CN203396841U - Phase locking apparatus of a variable-ratio water-drawing energy-storage set control system - Google Patents

Abstract

The utility model provides a phase locking apparatus of a variable-ratio water-drawing energy-storage set control system. The phase locking apparatus comprises a controller which comprises a phase-locked loop board card, n signal-generator board cards and a CPU, wherein the phase-locked loop board card and n signal-generator board cards are connected to the CPU, and the phase-locked loop board card acquires three-phase AC voltage signals. When three-phase voltage of an electrical network is imbalanced or the voltage contains harmonic wave, the MSOGI system can effectively eliminates influence of harmonic waves on the electrical network, accurately calculates the positive sequence component of the fundamental waves, and further obtains accurate rotary angle of voltage vector of the electrical network. When the frequency of the electrical network changes abruptly, the FLL system rapidly tracks the frequency of the electrical network. Even if the three-phase voltage of the electrical network contains harmonic waves, the influence of the harmonic wave can be eliminated, the frequency of the electrical network can be accurately detected, and the accuracy of the frequency detection can be improved.

Description

The phase-locking device of variable-ratio water-storage unit control system

Technical field

The utility model relates to a kind of control device of variable-ratio water-storage unit, specially refers to the anglec of rotation of line voltage vector and the detection technique of mains frequency.

Background technology

For the sustainable development of electric system, coordinate transferring electricity from the west to the east, improve the safety and stability ability of electrical network and networked system, need to build variable-ratio water-storage unit.The precision regulating in order to improve mains frequency, solves frequency instability problem and raising power system transient stability thereof that large-scale wind electricity generation grid-connecting brings, need to build variable-ratio water-storage unit.

In order to improve the efficiency of variable-ratio water-storage unit, need to carry out closed-loop control, wherein relate to the anglec of rotation and the line voltage frequency detecting technology of line voltage vector.When Voltage Harmonic pollution and frequency discontinuity, controller needs the anglec of rotation and the mains frequency of line voltage vector accurately and timely to be detected, to carry out rapidly closed-loop control.

Utility model content

The purpose of this utility model is to overcome the deficiency of existing phase-locked loop apparatus, and providing a kind of can affect by filtering mains by harmonics, accurately calculates the anglec of rotation of line voltage vector and the detection technique of mains frequency.

According to the phase-locking device of the variable-ratio water-storage unit control system providing of the present utility model, comprise controller, wherein, controller comprises phaselocked loop board, a n signal generator board, CPU, phaselocked loop board, a n signal generator board are all connected to CPU, and phaselocked loop board gathers three-phase alternating voltage signal.

Preferably, also comprise frequency converter, stator, wherein, CPU in controller connects respectively frequency converter, stator, the various signals that controller obtains according to phaselocked loop board, signal generator board are controlled variable-ratio water-storage unit control system, and frequency converter and stator are sent to instruction, thereby control in real time whole variable-ratio water-storage unit control system.

Preferably, phaselocked loop board comprises DSP, FPGA, and wherein, FPGA gathers three-phase alternating voltage signal and sends into DSP, and DSP completes the computing of phaselocked loop, obtains anglec of rotation θ and the mains frequency f of line voltage vector, is sent into the CPU of controller.

Preferably, DSP adopts the TMS28335 chip of TI company.

Preferably, FPGA adopts the A3P250 chip of ACTEL company.

