CN1808826A - Dynamic reactive compensation control method - Google Patents

Abstract

This invention relates to one dynamic powerless compensation method, which comprises the following steps: connecting one static powerless compensation device in the distribution network; then real time testing the static dynamic powerless compensation device joint voltage, load current, thyristor control separation resistance current signals; computing out static dynamic powerless compensation device each relative capacity value to realize the control to the trigger angle in the thyristor separation resistance and paralleled thyristor breaking control.

Description

Dynamic reactive compensation control method

Technical field

The present invention relates to a kind of dynamic reactive compensation control method.

Background technology

Along with the sustainable growth of China's economy, power load increases sharply, and user's reactive requirement also increases substantially, this give this China's electrical network of short of electricity bring more serious problem, so the effect of Static Type Dynamic Reactive Compensation Device just seems and becomes increasingly conspicuous.

The main target of industry Static Type Dynamic Reactive Compensation Device (Static Var Compensator is hereinafter to be referred as SVC) mainly comprises three aspects: suppress disturbance load and change voltage fluctuation and the flickering that causes; The needed reactive current of compensation load is improved power factor; Compensate the imbalance of meritorious and load or burden without work.The basic demand of industry two of SVC is rapidity and phase splitting compensation.Theoretical and engineering practice shows, determined its compensation effect to a great extent based on response time of the SVC device of Thyristor Controlled technology.Yet the inherent delay time of the thyristor angle of flow can't change, signal measurement that is merely able to be optimized and adjusting part.(for example: DSP and 64 RISC the time delay of) SVC controller numerical calculation can be ignored substantially, so the response time of SVC device depends mainly on compensation policy based on high-performance microprocessor.

The reactive load backoff algorithm is a hot issue of electric power system control worker research always.Classical load compensation algorithm is a C.P.Steinmetz equilibrating principle, but should theory only set up under the condition of stable state (or quasi-stable state) and sine wave.In the practical application, C.P.Steinmetz equilibrating principle has multiple implementation, and engineering practice also shows, based on the implementation of average power theory the such load of arc furnace is also had compensation effect preferably.For many years, numerous scholars have carried out more deep research to the load compensation algorithm, have proposed multiple backoff algorithm.Arindam Ghosh etc. has proposed a kind of load compensation algorithm based on instantaneous symmetrical component, and emulation shows that this algorithm can realize the purpose of equilibrating and Active PFC.Toshihiko Tanaka has proposed a kind of " accurate instantaneous reactive current " computational methods based on the instantaneous reactive theory, and emulation shows that this method also can realize the purpose of equilibrating and Active PFC.The instantaneous reactive theory based on average power that Xue Hui proposes also can realize equilibrating and Active PFC, and the theory of its starting point and Toshihiko Tanaka is similar.The load compensation algorithm based on the FBD theory of propositions such as Sun Zhuo is primarily aimed at the electric railway compensation, and result of the test shows this load compensation algorithm validity.In addition, also has traditional compensation method based on Fourier analysis etc.

These load compensation algorithms all differ from one another, and suitable application area is separately all arranged, but they all belong to open loop control, perhaps are called feedfoward control, all are difficult to guarantee the precision of dynamic passive compensation in the practical application.

Summary of the invention

The present invention is according to the compensation requirement of general industry load, load compensation principle based on a kind of instantaneous value has been proposed, and then proposed that a kind of open loop and closed loop are controlled simultaneously, can realize quick and high-precision dynamic reactive compensation control method, to overcome weak point of the prior art.

A kind of dynamic reactive compensation control method by this purpose design, it is characterized in that this control method is by in power distribution network and connect a Static Type Dynamic Reactive Compensation Device (SVC), detect the system voltage of this Static Type Dynamic Reactive Compensation Device access point then in real time, load current, the current signal of thyristor control separate type reactor (TCR), calculate each susceptance value that should compensate mutually of Static Type Dynamic Reactive Compensation Device in real time, thereby realize control that thyristor in the trigger angle of thyristor in the separate type reactor (TCR) and the thyristor switchable capacitor in parallel (TSC) is cut-off;

Because in engineering reality, the degree of asymmetry of system voltage and harmonic content are all less, can ignore, therefore as if being reference with a phase voltage, system voltage can be expressed as:

