CN110233494A - A kind of control method of grid-connected inverter of the specific component of degree n n feedforward of network voltage - Google Patents
A kind of control method of grid-connected inverter of the specific component of degree n n feedforward of network voltage Download PDFInfo
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Abstract
The invention discloses a kind of control method of grid-connected inverter of the specific component of degree n n feedforward of network voltage.The present invention the digital control lower gird-connected inverter to be feedovered entirely using network voltage there are aiming at the problem that, including grid-connected current harmonic suppression effect be deteriorated and weak grid under system may unstable two aspects, propose a kind of control strategy of the specific component of degree n n feedforward of network voltage.The strategy is by being added the filter being made of several resonance links in voltage feed-forward control access, the network voltage component for only extracting specific frequency feedovers, while guaranteeing that grid-connected inverter system is stablized under weak grid, by adjusting the parameter of resonance link, additionally it is possible to promote the harmonic suppression effect of grid-connected current.In addition to this, it joined self_adaptive adjusting in voltage feed-forward control access, to adapt to network voltage frequency fluctuation when practical application.
Description
Technical Field
The invention relates to a control method for grid voltage specific sub-component feedforward of a grid-connected inverter, in particular to a control strategy for grid voltage specific sub-component feedforward for improving grid-connected current harmonic suppression effect of the grid-connected inverter under a weak grid, and belongs to the field of new energy grid-connected power generation.
Background
In recent years, renewable energy sources such as wind energy and solar energy have been widely used to cope with problems such as energy crisis and environmental pollution. The grid-connected inverter is becoming a hot point for researchers at home and abroad as an interface between a distributed renewable power generation unit and a power grid. However, with the increase of grid-connected power of the distributed power generation system and the wide distribution of positions of accessing to the power grid, the power grid increasingly presents the characteristic of a weak power grid, and the background harmonic content in the voltage of the power grid is also increasingly abundant. Grid-connected inverter grid-connected current distortion can be caused by grid voltage background harmonic waves, and the problems of equipment loss increase, utilization rate reduction, service life reduction and the like are caused. The reliability and accuracy of the relay protection and metering devices are also affected.
In order to ensure that a grid is still safe, stable and high-quality to operate after the grid-connected inverter is accessed, a series of grid-connected inverter access standards and technical specifications are established at home and abroad, such as national standard GB/T19939-. Both these standards and specifications place a clear limit on the harmonic content of the grid-connected current. Therefore, in order to meet the relevant grid-connected current harmonic standard, the grid-connected inverter must be capable of effectively suppressing the grid-connected current harmonic caused by the grid voltage background harmonic.
To improve the suppression capability of the grid-connected inverter on grid-connected current harmonics caused by grid voltage background harmonics, two basic methods are available: 1) improving the loop gain of a grid-connected current loop; 2) and adopting power grid voltage feedforward control.
The method of adopting a multi-resonance regulator or a repetitive controller is adopted to improve the loop gain of the grid-connected current loop, but the method of adopting the multi-resonance regulator can influence the loop gain of the system and possibly cause the system to be unstable; the disadvantage of repetitive control is that the dynamic performance of the grid-connected inverter is poor. If the grid voltage is sampled and is superposed to the modulation wave v of the grid-connected inverter through a proper transfer functionMIn the method, the influence of the grid voltage on the grid-connected current is cancelled, and the suppression of the harmonic component of the grid-connected current can be realized as well.
The existing research provides a power grid voltage full feedforward control method aiming at a single-phase LCL type grid-connected inverter, and derives a power grid voltage full feedforward function which completely eliminates the influence of the power grid voltage on grid-connected current, so that the restraining capability of the grid-connected inverter on higher harmonics is greatly improved. However, due to the influence of digital control delay, the effect of grid-connected current harmonic suppression of grid voltage full feed-forward is deteriorated, and negative phase shift is introduced into output impedance of the grid-connected inverter, so that the stability of the inverter under a weak grid is deteriorated.
