CN105207236A - Suppression subsynchronous oscillation self-adaptive control system based on SVG - Google Patents

Abstract

The invention relates to a suppression subsynchronous oscillation self-adaptive control system based on SVG, and belongs to the field of power system stabilizing and control. The suppression subsynchronous oscillation self-adaptive control system based on the SVG comprises an AD data collection device, a front combined filter, a discrete Fourier transform and subsynchronous oscillation frequency recognizer, a multi-channel independent mode control ring, an online self-adaptive adjuster and a power signal generating device. A control signal is obtained through the self-adaptive control system, the power current of the suppressible subsynchronous oscillation based on the control signal is generated through the SVG, and the suppression subsynchronous oscillation self-adaptive control system is high in subsynchronous oscillation frequency self-adaptation, multifunctional and capable of effectively suppressing power grid subsynchronous oscillation.

Description

Based on the suppression sub-synchronous oscillation adaptive control system of SVG

Technical field

The present invention relates to power system stability and control field, particularly a kind of suppression sub-synchronous oscillation adaptive control system based on SVG.

Background technology

At present; the new energy developments such as China's wind energy turbine set photovoltaic plant present scale exploitation, centralized grid-connected, long-distance sand transport feature; and HVDC (High Voltage Direct Current) transmission system is as solving the interconnected effective means of Large Copacity long-distance sand transport, interconnected power network, domestic existing many circuits build up and in operation.But the HVDC transmission system of the new-energy grid-connected such as large-scale wind power, photovoltaic and fast Active control characteristic are easy to cause sub-synchronous oscillation, cause turbo generator set to be destroyed, serious threat safe operation of power system.

The supplementary excitation damping control that existing sub-synchronous oscillation suppression method mainly contains block filter, utilize SEDC/PSS to realize and utilize SVC/SVG additional longitudinal forces.

At present, the new energy grid connection system such as wind energy turbine set photovoltaic plant generally all configure the reactive compensation capacity of certain capacity, but most of SVC or SVG does not possess sub-synchronous oscillation inhibit feature or inhibit feature is very limited, main because SVC compensation equipment strategy is inadaptable, response speed is slow, voltage characteristic is poor.And the control system of the suppression sub-synchronous oscillation based on SVG of routine is based on speed feedback signal, this structure is often in the new energy grid connection system such as wind energy turbine set or photovoltaic plant on the one hand, cannot obtain this tach signal; On the other hand, its rotating speed input control system is single, and frequency content analysis is simple, cannot reach the desirable control effects of unit multi-mode oscillations frequency.

Summary of the invention

The object of the invention is to for the problems referred to above, provide a kind of suppression sub-synchronous oscillation adaptive control system based on SVG, the sub-synchronous oscillation that the new energy grid connection system such as typical wind energy turbine set or photovoltaic generation exist can be suppressed, strengthen system run all right and reliability.

The object of the present invention is achieved like this:

Based on a suppression sub-synchronous oscillation adaptive control system of SVG, comprising:

AD data acquisition unit, for gathering the voltage comprising sub-synchronous oscillation information of SVG compensation point or SVG place system public access point, electric current or power signal;

Preposition junction filter, voltage, electric current or power signal for collecting AD data acquisition unit carry out filtering, to obtain the subsynchronous and subsynchronous complement frequency signal in voltage, electric current or power signal, its implementation is various, can be that band leads to and band stop filter series system, or multiple band pass filter parallel way, or a low pass filter mode etc.; And this preposition junction filter is selective sections, if do not selected, the signal that AD data acquisition unit obtains will directly enter next data processing link;

Discrete Fourier transform and sub-synchronous oscillation frequency estimation device, the voltage containing subsynchronous and subsynchronous complement frequency signal, electric current or power signal for exporting AD data acquisition unit or preposition junction filter carry out discrete Fourier transform, to obtain amplitude and the phase place of each subsynchronous and subsynchronous complement frequency signal, and sub-synchronous oscillation frequency estimation is carried out to this amplitude and phase place, finally obtain amplitude and the frequency of the subsynchronous and subsynchronous complement frequency signal of each frequency;

Multichannel stand-alone mode control ring, comprises integrated mode filter, portfolio ratio phase shifter and the comprehensive regulator with multiple passage; The amplitude of the subsynchronous and subsynchronous complement frequency signal of each frequency that described integrated mode filter obtains in conjunction with discrete Fourier transform and sub-synchronous oscillation frequency estimation device and phase place, Pattern Filter is carried out to the voltage containing the subsynchronous and subsynchronous complement frequency signal of each frequency, electric current or power signal that AD data acquisition unit or preposition junction filter export, obtains the subsynchronous and subsynchronous complement frequency signal of each frequency; Described portfolio ratio phase shifter, for compensating the phase delay of the voltage containing subsynchronous and subsynchronous complement frequency signal, electric current or the power signal after integrated mode filter, and after being amplified by the signal passing ratio after phase compensation, be converted to the mode control signal of the subsynchronous and subsynchronous complement frequency signal of each frequency; Described comprehensive regulator, sues for peace and amplitude limiting processing for each mode control signal obtained portfolio ratio phase shifter, obtains last assemble mode control signal;

Online adaptive adjuster, for monitor when SVG controller exports without subsynchronous compensate component system there is subsynchronous component to be compensated time, enable the automatic adjustment of controling parameters, this controling parameters comprises the port number of Pattern Filter and each channel gain of portfolio ratio phase shifter and comprehensive regulator and each passage phase shift;

Power signal generating means, control signal needed for controlling for the assemble mode control signal that obtains according to multichannel stand-alone mode control ring and the direct voltage of SVG own etc., generate final current-order and be converted to power switch pulse signal, producing electric current and the power that can suppress sub-synchronous oscillation.