The phase-locking device providing according to the utility model, can realize a kind of phase-lock technique of variable-ratio water-storage unit control system, comprises the steps:

Step 1: three phase network voltage v _a, v _b, v _cbe converted into v _α, v _βthen perform step 2; Wherein, v _α, v _βbe respectively α axle, beta-axis component under two phase coordinate systems;

Step 2: by the v obtaining in step 1 _αand v _β, send into respectively MSOGI-FLL system, then perform step 3 and step 4 simultaneously; Wherein, MSOGI-FLL system is mainly used cross feedback network cooperation to form by FLL FLL and n independent second order improper integral orthogonal signal generator SOGI-QSG, each SOGI-QSG can regulate the multiple frequency of fundamental frequency, the input of FLL is provided by first SOGI-QSG, thereafter second input to n SOGI-QSG system is that the fundamental frequency that detected by FLL is multiplied by a coefficient and forms, and this coefficient has determined that the output of FLL is assigned to the order of different SOGI-QSG; And the gain of each SOGI-QSG is distinguished by this coefficient, to make the bandwidth of centre frequency and SOGI-QSG keep constant relation, the input signal of each SOGI-QSG is by original input signal v, to be deducted the output signal of all the other all SOGI-QSG; Described n independent second order improper integral orthogonal signal generator SOGI-QSG forms MSOGI system; In this manner, through of short duration calculating transient process, clean out in the input signal of each SOGI-QSG by the detected harmonic components of all the other SOGI-QSG, to reduce the disturbance of harmonic wave in output signal.

Step 3:v _αand v _βby MSOGI system, eliminate the impact of specifying harmonic wave, produce respectively two component v ' of quadrature _α, qv ' _αand v ' _β, qv ' _β., wherein, v ' _αbe α axle component under two phase coordinate systems, v ' _βbe beta-axis component under two phase coordinate systems, q is orthogonal operators;

Step 4: utilize the FLL module in MSOGI-FLL system, try to achieve rotation angle frequencies omega ', then perform step 5;

Step 5: utilize the v ' obtaining in step 3 _α, qv ' _αand v ' _β, qv ' _β, calculate α axle under two phase coordinate systems, β axle positive-sequence component

then perform step 6;

Step 6: utilize α axle, β axle positive-sequence component under two phase coordinate systems that step 5 obtains arc tangent obtains angle θ.

Preferably, described step 1, is specially: according to formula $\left[\begin{array}{c}{v}_{\mathrm{\α}}\\ v_{\mathrm{\β}}\end{array}\right]=\left[\begin{array}{ccc}\frac{2}{3}& -\frac{1}{3}& -\frac{1}{3}\\ 0& \frac{1}{\sqrt{3}}& -\frac{2}{\sqrt{3}}\end{array}\right]\·\left[\begin{array}{c}{v}_a\\ v_b\\ v_c\end{array}\right]$ To input three phase network voltage v _a, v _b, v _cbe converted into v _α, v _β.

Preferably, described step 3, is specially: the output signal v ' of input signal v and SOGI-QSG does after difference, obtains deviation signal ε _v, this deviation signal ε _vafter amplifier, be amplified signal k ε _v, k is enlargement factor, this amplifying signal k ε _vdo poorly with signal qv ', the signal obtaining is input to multiplier, and multiplier is by this signal and phase-locked angular frequency ' multiply each other, and the signal obtaining, after integral element, obtains output signal v '; V ' is after integral element for this output signal, and the signal obtaining is input to multiplier, and multiplier is by this signal and phase-locked angular frequency ' multiply each other by multiplier, the signal qv ' obtaining.

Preferably, described step 4, is specially: the output signal v ' of input signal v and SOGI-QSG does after difference, obtains deviation signal ε _v, multiplier is by deviation signal ε _vqv ' multiplies each other with output signal, obtains signal epsilon _f, this signal epsilon _fafter amplifier, the signal obtaining can obtain after by integral element phase-locked angular frequency ', according to Formula for Angular Velocity of Fuze ω=2 π f, can reverse obtain the frequency of electrical network.

