CN202617060U - Control system of variable speed constant frequency double-rotor permanent magnetic wind power generation system - Google Patents

Abstract

The utility model discloses a control system of a variable speed constant frequency double-rotor permanent magnetic wind power generation system. The control system comprises a double pulse width modulation (PWM) converter control system and a low-voltage traversing control device in a direct current link; the double PWM converter control system comprises a generator PWM converter control system and a network PWM converter control system; and the low-voltage traversing control device comprises an unloading circuit and a control circuit thereof, and the unloading circuit is connected in parallel at two ends of a direct current link capacitor C between the generator PWM converter control system and the network PWM converter control system. Through the system, the whole wind power system can realize a maximum wind energy tracking function of a motor, the voltage of the direct current link is stabilized, bidirectional flow and independent control of active power and reactive power of the system are realized, voltage drop of the direct current link of the system can be quickly compensated when a power grid fails, voltage stability of the direct current link is ensured, the system has low-voltage traversing capability, and safe and reliable operation of the unit are ensured.

Description

The control system of variable speed constant frequency birotor permanent magnetic wind generator system

Technical field

The utility model is about a kind of variable speed constant frequency birotor permanent magnetic Control Technology of Wind Power Generation System, belongs to the generation of electricity by new energy technical field.

Background technology

Wind energy is a kind of regenerative resource of cleaning; In today that energy crisis and environmental problem constantly highlight; Develop actively comprises that the generation technology of regenerative resources such as wind energy, solar energy is the task of top priority; Development be suitable for the utilization of wind energy effective conversion, reliable, control is convenient and lower-cost wind power generation system becomes current urgent and technical problem that influence is bigger; Simultaneously corresponding, how to make electric energy obtain that efficient is higher, more stable, the quality of power supply better and how to control and guarantee that power network safety operation becomes problem demanding prompt solution.

For the variable speed constant frequency control system of wind turbines; Adopt two pwm converters of two level; Middle DC link can be realized the decoupling zero of former and later two converters, makes that both control is relatively independent not disturb mutually, even slight fault appears in the net side; Also can be stable and do not influence the control of motor side converter through effectively control DC bus-bar voltage for the adjusting of grid side converter; Otherwise, when the abnormal running situation appears in motor side, as long as can guarantee that through control it is the realization of MPPT function that maximal wind-energy is followed the tracks of for the motor side converter; Only be equivalent to a load disturbance for grid side converter, both combinations can realize the two-way flow of power and for electric network fault certain adaptive capacity arranged.

For variable speed constant frequency birotor permanent magnetic wind-driven power generation control system; Adopted above-mentioned pair of pwm converter, realized control, can realize the two-way flow of maximal wind-energy tracking, unity power factor operation, stable DC link voltage and power for converter through flux linkage orientation and voltage oriented vector control strategy and SVPWM modulation algorithm; In addition; For strengthening the adaptive capacity for electric network fault, the DC link in the middle of converter adds discharging circuit, when dc tache voltage exceeds limit value; Can guarantee that dc tache voltage in safe range, improves the ability that runs without interruption of unit through the power device of control discharging circuit.

Summary of the invention

Technical problem: the purpose of the utility model is to provide a kind of variable speed constant frequency birotor permanent magnetic wind-driven power generation control system that is incorporated into the power networks that is applicable to; Make the maximal wind-energy following function of its pusher side of both can having realized generating electricity; The stable DC link voltage realizes the two-way flow of power, realizes the independent control of active power and reactive power; Again can be when electric network fault the falling of quick bucking-out system dc tache voltage; The assurance dc tache voltage is stable, and the system that makes has low voltage ride-through capability, guarantees the safe and reliable operation of unit.