Therefore, how to improve the suppression effect on the grid-connected current harmonic while ensuring the stability of the inverter under the weak grid is a problem that researchers in the field need to solve urgently.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provides a grid voltage specific sub-component feedforward control method of a grid-connected inverter under a weak grid.
In order to achieve the purpose, the technical scheme provided by the invention is as follows: a grid-connected inverter control method of specific sub-component feedforward of grid voltage comprises the following steps:
step one, collecting grid voltage v of grid-connected inverterpccCapacitance current iCAnd a grid-connected current i2；
Step two, obtaining and v through a phase-locked loop unitpccSynchronous phase theta and angular frequency omega, phase theta and amplitude I of current generated by external voltage loop*Together as a grid-connected current commandIs expressed asWill i2Sampling signals and instructions ofComparing to obtain error signal, and sending the error signal into current regulator Gi(s)；
Step three, subtracting the capacitance current i from the output of the current regulatorCThe sampled signal of (2), plus the grid voltage vpccAs a modulation signal vMModulating the signal vMAnd comparing with a triangular carrier, and modulating to obtain control signals to each switching tube of the inverter bridge through the sine pulse width of unipolar frequency multiplication.
The technical scheme is further designed as follows: the network voltage vpccThe feed forward quantity of (1) is the grid voltage vpccFeeding in a specific sub-feedforward function Gshff(s) the output produced, the feedforward function being expressed as:
Gshff(s)＝Gff(s)Hf(s)
wherein G isff(s) is a full feed-forward function of the grid voltage, and the expression is as follows:
Hi1is the capacitance current feedback coefficient, KPWMIs the transfer function of the inverter bridge, L1The inverter side inductor is used, and the C is a filter capacitor;
Hf(s) is a filter function consisting of a number of resonant elements, whose expression is:
Hf(s)＝∑Rk(s)
k is the harmonic order, ωiIs the bandwidth of the resonance term, ωkIs a characteristic frequency, omegaoIs the fundamental angular frequency.
In the resonance link, the compensation effect can be achieved by adjusting the parameters of the resonance link, and the harmonic suppression effect of the grid-connected current is improved; characteristic frequency omega of resonant linkkFundamental frequency omega obtained by phase-locked loopoIs changed to realize the self-adaption to the voltage frequency of the power grid, namely omegak＝kωo。
The phase-locked loop unit is a synchronous rotating coordinate system phase-locked loop which is based on power grid voltage instantaneous value sampling and has certain inhibition capacity on power grid voltage harmonic waves.
Said current regulator Gi(s), a proportional resonant regulator, whose expression is:
wherein, KpIs a proportionality coefficient, KrIs the resonance coefficient, omegao＝2πfoAt the fundamental angular frequency, ωiFor the resonance term bandwidth required to take-3 dB into account, i.e. at ωo±ωiGain of resonance term is 0.707Kr。
The invention has the beneficial effects that:
according to the invention, only a specific secondary component in the power grid voltage is extracted for feedforward by adding a filter consisting of a series of resonance links into a power grid voltage feedforward path, so that the stability of the grid-connected inverter can be ensured, and a harmonic suppression effect better than that of full feedforward of the power grid voltage can be realized by adjusting the characteristic frequency and the resonance term coefficient of the added resonance links.
Drawings
Fig. 1 is a schematic diagram (z domain) of an LCL type grid-connected inverter topology and a control structure thereof in the present invention.
Fig. 2 is an s-domain mathematical model of the LCL grid-connected inverter of the present invention.
Fig. 3 is an equivalent mathematical model of the LCL type grid-connected inverter of the present invention.
Fig. 4 is a schematic mathematical model of the grid voltage feed forward of the present invention.
Fig. 5 is an equivalent circuit of the LCL grid-connected inverter system according to the present invention.
Fig. 6 is an equivalent mathematical model one of the grid voltage feed forward in the present invention.