Wherein, described preposition junction filter can be set to one of following five kinds of implementations:

Mode one, for voltage and current signal, arrange two filters and carry out tandem compound, the first filter is second-order bandpass filter, and its transfer function is formula 1, and the second filter is divalent radical ripple band stop filter, and its transfer function is formula 2:

$\frac{G_{01}{\mathrm{\ω}}_{01}s}{s^2+2{\mathrm{\ξ}}_{01}{\mathrm{\ω}}_{01}s+{\mathrm{\ω}}_{01}^2}$ Formula 1

In formula 1, G ₀₁for the passband gain of band pass filter, ω ₀₁for band pass filter center angular frequency, ξ ₀₁for the damping coefficient of band pass filter;

$\frac{G_{02}(s^2+{\mathrm{\ω}}_{02}^2)}{s^2+2{\mathrm{\ξ}}_{02}{\mathrm{\ω}}_{02}s+{\mathrm{\ω}}_{02}^2}$ Formula 2

In formula 2, G ₀₂for the first-harmonic passband gain of band stop filter, ω ₀₂for band stop filter center angular frequency, ξ ₀₂for the damping coefficient of band stop filter;

Mode two, for voltage, current signal, arrange two band pass filters and carry out parallel combination, the first filter and the second filter are second-order bandpass filter, and its transfer function is formula 3:

$\frac{G_{03}{\mathrm{\ω}}_{03}s}{s^2+2{\mathrm{\ξ}}_{03}{\mathrm{\ω}}_{03}s+{\mathrm{\ω}}_{03}^2}$ Formula 3

In formula 3, G ₀₃for the passband gain of band pass filter, ω ₀₃for band pass filter center angular frequency, ξ ₀₃for the damping coefficient of filter;

Mode three, for voltage, current signal, arrange 1 second-order low-pass filter, its transfer function is formula 4:

$\frac{G_{04}{\mathrm{\ω}}_{04}^2}{s^2+2{\mathrm{\ξ}}_{04}{\mathrm{\ω}}_{04}s+{\mathrm{\ω}}_{04}^2}$ Formula 4

In formula 4, G ₀₄for the passband gain of low pass filter, ω ₀₄for low pass filter natural angular frequency, ξ ₀₄for the damping coefficient of filter;

Mode four, for voltage, electric current or power signal, arrange 1 second-order bandpass filter or more than 1 band is logical, low pass filter combination, low pass filter function is formula 4, and its band pass filter transfer function is formula 5:

$\frac{G_{05}{\mathrm{\ω}}_{05}s}{s^2+2{\mathrm{\ξ}}_{05}{\mathrm{\ω}}_{05}s+{\mathrm{\ω}}_{05}^2}$ Formula 5

In formula 5, G ₀₅for the passband gain of band pass filter, ω ₀₅for band pass filter center angular frequency, ξ ₀₅for the damping coefficient of filter;

Mode five, for voltage, current signal, described preposition junction filter is selective sections, does not carry out any process in this situation to the sub-synchronous oscillation voltage, electric current and the power signal that collect, and the data-signal that AD data acquisition unit obtains directly enters next data processing link.

Wherein, described discrete Fourier transform and sub-synchronous oscillation frequency estimation device can realize the Adaptive Identification of the sub-synchronous oscillation frequency of complete subsynchronous bandwidth and complement frequency thereof, and described Adaptive Identification specific implementation process is as follows:

First, two arrays are calculated through discrete fourier, array F=[F1,, Fm] and represent the frequency of each signal of voltage, electric current or power, amount to m frequency content, array A=[A1 ..., Am] and represent the amplitude of corresponding each frequency content in frequency signal array;

Then, according to following process identification sub-synchronous oscillation frequency and amplitude set:

Step 1 sets subsynchronous frequency set as Fs=[], is initially sky, and presetting initial bandwidth deltaf f is 4 ~ 10Hz;

Step 2 signal amplitude of setting all frequencies corresponding as Aj (j=1 ..., m), if Aj is less than or equal to presetting threshold amplitude Ath, then Aj is set to 0;

Step 3 take frequency as abscissa X, with each frequency its amplitude corresponding for ordinate Y, by frequency signal array [F1, Fm] and amplitude signal array [A1,, Am] and be depicted as an amplitude-frequency spectrogram, find out according to this spectrogram the magnitude peak point that in this figure, all frequency contents are corresponding, be set as frequency signal array FP=[Fp1,, Fpn], corresponding peak signal array AP=[AP1, APn], if Fpj is empty, represents in this electrical network and occur without the sub-synchronous oscillation of corresponding pj frequency, go to step 6;

If interval is all greater than Δ f/2 between each frequency of frequency signal array FP that all peak points of step 4 peak signal array AP are corresponding, then FP is the sub-synchronous oscillation frequency array that identification obtains, then complete identification, jump to step 6, otherwise continues to perform step 5;

Step 5 is for minimum two magnitude peak dot frequency Fpj and the Fpk (wherein Fpj < Fpk) of the frequency interval of frequency signal array FP, and these 2 frequencies are carried out merger, and the principle of merger is:

After merging, new peak point frequency is:

$Fpjk=\frac{Fpj*Fpj+Fpk*Fpk}{Apj+Apk}$

After merging, the peak value that new peak point frequency is corresponding is:

$Apjk=\left\{\begin{array}{cc}\frac{Apj(Fpk-Fpjk)+Apk(Fpjk-Fpj)}{Fpj+Fpk-2*Fpjk}& (Fpj+Apk-2*Fpjk\&NotEqual;0)\\ \frac{Apj}{(1-(1-1/\sqrt{2})*(\left(Fpk-Fpj\right)/\mathrm{\&Delta;}f)}& (Fpj+Apk-2*Fpjk=0)\end{array}\right.$

Carrying out after the new frequency of each Frequency point and peak value upgrade, upgrading aggregate frequency signal array FP and peak signal array AP, jumping to step 4;

Step 6 obtains frequency signal array FP and peak signal array AP, be the set that identification obtains subsynchronous Frequency point frequency and amplitude thereof, if K for this reason time frequency number of signals group FP medium frequency element number, if K is 0, then represent that sub-synchronous oscillation does not occur network system.