Technical scheme: the described variable speed constant frequency birotor permanent magnetic of the utility model wind-driven power generation control system comprises that the control system of two pwm converters and the low-voltage of DC link pass through control system.Wherein, described pair of pwm converter control system comprises generating pusher side and net side pwm power control control system.The former is earlier with the input signal of extraneous wind speed as the MPPT module; The reference rotation velocity signal of output and motor internal rotor rotating speed rotating speed detected value are as the input signal of rotational speed control module; The output signal is for handing over the axle reference current signal; Given direct-axis current reference value is zero; The ac-dc axis current reference signal is compared with internal rotor ac-dc axis current detection signal under the dq coordinate system that obtains after Clark conversion and the Park conversion respectively, participate in computing, its output signal and current feed-forward decoupling zero component are carried out plus and minus calculation as the input signal of two current control module; The inside and outside rotor-position difference of motor that the ac-dc axis reference voltage signal of output and speed measuring device obtain is connected to the transform vector module; Two phase voltages under the output α β coordinate system, at last with above-mentioned voltage signal and the input signal of dc tache voltage detected value as the SVPWM signal generating module, its output signal is for driving the SVPWM signal of the pusher side pwm converter that generates electricity; The latter is with dc voltage set-point and its voltage detecting value input signal as the voltage on line side control module; Output d-axis reference current; Given friendship axle reference current value is zero; The ac-dc axis current reference signal is compared with the off line top-cross direct-axis current of the dq coordinate system detection signal that after Clark conversion and Park conversion, obtains respectively; Participate in computing as the input signal of two current control module, will export signal and current feed-forward decoupling zero component, voltage compensation component carry out plus and minus calculation, the ac-dc axis reference voltage signal of output and the motor outer rotor positional value that Hall element obtains are as the input signal of transform vector module; Voltage signal is sent into the SVPWM signal generating module with the dc tache voltage detected value under the α β coordinate system of output, but the SVPWM signal of output Driving Net side pwm converter; In addition; The discharging circuit that the low-voltage of described DC link is passed through control device comprises power device and resistance, and both are in series, and is connected to the electric capacity two ends; Its discharging circuit control system comprises: the reference voltage by the detection signal of dc tache voltage during with malfunction is compared; Via sending into comparator behind the pi regulator, be used to generate the modulation signal of power controlling break-over of device duty ratio, thereby regulate direct voltage near set point.

Control for two pwm converters; Can realize the function of the MPPT control of generator, meritorious idle adjusting and stable DC link voltage; The vector control method that is adopted has stator magnetic linkage oriented vector control, line voltage vector control etc., helps to realize controlled function through current feed-forward decoupling-structure and electric voltage feed forward collocation structure etc.; Low-voltage pass through control device only when grid failure state work be used for the bucking voltage loss; When system normally moves; This control device is not worked, and this low-voltage traversing device adopts insulated gate bipolar transistor, the loss of compensating network voltage when realizing malfunction through the control for power device; The system that keeps normally moves, and guarantees that motor normally is incorporated into the power networks.

The SVPWM signal generating module can realize with DSP.

The control method of above-mentioned variable speed constant frequency birotor permanent magnetic wind generator system is: the generator side converter can be realized MPPT control through the method for best tip speed ratio method or Feedback of Power; The former compares the internal rotor tach signal of the wind velocity signal of gathering via MPPT module and actual acquisition; Obtain handing over the shaft current reference signal, the latter then is through stator magnetic linkage oriented control, obtains meritorious, the reactive power of stator side; Can know such relation that exists through deriving; Promptly get final product the independent regulation actual power, obtain stator and rotor side current relationship, the relation of stator current and power is changed into the relation of power and internal rotor side electric current through the magnetic linkage relation through regulating the stator DC and AC electric current; Make and to regulate the variation that to regulate power through internal rotor current; Obtain the mechanical output that blower fan obtains through the Bates theory, through confirm the best also speed reducing ratio obtain optimized rotating speed, corresponding optimal power curve when obtaining different wind speed; Power relation by double-rotor machine obtains corresponding optimum reference active power; Follow the trail of the optimum active power of reference through regulate the actual active power of motor for the control of internal rotor electric current, both compare and obtain handing over the reference signal of shaft current, can realize MPPT control equally; Given signal of resulting alternating current and the given signal of direct-axis current are together sent into current control module; Together send into current control module relatively with the rotor-side current signal that the actual acquisition conversion obtains; Pass through behind the transform vector among the supplied with digital signal processor DSP, the SVPWM signal of output is used for the drive motors side converter again.Grid side is through voltage oriented control; The virtual voltage of DC link is compared with the reference voltage of setting; Obtaining reference current signal compares with actual current signal; Obtain modulation signal via the voltage compensation link, the process transform vector is imported among the DSP at last and is exported SVPWM signal Driving Net side pwm converter with the stable DC link voltage again; Grid side converter is realized the Reactive Power Control of converter through given reactive current component, can realize that through vector control the active power of generator and reactive power independently control operation; In addition; During the line voltage malfunction; The low-voltage control of DC link compares through the direct voltage and the set point at the monitoring control devices storage capacitor two ends of discharging circuit; When direct voltage exceeded limit value, the power device that triggers discharging circuit guaranteed that to regulate direct voltage its value is in the scope of safety.