$\left\{\begin{array}{c}{u}_a=\sqrt{2}U\cos \mathrm{\ωt}\\ u_b=\sqrt{2}U\cos (\mathrm{\ωt}-2\mathrm{\π}/3)\\ u_c=\sqrt{2}U\cos (\mathrm{\ωt}+2\mathrm{\π}/3)\end{array}\right.---\left(a\right),$

Wherein: U-system phase voltage effective value;

ω-electrical network angular frequency;

u _a, u _bAnd u _cBe system voltage;

The t-system time;

The unbalanced three phase current of distortion can be expressed as:

Wherein: n--harmonic number, positive integer;

ω--electrical network angular frequency;

I _1n-nth harmonic forward-order current amplitude;

_1n-nth harmonic forward-order current initial phase angle;

I _2n-nth harmonic negative-sequence current amplitude;

_2n-nth harmonic negative-sequence current initial phase angle;

i _a, i _bAnd i _cBe electric current;

Be defined as follows:

Wherein: p ₁₁-fundamental positive sequence is meritorious, the active power that voltage fundamental positive sequence component and current first harmonics positive sequence component produce;

q ₁₁-fundamental positive sequence is idle, the reactive power that voltage fundamental positive sequence component and current first harmonics positive sequence component produce;

p ₂₁-first-harmonic negative phase-sequence is meritorious, the active power that voltage fundamental positive sequence component and current first harmonics negative sequence component produce;

q ₂₁-first-harmonic negative phase-sequence is idle, the reactive power that voltage fundamental positive sequence component and current first harmonics negative sequence component produce;

I ₁₁-fundamental positive sequence current amplitude;

₁₁-fundamental positive sequence electric current initial phase angle;

I ₂₁-fundamental negative sequence current amplitude;

₂₁-fundamental negative sequence current initial phase angle;

(1) real-time detection load electric current and load voltage;

With the sample frequency that is not less than 800Hz to system voltage u _a, u _bAnd u _c, load current i _La, i _LbAnd i _Lc, current i in the TCR angle _Tcra, i _TcrbAnd i _TcrcCarry out synchronized sampling;

(2) each phase susceptance of calculated load;

With the meritorious p of column count fundamental positive sequence under each numerical value substitution of aforementioned detection ₁₁With the idle q of fundamental positive sequence ₁₁Formula calculate,

$C_{\mathrm{abc}/\mathrm{\α\β}}=\sqrt{2/3}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right]---\left(d\right),$

$C_{\mathrm{pq}}=\left[\begin{array}{cc}{u}_{\mathrm{\α}}& u_{\mathrm{\β}}\\ u_{\mathrm{\β}}& -u_{\mathrm{\α}}\end{array}\right]---\left(e\right),$

C wherein _Abc/ _{α β}, C _PqBe transformation matrix;

With the aforementioned C that obtains _PqBy low pass filter (LPF), its filtering exponent number and cut-off frequency design according to current harmonic content, and low pass filter herein generally adopts the Butterworth filter;

With the meritorious p of column count first-harmonic negative phase-sequence under each numerical value substitution of aforementioned detection ₂₁With the idle q of first-harmonic negative phase-sequence ₂₁Formula calculate,

$C_{\mathrm{abc}/{\mathrm{\α}}^{\′}{\mathrm{\β}}^{\′}}=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& -\sqrt{3/2}& \sqrt{3/2}\end{array}\right]---\left(f\right),$

C wherein _Abc/ _{α ' β '}Be transformation matrix;

Utilize each phase susceptance of following formula calculated load:

$\left\{\begin{array}{c}{B}_{\mathrm{ab}}^L=\frac{1}{U^2}(-\frac{1}{9}{q}_{11}-\frac{1}{3\sqrt{3}}{P}_{21}-\frac{1}{9}{q}_{21})\\ B_{\mathrm{bc}}^L=\frac{1}{U^2}(-\frac{1}{9}{\mathrm{<figure-callout\; id="11"\; label="q"\; filenames="A20051010238900181.png"\; state="\{\{state\}\}">q</figure-callout>}}_{11}+\frac{2}{9}{q}_{21})\\ B_{\mathrm{ca}}^L=\frac{1}{U^2}(-\frac{1}{9}{\mathrm{<figure-callout\; id="11"\; label="q"\; filenames="A20051010238900181.png"\; state="\{\{state\}\}">q</figure-callout>}}_{11}+\frac{1}{3\sqrt{3}}{P}_{21}-\frac{1}{9}{q}_{21})\end{array}\right.---\left(g\right),$