Wherein, described integrated mode filter is a centre frequency and all adjustable band pass filter of bandwidth, and its transfer function is formula 6:

$\frac{G_i{\mathrm{\&omega;}}_{i}s}{s^2+2{\mathrm{\&xi;}}_i{\mathrm{\&omega;}}_{i}s+{\mathrm{\&omega;}}_i^2}$ Formula 6

In formula 6, G _ifor the passband gain of band pass filter, ω _ifor band pass filter center angular frequency, ξ _ifor the damping coefficient of filter, i ∈ [1, N].

Wherein, described portfolio ratio phase shifter is a ratio phase-correction filter, and its transfer function is formula 7:

$\frac{1-T_{c1}s}{1+T_{c2}s}{K}_c$ Formula 7

In formula 7, K _cfor the proportionality coefficient of ratio phase-correction filter, T _cfor the phase shift compensation time constant of ratio phase-correction filter, its value is determined by the frequency of variable subsynchronous and subsynchronous complement frequency signal, fixed sample delay time constant and fixing control lag time constant;

Described ratio phase-correction filter is used for containing in subsynchronous and subsynchronous complement frequency component signal because of analog measurement the acquisition of integrated mode filter, the phase delay that integrated mode filtering and SVG control lag cause carries out phase compensation, the phase delay that sampling because of analog measurement keeps link to cause, the band pass filter adopted in integrated mode filter is for the inconsistent phase shift caused of phase-shift characterisitc of different frequency component, and by the delay of SVG controlling unit generating power signal, need to compensate the deviation of phase place, Compensation Objectives is the place's phase shift of Pattern Filter centre frequency is zero phase shift that also compensation film analog quantity data acquisition and controlling constant time of delay is corresponding.

Wherein, described online adaptive adjuster can carry out the online adaptive adjustment of parameter, at SVG controller without in subsynchronous compensate component output situation, when there is subsynchronous component to be compensated in the system of monitoring, then enable this online adaptive adjuster, this controling parameters comprises the port number of Pattern Filter, can carry out online updating; For the described portfolio ratio phase shifter of multichannel stand-alone mode control ring and the channel gain of comprehensive regulator and passage phase shift, the subsynchronous component peak signal to be compensated that the adjustment of channel gain and described discrete Fourier transform and sub-synchronous oscillation frequency estimation device obtain is in direct ratio, and the assemble mode control signal that multichannel stand-alone mode control ring produces is no more than 50% of the own rated current of SVG; The adjustment basic principle of each channel compensation phase place is the sub-synchronous oscillation current/power homophase that current/power that SVG device is absorbed and sub-synchronous oscillation source exist, or operational mode bias internal amount possible in the various operating mode of reality is no more than 60 degree.

Beneficial effect of the present invention is:

1, realize the compensation to each sub-synchronous oscillation frequency and complement frequency wide region thereof, multi-frequency point, inhibit feature is comprehensive.

2, based on the additional longitudinal forces of SVG, can multiple spot distributed compensation, without the need to extra cost, realize simple, adaptive control, applicability is wide.

Accompanying drawing explanation

Fig. 1 is control system block diagram of the present invention.

Fig. 2 is the subsynchronous current source waveform figure of emulation experiment in the embodiment of the present invention.

Fig. 3 is the spectrogram that the discrete Fourier transform of emulation experiment in the embodiment of the present invention and sub-synchronous oscillation frequency estimation device export.

Fig. 4 is the comparison of wave shape figure that in the embodiment of the present invention, emulation experiment is simulated the 5Hz original waveform in sub-synchronous oscillation current source multi-frequency composition and obtained after this control system process reduction.

Embodiment

Below in conjunction with specific embodiments and the drawings, set forth the present invention further.

As shown in Figure 1, based on a suppression sub-synchronous oscillation adaptive control system of SVG, comprise AD data acquisition unit 1, preposition junction filter 2, discrete Fourier transform and sub-synchronous oscillation frequency estimation device 3, multichannel stand-alone mode control ring 4, online adaptive adjuster 5 and power signal generating means 6.

Described AD data acquisition unit 1, for gathering the voltage comprising sub-synchronous oscillation information of SVG compensation point or SVG place system public access point, electric current or power signal.

Described preposition junction filter 2, sub-synchronous oscillation voltage, electric current or power signal for collecting AD data acquisition unit 1 carry out low pass, band leads to or bandreject filtering, to obtain the subsynchronous and subsynchronous complement frequency signal in voltage, electric current or power signal.

The implementation of this preposition junction filter 2 forms or selects without any filter for selecting by multiple filter bank, according to different situation, specifically can be set to one of following five kinds of implementations:

Mode one, for voltage and current signal, arrange two filters and carry out tandem compound, the first filter is second-order bandpass filter, and its transfer function is formula 1, and the second filter is divalent radical ripple band stop filter, and its transfer function is formula 2:

$\frac{G_{01}{\mathrm{\&omega;}}_{01}s}{s^2+2{\mathrm{\&xi;}}_{01}{\mathrm{\&omega;}}_{01}s+{\mathrm{\&omega;}}_{01}^2}$ Formula 1

In formula 1, G ₀₁for the passband gain of band pass filter, ω ₀₁for band pass filter center angular frequency, ξ ₀₁for the damping coefficient of band pass filter;

$\frac{G_{02}(s^2+{\mathrm{\&omega;}}_{02}^2)}{s^2+2{\mathrm{\&xi;}}_{02}{\mathrm{\&omega;}}_{02}s+{\mathrm{\&omega;}}_{02}^2}$ Formula 2

In formula 2, G ₀₂for the first-harmonic passband gain of band stop filter, ω ₀₂for band stop filter center angular frequency, ξ ₀₂for the damping coefficient of band stop filter;

