets in the PC database by wind power prediction software, remove to control the PLC switch board according to these simulated datas then, the PLC controller sends corresponding control signal to control module respectively, the scheme difference of selecting, the control signal of sending is also inequality, according to the scheme of selecting, control strategy is correspondingly surveyed in each control module choosing, along with the real-time change of wind speed, control module and can carry out speed governing to prime mover according to wind conditions.When speed reaches set grid-connection speed, the unit current transformer is connected to the grid unit, and after being connected to the grid, move in the current transformer allowed band by adjusting prime mover rotating speed, given by the power factor of adjusting current transformer, can realize the adjusting of generated energy and power factor.

As shown in fig. 1, on-the-spot anemometer tower measured data passes on the PC by Profibus, PC carries out analog to digital conversion to the data after gathering, the inspection of making zero, the dead band checks, limit value checks, rate of change checks, correlation test, the processing of average and standard deviation check, unreasonable and defective data are carried out interpolation and alternative, data after will handling at last are stored in the database of described database server, measurement module reads current output of wind electric field from the electric network data storehouse, and be input quantity with current output of wind electric field, be that correction is predicted with the historical data, draw wind power prediction scope in the next time window, simultaneously the wind energy quality of wind energy turbine set is assessed, estimation range and assessment result deposit wind power data storehouse on the one hand in, show by man-machine interface on the other hand.

The function of PLC switch board is to send control signal according to presetting different simulation wind direction PLC switch boards in actual measurement wind speed or the PC database among Fig. 1, the PLC switch board sends instruction to control module, thereby the rotating speed of control prime mover, namely control the rotating speed of generator, when wind speed reaches cutting speed, control system is sent the instruction of being incorporated into the power networks, thereby realizes the energy conversion of wind-powered electricity generation.The electricity that sends all feeds back to substation transformer by feeder cabinet.

Fig. 2 is two-way wind-powered electricity generation energy flow graph, and redness is scheme 2, and black is scheme 1.

When experiment operator need select double feedback electric engine of the present utility model to generate electricity by course, selection scheme 1 in the PC operation interface, PC sends instruction according to presetting air speed data in actual measurement wind speed or the database to the PLC switch board simultaneously, the PLC switch board sends corresponding work order to full power convertor and back-to-back converter respectively again, full power convertor goes control in real time to drag the rotating speed of asynchronous machine according to the real time modelling data of surveying or preset wind among the PC, thereby change the double fed electric machine rotor rotational speed, rotor-side is carried out adjustment of field excitation by back-to-back converter to it, the rotational speed and torque measuring instrument carries out the rotational speed and torque measurement to the coupling shaft of asynchronous machine and double feedback electric engine simultaneously, measurement data feeds back to PC respectively, so that its rotating speed is controlled in real time, simultaneously the quality of power supply of sending electricity is detected in real time, in addition can according to these the phase sequence of the electricity that sends of the stator of the rotating speed of surveying and double feedback electric engine, voltage, can frequency is judged be incorporated into the power networks its workflow such as Fig. 3.

When experiment operator need be selected the asynchronous machine generating by course, selection scheme 2 in the PC operation interface, this moment, PC sent instruction according to presetting air speed data in actual measurement wind speed or the database to the PLC switch board, the PLC switch board sends corresponding work order respectively again in back-to-back converter and full power convertor, at this moment, the stator of double feedback electric engine directly connects electrical network, by the rotor-side back-to-back converter it is carried out slip regulating speed, back-to-back converter removes to control the rotor-exciting of double feedback electric engine according to the real time modelling data of surveying or preset wind among the PC, thereby change the rotational speed of double fed electric machine rotor, namely change the rotational speed of asynchronous machine, the electricity that asynchronous machine sends directly connects full power convertor, in the time of the DFIG rotation, the rotational speed and torque measuring instrument carries out the rotational speed and torque measurement to the coupling shaft of asynchronous machine and double feedback electric engine, measurement data feeds back to PC respectively, so that its rotating speed is controlled in real time, simultaneously the quality of power supply after the full power convertor is detected in real time and analyzes, in addition can according to these the phase sequence of the electricity that sends of the stator of the rotating speed of surveying and double feedback electric engine, voltage, can frequency is judged be incorporated into the power networks its workflow such as Fig. 4.