Preferably, described step 5, is specially: by the v ' obtaining in step 3 _αqv ' _αand v ' _β, qv ' _β, utilize positive-negative sequence calculated signals module (PNSC, Positive-/Negative-Sequence Calculator) to solve and obtain calculating α axle under two phase coordinate systems, β axle positive-sequence component

computing formula is $\left\{\begin{array}{c}{v}_{\mathrm{\α}}^{{+}^{\′}}=v_{\mathrm{\α}}^{\′}+{\mathrm{qv}}_{\mathrm{\β}}^{\′}\\ v_{\mathrm{\β}}^{{+}^{\′}}={\mathrm{qv}}_{\mathrm{\α}}^{\′}+v_{\mathrm{\β}}^{\′}\end{array}\right..$

Preferably, described step 6, is specially: α axle, β axle positive-sequence component under two phase coordinate systems that obtain according to step 5

utilize formula arc tangent obtains angle θ.

Compared with prior art, the utlity model has following beneficial effect:

1, when electrical network three-phase voltage occurs that uneven and line voltage contains harmonic content, adopt the effectively impact of filtering mains by harmonics of MSOGI system, accurately calculate its fundamental positive sequence, and then accurately try to achieve the anglec of rotation of line voltage vector.

2, when sudden change appears in mains frequency, adopt FLL system Tracking Frequency of Power Grids fast, even when electrical network three-phase voltage contains harmonic wave, impact that also can filtering harmonic wave, detects mains frequency exactly, has improved the accuracy of frequency detecting.

Accompanying drawing explanation

By reading the detailed description of non-limiting example being done with reference to the following drawings, it is more obvious that other features, objects and advantages of the present utility model will become:

Fig. 1 is the computation structure block diagram of positive sequence/negative sequence voltage;

Fig. 2 is the sef-adapting filter based on SOGI;

Fig. 3 is the system chart based on SOGI-FLL;

Fig. 4 is that the positive sequence/negative sequence component based on DSOGI-FLL calculates;

Fig. 5 is the system chart based on MSOGI-FLL; In Fig. 5, e represents error signal;

Fig. 6 is the frequency-tracking waveform based on MSOGI-FLL;

Fig. 7 is based on MSOGI-FLL result of calculation waveform;

Fig. 8 is system chart of the present utility model;

Fig. 9 is structural representation of the present utility model.

In figure:

1 is main-transformer;

2 is exciting transformer;

3 is generator;

4 is the hydraulic turbine;

91 is controller;

911 is phaselocked loop board;

912 is signal generator board;

913 is CPU;

92 is frequency converter;

93 is stator.

Embodiment

Below in conjunction with specific embodiment, the utility model is elaborated.Following examples will contribute to those skilled in the art further to understand the utility model, but not limit in any form the utility model.It should be pointed out that to those skilled in the art, without departing from the concept of the premise utility, can also make some distortion and improvement.These all belong to protection domain of the present utility model.

Three phase network voltage, can be decomposed into positive sequence, negative phase-sequence and residual voltage, and it is zero that residual voltage is cancelled out each other after converting by Clark, thereby has suppressed the impact of residual voltage.If

with

represent respectively positive sequence voltage vector negative sequence voltage vector, so, voltage vector V _abc=[v _av _bv _c] ^tcan be obtained by formula (1):

$V_{\mathrm{abc}}^{+}={\left[\begin{array}{ccc}{v}_a^{+}& v_b^{+}& v_c^{+}\end{array}\right]}^T=\left[T_{+}\right]V_{\mathrm{abc}}$ Formula (1)

$V_{\mathrm{abc}}^{-}={\left[\begin{array}{ccc}{v}_a^{-}& v_b^{-}& v_c^{-}\end{array}\right]}^T=\left[T_{-}\right]V_{\mathrm{abc}}$

Wherein, v _a, v _b, v _cbe respectively three phase network voltage,

be respectively electrical network three-phase positive sequence voltage,

be respectively electrical network three-phase negative/positive voltage, [T ₊] and [T _-] be:

$\left[T_{+}\right]=\frac{1}{3}\left[\begin{array}{ccc}1& a& a^2\\ a^2& 1& a\\ a& a^2& 1\end{array}\right];$ $\left[T_{-}\right]=\frac{1}{3}\left[\begin{array}{ccc}1& a^2& a\\ a& 1& a^2\\ a^2& a& 1\end{array}\right]$ Formula (2)

Parameter wherein

wherein, j is the imaginary axis.Only consider positive sequence voltage and negative sequence voltage, by formula (3), by Clark, convert voltage vector is transformed into two phase coordinate systems from three phase coordinate systems.