Mode two, for voltage, current signal, arrange two band pass filters and carry out parallel combination, the first filter and the second filter are second-order bandpass filter, and its transfer function is formula 3:

$\frac{G_{03}{\mathrm{\&omega;}}_{03}s}{s^2+2{\mathrm{\&xi;}}_{03}{\mathrm{\&omega;}}_{03}s+{\mathrm{\&omega;}}_{03}^2}$ Formula 3

In formula 3, G ₀₃for the passband gain of band pass filter, ω ₀₃for band pass filter center angular frequency, ξ ₀₃for the damping coefficient of filter;

Mode three, for voltage, current signal, arrange 1 second-order low-pass filter, its transfer function is formula 4:

$\frac{G_{04}{\mathrm{\&omega;}}_{04}^2}{s^2+2{\mathrm{\&xi;}}_{04}{\mathrm{\&omega;}}_{04}s+{\mathrm{\&omega;}}_{04}^2}$ Formula 4

In formula 4, G ₀₄for the passband gain of low pass filter, ω ₀₄for low pass filter natural angular frequency, ξ ₀₄for the damping coefficient of filter;

Mode four, for voltage, electric current or power signal, arrange 1 second-order bandpass filter or more than 1 band is logical, low pass filter combination, low pass filter function is formula 4, and its band pass filter transfer function is formula 5:

$\frac{G_{05}{\mathrm{\&omega;}}_{05}s}{s^2+2{\mathrm{\&xi;}}_{05}{\mathrm{\&omega;}}_{05}s+{\mathrm{\&omega;}}_{05}^2}$ Formula 5

In formula 5, G ₀₅for the passband gain of band pass filter, ω ₀₅for band pass filter center angular frequency, ξ ₀₅for the damping coefficient of filter;

Mode five, for voltage, current signal, described preposition junction filter is selective sections, does not carry out any process in this situation to the sub-synchronous oscillation voltage, electric current and the power signal that collect, and the data-signal that AD data acquisition unit obtains directly enters next data processing link.

Described discrete Fourier transform and sub-synchronous oscillation frequency estimation device 3, the voltage containing subsynchronous and subsynchronous complement frequency signal, electric current or power signal for obtaining AD data acquisition unit 1 or preposition junction filter 2 carry out discrete Fourier transform, to obtain amplitude and the phase place of each subsynchronous and subsynchronous complement frequency signal, and sub-synchronous oscillation frequency estimation is carried out to this amplitude and phase place, finally obtain amplitude and the frequency of the subsynchronous and subsynchronous complement frequency signal of each frequency.This discrete Fourier transform and sub-synchronous oscillation frequency estimation device 3 can realize the Adaptive Identification of the sub-synchronous oscillation frequency of complete subsynchronous bandwidth and complement frequency thereof, and wherein the optimum range of subsynchronous bandwidth is 2 ~ 50hz, and its Adaptive Identification process is specific as follows:

First, two arrays are calculated through discrete fourier, array F=[F1,, Fm] and represent the frequency of each signal of voltage, electric current or power, amount to m frequency content, array A=[A1 ..., Am] and represent the amplitude of the corresponding each frequency content of frequency signal array.

Then, according to following process identification sub-synchronous oscillation frequency and amplitude set:

Step 1 sets subsynchronous frequency set as Fs=[], is initially sky, and presetting initial bandwidth deltaf f is 4 ~ 10Hz;

Step 2 signal amplitude of setting all frequencies corresponding as Aj (j=1 ..., m), if Aj is less than or equal to presetting threshold amplitude Ath, then Aj is set to 0;

Step 3 take frequency as abscissa X, take amplitude as ordinate Y, by frequency signal array [F1, Fm] and amplitude signal array [A1,, Am] and be depicted as an amplitude-frequency spectrogram, find out according to this spectrogram the magnitude peak point that in this figure, all frequency contents are corresponding, be set as frequency signal array FP=[Fp1,, Fpn], corresponding peak signal array AP=[AP1, APn], if Fpj is empty, represents in this electrical network and occur without the sub-synchronous oscillation of corresponding pj frequency, go to step 6;

If interval is all greater than Δ f/2 between each frequency of frequency signal array FP that all peak points of step 4 peak signal array AP are corresponding, then FP is the sub-synchronous oscillation frequency array that identification obtains, then complete identification, jump to step 6, otherwise continues to perform step 5;

Step 5 is for minimum two magnitude peak dot frequency Fpj and the Fpk (wherein Fpj < Fpk) of the frequency interval of frequency signal array FP, and these 2 frequencies are carried out merger, and the principle of merger is:

After merging, new peak point frequency is:

$Fpjk=\frac{Fpj*Fpj+Fpk*Fpk}{Apj+Apk}$

After merging, the peak value that new peak point frequency is corresponding is:

$Apjk=\left\{\begin{array}{cc}\frac{Apj(Fpk-Fpjk)+Apk(Fpjk-Fpj)}{Fpj+Fpk-2*Fpjk}& (Fpj+Apk-2*Fpjk\&NotEqual;0)\\ \frac{Apj}{(1-(1-1/\sqrt{2})*(\left(Fpk-Fpj\right)/\mathrm{\&Delta;}f)}& (Fpj+Apk-2*Fpjk=0)\end{array}\right.$

Carrying out after the new frequency of each Frequency point and peak value upgrade, upgrading aggregate frequency signal array FP and peak signal array AP, jumping to step 4;

Step 6 obtains frequency signal array FP and peak signal array AP, be the set that identification obtains subsynchronous Frequency point frequency and amplitude thereof, if K for this reason time frequency number of signals group FP medium frequency element number, if K is 0, then represent that sub-synchronous oscillation does not occur network system.

Described multichannel stand-alone mode control ring 4, comprises integrated mode filter, portfolio ratio phase shifter and the comprehensive regulator with multiple passage.