As shown in Figure 5, we introduce the detection method that three-phase synchronous generator directly is incorporated into the power networks and allow the student understand synchronized process here, prevent that simultaneously direct control is incorporated into the power networks switch damaging current transformer and gen-set, even electrical network is impacted.So before carrying out wind-power electricity generation, check that at first whether phase sequence satisfies the condition that is incorporated into the power networks, for detection method, with three direct cross-over connections of bulb between the corresponding phase of electrical network and double-fed generator stator.Combination method is: 1. the size by double-feed current transformer regulator generator rotor excitation current changes the stator terminal induced voltage, and it is identical with amplitude, frequency and the phase place of line voltage that stator-induced electromagnetic is pressed; 2. after voltage is adjusted, if phase sequence unanimity, light should show as light and shade alternately, if not being light and shade, light do not replace, illustrate that then phase sequence is inconsistent, at this moment should adjust the outlet phase sequence (noting: can not adjust the charged danger of grid side phase sequence) of generator, must stop dragging system and wait until that generator speed is zero (because there is remanent magnetism to exist in double-fed generator rotor and the stator winding, as long as the non-vanishing generator unit stator of generator speed just has induced voltage).Adjust rotor phase sequence or the realization of stator phase sequence, strict guarantee phase sequence unanimity after can disconnecting S2 and S3 disconnector.3. according to f ₁=f ₂+ f _m, f wherein ₁The voltage on line side frequency, f ₂The exciting current frequency, f _mThe generator shaft gyro frequency), the frequency of regulator generator rotating speed or adjusting double-feed current transformer exciting current changes the frequency of stator side induced voltage when the light light and shade is alternately very slow, frequency and line voltage frequency that the stator-induced electromagnetic pressure is described are very approaching, at this moment the moment of waiting for the complete deepening of light arrives, and the switch that is incorporated into the power networks can close a floodgate.

As shown in Figure 6, be respectively the power detection instrument of this experiment table, they are gathered the model image data and are converted to digital signal by multi-channel high-speed, are sent to the digital quantity output module through digital processing system then.It is connected on after the switch cubicle that is incorporated into the power networks, as shown in Figure 1, respectively size, frequency and the phase place of measuring appliance electric current and voltage, thus draw parameters such as the active power sent, reactive power, power factor, and show by display.

As shown in Figure 7, be the process flow diagram of the power quality analyzer principle of work of this testing table, if double-fed wind power generator then the Power Quality Detection point be connected in after the stator terminal and back-to-back converter of double feedback electric engine; If asynchronous machine as generator then the Power Quality Detection point be connected after the full power convertor, as shown in Figure 1, under corresponding scheme, detect the corresponding quality of power supply, to understand the wind-power electricity generation situation.The testing process of the quality of power supply as shown in Figure 5.Carry out data acquisition by the multi-channel data acquisition unit, then the data that collect are carried out analog to digital conversion, be converted to digital signal, through too much DSP data processing.To guarantee the accurate measurement of parameter, then corresponding parameter and waveform are shown by display, wherein the 2-63 subharmonic of cocoa measuring voltage and electric current; But the measuring voltage deviation, frequency departure, various power quality parameters such as voltage fluctuation and flickering.Temporal Datas such as tri-phase unbalance factor, polar plot demonstration, voltage swells, voltage dip, superpotential, under-voltage are measured, three and individual event power, applied power, active power, reactive power, phasor power factor, total power factor etc.

As shown in Figure 8, be the current transformer control strategy of this experiment table, what outer shroud control was selected for use is meritorious and idle control, and in addition, the active power outer shroud can be torque or the control of rotating speed outer shroud, and interior ring device processed is current closed-loop control.Stator side active power p wherein _s, the stator side reactive power Q _s, electromagnetic torque T _eWith rotor speed ω _rThe numerical value of surveying for testing tool feeds back in the controller.Be example to adopt direct Power Control, the position signalling of the error of concrete instantaneous meritorious, reactive power by detecting stator output and the magnetic linkage of rotor, meritorious instruction catches principle according to machine unit characteristic by maximal wind-energy and provides, idle instruction is according to the electrical network requirements set, according to comparing with detected power and given power, error is carried out computing by the PI power governor, the respectively meritorious and idle component instruction of output motor stator current is then with the meritorious idle component current i of the actual rotor of feedback _Rd, i _RqError be converted into voltage instruction by pi regulator, judge the residing sector of voltage vector according to voltage instruction, be to select optimum voltage vector to follow the tracks of institute with the meritorious reactive power of control generator the scale to be given the variation of instructing from switch, other control method is similar with this.Stator side active power P wherein _s, the stator side reactive power Q _s, electromagnetic torque T _eWith rotor speed ω _rWith the pass of rotor current be:

T _e＝n _pL ₀(i _qsi _dr-i _dsi _qr)＝L ₀n _pψ _si _qr/L _s＝L ₀n _pU _si _qr/(L _sω ₁) (4)

P _s＝u _dsi _ds+u _qsi _qs＝U _si _qs＝U _sL ₀i _qr/L _s (5)

Q _s＝u _qsi _ds-u _dsi _qs (6)