Wherein: B _Ab ^LThe alternate susceptance of-load ab;

B _Bc ^LThe alternate susceptance of-load bc;

B _Ca ^LThe alternate susceptance of-load ca;

U-SVC access point voltage effective value;

(3) each has exported susceptance mutually to calculate silent oscillation dynamic passive compensation compensation arrangement SVC;

For thyristor control separate type reactor (TCR), adopts the method identical with (2), can export susceptance in the hope of the respectively phase that thyristor is controlled separate type reactor (TCR):

$\left\{\begin{array}{c}{B}_{\mathrm{ab}}^{\mathrm{tcr}}=\frac{1}{U^2}(-\frac{1}{9}{q}_{\mathrm{tcr}11}-\frac{1}{3\sqrt{3}}{P}_{\mathrm{tcr}21}-\frac{1}{9}{q}_{\mathrm{tcr}21})\\ B_{\mathrm{bc}}^{\mathrm{tcr}}=\frac{1}{U^2}(-\frac{1}{9}{\mathrm{<figure-callout\; id="11"\; label="q\; tcr"\; filenames="A20051010238900181.png"\; state="\{\{state\}\}">q</figure-callout>}}_{\mathrm{tcr}}+\frac{2}{9}{q}_{\mathrm{tcr}21})\\ B_{\mathrm{ca}}^{\mathrm{tcr}}=\frac{1}{U^2}(-\frac{1}{9}{\mathrm{<figure-callout\; id="11"\; label="q\; tcr"\; filenames="A20051010238900181.png"\; state="\{\{state\}\}">q</figure-callout>}}_{\mathrm{tcr}}+\frac{1}{3\sqrt{3}}{P}_{\mathrm{tcr}21}-\frac{1}{9}{q}_{\mathrm{tcr}21})\end{array}\right.---\left(h\right),$

Wherein:

B _Ab ^TcrThe alternate susceptance of-TCR ab;

B _Bc ^TcrThe alternate susceptance of-TCR bc;

B _Ca ^TcrThe alternate susceptance of-TCR ca;

U-SVC access point voltage effective value;

Qt _Cr11-TCR fundamental positive sequence is idle;

p _Tcr21-TCR first-harmonic negative phase-sequence is meritorious;

q _Tcr21-TCR first-harmonic negative phase-sequence is idle;

In addition, suppose that fixed filters group and the susceptance that has dropped into thyristor switchable capacitor (TSC) are B ^cThen SVC each mutually exported susceptance and be:

$\left\{\begin{array}{c}{B}_{\mathrm{ab}}^{\mathrm{svc}}=B_{\mathrm{ab}}^{\mathrm{tcr}}+B^c\\ B_{\mathrm{bc}}^{\mathrm{svc}}=B_{\mathrm{bc}}^{\mathrm{tcr}}+B^c\\ B_{\mathrm{ca}}^{\mathrm{svc}}=B_{\mathrm{ca}}^{\mathrm{tcr}}+B^c\end{array}\right.---\left(i\right),$

Wherein:

B _Ab ^SvcThe alternate output susceptance of-SVC device ab;

B _Bc ^SvcThe alternate output susceptance of-SVC device bc;

B _Ca ^SvcThe alternate output susceptance of-SVC device ca;

B ^c-fixed filters branch road and dropped into the susceptance of thyristor switchable capacitor TSC branch road;

(4) proportion of utilization-integration (PI) adjuster calculates each susceptance that should export mutually of Static Type Dynamic Reactive Compensation Device (SVC);

Respectively needing to compensate susceptance mutually with load is reference quantity, and each actual mutually output susceptance of Static Type Dynamic Reactive Compensation Device (SVC) is a feedback quantity, and each phase of proportion of utilization-integration (PI) algorithm computation Static Type Dynamic Reactive Compensation Device (SVC) should be exported the susceptance value; Wherein the integration time constant of ratio-integration (PI) adjuster is got 100ms～300ms, the controlled range of ratio-integration (PI) adjuster be Static Type Dynamic Reactive Compensation Device (SVC) variable capacity ± 10%;