The amplitude of the subsynchronous and subsynchronous complement frequency signal of each frequency that integrated mode filter is obtained by discrete Fourier transform and sub-synchronous oscillation frequency estimation device 3 and phase place, obtain the subsynchronous and subsynchronous complement frequency signal of each frequency, then Pattern Filter is carried out to the voltage containing the subsynchronous and subsynchronous complement frequency signal of each frequency, electric current or power signal that AD data acquisition unit 1 or preposition junction filter 2 obtain.In native system, integrated mode filter specifically adopts a centre frequency and all adjustable band pass filter of bandwidth, and its transfer function is formula 6:

$\frac{G_i{\mathrm{\&omega;}}_{i}s}{s^2+2{\mathrm{\&xi;}}_i{\mathrm{\&omega;}}_{i}s+{\mathrm{\&omega;}}_i^2}$ Formula 6

In formula 6, G _ifor the passband gain of band pass filter, ω _ifor band pass filter center angular frequency, ξ _ifor the damping coefficient of filter, i ∈ [1, N].

7. portfolio ratio phase shifter is used for compensating the phase delay of the voltage containing subsynchronous and subsynchronous complement frequency signal, electric current or power signal after integrated mode filter, and after being amplified by the signal passing ratio after phase compensation, be converted to the mode control signal of the subsynchronous and subsynchronous complement frequency signal of each frequency.In native system, portfolio ratio phase shifter needs the voltage to the subsynchronous and subsynchronous complement frequency signal containing each frequency that integrated mode filter obtains, because of analog measurement in electric current or power signal, the phase delay that integrated mode filtering and SVG control lag cause carries out phase compensation, also need the phase delay keeping link to cause to the sampling because of analog measurement, the band pass filter adopted in integrated mode filter is for the inconsistent phase shift caused of phase-shift characterisitc of different frequency component, and the compensation of phase deviation is carried out by the delay of SVG controlling unit generating power signal.Compensation Objectives is the place's phase shift of Pattern Filter centre frequency is zero, and the phase shift that compensation film analog quantity data acquisition and controlling constant time of delay is corresponding.Thus, the portfolio ratio phase shifter of the employing in native system is a ratio phase-correction filter, and its transfer function is formula 7:

$\frac{1-T_{c1}s}{1+T_{c2}s}{K}_c$ Formula 7

In formula 7, K _cfor the proportionality coefficient of ratio phase-correction filter, T _cfor the phase shift compensation time constant of ratio phase-correction filter, its value is determined by the frequency of the subsynchronous and subsynchronous complement frequency signal of variable difference, fixed sample delay time constant and fixing control lag time constant;

Each mode control signal that comprehensive regulator is used for portfolio ratio phase shifter obtains is sued for peace and amplitude limiting processing, finally obtains assemble mode control signal.

Described online adaptive adjuster 5, for monitor when SVG controller exports without subsynchronous compensate component system there is subsynchronous component to be compensated time, enable the automatic adjustment of controling parameters, this controling parameters comprises the port number N of Pattern Filter and each channel gain K of portfolio ratio phase shifter and comprehensive regulator _i(i=1 ... and each passage phase shift T N) _i(i=1 ... N).Wherein, the port number N of Pattern Filter can carry out online updating; The channel gain K of portfolio ratio phase shifter and comprehensive regulator _i(i=1, the peak signal of the subsynchronous signal N) obtained with sub-synchronous oscillation frequency estimation device 3 with discrete Fourier transform becomes positive example, multichannel stand-alone mode control ring 4 assemble mode control signal is mated with the output capacity of SVG own, and general control is being no more than 50% of the own rated current of SVG; The adjustment basic principle of each channel compensation phase place is the sub-synchronous oscillation current/power homophase that current/power that SVG device is absorbed and sub-synchronous oscillation source exist, or operational mode bias internal amount possible in the various operating mode of reality is no more than 60 degree.

Described power signal generating means 6, control signal needed for controlling for the assemble mode control signal that obtains according to N channel stand-alone mode control ring and the direct voltage of SVG own etc., generate final current-order and be converted to power switch pulse signal, producing electric current and the power that can suppress sub-synchronous oscillation.

Here, the course of work of native system is described by a simulation embodiment, specific as follows:

The first step, by AD data acquisition unit 1, gathers the sub-synchronous oscillation electric current of SVG compensation point load side or SVG place system public access point system side.Can also voltage be gathered herein, power signal then by collect voltage, current signal calculate obtain.Native system adopts MATLAB emulation to carry out preliminary identification, and wherein, sub-synchronous oscillation multi-frequency current source waveform as shown in Figure 2.

It should be noted that, before entering AD data acquisition unit 1, voltage and current signal all should carry out ratio or phase transition, make to export with SVG or SVG access point voltage and electric current reach unified magnitude; And system power or voltage can be not only subsynchronous components can also be and subsynchronous frequency content complementary components.

Second step, utilizes preposition junction filter 2 that the sub-synchronous oscillation voltage, electric current and the power signal that collect are carried out to low pass, are with logical and bandreject filtering, the fundamental frequency in filtering voltage, electric current or power and high frequency signal components.Wherein, fundamental frequency refers to the frequency of 50Hz frequency or controller and synchronized, and high frequency refers to more than 100Hz frequency content.

It should be noted that, the selection of this preposition junction filter 2 as the case may be, selects the one in aforementioned five kinds of implementations; And under number of filter is greater than two situations, filter cascade is placed does not have exact sequence relation.

Herein, preposition junction filter 2 is chosen as a low pass filter, and transfer function is formula 8,

$\frac{{\mathrm{\&omega;}}_l^2}{s^2+2{\mathrm{\&xi;}}_l{\mathrm{\&omega;}}_{l}s+{\mathrm{\&omega;}}_l^2}$ Formula 8

In formula 8, G _lfor the passband gain of low pass filter, ω _lfor low pass filter natural angular frequency, ξ _lfor the damping coefficient of presetting low pass filter.