$V_{\mathrm{\α\β}}=\left[T_{\mathrm{\α\β}}\right]V_{\mathrm{abc}};\left[T_{\mathrm{\α\β}}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]$ Formula (3)

Wherein, V _{α β}it is the voltage vector under two phase coordinate systems.

So, instantaneous positive sequence voltage under alpha-beta coordinate system

with negative sequence voltage

be respectively:

$V_{\mathrm{\α\β}}^{+}=\left[T_{\mathrm{\α\β}}\right]V_{\mathrm{abc}}^{+}=\left[T_{\mathrm{\α\β}}\right]\left[T_{+}\right]V_{\mathrm{abc}}$

$=\left[T_{\mathrm{\α\β}}\right]\left[T_{+}\right]{\left[T_{\mathrm{\α\β}}\right]}^T{V}_{\mathrm{\α\β}}=\frac{1}{2}\left[\begin{array}{cc}1& -q\\ q& 1\end{array}\right]V_{\mathrm{\α\β}}$ Formula (4)

$V_{\mathrm{\α\β}}^{-}=\left[T_{\mathrm{\α\β}}\right]V_{\mathrm{abc}}^{-}=\left[T_{\mathrm{\α\β}}\right]\left[T_{-}\right]V_{\mathrm{abc}}$

$=\left[T_{\mathrm{\α\β}}\right]\left[T_{-}\right]{\left[T_{\mathrm{\α\β}}\right]}^T{V}_{\mathrm{\α\β}}=\frac{1}{2}\left[\begin{array}{cc}1& q\\ -q& 1\end{array}\right]V_{\mathrm{\α\β}}$

Wherein, parameter q=-j computing can obtain orthogonal signal, and wherein, j is the imaginary axis.Fig. 1 has described Quadrature signal generation module (QSG, Quadrature-Signals Generator) and positive-negative sequence calculated signals module (PNSC, Positive-/Negative-Sequence Calculator).

In order to obtain two orthogonal signal, need to adopt second order improper integral device (SOGI, Second Order Generalized Integrator).Fig. 2 represents SOGI-QSG system, and wherein the transport function of SOGI is:

$\mathrm{SOGI}\left(s\right)=\frac{v^{\′}}{k{\mathrm{\ϵ}}_v}\left(s\right)=\frac{{\mathrm{\ω}}^{\′}s}{s^2+{\mathrm{\ω}}^{\′2}}$ Formula (5)

Transport function formula (5) prove when incoming frequency f be while take the sinusoidal signal that ω ' is frequency, SOGI is an integrator that gain is infinite.In addition, SOGI-QSG system can be used for following the tracks of input signal v, and system transter is:

$D\left(s\right)=\frac{v^{\′}}{v}\left(s\right)=\frac{k{\mathrm{\ω}}^{\′}s}{s^2+k{\mathrm{\ω}}^{\′}s+{\mathrm{\ω}}^{\′2}}$ Formula (6)

$Q\left(s\right)\frac{{\mathrm{qv}}^{\&prime;}}{v}\left(s\right)=\frac{{\mathrm{k\&omega;}}^{\&prime;2}}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HSA00000923018100022.png,HSA00000923018100032.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+k{\mathrm{\&omega;}}^{\&prime;}s+{\mathrm{\&omega;}}^{\&prime;2}}$

Wherein ω ' and k are respectively resonance frequency and ratio of damping.If v is frequency is the sinusoidal signal of ω, SOGI-QSG output signal qv ' falls behind 90 ° of v ' always, and irrelevant with the value of v, ω ' and k.Therefore, this system can be used for producing the signal of two quadratures.V ' and qv ' are the signals of two quadratures, and SOGI-QSG system has the logical and low-frequency filter characteristics of band to output signal v ' and qv ', and wherein k value is less, more has better filtering characteristic, but stabilization time is longer.Typical case's damping response is to get

now, system has good amplitude-frequency response.