Fig. 7 is an equivalent mathematical model two of the grid voltage feed forward in the present invention.
Fig. 8 is an equivalent mathematical model three of the grid voltage feed forward in the present invention.
Fig. 9 is a bode plot of the grid voltage full feed forward versus the negation terms fv(s) in the present invention.
Fig. 10 is a schematic diagram of the full feed-forward action vector of the grid voltage in the present invention.
Fig. 11 is a bode plot of grid-tied inverter output impedance and grid impedance in accordance with the present invention.
Fig. 12 is a feedforward mathematical model of the grid voltage specific secondary component of the present invention.
Fig. 13 is a bode plot of grid-tied inverter output impedance and grid impedance in accordance with the present invention.
Fig. 14 is a diagram showing a mechanism of compensating for a resonant link in the present invention.
FIG. 15 is a waveform diagram of simulation in the present invention when feed forward is not used in a weak grid.
FIG. 16 is a waveform diagram of simulation of the present invention when full grid voltage feed forward is used in a strong power grid.
Fig. 17 is a waveform diagram of simulation in the present invention when full feed forward of the grid voltage is used in weak grid.
Fig. 18 is a waveform diagram of simulation in the present invention when using grid voltage specific secondary component feed forward in weak grid.
Fig. 19 is a graph of simulated waveforms using grid voltage specific secondary component feed forward at a fundamental frequency of the grid voltage of 49.5 Hz.
Fig. 20 is a graph of simulated waveforms using grid voltage specific secondary component feed forward at a grid voltage fundamental frequency of 50.5 Hz.
Detailed Description
The invention is described in detail below with reference to the figures and the specific embodiments.
Comparative example
The LCL type grid-connected inverter topology and the control structure thereof related to the invention are shown in figure 1, wherein L1Is inverter side inductor, C is filter capacitor, L2Are net side inductors, which constitute the LCL filter. For grid-connected inverters, the primary objective is to control the grid-connection currenti2To be connected to the grid voltage vg(vpcc) Synchronising and causing the amplitude thereof to track the set value I*。
V in the grid-connected inverter control method of the present comparative examplegIs obtained by a phase-locked loop unit, I*Generated by the outer voltage loop. The response speed of the voltage loop is far lower than that of the grid-connected current loop, so that the grid-connected current loop can be analyzed independently. In FIG. 1, HvAnd Hi2Are each vgAnd i2The sampling coefficient of (2). The amplitude I of the current generated by the phase theta and the outer voltage loop*Together as a grid-connected current commandWill i2Sampling signals and instructions ofComparing to obtain error signal, and sending the obtained error signal into current regulator Gi(z). By feeding back the capacitor current iCActive damping, H, of LCL filter resonant spikesi1Is its feedback coefficient. The output signal of the current regulator is differentiated by the feedback signal of the capacitor current to generate a modulated wave signal vM. V is to beMCompared with the triangular carrier, the control signals of the switching tubes of the inverter bridge can be obtained through the sine pulse width modulation of unipolar frequency multiplication, and the power devices of the single-phase full-bridge inverter are controlled to be switched on and off through the drive protection circuit. In the comparative example, no grid voltage feed-forward is added to the control loop of the grid-connected inverter.
Next, the stability of the grid-connected inverter under the control method according to the comparative example is judged through a series of equivalent models.
Fig. 2 shows an s-domain model, K, corresponding to the LCL grid-connected inverter of fig. 1PWMIs equal to Vin/Vtri，(VinFor input voltage, VtriRefers to the magnitude of the triangular carrier). Gd(s) is a digital control delay link, comprising one beatCalculating the time delay and the half-beat PWM time delay, wherein the expression is as follows: gd(s)＝e-1.5sTs. The mathematical model of fig. 2 is equivalently transformed and can be reduced to the form of fig. 3. Wherein,
the loop gain of the closed loop system is:
for i in FIG. 32The feedback point of (c) is shifted backward, an equivalent model (divided by-Z) as shown in fig. 4 can be obtainedo(s) branch), the output impedance of the grid-connected inverter can be intuitively obtained from fig. 4:
the grid-connected current expression of the inverter is as follows:
as shown in fig. 4, may be passed from vpccIntroducing a transfer function of-Zo(s) branch, equivalent to connecting a branch with-Z size in parallel at the output end of the power grido(s) impedance, as shown in the equivalent circuit of FIG. 5, so that the system output impedance is ideally corrected to infinity and the net current harmonics are completely eliminated.