3rd step, utilize discrete Fourier transform and sub-synchronous oscillation frequency estimation device 3, discrete Fourier transform is carried out to the voltage containing subsynchronous and subsynchronous complement frequency signal, electric current or power signal, obtain amplitude and the phase place of each subsynchronous and subsynchronous complement frequency signal, and sub-synchronous oscillation frequency estimation is carried out to this amplitude and phase signal, obtain amplitude and the frequency of the subsynchronous and subsynchronous complement frequency signal of each frequency.

Here, concrete setting initial identification bandwidth deltaf f is 5Hz, and the signal amplitude threshold amplitude Ath that predetermined frequency is corresponding is 16.5A, namely 35kV side system electric current finally obtains frequency signal array FP=[Fp1, Fp2, Fp3, Fp4]=[5,10,25,40], corresponding peak signal array AP=[AP1, AP2, AP3, AP4]=[50,50,200,50]; Spectrogram as shown in Figure 3.

4th step, utilizes multichannel stand-alone mode control ring 4, comprises integrated mode filter, portfolio ratio phase shifter and the comprehensive regulator with 4 passages.

Voltage, electric current or power signal that the integrated mode filter of each passage is used for the subsynchronous and subsynchronous complement frequency signal containing each frequency carry out Pattern Filter, the amplitude of 4 subsynchronous components that obtained by discrete Fourier transform and sub-synchronous oscillation frequency estimation device 3 of each mode filter and frequency herein, obtain 5Hz, 10Hz, the subsynchronous frequency signal of each frequency of 25Hz, 40Hz.Specifically for integrated mode filter 1, its job step is described, integrated mode filter 1 transfer function is formula 9,

$\frac{G_1{\mathrm{\&omega;}}_{1}s}{s^2+2{\mathrm{\&xi;}}_1{\mathrm{\&omega;}}_{1}s+{\mathrm{\&omega;}}_1^2}$ Formula 9

In formula 9, G ₁for the passband gain of pattern 1 band pass filter, portfolio ratio phase shifter will carry out gain scale adjustment, be set to 1, ω herein ₁for mode 1 band pass filter center angular frequency, its value is 10 π, ξ ₁for the damping coefficient of mode 1 band pass filter, its value is 0.08, and bandwidth is 0.8Hz.

Portfolio ratio phase shifter, phase delay for causing because of measurement, filter conformance control the voltage containing subsynchronous and subsynchronous complement frequency signal, electric current or the power signal after integrated mode filter compensates, and the signal passing ratio after phase compensation is amplified, consider the passband gain of pattern 1 band pass filter simultaneously, be converted to the mode control signal of the subsynchronous frequency signal of each frequency.

Here, portfolio ratio phase shifter specifically adopts a ratio phase-correction filter, this filter parameter T _cfor phase shift compensation time constant, its value is determined according to the frequency of the subsynchronous and subsynchronous complement frequency component of variable difference, fixed sample delay time constant, fixing control lag time constant.For the subsynchronous signal of 5Hz, filter phase shift compensation time constant T _c1with T _c2be 0.0062, proportional gain K _cbe 0.6, final portfolio ratio phase shifter transfer function is formula 10,

$\frac{1-T_{c1}s}{1+T_{c2}s}{K}_c$ Formula 10

Accompanying drawing 4 is the 5Hz original waveform simulated in sub-synchronous oscillation current source multi-frequency composition and the comparison of wave shape figure obtained after this control system process reduction thereof.

Finally, comprehensive regulator, sues for peace and amplitude limiting processing for the mode control signal obtained portfolio ratio phase shifter, obtains last assemble mode control signal.

4th step, utilize online adaptive adjuster 5, at SVG controller without in subsynchronous compensate component output situation, enable the automatic adjustment of controling parameters, this controling parameters comprises the channel gain K of the port number N of Pattern Filter, portfolio ratio phase shifter and comprehensive regulator _i(i=1 ... and passage phase shift T N) _i(i=1 ... N); Under this basic principle, without the need to simulating each operating mode, will not adjust herein.

5th step, utilize power signal generating means 6, the assemble mode control signal obtained according to described multichannel stand-alone mode control ring 4 and the control signal needed for the DC control of SVG own, generate final current-order and be converted to power switch pulse signal, producing electric current and the power that can suppress sub-synchronous oscillation.This power signal generating means 6 used herein is standard application, and it will not go into details herein.

The Project Realization of native system is simple, changes or transformation, only need to carry out the upgrading of SVG controller system, be upgraded to and possess sub-synchronous oscillation inhibit feature without the need to Other Engineering.Simultaneously, for the particularity of the signal characteristic such as frequency, amplitude of the sub-synchronous oscillation signal of different network system, aforementioned combinatorial mode filter, the parameter such as ratio, phase shift, amplitude limit that portfolio ratio phase shifter is relevant to comprehensive regulator need through debugging and the improvement necessarily in conjunction with field working conditions and demand, thus the normal performance of assurance function, reach subsynchronous suppression object.

Above embodiment is only the simulation embodiment that the present invention recommends, and its concrete structure and parameter do not limit the present invention in any form.These those skilled in the art make based on any amendment in summary of the invention principle, change and improvement etc., this invention essential content will not be affected, all should in the scope of the present invention.

