CN201699420U - Repetitive controller with specific times - Google Patents

Abstract

The utility model discloses a repetitive controller of a specific subharmonic. The controller comprises a repetitive control gain module, a negative feedforward gain module, a positive feedforward gain module, an addition ring, two subtraction rings and three time delay modules. The error-free tracking or elimination of a subharmonic (nk+/-m) is realized by the combination of a main path, a positive feedforward path, a negative feedforward path and a positive feedback path, wherein the parameters of the positive feedforward gain module and the negative feedforward gain module are determined according to the times of the frequency of a harmonic to be tracked or eliminated, and the speed of the elimination of an error is regulated by the repetitive control gain module. The utility model has the advantages that the speed of the elimination of the error is higher, storage units required when digitization is realized are less, and the expression form of a universal repetitive controller is provided. In order to enhance the stability and the anti-jamming capability of a control system, an improved subharmonic (nk+/-m) repetitive controller added with a low-pass filter and a phase advancer is also provided so as to meet the requirement of actual application.

Description

A kind of specific repetitive controller

Technical field

The utility model proposes a kind of specific subharmonic repetitive controller, be used for that (the error free tracking of the rd harmonic signal of nk ± m) or eliminate fully belongs to the repetitive controller field of Industry Control.

Background technology

For many years, the tracking of cyclical signal and Disturbance Rejection compensation problem are the problems that numerous researchers pay close attention to always, and based on internal model principle to repeat control be exactly a kind of highly effective control device.It is T that general repetitive controller adopts delay time T _oThe positive feedback form of delay link

Constructing the primitive period is T _oThe internal mold of periodic signal, and with in it embedding control loop, thereby can implement static indifference tracking Control or disturbance is eliminated to this kind cyclical signal (comprising sinusoidal fundamental wave and each harmonic thereof), because such repetitive controller is by being the time of delay that is input to output primitive period T _o, its response speed is relatively slow, and repetitive controller is many with digital form z in the middle of actual ^-N/ (1-z ^-N) (N=T wherein _o/ T _sBe integer, T _sBe the sampling time) realize the internal mold of this cyclical signal, its shared internal storage location number is at least N.Yet in some practical applications, the harmonic wave that needs to follow the tracks of or eliminate is confined to some specific frequency, for example the three phase rectifier load concentrates on 6k ± 1 (k=1 for the harmonic pollution overwhelming majority that power-supply system caused, 2, ...) the subfrequency place, and the single-phase rectifier load give the harmonic pollution overwhelming majority that power-supply system caused concentrate on 4k ± 1 (k=1,2 ...) and subfrequency (being odd harmonic frequencies) locates.If (the periodic disturbance phenomenon very slowly that disappears can appear in the subharmonic of nk ± m), often can't satisfy the requirement of real system to control performance to adopt general repetitive controller to eliminate this class.If can propose new repetitive controller only compensates at these frequencies, by transforming the internal mold of signal in the controller, its control lag time is shortened, and the speed of disturbance is eliminated by raising system greatly, and significantly reduces the required memory space that takies of its Digital Implementation.Therefore be necessary still that the multiple control technology of counterweight does further research.

The utility model content

Technical problem: the purpose of this utility model is to propose a kind of specific repetitive controller, this repetitive controller is only at (nk ± m) rd harmonic signal is followed the tracks of fully or eliminated, it is far away from general repetitive controller that the speed of its tracking or harmonic carcellation signal is wanted, and the shared memory space of its Digital Implementation still less, and its cost performance promotes greatly.