Beneficial effect: the advantage of the utility model is: a kind of variable speed constant frequency birotor permanent magnetic wind-driven power generation control system that is incorporated into the power networks that is applicable to; Make the whole wind electric system both can realize the maximal wind-energy following function of motor side; The stable DC link voltage; Realize the two-way flow of power and the independent control of system's active power and reactive power, again can be when electric network fault the falling of quick bucking-out system dc tache voltage, guarantee that dc tache voltage stablizes; The system that makes has low voltage ride-through capability, guarantees the safe and reliable operation of unit; Generating pusher side in the controller of two pwm converters and net side pwm power converter controller circuit comprise electric current, voltage sampling circuit, rotating speed P-pulse Acquisition Circuit and corresponding signal processing circuit and can produce the work of SVPWM signal driving power converter realizes that speed change is regulated and the DSP signal processing circuit of stable DC link voltage; Circuit structure is simple; Control flexibly; Feedback of Power control of adopting and electric current decoupling zero control algolithm can realize meritorious idle independent control; Help the adjusting of power factor, the use that low-voltage is passed through control device then makes dynamic performance more carefully, reduces the transient current response that electric motor starting combined floodgate impulse current, electric network fault and various disturbance cause; The dynamic and static performance of raising system has been optimized the quality of power supply.

Description of drawings

Fig. 1 comprises the variable speed constant frequency dual-rotor wind power generation system diagram that the DC link low-voltage is passed through control device;

Fig. 2 is a variable speed constant frequency dual-rotor wind power generation control system structure chart;

Fig. 3 is a variable speed constant frequency dual-rotor wind power generation control system schematic diagram.

Embodiment

A kind of control method of variable speed constant frequency birotor permanent magnetic wind generator system, step comprises:

A, to the control of generating pusher side pwm converter, can realize that respectively the maximal wind-energy tracking module is the MPPT module controls through best tip speed ratio method or two kinds of methods of Feedback of Power method:

Best tip speed ratio method promptly refers to for a definite wind energy conversion system, when keeping slurry elongation β constant, always has one corresponding to maximal wind-energy usage factor C _PmaxBest tip speed ratio λ _Opt, make that the conversion efficiency of wind energy conversion system this moment is the highest, that is to say that for a specific wind speed v, wind energy conversion system only operates in a specific rotational speed omega _r ^*Just have down the highest wind energy conversion efficiency, owing to constantly change during extraneous wind speed, therefore, must, wind speed in time adjust the wind energy conversion system rotational speed omega when changing _r, make it to satisfy relational expression ω _r=λ _OptV/R makes C _pRemain at optimal value C _Pmax, and then realize MPPT control.In the control wind velocity signal of gathering is passed through relational expression ω in the MPPT module _r=λ _OptV/R calculates the reference rotation velocity ω of wind energy conversion system operation _r ^*, and wind energy conversion system directly links to each other with the motor internal rotor is coaxial, and both rotating speeds are identical, and promptly the reference rotation velocity of motor internal rotor also is ω _r ^*, with itself and the internal rotor tach signal ω that collects _iCompare,, can obtain handing over the reference signal of shaft current through pi regulator.

In the prior art, the Feedback of Power method promptly refers to the power output P and the wind speed v of wind wheel are connected, and utilizes the ω=λ that concerns that wind speed v and rotational speed omega satisfy _OptV/R has a specific rotational speed omega for each power output ^*, obtain constant tip speed ratio λ _Opt, promptly under any wind speed,, its blade tip linear velocity and the ratio of wind speed are remained unchanged, and all satisfy λ=λ through regulating rotation speed of fan ω _Opt, then under the immesurable situation of wind speed, through the wind energy conversion system rotating speed that records, can obtain corresponding air speed this moment, thereby confirm the maximum power of this moment according to the power curve of wind energy conversion system, can realize MPPT control.Adopt stator magnetic linkage oriented control, exist to concern ψ _Ds=ψ ₁, ψ _Qs=0 and U _Ds=0, U _Qs=-U ₁Set up, wherein, ψ _DsAnd ψ _QsRepresent generator unit stator d-axis magnetic linkage respectively and hand over axle magnetic linkage, ψ ₁Represent the desirable stator d-axis magnetic linkage under the stator magnetic linkage oriented situation, U _DsAnd U _QsRepresent generator unit stator direct-axis voltage and quadrature-axis voltage respectively, U ₁Expression motor stator terminal voltage amplitude, i _DsAnd i _QsExpression motor stator winding direct-axis current and friendship shaft current; Calculate optimized rotating speed according to the Feedback of Power method through wind speed and best tip speed ratio value again, and then obtain the maximum power of blower fan output:

$P_{\max }={\mathrm{kw}}_m^3,k=\mathrm{\ρA}{(R/{\mathrm{\λ}}_{\mathrm{opt}})}^3{C}_{p\max }/2$

In the formula, P _MaxThe maximum power of expression wind energy conversion system output, w _mThe mechanical separator speed of expression wind energy conversion system, A is the inswept area of wind energy conversion system fan blade, A=π R ², R is the blade radius of blower fan, ρ representes atmospheric density, C _PmaxExpression maximal wind-energy usage factor, λ _OptRepresent best tip speed ratio.

Can obtain optimum reference power under the different wind speed according to above-mentioned power relation, depict the optimal power curve, and then the instruction of structure stator active power of output:

$P^{*}=P_{\max }/(1-s)-\mathrm{\ΔP}={\mathrm{kw}}_m^3/(1-s)-\mathrm{\ΔP}$

In the formula, P ^*The optimum active power reference value of expression stator terminal output, P _MaxThe maximum power of expression wind energy conversion system output, s representes the slip of inner and outer rotors, Δ P representes power loss.

There are such relation in magnetic linkage and electric current:

ψ _ds＝ψ _mo+L _si _ds+L _mi _dr

ψ _qs＝L _si _qs+L _mi _qr

ψ _dr＝ψ _mi+L _ri _dr+L _mi _ds

ψ _qr＝L _ri _qr+L _mi _qs

In the formula, ψ _Dsψ _QsThe expression motor stator is straight, a friendship axle magnetic linkage, ψ _Drψ _QrExpression motor internal rotor is straight, a friendship axle magnetic linkage,

Expression motor outer rotor both sides permanent magnetism is at the permanent magnetism magnetic linkage of stator and internal rotor side, i _Dsi _QsThe expression motor stator winding is straight, the friendship shaft current, i _Dri _QrStraight, the friendship shaft current of expression motor internal rotor winding, L _sExpression motor stator inductance, L _rExpression motor internal rotor inductance, L _mMutual inductance between expression motor stator and internal rotor.

Know the relation of stator and rotor side electric current by inference through following formula, obtain that stator side is meritorious, reactive power exists as follows with the stator current component and concerns:

P＝-U ₁i _qs

Q＝-U ₁i _ds

But can know through regulating stator DC and AC electric current independent regulation stator side actual power by following formula; Again according to the relation of stator and rotor electric current, can the stator side that obtain is meritorious, reactive power and the stator current relation converts into and the internal rotor electric current between relation, then can regulate power through internal rotor current; Reference power compared with actual feedback power can obtain the reference value of internal rotor ac-dc axis electric current, can realize the MPPT module controls equally;

Above-mentioned two kinds of methods all can realize MPPT control; And then obtain the internal rotor ac-dc axis current reference signal that the Current Control link needs; The rotor-side current feedback signal that the more given signal of the alternating current that obtains, the given signal of direct-axis current and actual acquisition and conversion is obtained compares; Send into the SVPWM signal generating module to comparative result through behind the transform vector again, the SVPWM signal of output is used for the drive motors side converter;

B, to the control of net side PWM controller:

Through voltage oriented control, the virtual voltage of DC link is compared with the reference voltage of setting earlier, obtain reference current signal; Compare this reference current signal with actual current signal again, then according to comparative result via the voltage compensation link:

${u_d}^{*}-u_d-({i_{\mathrm{ds}}}^{*}-i_{\mathrm{ds}})(K_p+\frac{K_i}{s})+\mathrm{\ω}{\mathrm{Li}}_{\mathrm{qs}}$