(5) control method of realization open loop+closed loop;

Wherein each phase susceptance controlled quentity controlled variable of SVC is:

$\left\{\begin{array}{c}{B}_{\mathrm{ab}}^{\left(c\right)}=-B_{\mathrm{ab}}^L+B_{\mathrm{ab}}^{\mathrm{pi}}\\ B_{\mathrm{bc}}^{\left(c\right)}=-B_{\mathrm{bc}}^L+B_{\mathrm{ab}}^{\mathrm{pi}}\\ B_{\mathrm{ca}}^{\left(c\right)}=-B_{\mathrm{ca}}^L+B_{\mathrm{ab}}^{\mathrm{pi}}\end{array}\right.---\left(j\right)$

Wherein:

B _Ab ^(c)The alternate total compensation susceptance of-SVC device ab;

B _Bc ^(c)The alternate total compensation susceptance of-SVC device bc;

B _Ca ^(c)The alternate total compensation susceptance of-SVC device ca;

B _Ab ^Pi-alternate compensation the susceptance of ab that utilizes pi regulator to calculate;

B _Bc ^Pi-alternate compensation the susceptance of bc that utilizes pi regulator to calculate;

B _Ca ^Pi-alternate compensation the susceptance of ca that utilizes pi regulator to calculate.

Above-mentioned Static Type Dynamic Reactive Compensation Device comprises a main circuit, this main circuit comprises: filter circuit in parallel, thyristor switchable capacitor in parallel (TSC), thyristor in parallel control separate type reactor (TCR) and be serially connected in TSC and the TCR branch road in thyristor valve, wherein: filter circuit in parallel, form by ac filter inductance and electric capacity, fixedly capacitive reactive power and filtering harmonic wave are provided; Thyristor switchable capacitor (TSC) in parallel is made up of current-limiting inductance, thyristor and capacitance series, controls switching so that capacitive reactive power to be provided by thyristor; Thyristor in parallel is controlled separate type reactor (TCR), cooperates perception and capacitive reactive power so that continuous variable to be provided with filter circuit in parallel; Thyristor valve, the thyristor right by inverse parallel is in series, be serially connected in current limiting reactor and capacitor in thyristor control separate type reactor (TCR) or the thyristor switchable capacitor in parallel (TSC) between.

When above-mentioned real-time detection load electric current and load voltage, the sample frequency of getting 1600Hz～6400Hz at least is to system voltage u _a, u _bAnd u _c, load current i _La, i _LbAnd i _Lc, current i in thyristor control separate type reactor (TCR) angle _Tcra, i _TcrbAnd i _TcrcCarry out synchronized sampling.

The dynamic reactive compensation control method that is proposed by the present invention as seen, the present invention can be by detecting the system voltage of silent oscillation reactive power compensator access point in real time, load current, the current signal of thyristor control separate type reactor in parallel (TCR) calculates each susceptance value that should compensate mutually of Static Type Dynamic Reactive Compensation Device in real time, thereby realize control that thyristor control separate type reactor (TCR) trigger angle in parallel and thyristor switchable capacitor in parallel (TSC) are cut-off, thereby realize quick tracking to dynamic load, guaranteed Static Type Dynamic Reactive Compensation Device dynamic response time and stable state accuracy.

Distinguishing feature of the present invention is to utilize open loop control to guarantee the dynamic response time of Static Type Dynamic Reactive Compensation Device (SVC), utilizes closed-loop control to guarantee the stable state accuracy of whole device.

The present invention can be applied to quick, the frequent occasion of load change, has a good application prospect.

The present invention can form industrial Static Type Dynamic Reactive Compensation Device (SVC) device of thyristor control separate type reactor (TCR)+thyristor switchable capacitor (TSC)+fixed filters (FC) in parallel or thyristor in parallel control separate type reactor (TCR)+fixed filters (FC) type, and this device can direct screening carry out dynamic passive compensation in 35kV and 10kV system.

Description of drawings

Fig. 1 is one embodiment of the invention structural representation.

Fig. 2 detects theory diagram in real time for fundamental positive sequence power.

Fig. 3 is that the first-harmonic negative sequence power detects theory diagram in real time.