$J\frac{{\mathrm{d\&omega;}}_r}{\mathrm{dt}}+B{\mathrm{\&omega;}}_r=n_p(T_m-\frac{L_0{n}_p{U}_s{i}_{\mathrm{qr}}}{L_s{\mathrm{\&omega;}}_1})---\left(7\right)$

L _sSelf-induction for stator winding under the dq coordinate system; L ₀Be the equivalent mutual inductance between stator winding under the dq coordinate system and rotor winding.u _DsAnd u _QsBe respectively stator voltage dq axle component, i _DsAnd i _QsBe respectively stator current dq axle component, i _DrAnd i _QrBe respectively rotor current dq axle component, ψ _DsAnd ψ _QsBe respectively stator magnetic linkage dq axle component, J is moment of inertia.

As shown in Figure 9, the motor control strategy figure during as dragging motor for the cage induction motor in this experiment table.At this moment, cage induction motor adopts the vector control strategy based on the air-gap field orientation.System adopts speed closed loop control, is characterized in that vector control system is simple, and air-gap flux is easy to detect, and is saturated in order to processing and control magnetic circuit.Torque controller is pi regulator, and torque reference value is provided After conversion, obtain the current component reference value

$T_e=p_n{\mathrm{\&psi;}}_m^M\&times;i_s^M=p_n{L}_m{i}_{\mathrm{mm}}{i}_T---\left(8\right)$

${\mathrm{\&omega;}}_f=\frac{(1+T_{\mathrm{r\&sigma;}}p)i_T}{T_r{i}_{\mathrm{mm}}-T_{\mathrm{r\&sigma;}}{i}_M}---\left(9\right)$

$i_M=\frac{(1+T_{r}p)i_{\mathrm{mm}}+T_{\mathrm{r\&sigma;}}{\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="1"\; label="f\; i\; T"\; filenames="121129154132.png"\; state="\{\{state\}\}">f</figure-callout>}}{i}_T{}_{}}{1+T_{\mathrm{r\&sigma;}}p}---\left(10\right)$

In the formula: p is differentiating operator; T _{R σ}Be the rotor leakage time constant; T _rBe rotor time constant; p _nBe number of pole-pairs.When the cage induction motor in the experiment table during as generator its control strategy the control strategy during as generator is identical with double feedback electric engine, just current transformer is full power convertor.

In addition, this testing table also is furnished with Programmable Logic Controller, and the experimenter can download to the control strategy of oneself in the controller and experimentize, and makes things convenient for the control strategy optimization of wind-powered electricity generation energy conversion to study.

The utility model has well solved the existing problem of existing experiment table, and its effect is obvious, and is rational in infrastructure, convenient to use, and favorable expandability can be good at satisfying teaching demand, is beneficial in the instrument and equipment field to apply.

Claims (4)

1. the two-way wind-powered electricity generation energy conversion of the dynamic model based on double-fed generator experiment table, it is characterized in that: this experiment table comprises PLC switch board, asynchronous machine, double-fed generator, full power convertor, feeder cabinet, back-to-back converter, substation transformer and quality of power supply surveying instrument; The PLC switch board is connected to frequency converter, frequency converter is connected to asynchronous machine, asynchronous machine links to each other with the axle of double-fed generator and can reciprocally generate electricity, asynchronous machine is connected to full power convertor, full power convertor is connected to feeder cabinet, feeder cabinet is connected to substation transformer, and substation transformer is connected to frequency converter; Double-fed generator also is connected to feeder cabinet on the one hand, is connected with back-to-back converter on the other hand; The PLC switch board is connected with back-to-back converter with full power convertor respectively; The PLC switch board connects PC.

2. the two-way wind-powered electricity generation energy conversion of the dynamic model based on double-fed generator according to claim 1 experiment table, it is characterized in that: full power convertor and double-fed generator all are connected to feeder cabinet by the switch cubicle that is incorporated into the power networks/drags.

3. the two-way wind-powered electricity generation energy conversion of the dynamic model based on double-fed generator according to claim 2 experiment table, it is characterized in that: be connected an identical quality of power supply surveying instrument respectively after back-to-back converter and full power convertor, quality of power supply surveying instrument comprises power quality analyzer, power measurement instruments and waveform recording camera.

4. according to claim 1 or the two-way wind-powered electricity generation energy conversion of 3 described dynamic models based on double-fed generator experiment table, it is characterized in that: the crowbar holding circuit of a protection current transformer in parallel and direct supply between the rotor-side of double-fed wind power generator and back-to-back converter respectively; The full power convertor centre also connects a chopper leadage circuit; A tachometer torquemeter also is housed between asynchronous machine and double-fed generator.

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