${u_q}^{*}-u_q-({i_{\mathrm{qs}}}^{*}-i_{\mathrm{qs}})(K_p+\frac{K_i}{s})+\mathrm{\ω}{\mathrm{Li}}_{\mathrm{ds}}$

In the formula, u _du _qElectrical network d-axis and quadrature-axis voltage that the expression synchronous rotating frame is gathered down in real time, i _Dsi _QsRepresent stator terminal d-axis and friendship shaft current, i that synchronous rotating frame is gathered down in real time _Ds ^*i _Qs ^*The given reference value of biphase current under the expression synchronous rotating frame, K _pK _iBe the proportionality coefficient of pi regulator, ω representes the external rotor rotating speed, and L representes the inlet wire reactance value of electrical network, u _d ^*u _q ^*D-axis and quadrature-axis voltage under the expression synchronous rotating frame.

Carry out voltage compensation through above-mentioned link, obtain modulation signal; This modulation signal is exported SVPWM signal Driving Net side pwm converter with the stable DC link voltage by the SVPWM signal generating module at last through input SVPWM signal generating module behind the transform vector at last;

C, in DC link; The direct voltage at the DC link capacitor C two ends between monitoring generating pusher side pwm converter and the net side pwm converter; Compare this direct voltage and set point; When direct voltage surpasses limit value, regulate direct voltage and guarantee that dc voltage value is in the scope of safety.

A kind of control system of variable speed constant frequency birotor permanent magnetic wind generator system, this control system comprise that the low-voltage of two pwm converter control system and DC link passes through control device; Two pwm converter control system comprise generating pusher side pwm converter control system and net side pwm converter control system; Low-voltage is passed through control device and is comprised discharging circuit and control circuit thereof, and discharging circuit is connected to the DC link capacitor C two ends between generating pusher side pwm converter and the net side pwm converter;

A, generating pusher side pwm converter control system, comprising: the maximal wind-energy tracking module is MPPT module, rotational speed control module, current control module and SVPWM signal generating module;

Extraneous wind velocity signal is as the input signal of MPPT module; The reference rotation velocity signal of MPPT module output and the rotating speed detected value signal of motor internal rotor are as the input signal of rotational speed control module; The output signal of rotational speed control module is for handing over the axle reference current signal, and simultaneously, given direct-axis current reference value is zero; Friendship, direct-axis current reference signal are inputed to comparator and compare with the friendship of internal rotor under the dq coordinate system that obtains after Clark conversion and the Park conversion, direct-axis current detected value signal respectively, and comparative result is as the input signal of current control module; Current control module output signal and current feed-forward decoupling zero component are exported friendship, d-axis reference voltage signal through adder and subtracter respectively; Difference signal between the inside and outside rotor-position of the motor that speed measuring device records and friendship, d-axis reference voltage signal be as the input signal of transform vector module, two phase voltage signals under the transform vector module output α β coordinate system; Two phase voltage signals and dc tache voltage detected value signal are as the input signal of SVPWM signal generating module under the α β coordinate system, and SVPWM signal generating module output signal is the SVPWM signal that can drive generating pusher side pwm converter;

B, net side pwm converter control system comprise: voltage on line side control module, current control module and SVPWM signal generating module;

With dc voltage set-point and its dc voltage detected value input signal as the voltage on line side control module; Voltage on line side control module output d-axis reference current, simultaneously, given friendship axle reference current value is zero; This friendship, direct-axis current reference signal are compared with the off line top-cross of dq coordinate system that after Clark conversion and Park conversion, obtains, direct-axis current detection signal input comparator respectively, and comparative result is as the input signal of current control module; The output signal of current feed-forward decoupling zero component, voltage compensation component and current control module is through adder output friendship, d-axis reference voltage signal; The motor outer rotor positional value that friendship, d-axis reference voltage signal and Hall element record is as the input signal of transform vector module; Voltage signal under the transform vector module output α β coordinate system; Voltage signal and dc tache voltage detected value signal are as the input signal of SVPWM signal generating module under the α β coordinate system, and the output signal of SVPWM signal generating module gets final product the SVPWM signal of Driving Net side pwm converter;

C, said discharging circuit comprise power device and resistance, and the I/O end of power device is connected in the capacitor C two ends with after resistance is connected;

The discharging circuit control circuit comprises pi regulator and comparator; After reference voltage by the dc tache voltage detected value during with malfunction is compared, behind pi regulator, send into an input of comparator, another input input clock pulse signals of comparator; The output of comparator connects the control end of power device.