Fig. 4 is industrial SVC open loop+closed loop control method FB(flow block).

Embodiment

Below in conjunction with drawings and Examples the present invention is further described.

Referring to Fig. 1 and Fig. 4, the invention provides a kind of dynamic reactive compensation control method, this control method is by in power distribution network and connect a Static Type Dynamic Reactive Compensation Device (SVC), detect the system voltage of this Static Type Dynamic Reactive Compensation Device access point then in real time, load current, the current signal of thyristor control separate type reactor (TCR), calculate susceptance value that Static Type Dynamic Reactive Compensation Device respectively should compensate mutually in real time, thereby realize thyristor is controlled the trigger angle of thyristor in the separate type reactor (TCR) and the control that the middle thyristor of thyristor switchable capacitor in parallel (TSC) cut-offs; See Fig. 1, carry out dynamic passive compensation in the system of Static Type Dynamic Reactive Compensation Device access 35KV or 10KV.Frame of broken lines inside is divided into the main circuit in the Static Type Dynamic Reactive Compensation Device, main circuit comprises: filter circuit in parallel, thyristor switchable capacitor in parallel (TSC), thyristor in parallel control separate type reactor (TCR) and be serially connected in thyristor switchable capacitor in parallel (TSC) and separating thyristor in parallel is controlled thyristor valve in reactor (TCR) branch road, wherein: filter circuit in parallel, form by ac filter inductance and electric capacity, fixedly capacitive reactive power and filtering harmonic wave are provided; Thyristor switchable capacitor (TSC) in parallel is made up of current-limiting inductance, thyristor and capacitance series, controls switching so that capacitive reactive power to be provided by thyristor; Separating thyristor in parallel is controlled reactor (TCR), cooperates perception and capacitive reactive power so that continuous variable to be provided with filter circuit in parallel; Thyristor valve, the thyristor right by inverse parallel is in series, be serially connected in current limiting reactor and capacitor in separating thyristor control reactor (TCR) or the thyristor switchable capacitor in parallel (TSC) between, current transformer CT1 can be serially connected on the loop of load 3.

The phase voltage U of system after voltage transformer pt is handled, the load current i after current transformer CT1 handles _lAnd current i in the separating thyristor control reactor TCR in parallel angle of actual measurement _TcrBe input to respectively and carry out signal processing in the controller 2, calculate each phase susceptance of load and each phase susceptance of Static Type Dynamic Reactive Compensation Device SVC respectively in the formula below the substitution,

When real-time detection load electric current and load voltage, the sample frequency of getting 1600Hz～6400Hz at least.

$\left\{\begin{array}{c}{B}_{\mathrm{ab}}^L=\frac{1}{U^2}(-\frac{1}{9}{q}_{11}-\frac{1}{3\sqrt{3}}{P}_{21}-\frac{1}{9}{q}_{21})\\ B_{\mathrm{bc}}^L=\frac{1}{U^2}(-\frac{1}{9}{\mathrm{<figure-callout\; id="11"\; label="q"\; filenames="A20051010238900181.png"\; state="\{\{state\}\}">q</figure-callout>}}_{11}+\frac{2}{9}{q}_{21})\\ B_{\mathrm{ca}}^L=\frac{1}{U^2}(-\frac{1}{9}{\mathrm{<figure-callout\; id="11"\; label="q"\; filenames="A20051010238900181.png"\; state="\{\{state\}\}">q</figure-callout>}}_{11}+\frac{1}{3\sqrt{3}}{P}_{21}-\frac{1}{9}{q}_{21})\end{array}\right.$

$\left\{\begin{array}{c}{B}_{\mathrm{ab}}^{\mathrm{tcr}}=\frac{1}{U^2}(-\frac{1}{9}{q}_{\mathrm{tcr}11}-\frac{1}{3\sqrt{3}}{P}_{\mathrm{tcr}21}-\frac{1}{9}{q}_{\mathrm{tcr}21})\\ B_{\mathrm{bc}}^{\mathrm{tcr}}=\frac{1}{U^2}(-\frac{1}{9}{\mathrm{<figure-callout\; id="11"\; label="q\; tcr"\; filenames="A20051010238900181.png"\; state="\{\{state\}\}">q</figure-callout>}}_{\mathrm{tcr}}+\frac{2}{9}{q}_{\mathrm{tcr}21})\\ B_{\mathrm{ca}}^{\mathrm{tcr}}=\frac{1}{U^2}(-\frac{1}{9}{\mathrm{<figure-callout\; id="11"\; label="q\; tcr"\; filenames="A20051010238900181.png"\; state="\{\{state\}\}">q</figure-callout>}}_{\mathrm{tcr}}+\frac{1}{3\sqrt{3}}{P}_{\mathrm{tcr}21}-\frac{1}{9}{q}_{\mathrm{tcr}21})\end{array}\right.$