Moving the feedforward point in fig. 4 to the modulation wavefront, obtaining the ideal grid voltage full feedforward transfer function:
but due to the leading link 1/Gd(s) cannot be physically implemented, and the full feedforward function that can be practically used is:
an equivalent mathematical model using grid voltage feed forward is shown in figure 6. To more intuitively analyze the impact of grid voltage full feed forward on the grid-tied inverter output impedance, fig. 7 and 8 make further equivalence to the grid voltage full feed forward branch, where,
FF(s)＝1-FV(s)＝1-Gd(s)(9)
at this time, the system output impedance expression is:
wherein FV(s) is a cancellation term introduced by full feed-forward of the grid voltage, FF(s) is a residual term of the action of the grid voltage, and Zo_nff(s) represents the output impedance of the system without feed forward, Zo_ff(s) represents the output impedance of the system when full feed forward is added. If under analog control, the full feed-forward of the grid voltage can be ideally realized, the cancellation term FV(s) is 1, and the rest termsFf(s) ═ 0, indicating that the grid voltage effect on the grid-tied current is completely eliminated.
Fig. 9 shows the frequency response curve of fv(s), and it can be seen that at low frequencies, fv(s) has a gain of approximately 1 and a slight phase lag. FIG. 10 shows the lower frequency time (f)<2KHz) power grid voltage full feedforward vector action schematic diagram, and it can be seen that cancellation term lag introduced by power grid voltage full feedforward represents the '1' vector delta theta of original power grid voltage actiondThe vector grid voltage residual vector FF(s) leads the vector delta theta of 1, and the delta theta is approximately equal to 90 degrees at low frequency, which can be known from the formula (9), and the output impedance Z of the system adopting grid voltage full feed-forward is showno_ff(s) will lag Zo_nff(s) is about 90. This corresponds to the output impedance bode plot of the grid-tied inverter shown in fig. 11.
The grid-connected inverter stability criterion based on the impedance is as follows:
according to the grid-connected inverter equivalent circuit shown in FIG. 5 (ignore-Z)o(s) branch), the expression of the grid-connected current can be obtained as follows:
the above formula can be rewritten as:
wherein N(s) is:
since the grid impedance is not taken into account, i.e. ZgWhen(s) is 0, the grid-connected inverter is designed as a stable system, and therefore: (in equation (12))is(s)-vg(s)/Zo(s)) do not contain a right half-plane pole. Then, the stability of the grid-tied inverter, taking into account the grid impedance, depends on whether n(s) is stable or not. As can be seen from equation (13), N(s) can be equivalent to a forward path transfer function of 1 and a feedback path transfer function of Zg(s)/Zo(s) negative feedback closed loop control system transfer function, Zg(s)/Zo(s) is an equivalent loop gain for the system. According to the linear control theory, if Zg(s)/Zo(s) satisfy the Nyquist stability criterion, then N(s) are stable, and thus, the grid-connected system is also stable.