Technical scheme:

The utility model adopts following technical scheme for achieving the above object:

A kind of repetitive controller of the utility model, comprise repetition ride gain module, negative feedforward gain module, positive feedforward gain module, the addition ring, two time delay modules that the subtraction ring is identical with three, the output that wherein repeats the ride gain module connects the input of addition ring and negative feedforward gain module respectively, connect the input of the second time delay module and positive feedforward gain module behind the output serial connection very first time Postponement module of addition ring respectively, the output of negative feedforward gain module is connected in series the negative input end that connects the second subtraction ring after the 3rd time delay module, the negative input end of the output termination first subtraction ring of the second time delay module, the positive input terminal of the output termination first subtraction ring of positive feedforward gain module, the positive input terminal of the output termination second subtraction ring of the first subtraction ring, the input of the output termination addition ring of the second subtraction ring.

Preferably, the output of described three identical time delay modules is connected in series low pass filter respectively, the output serial connection phase lead compensation module of the described second subtraction ring.

Preferably, described time delay module is an analog or digital time delay module.

Beneficial effect:

1, the utility model proposed, and (the subharmonic repetitive controller of nk ± m) is specially at (rd harmonic signal of nk ± m) carries out error free tracking or disturbance is eliminated, can customize different n and the numerical value of m according to the actual demand of harmonic carcellation disturbing signal or tracking reference signal.As at eliminating (6k ± 1) subharmonic in the three-phase inversion and following the tracks of the needs of first-harmonic reference signal, only need make n=6 and m=1 get final product; To eliminating odd harmonic in the single-phase inversion and following the tracks of the needs of first-harmonic reference signal, only need make n=4 and m=1 get final product.Compare with general repetitive controller, its speed of eliminating disturbance improves greatly.

2, (nk ± m) number of the required memory cell of Digital Implementation of subharmonic repetitive controller also is significantly less than general repetition of figures controller.

3, (nk ± m) the subharmonic repetitive controller has provided a kind of universal expression formula of repetitive controller, unified multiple repetitive controller, " the Zero-phase Odd-harmonic Repetitive Controller fora Single-phase PWM Inverter " that is shown as document Keliang Zhou etc., IEEE Trans.on Power Electronics, Vol.21, No.1, pp.193-201, applied odd harmonic repetitive controller is the utility model (special case of subharmonic repetitive controller when n=4 and m=1 of nk ± m) in 2,006 one literary compositions; And general repetitive controller can (nk ± m) the subharmonic repetitive controller makes n=1 and m=0 obtain by the utility model.

4, (ratio that the subharmonic repetitive controller of nk ± m) is used for eliminating nk+m and these two kinds of frequencies of nk-m only needs a kind of time delay link to construct the disturbing signal internal mold during not for the disturbance of integral multiple relation, has therefore simplified the design of time delay link in the repetitive controller.

Description of drawings

Fig. 1 is (the subharmonic repetitive controller of nk ± m) that the utility model proposes.

Fig. 2 is the Digital Implementation form of Fig. 1, is (the subharmonic repetition of figures controller of nk ± m).

Fig. 3 is improved (the subharmonic repetitive controller of nk ± m) that adds low-pass filtering link and phase lead compensation link on Fig. 1 basis.

Fig. 4 is the Digital Implementation form of Fig. 3, is improved (the subharmonic repetition of figures controller of nk ± m).

Fig. 5 is improved (the subharmonic repetition of figures controller of nk ± m) the control system structured flowchart of general feedback controller that superposes.

Embodiment

Be elaborated below in conjunction with the technical scheme of accompanying drawing to utility model:

The utility model proposed (the subharmonic repetitive controller structured flowchart of nk ± m) as shown in Figure 1, its transfer function is:

$G_{\mathrm{rc}}\left(s\right)=\frac{c\left(s\right)}{e\left(s\right)}=k_r\·\frac{\cos \left(\frac{2\mathrm{\π}}{n}m\right)e^{s\frac{T_o}{n}}-1}{e^{s\frac{2T_o}{n}}-2\cos \left(\frac{2\mathrm{\π}}{n}m\right)e^{s\frac{T_o}{n}}+1}$