Proportion of utilization-integration (PI) adjuster calculates each susceptance that should export mutually of Static Type Dynamic Reactive Compensation Device (SVC) then;

Respectively needing to compensate susceptance mutually with load is reference quantity, and each actual mutually output susceptance of Static Type Dynamic Reactive Compensation Device (SVC) is a feedback quantity, and each phase of proportion of utilization-integration (PI) algorithm computation Static Type Dynamic Reactive Compensation Device (SVC) should be exported the susceptance value; Wherein the integration time constant of ratio-integration (PI) adjuster is got 100ms～300ms, the controlled range of ratio-integration (PI) adjuster be Static Type Dynamic Reactive Compensation Device (SVC) variable capacity ± 10%;

The control method of utilizing open loop+closed loop to combine again calculates the reference susceptance Bref that Static Type Dynamic Reactive Compensation Device (SVC) should be exported, with the angle of flow of control thyristor control separate type reactor (TCR) thyristor and cut-offfing of the middle thyristor of thyristor switchable capacitor in parallel (TSC).

Among Fig. 1 and Fig. 4,1 is Static Type Dynamic Reactive Compensation Device, and 2 is controller, and 3 are load, and u is a system voltage, i _lBe load current, i _TcrBe the TCR electric current, PT is a voltage transformer, and CT1, CT2 are current transformer, and Y represents star-star connection, and Δ is represented delta connection, and FC1, FC2 are filter, i _TcrBe electric current in the TCR angle, TCR is a thyristor control separate type reactor, and TSC is a thyristor switchable capacitor in parallel.

Referring to Fig. 2, because in engineering reality, the degree of asymmetry of system voltage and harmonic content are all less, can ignore, therefore as if being reference with a phase voltage, system voltage can be expressed as:

$\left\{\begin{array}{c}{u}_a=\sqrt{2}U\cos \mathrm{\&omega;t}\\ u_b=\sqrt{2}U\cos (\mathrm{\&omega;t}-2\mathrm{\&pi;}/3)\\ u_c=\sqrt{2}U\cos (\mathrm{\&omega;t}+2\mathrm{\&pi;}/3)\end{array}\right.$

The load current current i _La, i _Lb, i _LcWith the TCR current i _Tcra, i _Tcrb, i _Tcrc, can be expressed as following form:

The system voltage u of actual measurement _a, u _bAnd u _cWith load current i _La, i _Lb, i _Lc(or TCR current i _Tcra, i _Tcrb, i _Tcrc) through C _{Abc/ α β}And C _PqShown in obtain containing the instantaneous meritorious p of positive sequence and the instantaneous reactive power q of the load (or TCR) of harmonic components after the coordinate transform, and then just obtain the meritorious p of fundamental positive sequence of load (or TCR) through low-pass filtering LPF ₁₁With fundamental wave reactive power q ₁₁

$C_{\mathrm{abc}/\mathrm{\&alpha;\&beta;}}=\sqrt{2/3}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right]$

$C_{\mathrm{pq}}=\left[\begin{array}{cc}{u}_{\mathrm{\&alpha;}}& u_{\mathrm{\&beta;}}\\ u_{\mathrm{\&beta;}}& u_{\mathrm{\&alpha;}}\end{array}\right]$

C wherein _{Abc/ α β}, C _PqBe transformation matrix;

Referring to Fig. 3, be reference with a phase voltage, system voltage can be expressed as:

$\left\{\begin{array}{c}{u}_a=\sqrt{2}U\cos \mathrm{\&omega;t}\\ u_b=\sqrt{2}U\cos (\mathrm{\&omega;t}-2\mathrm{\&pi;}/3)\\ u_c=\sqrt{2}U\cos (\mathrm{\&omega;t}+2\mathrm{\&pi;}/3)\end{array}\right.$