According to the above derivation, the impedance-based grid-connected inverter stability criterion is summarized as follows:
1. the grid-connected inverter can stably work under a strong power grid;
2. impedance ratio Zg(s)/Zo(s) satisfy the Nyquist stability criterion. Namely, Zg(s) and Zo(s) amplitude-frequency curve without cross-section or cross-section frequency fiThe phase margin at (a) is positive. The expression of the phase margin here is:
PM＝180°-(∠Zg(j2πfi)-∠Zo(j2πfi)) (14)
according to the grid-connected inverter stability criterion based on impedance, in order to ensure the stable work of the grid-connected inverter under the weak grid, the impedance ratio Zg(s)/Zo(s) the Nyquist criterion for stability needs to be fulfilled. When using a Bode diagram for analysis, this requires Z according to formula (14)g(s) and ZoThe phase difference at the intersection point of the(s) amplitude-frequency curve should be less than 180 DEG because of ZgThe(s) phase is constantly 90. That means at the crossover frequency, ZoThe phase of(s) is higher than-90 deg..
As can be seen from FIG. 11, LgZ of grid-connected inverter added with full feed-forward grid voltage at 43 mu Ho(s) and ZgThe amplitude-frequency curve of(s) is truncated at about 4kHz, ZoThe phase of(s) is about-90 deg., and the grid-connected inverter is critically stable. When L isgWhen increasing, Zg(s) amplitude-frequency curve up-shift, adding Z of grid-connected inverter of full feed-forward of grid voltageo(s) the phase at the intersection of the amplitude-frequency curve will be lower than-90 °, and the grid-connected inverter will be unstable. And Z of grid-connected inverter without grid voltage feedforward controloAnd(s) the phase is higher than-90 degrees in a full frequency band, and the grid-connected inverter has good stability.
Examples
In the embodiment, on the basis of the comparative example, a plurality of resonance links are added in the feed-through circuit, and only specific sub-components of the power grid voltage are extracted for feed-forward, namely the capacitance current i is subtracted from the output of the current regulatorCThe sampled signal of (2), plus the grid voltage vpccAs a modulation signal vM. As shown in fig. 12, this embodiment can solve the problem of instability of the system in the weak grid, and the specific subcomponent feedforward function added is:
Gshff(s)＝Gff(s)Hf(s) (15)
taking 3, 5, 7, 21,23 harmonics as an example for explanation, a bode diagram of the system output impedance after applying a specific sub-component feedforward function is shown in fig. 13, and it can be seen from the diagram that the system output impedance is corrected to be very high at 3, 5, 7 harmonics outside the cross-over frequency range of the amplitude-frequency curve, which indicates that the grid-connected current harmonics at these frequencies have a very good suppression effect. The output impedance phases of the system at the 21,23 th harmonic frequencies in the amplitude-frequency curve cross-cut frequency band are all above-90 degrees, and the grid-connected inverter system is stable.
The resonance link added in the embodiment not only plays a role in extracting the power grid electricityThe voltage specific sub-component also plays a role in compensating the full feed-forward of the grid voltage for the elimination terms FV(s) so as to obtain a better effect of suppressing the harmonic wave of the grid-connected current. The compensation mechanism is shown in figure 14, and the resonant link R is finely adjustedkCoefficient of resonance term K of(s)rkAnd a characteristic frequency omegakCan make the resonance link at the harmonic frequency fkAt a positive phase angle delta thetadThe gain should be 1/FV (j ω)k). Ideally fv(s) can be compensated to a "1" vector, the grid voltage contribution residual vector ff(s) becomes 0, the system output impedance is infinite, and the grid-connected current harmonics at this frequency are suppressed to 0.
But if the harmonic frequency omegakIn the cross-cut frequency band, if FV(s) is still compensated to be a vector of '1', the phase angle of the output impedance of the system is lower than-90 degrees, and the grid-connected inverter system is unstable; therefore, a certain compensation effect is sacrificed to preferentially ensure the stability of the system, so that the output impedance of the system at the 21 st harmonic frequency and the 23 rd harmonic frequency in fig. 14 is not corrected to be very high.