Wherein c (s) is the output variable of repetitive controller, and e (s) is the input variable of repetitive controller that is the departure amount of control system, k _rFor repeating ride gain, T _oBe the primitive period, T _o=2 π/ω _o=1/f _o, f _oBe fundamental frequency, ω _oBe the first-harmonic angular frequency, n, k and m are not less than zero integer and n ≠ 0, n＞m.By regulating gain coefficient k _rNumerical value, can change the convergence rate of system, k _rBig more, the speed of system's convergence is fast more, but k _rCross conference and cause system to exceed stability range, so k _rCan only improve the convergence rate of system within the specific limits.Three delay links among Fig. 1 are identical, and its delay time T all equals primitive period T _oN/one, long delay time path is made up of two above-mentioned delay links, so its total delay time is (2T _o/ n)＜＜T _o, therefore repeating ride gain k _rUnder the identical situation, the response speed of this repetitive controller is more faster than general repetitive controller, and this is (the big advantage of subharmonic repetitive controller of nk ± m).

Because the transfer function of the repetitive controller that the utility model is shown in Figure 1 can be rewritten as follows:

$G_{\mathrm{rc}}\left(s\right)=k_r\·\frac{\cos \left(\frac{2\mathrm{\π}}{n}m\right)e^{s\frac{T_o}{n}}-1}{e^{2s\frac{T_o}{n}}-2\cos \left(\frac{2\mathrm{\π}}{n}m\right)e^{s\frac{T_o}{n}}+1}=k_r\·\frac{\cos \left(\frac{2\mathrm{\π}}{n}m\right)-e^{-s\frac{T_o}{n}}}{e^{s\frac{T_o}{n}}+e^{-s\frac{T_o}{n}}-2\cos \left(\frac{2\mathrm{\π}}{n}m\right)}$

$=\frac{1}{2}{k}_r\·\frac{\cos \left(\frac{2\mathrm{\π}}{n}m\right){-e}^{-s\frac{T_o}{n}}}{\cosh \left(s\frac{T_o}{n}\right)-\cos \left(\frac{2\mathrm{\π}}{n}m\right)}$

$=\frac{1}{2}{k}_r\&CenterDot;\frac{\cos \left(\frac{2\mathrm{\&pi;}}{n}m\right){-e}^{-s\frac{T_o}{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HSA00000176174200011.png,HSA00000176174200013.png"\; state="\{\{state\}\}">n</figure-callout>}}}}{2{\sin }^2\left(\frac{2\mathrm{\&pi;}}{\mathrm{<figure-callout\; id="1"\; label="n\; m"\; filenames="HSA00000176174200021.png"\; state="\{\{state\}\}">n</figure-callout>}}m\frac{1}{2}\right)\&CenterDot;\underset{k=-\&infin;}{\overset{\&infin;}{\mathrm{\&Pi;}}}[1+\frac{s^2}{{(\mathrm{nk}+m)}^2{\mathrm{\&omega;}}_o^2}]}$

Following formula requires m ≠ 0; When m=0, eliminate (nk ± m) the repetitive controller transfer function of subharmonic can change into following form:

$G_{\mathrm{rc}}\left(s\right)=\frac{c\left(s\right)}{e\left(s\right)}=k_r\&CenterDot;\frac{\cos \left(\frac{2\mathrm{\&pi;}}{n}m\right)e^{s\frac{T_o}{n}}-1}{e^{2s\frac{T_o}{n}}-2\cos \left(\frac{2\mathrm{\&pi;}}{n}m\right)e^{s\frac{T_o}{n}}+1}{|}_{m=0}=k_r\&CenterDot;\frac{e^{s\frac{T_o}{n}}-1}{e^{2s\frac{T_o}{n}}-2e^{s\frac{T_o}{n}}+1}$

$=k_r\&CenterDot;\frac{e^{s\frac{T_o}{n}}-1}{{(e^{s\frac{T_o}{n}}-1)}^2}=k_r\&CenterDot;\frac{1}{e^{s\frac{T_o}{n}}-1}$