Accompanying drawing discloses the concrete structure of the utility model embodiment without limitation, below in conjunction with accompanying drawing the utility model is described further.

Visible by Fig. 1; Comprise the DC link low-voltage and pass through the variable speed constant frequency dual-rotor wind power generation system composition of control device; Its connected mode is that generating pusher side pwm converter is connected with the internal rotor winding of birotor permanent magnetic generator; King's side pwm converter is connected with electrical network, and the low-voltage traversing device is connected to the DC link electric capacity two ends of two pwm converters.

Visible by Fig. 2; Variable speed constant frequency birotor permanent magnetic wind-driven power generation control system comprises: the generating pusher side passes through control device with the control system of net side pwm converter and the low-voltage of DC link; Wherein, Generating pusher side pwm converter control circuit comprises maximal wind-energy tracking module MPPT, rotational speed control module, current control module, and net side pwm converter comprises voltage control module and current control module, and the low-voltage traversing device comprises discharging circuit and control circuit thereof; Wherein, discharging circuit is connected to two pwm converter intermediate dc link electric capacity two ends.

Visible by Fig. 3, system's control comprises the control technology of passing through for the control and the DC link low-voltage of two pwm converters.Wherein, the control of generating pusher side pwm power converter comprises that best tip speed ratio control, vector control and SVPWM modulation signal produce link and constitute, and realizes and export the SVPWM modulation signal being used to drive the pwm power converter; The control of net side pwm converter is similar with the generating pusher side, by the SVPWM modulation signal Driving Net side pwm power converter that produces; DC link low-voltage traversing device comprises discharging circuit and control circuit thereof, and the direct voltage and the set point at the monitoring control devices storage capacitor two ends through discharging circuit compare, and carry out corresponding control, guarantees that voltage moves in safe range.

When system moves,, collect the internal rotor three-phase current, obtain the biphase current i under the synchronous rotating frame through Clark conversion and Park conversion by current sensor for generating pusher side pwm power converter _di _q, and with the given reference value i of biphase current under the controlled motor synchronous rotating coordinate system _d ^*i _q ^*Send into the current PI adjuster with the error that the above-mentioned biphase current detected value that collects is in real time compared, wherein, hand over the given reference current i of axle _q ^*Be through speed reference ω ^*With the internal rotor rotating speed detected value ω that collects _iCompare and obtain ω through the rotating speed pi regulator ^*Be to calculate by the nature wind speed that collects, adopt d-axis reference current i through best tip speed ratio method _d ^*=0 provides the direct-axis current set-point; Consider the current feed-forward decoupling zero, with the magnitude of voltage u of above-mentioned current PI adjuster output _du _qAdd and subtract the set-point u that obtains two voltages mutually with the feedforward compensation component _d ^*u _q ^*, obtain the voltage u under the two phase rest frames through the Park inverse transformation again _α ^*u _β ^*, its angle value θ that participates in the Park conversion is the difference of the inside and outside rotor-position signal that obtains through Hall element and photoelectric encoder; With two phase voltage value u under the above-mentioned rest frame that obtains _a ^*u _β ^*With the dc tache voltage value U that collects _DcSend into SVPWM signal generator link together, the space vector modulation signal that is used for drive motors side pwm converter after can obtaining modulating.

For net side pwm power converter, collect grid side three-phase current, three-phase voltage signal by electric current, voltage sensor, obtain the biphase current i under the synchronous rotating frame through Clark conversion and Park conversion _Dsi _Qs, voltage u _du _q, with the given reference value i of biphase current under the controlled motor synchronous rotating coordinate system _Ds ^*i _Qs ^*With the above-mentioned biphase current detected value i that collects in real time _Dsi _QsError signal is relatively sent into the current PI adjuster, wherein, and the given reference current i of d-axis _Ds ^*Be through dc tache voltage reference value V _Dc ^*With the DC link detected value V that collects in real time _DcComparing obtains through the voltage pi regulator, adopts and hands over axle reference current i _Qs ^*=0 provides friendship shaft current set-point; Consider current feed-forward decoupling zero link and voltage compensation link, with the real-time voltage value u of the magnitude of voltage of above-mentioned current PI adjuster output and feedforward compensation component and the net side that collects _du _q, three's plus-minus obtains the set-point u of two voltages _d ^*u _q ^*, obtain the voltage u under the two phase rest frames through the Park inverse transformation again _α ^*u _β ^*, its angle value θ that participates in the Park conversion is the external rotor position signalling that obtains through Hall element; With two phase voltage value u under the above-mentioned rest frame that obtains _α ^*u _β ^*With the dc tache voltage value U that collects _DcSend into SVPWM signal generator link together, the space vector modulation signal that is used for Driving Net side pwm converter after can obtaining modulating.