Claims (6)

1., based on a suppression sub-synchronous oscillation adaptive control system of SVG, comprising:

AD data acquisition unit, for gathering the voltage comprising sub-synchronous oscillation information of SVG compensation point or SVG place system public access point, electric current or power signal;

Preposition junction filter, voltage, electric current or power signal for collecting AD data acquisition unit carry out filtering, to obtain the subsynchronous and subsynchronous complement frequency signal in voltage, electric current or power signal, its implementation is various, can be that band leads to and band stop filter series system, or multiple band pass filter parallel way, or a low pass filter mode etc.; And this preposition junction filter is selective sections, if do not selected, the signal that AD data acquisition unit obtains will directly enter next data processing link;

Discrete Fourier transform and sub-synchronous oscillation frequency estimation device, the voltage containing subsynchronous and subsynchronous complement frequency signal, electric current or power signal for exporting AD data acquisition unit or preposition junction filter carry out discrete Fourier transform, to obtain amplitude and the phase place of each subsynchronous and subsynchronous complement frequency signal, and sub-synchronous oscillation frequency estimation is carried out to this amplitude and phase place, finally obtain amplitude and the frequency of the subsynchronous and subsynchronous complement frequency signal of each frequency;

Multichannel stand-alone mode control ring, comprises integrated mode filter, portfolio ratio phase shifter and the comprehensive regulator with multiple passage; The amplitude of the subsynchronous and subsynchronous complement frequency signal of each frequency that described integrated mode filter obtains in conjunction with discrete Fourier transform and sub-synchronous oscillation frequency estimation device and phase place, Pattern Filter is carried out to the voltage containing the subsynchronous and subsynchronous complement frequency signal of each frequency, electric current or power signal that AD data acquisition unit or preposition junction filter export, obtains the subsynchronous and subsynchronous complement frequency signal of each frequency; Described portfolio ratio phase shifter, for compensating the phase delay of the voltage containing subsynchronous and subsynchronous complement frequency signal, electric current or the power signal after integrated mode filter, and after being amplified by the signal passing ratio after phase compensation, be converted to the mode control signal of the subsynchronous and subsynchronous complement frequency signal of each frequency; Described comprehensive regulator, sues for peace and amplitude limiting processing for each mode control signal obtained portfolio ratio phase shifter, obtains last assemble mode control signal;

Online adaptive adjuster, for monitor when SVG controller exports without subsynchronous compensate component system there is subsynchronous component to be compensated time, enable the automatic adjustment of controling parameters, this controling parameters comprises the port number of Pattern Filter and each channel gain of portfolio ratio phase shifter and comprehensive regulator and each passage phase shift;

Power signal generating means, control signal needed for controlling for the assemble mode control signal that obtains according to multichannel stand-alone mode control ring and the direct voltage of SVG own etc., generate final current-order and be converted to power switch pulse signal, producing electric current and the power that can suppress sub-synchronous oscillation.

2. a kind of suppression sub-synchronous oscillation adaptive control system based on SVG according to claim 1, it is characterized in that, described preposition junction filter can be set to one of following five kinds of implementations:

Mode one, for voltage and current signal, arrange two filters and carry out tandem compound, the first filter is second-order bandpass filter, and its transfer function is formula 1, and the second filter is divalent radical ripple band stop filter, and its transfer function is formula 2:

$\frac{G_{01}{\mathrm{\&omega;}}_{01}s}{s^2+2{\mathrm{\&xi;}}_{01}{\mathrm{\&omega;}}_{01}s+{\mathrm{\&omega;}}_{01}^2}$ Formula 1

In formula 1, G ₀₁for the passband gain of band pass filter, ω ₀₁for band pass filter center angular frequency, ξ ₀₁for the damping coefficient of band pass filter;

$\frac{G_{02}(s^2+{\mathrm{\&omega;}}_{02}^2)}{s^2+2{\mathrm{\&xi;}}_{02}{\mathrm{\&omega;}}_{02}s+{\mathrm{\&omega;}}_{02}^2}$ Formula 2

In formula 2, G ₀₂for the first-harmonic passband gain of band stop filter, ω ₀₂for band stop filter center angular frequency, ξ ₀₂for the damping coefficient of band stop filter;

Mode two, for voltage, current signal, arrange two band pass filters and carry out parallel combination, the first filter and the second filter are second-order bandpass filter, and its transfer function is formula 3:

$\frac{G_{03}{\mathrm{\&omega;}}_{03}s}{s^2+2{\mathrm{\&xi;}}_{03}{\mathrm{\&omega;}}_{03}s+{\mathrm{\&omega;}}_{03}^2}$ Formula 3

In formula 3, G ₀₃for the passband gain of band pass filter, ω ₀₃for band pass filter center angular frequency, ξ ₀₃for the damping coefficient of filter;

Mode three, for voltage, current signal, arrange 1 second-order low-pass filter, its transfer function is formula 4:

$\frac{G_{04}{\mathrm{\&omega;}}_{04}^2}{S^2+2{\mathrm{\&xi;}}_{04}{\mathrm{\&omega;}}_{04}s+{\mathrm{\&omega;}}_{04}^2}$ Formula 4

In formula 4, G ₀₄for the passband gain of low pass filter, ω ₀₄for low pass filter natural angular frequency, ξ ₀₄for the damping coefficient of filter;

Mode four, for voltage, electric current or power signal, arrange 1 second-order bandpass filter or more than 1 band is logical, low pass filter combination, low pass filter function is formula 4, and its band pass filter transfer function is formula 5:

$\frac{G_{05}{\mathrm{\&omega;}}_{05}s}{s^2+2{\mathrm{\&xi;}}_{05}{\mathrm{\&omega;}}_{05}s+{\mathrm{\&omega;}}_{05}^2}$ Formula 5

In formula 5, G ₀₅for the passband gain of band pass filter, ω ₀₅for band pass filter center angular frequency, ξ ₀₅for the damping coefficient of filter;

Mode five, for voltage, current signal, described preposition junction filter is selective sections, does not carry out any process in this situation to the sub-synchronous oscillation voltage, electric current and the power signal that collect, and the data-signal that AD data acquisition unit obtains directly enters next data processing link.