When input signal is identical with SOGI resonance frequency, two output signals of SOGI-QSG have identical amplitude.Therefore,, in order to obtain two positive blending output signals with identical amplitude, it is identical with the frequency of input signal that the centre frequency of SOGI-QSG should be adjusted to.The utility model adopts FLL (Frequency-Locked Loop, FLL) to realize SOGI-QSG centre frequency self-adaptation, and as shown in Figure 3, this system can be used for detecting the frequency of input signal to the SOGI-FLL system that contains FLL.

Orthogonal signal qv ' and error signal _vcan embody the performance of FLL.Input signal v and error signal _vtransport function E (s) be:

$E\left(s\right)=\frac{{\mathrm{\&epsiv;}}_v}{v}\left(s\right)=\frac{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HSA00000923018100022.png,HSA00000923018100032.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+{\mathrm{\&omega;}}^{\&prime;2}}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HSA00000923018100022.png,HSA00000923018100032.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+k{\mathrm{\&omega;}}^{\&prime;}s+{\mathrm{\&omega;}}^{\&prime;2}}$ Formula (7)

When frequency input signal is less than SOGI resonance frequency (ω < ω '), qv ' and ε _vsame-phase; When frequency input signal is greater than SOGI resonance frequency (ω > ω '), qv ' and ε _vantiphase.Therefore, qv ' and ε _vproduct can be defined as the error signal of variation _f,

for error signal mean value.When ω < ω ' time,

for just; When ω=ω ',

be zero; When ω > ω ' time,

for negative.Therefore, the integrator that scale-up factor is-γ can regulating error signal be 0, until SOGI resonance frequency is identical with incoming frequency.

If SOGI-QSG inputs sinusoidal signal v=Vsin (ω t+ φ), output signal is:

$v^{\&prime;}=-\frac{V}{\mathrm{\&lambda;}}\sin \left(\mathrm{\&lambda;\&omega;t}\right)\&CenterDot;e^{-\frac{k{\mathrm{\&omega;}}^{\&prime;}}{2}t}+V\sin \left(\mathrm{\&omega;t}\right)$

${\mathrm{qv}}^{\&prime;}=V[\cos \left(\mathrm{\&lambda;\&omega;t}\right)+\frac{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="HSA00000923018100022.png,HSA00000923018100032.png"\; state="\{\{state\}\}">k</figure-callout>}}{2\mathrm{\&lambda;}}\&CenterDot;\sin \left(\mathrm{\&lambda;\&omega;t}\right)]e^{-\frac{k{\mathrm{\&omega;}}^{\&prime;}}{2}t}-V\cos \left(\mathrm{\&omega;t}\right)$ Formula (8)

Wherein, parameter

and k < 2, V is sinusoidal signal amplitude, and ω is sinusoidal signal angular frequency, and t is time variable, and ω ' is SOGI resonance frequency.In order to consider adjusting time, overshoot and harmonic suppression effect, the gain of SOGI-QSG is set to

through type (9) can carry out standardization by γ,

$\mathrm{\&gamma;}=\frac{k{\mathrm{\&omega;}}^{\&prime;}}{{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000923018100022.png,HSA00000923018100032.png"\; state="\{\{state\}\}">V</figure-callout>}}^2}\mathrm{\&Gamma;}$ Formula (9)

Therefore, regulate time t _{s (FLL)}depend on parameter Γ, be approximately equal to:

$t_{s\left(\mathrm{FLL}\right)}\&ap;\frac{5}{\mathrm{\&Gamma;}}$ Formula (10)

By feedback operation of power networks status signal, adjust in time the gain of FLL, to guarantee that the adjusting time is constant and do not depend on the characteristic of input signal.If Γ=50 are set, can draw t _{s (FLL)}≈ 100ms, system can accurately be followed the tracks of the frequency of electrical network in 100ms, and system has good rapidity.