$=k_r\&CenterDot;\frac{1}{\frac{{\mathrm{sT}}_o}{n}\&CenterDot;e^{\frac{s{T}_o}{2n}}\&CenterDot;\underset{k=-\&infin;}{\overset{\&infin;}{\mathrm{\&Pi;}}}[1+\frac{s^2}{{\left(\mathrm{nk}\right)}^2{\mathrm{\&omega;}}_o^2}]}$

Comprehensive above-mentioned two formulas, the limit that therefore can get repetitive controller shown in Figure 1 is the (ω of nk ± m) in frequency _oThe place, promptly pole frequency is m ω _o, (the ω of n ± m) _o, (the ω of 2n ± m) _o..., (the ω of in ± m) _o... (i=1 wherein, 2,3...).Because this repetitive controller is the (ω of nk ± m) in frequency _oThe gain at place be infinitely great, therefore can thoroughly eliminate frequency among the departure e (s) and be (the ω of nk ± m) _oHarmonic component, thereby realize (nk ± m) elimination fully or the error free tracking of subharmonic disturbance is so with this repetitive controller, the specific subharmonic repetitive controller that promptly the utility model proposes is called (the subharmonic repetitive controller of nk ± m).In the middle of the practical application, can be at the demand of different occasions, give m and n with different numerical value, can realize specific (nk ± m) the error free tracking or the Disturbance Rejection of subharmonic.For example for the situation of three-phase inverter band three phase rectifier load, because its harmonic wave mainly concentrates on (6k ± 1) inferior (i.e. 5,7,11,13 grades) harmonics frequency component place, and often need follow the tracks of the first-harmonic reference signal, so only need make n=6 and m=1, just can realize to the error free tracking of first-harmonic reference signal with to the elimination fully of (6k ± 1) subharmonic; Situation for single-phase inverter band single-phase rectifier load, because its harmonic wave mainly concentrates on (4k ± 1) inferior (promptly 3,5,7,9 etc. odd) frequency component place, and often need follow the tracks of the first-harmonic reference signal, so only need make n=4 and m=1, just can realize to the error free tracking of first-harmonic reference signal with to the elimination fully of odd harmonic.

Repetitive controller is many in the middle of actual is realized and is used with digital form.The pairing Digital Implementation of repetitive controller shown in Figure 1 as shown in Figure 2, its transfer function is:

$G_{\mathrm{rc}}\left(z\right)=\frac{c\left(z\right)}{e\left(z\right)}=k_r\&CenterDot;\frac{\cos \left(\frac{2\mathrm{\&pi;}}{n}m\right)\&CenterDot;z^{\frac{N}{n}}-1}{z^{2\&CenterDot;\frac{N}{n}}-2\cos \left(\frac{2\mathrm{\&pi;}}{n}m\right)\&CenterDot;z^{\frac{N}{n}}+1}$

Wherein c (z) is the output variable of repetitive controller, and e (z) is the input variable of repetitive controller that is the departure amount of control system, k _rFor repeating ride gain, N=T _o/ T _sBe integer, T _oBe the primitive period, T _o=2 π/ω _o=1/f _o, f _oBe fundamental frequency, ω _oBe first-harmonic angular frequency, T _sBe the sampling period, n, k and m are not less than zero integer and n ≠ 0, n＞m.Three time delay links among Fig. 2 are identical, the internal storage location number that takies all is N/n, therefore its total internal storage location number is (3N/n), therefore (memory space that the subharmonic repetition of figures controller of nk ± m) takies is wanted much less than general repetition of figures controller, and this is (another big advantage of subharmonic repetitive controller of nk ± m).