3. a kind of suppression sub-synchronous oscillation adaptive control system based on SVG according to claim 1, it is characterized in that, described discrete Fourier transform and sub-synchronous oscillation frequency estimation device can realize the Adaptive Identification of the sub-synchronous oscillation frequency of complete subsynchronous bandwidth and complement frequency thereof, and described Adaptive Identification specific implementation process is as follows:

First, two arrays are calculated through discrete fourier, array F=[F1, ..., Fm] represent the frequency of each signal of voltage, electric current or power, amount to m frequency content, array A=[A1 ..., Am] represent the amplitude of corresponding each frequency content in frequency signal array;

Then, according to following process identification sub-synchronous oscillation frequency and amplitude set:

Step 1 sets subsynchronous frequency set as Fs=[], is initially sky, and presetting initial bandwidth deltaf f is 4 ~ 10Hz;

Step 2 signal amplitude of setting all frequencies corresponding as Aj (j=1 ..., m), if Aj is less than or equal to presetting threshold amplitude Ath, then Aj is set to 0;

Step 3 take frequency as abscissa X, with each frequency its amplitude corresponding for ordinate Y, by frequency signal array [F1, ..., Fm] and amplitude signal array [A1, ..., Am] be depicted as an amplitude-frequency spectrogram, find out according to this spectrogram the magnitude peak point that in this figure, all frequency contents are corresponding, be set as frequency signal array FP=[Fp1, ..., Fpn], corresponding peak signal array AP=[AP1, ..., APn], if Fpj is empty, represents in this electrical network and occur without the sub-synchronous oscillation of corresponding pj frequency, go to step 6;

If interval is all greater than Δ f/2 between each frequency of frequency signal array FP that all peak points of step 4 peak signal array AP are corresponding, then FP is the sub-synchronous oscillation frequency array that identification obtains, then complete identification, jump to step 6, otherwise continues to perform step 5;

Step 5 is for minimum two magnitude peak dot frequency Fpj and the Fpk (wherein Fpj < Fpk) of the frequency interval of frequency signal array FP, and these 2 frequencies are carried out merger, and the principle of merger is:

After merging, new peak point frequency is:

$Fpjk=\frac{Fpj*Fpj+Fpk*Fpk}{Apj+Apk}$

After merging, the peak value that new peak point frequency is corresponding is:

$Apjk=\left\{\begin{array}{cc}\frac{Apj(Fpk-Fpjk)+Apk(Fpjk-Fpj)}{Fpj+Fpk-2*Fpjk}& (Fpj+Apk-2*Fpjk\&NotEqual;0)\\ \frac{Apj}{(1-(1-1/\sqrt{2})*((Fpk-Fpj)/\mathrm{\&Delta;}f)}& (Fpj+Apk-2*Fpjk=0)\end{array}\right.$

Carrying out after the new frequency of each Frequency point and peak value upgrade, upgrading aggregate frequency signal array FP and peak signal array AP, jumping to step 4;

Step 6 obtains frequency signal array FP and peak signal array AP, be the set that identification obtains subsynchronous Frequency point frequency and amplitude thereof, if K for this reason time frequency number of signals group FP medium frequency element number, if K is 0, then represent that sub-synchronous oscillation does not occur network system.

4. a kind of suppression sub-synchronous oscillation adaptive control system based on SVG according to claim 1, is characterized in that, described integrated mode filter is a centre frequency and all adjustable band pass filter of bandwidth, and its transfer function is formula 6:

$\frac{G_i{\mathrm{\&omega;}}_{i}s}{s^2+2{\mathrm{\&xi;}}_i{\mathrm{\&omega;}}_{i}s+{\mathrm{\&omega;}}_i^2}$ Formula 6

In formula 6, G _ifor the passband gain of band pass filter, ω _ifor band pass filter center angular frequency, ξ _ifor the damping coefficient of filter, i ∈ [1, N].

5. a kind of suppression sub-synchronous oscillation adaptive control system based on SVG according to claim 1, it is characterized in that, described portfolio ratio phase shifter is a ratio phase-correction filter, and its transfer function is formula 7:

$\frac{1-T_{c1}s}{1+T_{c2}s}{K}_c$ Formula 7

In formula 7, K _cfor the proportionality coefficient of ratio phase-correction filter, T _cfor the phase shift compensation time constant of ratio phase-correction filter, its value is determined by the frequency of variable subsynchronous and subsynchronous complement frequency signal, fixed sample delay time constant and fixing control lag time constant;

Described ratio phase-correction filter is used for containing in subsynchronous and subsynchronous complement frequency component signal because of analog measurement the acquisition of integrated mode filter, the phase delay that integrated mode filtering and SVG control lag cause carries out phase compensation, the phase delay that sampling because of analog measurement keeps link to cause, the band pass filter adopted in integrated mode filter is for the inconsistent phase shift caused of phase-shift characterisitc of different frequency component, and by the delay of SVG controlling unit generating power signal, need to compensate the deviation of phase place, Compensation Objectives is the place's phase shift of Pattern Filter centre frequency is zero phase shift that also compensation film analog quantity data acquisition and controlling constant time of delay is corresponding.

6. a kind of suppression sub-synchronous oscillation adaptive control system based on SVG according to claim 1, it is characterized in that, described online adaptive adjuster can carry out the online adaptive adjustment of parameter, at SVG controller without in subsynchronous compensate component output situation, when there is subsynchronous component to be compensated in the system of monitoring, then enable this online adaptive adjuster, this controling parameters comprises the port number of Pattern Filter, can carry out online updating; For the described portfolio ratio phase shifter of multichannel stand-alone mode control ring and the channel gain of comprehensive regulator and passage phase shift, the subsynchronous component peak signal to be compensated that the adjustment of channel gain and described discrete Fourier transform and sub-synchronous oscillation frequency estimation device obtain is in direct ratio, and the assemble mode control signal that multichannel stand-alone mode control ring produces is no more than 50% of the own rated current of SVG; The adjustment basic principle of each channel compensation phase place is the sub-synchronous oscillation current/power homophase that current/power that SVG device is absorbed and sub-synchronous oscillation source exist, or operational mode bias internal amount possible in the various operating mode of reality is no more than 60 degree.