As shown in Figure 4, two SOGI-QSG and a FLL form DSOGI-FLL (Dual SOGI-FLL) system, and the output signal of DSOGI-FLL is the input signal of PNSC under alpha-beta coordinate system.DSOGI-FLL system is simple, under normal electrical network operation condition, can differentiate positive sequence voltage and negative sequence voltage.As the frequency v that is ω _{α β}during for positive sequence balance sinusoidal voltage, its alpha-beta component v _α, v _βthe relation that has formula (11):

$v_{\mathrm{\&beta;}}\left(s\right)=-\frac{s}{\mathrm{\&omega;}}{v}_{\mathrm{\&alpha;}}\left(s\right)$ Formula (11)

Consider

$v_{\mathrm{\&alpha;}}^{{+}^{\&prime;}}\left(s\right)=\frac{1}{2}(v_{\mathrm{\&alpha;}}^{\&prime;}\left(s\right)-{\mathrm{qv}}_{\mathrm{\&beta;}}^{\&prime;}\left(s\right))=\frac{1}{2}(D\left(s\right)+\frac{s}{\mathrm{\&omega;}}Q\left(s\right))v_{\mathrm{\&alpha;}}\left(s\right)$ Formula (12)

Wherein,

be α axle positive-sequence component under two phase coordinate systems, v ' _αbe α axle component under two phase coordinate systems, v ' _βit is beta-axis component under two phase coordinate systems.

The transport function P of PNSC based on DSOGI-QSG (j ω) is obtained by formula (13):

$P\left(\mathrm{j\&omega;}\right)=\frac{v_{\mathrm{\&alpha;}}^{{+}^{\&prime;}}}{v_{\mathrm{\&alpha;}}}\left(\mathrm{j\&omega;}\right)=\frac{1}{2}\frac{{\mathrm{k\&omega;}}^{\&prime;}(\mathrm{\&omega;}+{\mathrm{\&omega;}}^{\&prime;})}{{\mathrm{k\&omega;}}^{\&prime;}\mathrm{\&omega;}+j({\mathrm{\&omega;}}^2+{\mathrm{\&omega;}}^{\&prime;2})}$ Formula (13)

ω ' is obtained by FLL under stable state.In like manner, can obtain β axis signal, β axle and α axle positive-sequence component under two phase coordinate systems

with

amplitude is identical, but falls behind

work as v _{α β}while being negative phase-sequence vector, only ω need to be replaced to-ω substitution formula (13) just can obtain negative sequence component under two phase coordinate systems

in like manner, if definition for containing the voltage vector of nth harmonic, the amplitude versus frequency characte that can obtain PNSC by formula (14) is:

$v_{\mathrm{\&alpha;}}^{+}={\mathrm{Pv}}_{\mathrm{\&alpha;}}^n\left\{\begin{array}{c}\left|P^n\right|=\frac{k{\mathrm{\&omega;}}^{\&prime;}}{2}\sqrt{\frac{{(\mathrm{n\&omega;}+{\mathrm{\&omega;}}^{\&prime;})}^2}{{\left(\mathrm{kn\&omega;}{\mathrm{\&omega;}}^{\&prime;}\right)}^2+{({\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HSA00000923018100022.png,HSA00000923018100032.png"\; state="\{\{state\}\}">n</figure-callout>}}^2{\mathrm{\&omega;}}^2-{\mathrm{\&omega;}}^{\&prime;2})}^2}}\\ \&angle;P^n=\mathrm{sgn}\left(n\right){\tan }^{-1}\left(\frac{{\mathrm{\&omega;}}^{\&prime;2}-{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HSA00000923018100022.png,HSA00000923018100032.png"\; state="\{\{state\}\}">n</figure-callout>}}^2{\mathrm{\&omega;}}^2}{\mathrm{kn\&omega;}{\mathrm{\&omega;}}^{\&prime;}}\right)-\frac{\mathrm{\&pi;}}{2}(1-\mathrm{sgn}({\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HSA00000923018100022.png,HSA00000923018100032.png"\; state="\{\{state\}\}">n</figure-callout>}}^2\mathrm{\&omega;}+n{\mathrm{\&omega;}}^{\&prime;}))\end{array}\right.$ Formula (14)