Pass through control device for the DC link low-voltage, under the situation that low voltage failure takes place, start this control module, through DC side storage capacitor two ends direct voltage measured value V _DcDc tache voltage set point V with malfunction _{Dc_ref}Comparing element obtains deviation signal Δ V _Dc, deviation signal obtains reference current i through pi regulator _d ^*Send into comparator again, generate the conducting duty ratio of power controlling device, the conducting of power controlling device and shutoff, thus regulate dc voltage value near set point.

Claims (1)

1. the control system of a variable speed constant frequency birotor permanent magnetic wind generator system is characterized in that this control system comprises that the low-voltage of two pwm converter control system and DC link passes through control device; Two pwm converter control system comprise generating pusher side pwm converter control system and net side pwm converter control system; Low-voltage is passed through control device and is comprised discharging circuit and control circuit thereof, and discharging circuit is connected to the DC link capacitor C two ends between generating pusher side pwm converter and the net side pwm converter;

A, generating pusher side pwm converter control system, comprising: the maximal wind-energy tracking module is MPPT module, rotational speed control module, current control module and SVPWM signal generating module;

Extraneous wind velocity signal is as the input signal of MPPT module; The reference rotation velocity signal of MPPT module output and the rotating speed detected value signal of motor internal rotor are as the input signal of rotational speed control module; The output signal of rotational speed control module is for handing over the axle reference current signal, and simultaneously, given direct-axis current reference value is zero; Friendship, direct-axis current reference signal are inputed to comparator and compare with the friendship of internal rotor under the dq coordinate system that obtains after Clark conversion and the Park conversion, direct-axis current detected value signal respectively, and comparative result is as the input signal of current control module; Current control module output signal and current feed-forward decoupling zero component are exported friendship, d-axis reference voltage signal through adder and subtracter respectively; Difference signal between the inside and outside rotor-position of the motor that speed measuring device records and friendship, d-axis reference voltage signal be as the input signal of transform vector module, two phase voltage signals under the transform vector module output α β coordinate system; Two phase voltage signals and dc tache voltage detected value signal are as the input signal of SVPWM signal generating module under the α β coordinate system, and SVPWM signal generating module output signal is the SVPWM signal that can drive generating pusher side pwm converter;

B, net side pwm converter control system comprise: voltage on line side control module, current control module and SVPWM signal generating module;

With dc voltage set-point and its dc voltage detected value input signal as the voltage on line side control module; Voltage on line side control module output d-axis reference current, simultaneously, given friendship axle reference current value is zero; This friendship, direct-axis current reference signal are compared with the off line top-cross of dq coordinate system that after Clark conversion and Park conversion, obtains, direct-axis current detection signal input comparator respectively, and comparative result is as the input signal of current control module; The output signal of current feed-forward decoupling zero component, voltage compensation component and current control module is through adder output friendship, d-axis reference voltage signal; The motor outer rotor positional value that friendship, d-axis reference voltage signal and Hall element record is as the input signal of transform vector module; Voltage signal under the transform vector module output α β coordinate system; Voltage signal and dc tache voltage detected value signal are as the input signal of SVPWM signal generating module under the α β coordinate system, and the output signal of SVPWM signal generating module gets final product the SVPWM signal of Driving Net side pwm converter;

C, said discharging circuit comprise power device and resistance, and the I/O end of power device is connected in the capacitor C two ends with after resistance is connected;

The discharging circuit control circuit comprises pi regulator and comparator; After reference voltage by the dc tache voltage detected value during with malfunction is compared, behind pi regulator, send into an input of comparator, another input input clock pulse signals of comparator; The output of comparator connects the control end of power device.

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