In actual applications, for improving the stability and the antijamming capability of control system, usually need among Fig. 1 or Fig. 2 (nk ± m) the subharmonic repetitive controller is improved, improved method is to add low pass filter link Q (s) or Q (z) and phase lead compensation link A (s) or A (z) in repetitive controller, as shown in Figure 3 and Figure 4, wherein Fig. 4 is the Digital Implementation form of Fig. 3.Shown in Figure 3 improved (nk ± m) transfer function of subharmonic repetitive controller can be write as following form:

$G_{\mathrm{rc}}\left(s\right)=\frac{c\left(s\right)}{e\left(s\right)}=k_r\&CenterDot;\frac{\cos \left(\frac{2\mathrm{\&pi;}}{n}m\right)e^{s\frac{T_o}{n}}\&CenterDot;Q\left(s\right)-Q^2\left(s\right)}{e^{s\frac{2T_o}{n}}-2\cos \left(\frac{2\mathrm{\&pi;}}{n}m\right)e^{s\frac{T_o}{n}}\&CenterDot;Q\left(s\right)+Q^2\left(s\right)}\&CenterDot;A\left(s\right)$

Shown in Figure 4 improved (nk ± m) transfer function of subharmonic repetition of figures controller can be write as following form:

$G_{\mathrm{rc}}\left(z\right)=\frac{c\left(z\right)}{e\left(z\right)}=k_r\&CenterDot;\frac{\cos \left(\frac{2\mathrm{\&pi;}}{n}m\right)\&CenterDot;z^{\frac{N}{n}}\&CenterDot;Q\left(z\right)-Q^2\left(z\right)}{z^{2\&CenterDot;\frac{N}{n}}-2\cos \left(\frac{2\mathrm{\&pi;}}{n}m\right)\&CenterDot;z^{\frac{N}{n}}\&CenterDot;Q\left(z\right)+Q^2\left(z\right)}\&CenterDot;A\left(z\right)$

It is of the present utility model that (the subharmonic repetitive controller of nk ± m) can be to insert or cascade system joins the (order harmonic components of nk ± m) that is used in the general feedback control system to eliminate in the middle of the departure.Below with will (it be example that the subharmonic repetition of figures controller of nk ± m) joins in the general reponse system with inserted mode, (the embodiment of subharmonic repetitive controller of nk ± m) of introducing that the utility model proposes.Shown in Figure 5 is that (nk ± m) subharmonic repetition of figures controller joins the structured flowchart in the general feedback control system, wherein G with improved _Rc(z) be improved (the subharmonic repetition of figures controller of nk ± m), G _c(z) be conventional feedback controller, G _s(z) be controlling object, y _d(z) for reference of system input and be generally the first-harmonic reference signal, y (z) be the actual output of system, and e (z) is reference and the error while of actual signal also is repetitive controller G _Rc(z) input signal, c (z) is repetitive controller G _Rc(z) output signal simultaneously also after error signal e (z) addition as conventional feedback controller G _c(z) input, u (z) is conventional feedback controller G _c(z) output signal also is controlling object G simultaneously _s(z) input signal, d (z) are the disturbance input signal of system, it and controlling object G _s(z) output signal addition forms real output signal y (z).

Claims (3)

1. specific repetitive controller, it is characterized in that comprising repetition ride gain module, negative feedforward gain module, positive feedforward gain module, the addition ring, two time delay modules that the subtraction ring is identical with three, the output that wherein repeats the ride gain module connects the input of addition ring and negative feedforward gain module respectively, connect the input of the second time delay module and positive feedforward gain module behind the output serial connection very first time Postponement module of addition ring respectively, the output of negative feedforward gain module is connected in series the negative input end that connects the second subtraction ring after the 3rd time delay module, the negative input end of the output termination first subtraction ring of the second time delay module, the positive input terminal of the output termination first subtraction ring of positive feedforward gain module, the positive input terminal of the output termination second subtraction ring of the first subtraction ring, the input of the output termination addition ring of the second subtraction ring.

2. a kind of specific repetitive controller according to claim 1 is characterized in that the output of described three identical time delay modules is connected in series low pass filter respectively, the output serial connection phase lead compensation module of the described second subtraction ring.

3. a kind of specific repetitive controller according to claim 1 and 2 is characterized in that described time delay module is an analog or digital time delay module.

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