$\left|v_{\mathrm{\&beta;}}^{+}\right|=\left|v_{\mathrm{\&alpha;}}^{+}\right|;$ $\&angle;v_{\mathrm{\&beta;}}^{+}=\&angle;v_{\mathrm{\&alpha;}}^{+}-\mathrm{sgn}\left(n\right)\frac{\mathrm{\&pi;}}{2}$

Wherein, the transport function that P is PNSC, n is overtone order.

While only detecting positive sequence voltage under stable state, DSOGI-FLL shows low-frequency filter characteristics for positive sequence voltage, for negative sequence voltage, shows trap characteristic.And k value is less, the frequency selectivity of system is better, is more beneficial to elimination mains by harmonics.Frequency selectivity is better, and steady-state response vibration is larger, and the stable state time is longer.Frequency selectivity can restrict mutually with response speed.In addition, this system also has certain weakening effect to higher hamonic wave.

The typical harmonic wave that line voltage exists has 3 times, 5 times, 7 times, 11 times, 13 inferior, in order to suppress mains by harmonics to the impact of phaselocked loop and a pure output to be provided, need to improve DSOGI-FLL.The utility model adopts a cross feedback network that can regulate different frequency consisting of a plurality of SOGI-QSG, even in the situation that grid disturbance is very large, this network also can accurately detect the positive-negative sequence component of line voltage.This system as shown in Figure 5, is MSOGI-FLL (Multiple SOGI-FLL) system.

MSOGI-FLL is used cross feedback network cooperation to form by n independent SOGI-QSG, and each SOGI-QSG can regulate the multiple frequency of fundamental frequency.The input of FLL is provided by SOGI-QSG-1, can regulate fundamental frequency.Thereafter the input of SOGI-QSG (from 2 to n) is that the fundamental frequency that detected by FLL is multiplied by a coefficient and forms, and this coefficient has determined that the output of FLL is assigned to the order of different SOGI-QSG.And the gain of each SOGI-QSG is distinguished by this coefficient, to make the bandwidth of centre frequency and SOGI-QSG keep constant relation.Use the MSOGI-FLL of cross feedback network have can filtering harmonic wave characteristic, as shown in Figure 5, the input signal of each SOGI-QSG is by original input signal v, to be deducted the output signal of all the other all SOGI-QSG.In this manner, through of short duration calculating transient process, can clean out in the input signal of each SOGI-QSG by the detected harmonic components of all the other SOGI-QSG, so just reduce the disturbance of harmonic wave in output signal.

Therefore, in having the MOSGI-FLL of n element, the output signal v ' of i SOGI-QSG _ifor:

$v_i^{\&prime;}=D_i\left(s\right)(v-\underset{\underset{j\mathrm{\&NotEqual;}i}{j=1}}{\overset{n}{\mathrm{\&Sigma;}}}{v}_j^{\&prime;})$ Formula (15)

Wherein, D _i(s) be the transport function of independent SOGI-QSG, v ' _jbe the output signal of j SOGI-QSG, centre frequency is made as i ω ', fundamental frequency omega ' detected and obtained by FLL.From formula (15), can derive the transport function of i SOGI-QSG system:

$v_i^{\&prime;}=\left[D_i\left(s\right)\underset{\underset{j\&NotEqual;i}{j=1}}{\overset{n}{\mathrm{\&prod;}}}\left(\frac{1-D_j\left(s\right)}{1-D_i\left(s\right)D_j\left(s\right)}\right)\right]v$ Formula (16)

Wherein, D _j(s) be the transport function of j SOGI-QSG.