In addition, because the fundamental frequency of the grid voltage always has fluctuation of +/-0.5 Hz, a self-adaptive adjusting method is added in the resonance link, so that the characteristic frequency omega of the resonance linkkV obtained with phase-locked looppccIs changed, in particular omegak＝kωo。
A simulation example of the present invention is given below:
according to the parameters of the 6kW single-phase LCL type grid-connected inverter given in the table 1, a simulation model is built in Matlab for simulation, and the content of the power grid voltage injection harmonic waves is given in the table 2. Fig. 15 shows simulation waveforms of grid voltage and grid current of the grid-connected system when there is no grid voltage feedforward in the weak grid, and it can be seen that the grid-connected current has significant Distortion and the Total Harmonic Distortion (THD) is high. Fig. 16 shows a simulation waveform of a grid voltage full feedforward strategy used in a strong power grid, where the suppression effect of grid-connected current harmonics is good, and THD is 0.79%; however, under weak current network, when Lg43 muH, as shown in FIG. 17The grid-connected current begins to obviously oscillate, which indicates that a grid-connected inverter system begins to be unstable, and when the impedance of a power grid is further increased, the oscillation of the grid-connected current is more severe. FIG. 18 shows a graph at LgUnder the condition of 2.6mH, the simulation oscillogram of the specific sub-component feedforward of the power grid voltage is adopted, and it can be seen that after the specific sub-component feedforward of the power grid voltage is adopted under the condition of a weak power grid, a grid-connected inverter system is stable, the suppression effect of grid-connected current harmonics is very good, and the THD is only 0.49%. When the fundamental frequency of the grid voltage fluctuates, the feedforward control method is adopted, as shown in fig. 19 and 20, the sine degree of the grid-connected current is still high due to the action of the adaptive adjustment method, and the THD is only 0.64% and 0.48% respectively.
TABLE 16 kW simulation parameters of single-phase LCL grid-connected inverter
| Parameter(s) | Symbol | Numerical value | Parameter(s) | Symbol | Numerical value |
| Input voltage | Vin | 360V | Filter capacitor | C | 10μF |
| Effective value of network phase voltage | Vg | 220V | Network side inductor | L2 | 230μH |
| Output power | Po | 6kW | Amplitude of carrier wave | Vtri | 4.578V |
| Frequency of the grid | fo | 50Hz | Feedback coefficient of capacitor circuit | Hi1 | 0.11 |
| Switching frequency | fsw | 15kHz | Grid-connected current feedback coefficient | Hi2 | 0.15 |
| Sampling frequency | fs | 30kHz | PR regulator ratioCoefficient of performance | Kp | 0.60725 |
| Inverter side inductor | L1 | 720μH | Resonance coefficient of PR regulator | Kr | 151 |
TABLE 2 network Voltage injection harmonic content
| Number of harmonics | 3 | 5 | 7 | 21 | 23 |
| The harmonic content is in the fundamental proportion | 10％ | 5％ | 3％ | 1％ | 1％ |
| Phase position | 0° | 0° | 0° | 0° | 0° |
The technical solutions of the present invention are not limited to the above embodiments, and all technical solutions obtained by using equivalent substitution modes fall within the scope of the present invention.
Claims (5)
1. A grid-connected inverter control method of specific sub-component feed-forward of grid voltage is characterized by comprising the following steps:
step one, collecting grid voltage v of grid-connected inverterpccCapacitance current iCAnd a grid-connected current i2；
Step two, obtaining and v through a phase-locked loop unitpccSynchronous phase theta and angular frequency omega, phase theta and amplitude I of current generated by the outer voltage loop*Together as a grid-connected current commandIs expressed asWill i2Sampling signals and instructions ofComparing to obtain error signal, and sending the error signal into current regulator Gi(s)；
Step three, subtracting the capacitance current i from the output of the current regulatorCThe sampled signal of (2), plus the grid voltage vpccAs a modulation signal vMModulating the signal vMAnd comparing with a triangular carrier, and obtaining control signals of each switching tube of the inverter bridge through unipolar frequency multiplication sine pulse width modulation.