In the MOSGI-FLL system of this figure, contain four SOGI-QSG, wherein each SOGI-QSG can regulate respectively 2 times, 4 times, 5 times and 7 subharmonic.This system can be to specifying subharmonic to have trap characteristic.Therefore, even when input voltage contains a large amount of harmonic wave, also can be by improving the filtering selectivity characteristic of each SOGI-QSG, total the output of raising system response.

Identical with DSOGI-FLL system, the system applies shown in Fig. 5 under alpha-beta coordinate system, can obtain three-phase MSOGI-FLL system, the output of SOGI-QSG-1 is as the input of FLL, by PNSC, calculate, just the fundamental positive sequence of line voltage can be drawn, and then the line voltage vector synchronization anglec of rotation can be obtained.

When desirable line voltage is when the time is 0.2s, electrical network harmonic again on unbalanced basis, wherein has 10% 5 subharmonic, 5% 7 subharmonic, 3.3% 11 subharmonic.Now, as shown in Figure 6, frequency detecting waveform is level and smooth, has removed the harmonic wave in line voltage, has reduced the fluctuation of frequency detecting, has improved the accuracy of frequency detecting for the frequency that use MSOGI-FLL measures.In addition, Γ=50 item are set and can draw t _{s (FLL)}≈ 100ms, system can accurately be followed the tracks of the frequency of electrical network in 100ms, and system has good rapidity.

Fig. 7 is the electrical network three-phase voltage V that MSOGI-FLL calculates while containing harmonic wave _abc, three-phase positive sequence voltage V ⁺, three-phase negative/positive voltage V, positive-negative sequence voltage vector amplitude | the waveform of V| and anglec of rotation θ.When electrical network, contain the electric network pollutions such as harmonic wave, unbalanced source voltage when serious, MSOGI-FLL still can filter 5 times, 7 times and the correct detected positive-negative sequence voltage of 11 subharmonic and the anglec of rotation thereof.

Above specific embodiment of the utility model is described.It will be appreciated that, the utility model is not limited to above-mentioned particular implementation, and those skilled in the art can make various distortion or modification within the scope of the claims, and this does not affect flesh and blood of the present utility model.

Claims (5)

1. the phase-locking device of a variable-ratio water-storage unit control system, it is characterized in that, comprise controller, wherein, controller comprises phaselocked loop board, a n signal generator board, CPU, phaselocked loop board, a n signal generator board are all connected to CPU, and phaselocked loop board gathers three-phase alternating voltage signal.

2. the phase-locking device of variable-ratio water-storage unit control system according to claim 1, it is characterized in that, also comprise frequency converter, stator, wherein, CPU in controller connects respectively frequency converter, stator, the various signals that controller obtains according to phaselocked loop board, signal generator board are controlled variable-ratio water-storage unit control system, and frequency converter and stator are sent to instruction, thereby control in real time whole variable-ratio water-storage unit control system.

3. the phase-locking device of variable-ratio water-storage unit control system according to claim 1, it is characterized in that, phaselocked loop board comprises DSP, FPGA, wherein, FPGA gathers three-phase alternating voltage signal and sends into DSP, DSP completes the computing of phaselocked loop, obtains anglec of rotation θ and the mains frequency f of line voltage vector, is sent into the CPU of controller.

4. the phase-locking device of variable-ratio water-storage unit control system according to claim 3, is characterized in that, DSP adopts the TMS28335 chip of TI company.

5. the phase-locking device of variable-ratio water-storage unit control system according to claim 3, is characterized in that, FPGA adopts the A3P250 chip of ACTEL company.

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