2. The grid-connected inverter control method of grid voltage specific secondary component feed-forward according to claim 1, characterized in that: the network voltage vpccThe feed forward quantity of (1) is the grid voltage vpccFeeding into a specific sub-feedforward function Gshff(s) the output produced, the feedforward function being expressed as:
Gshff(s)＝Gff(s)Hf(s)
wherein G isff(s) is a full feed-forward function of the grid voltage, and the expression is as follows:
Hi1is the capacitance current feedback coefficient, KPWMIs the transfer function of the inverter bridge, L1The inverter side inductor is used, and the C is a filter capacitor;
Hf(s) is a filter function consisting of a number of resonant elements, whose expression is:
k is the harmonic order, ωiIs the bandwidth of the resonance term, ωkIs a characteristic frequency, omegaoIs the fundamental angular frequency.
3. The grid-connected inverter control method of grid voltage specific secondary component feed-forward according to claim 2, characterized in that: characteristic frequency omega of the resonant linkkFundamental angular frequency omega obtained with phase-locked loop unitoIs changed, i.e. ωk＝kωo。
4. The grid-connected inverter control method of grid voltage specific secondary component feed-forward according to claim 1, characterized in that: the phase-locked loop unit is a synchronous rotating coordinate system phase-locked loop.
5. The grid-connected inverter control method of grid voltage specific secondary component feed-forward according to claim 1, characterized in that: said current regulator Gi(s), a proportional resonant regulator, whose expression is:
wherein, KpIs a proportionality coefficient, KrIs the resonance coefficient, omegao＝2πfoAt the fundamental angular frequency, ωiFor the resonance term bandwidth required to take-3 dB into account, i.e. at ωo±ωiGain of resonance term is 0.707Kr。
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Cited By (5)
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|---|---|---|---|---|
| CN110718934A (en) * | 2019-10-12 | 2020-01-21 | 兰州理工大学 | LLCL grid-connected inverter resonance suppression method adapting to power grid impedance change |
| CN112671010A (en) * | 2021-01-14 | 2021-04-16 | 国网陕西省电力公司电力科学研究院 | Virtual impedance-based fan grid-connected subsynchronous oscillation suppression and high-frequency harmonic suppression method |
| CN113644836A (en) * | 2021-07-28 | 2021-11-12 | 江苏南自通华智慧能源股份有限公司 | Robust control method suitable for LCL type grid-connected inverter |
| CN114640123A (en) * | 2020-12-15 | 2022-06-17 | 新疆金风科技股份有限公司 | Feedforward control method and device of grid-connected inverter, medium and wind generating set |
| WO2022127268A1 (en) * | 2020-12-15 | 2022-06-23 | 新疆金风科技股份有限公司 | Wind turbine generator system, and grid-tie inverter and feedforward control method therefor and apparatus thereof |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110718934A (en) * | 2019-10-12 | 2020-01-21 | 兰州理工大学 | LLCL grid-connected inverter resonance suppression method adapting to power grid impedance change |
| CN114640123A (en) * | 2020-12-15 | 2022-06-17 | 新疆金风科技股份有限公司 | Feedforward control method and device of grid-connected inverter, medium and wind generating set |
| WO2022127268A1 (en) * | 2020-12-15 | 2022-06-23 | 新疆金风科技股份有限公司 | Wind turbine generator system, and grid-tie inverter and feedforward control method therefor and apparatus thereof |
| CN112671010A (en) * | 2021-01-14 | 2021-04-16 | 国网陕西省电力公司电力科学研究院 | Virtual impedance-based fan grid-connected subsynchronous oscillation suppression and high-frequency harmonic suppression method |
| CN113644836A (en) * | 2021-07-28 | 2021-11-12 | 江苏南自通华智慧能源股份有限公司 | Robust control method suitable for LCL type grid-connected inverter |
| CN113644836B (en) * | 2021-07-28 | 2023-02-28 | 江苏南自通华智慧能源股份有限公司 | Robust control method suitable for LCL type grid-connected inverter |
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