The load current current i _La, i _Lb, i _LcWith the TCR current i _Tcra, i _Tcrb, i _Tcrc, can be expressed as following form:

The system voltage u of actual measurement _a, u _bAnd u _cWith load current i _La, i _Lb, i _Lc(or TCR current i _Tcra, i _Tcrb, i _Tcrc) through C _{Abc/ α ' β '}And C _PqShown in obtain containing the instantaneous meritorious p ' of load (or TCR) negative phase-sequence and the instantaneous reactive power q ' of harmonic components after the coordinate transform, and then just obtain the meritorious p of load (or TCR) first-harmonic negative phase-sequence through low-pass filtering LPF ₂₁With fundamental wave reactive power q ₂₁

$C_{\mathrm{abc}/{\mathrm{\&alpha;}}^{\&prime;}{\mathrm{\&beta;}}^{\&prime;}}=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& -\sqrt{3/2}& \sqrt{3/2}\end{array}\right]$

$C_{\mathrm{pq}}=\left[\begin{array}{cc}{u}_{\mathrm{\&alpha;}}& u_{\mathrm{\&beta;}}\\ u_{\mathrm{\&beta;}}& -u_{\mathrm{\&alpha;}}\end{array}\right]$

C wherein _{Abc/ α ' β '}, C _PqBe transformation matrix.

Claims (3)

1. dynamic reactive compensation control method, it is characterized in that this control method is by in power distribution network and connect a Static Type Dynamic Reactive Compensation Device (SVC), detect the system voltage of this Static Type Dynamic Reactive Compensation Device access point then in real time, load current, the current signal of thyristor control separate type reactor (TCR), calculate susceptance value that Static Type Dynamic Reactive Compensation Device respectively should compensate mutually in real time, thereby realize thyristor is controlled the trigger angle of thyristor in the separate type reactor (TCR) and the control that the middle thyristor of thyristor switchable capacitor in parallel (TSC) cut-offs;

Because in engineering reality, the degree of asymmetry of system voltage and harmonic content are all less,

Can ignore, therefore as if being reference with a phase voltage, system voltage can be expressed as:

$\left\{\begin{array}{c}{u}_a=\sqrt{2}U\cos \mathrm{\&omega;t}\\ u_b=\sqrt{2}U\cos (\mathrm{\&omega;t}-2\mathrm{\&pi;}/3)\\ U_c=\sqrt{2}U\cos (\mathrm{\&omega;t}+2\mathrm{\&pi;}/3)\end{array}\right.---\left(a\right),$

Wherein: U-system phase voltage effective value;

ω-electrical network angular frequency;

u _a, u _bAnd u _cBe system voltage;

The t-system time;

The unbalanced three phase current of distortion can be expressed as:

Wherein: n-harmonic number, positive integer;

ω-electrical network angular frequency;

I _1n-nth harmonic forward-order current amplitude;

_1n-nth harmonic forward-order current initial phase angle;

I _2n-nth harmonic negative-sequence current amplitude;

_2n-nth harmonic negative-sequence current initial phase angle;

i _a, i _bAnd i _cBe electric current;

Be defined as follows:

Wherein: p ₁₁-fundamental positive sequence is meritorious, the active power that voltage fundamental positive sequence component and current first harmonics positive sequence component produce;

q ₁₁-fundamental positive sequence is idle, the reactive power that voltage fundamental positive sequence component and current first harmonics positive sequence component produce;

p ₂₁-first-harmonic negative phase-sequence is meritorious, the active power that voltage fundamental positive sequence component and current first harmonics negative sequence component produce;

q ₂₁-first-harmonic negative phase-sequence is idle, the reactive power that voltage fundamental positive sequence component and current first harmonics negative sequence component produce;

U-system phase voltage effective value;

I ₁₁-fundamental positive sequence current amplitude;

₁₁-fundamental positive sequence electric current initial phase angle;

I ₂₁-fundamental negative sequence current amplitude;

₂₁-fundamental negative sequence current initial phase angle;

(1) real-time detection load electric current and load voltage;

With the sample frequency that is not less than 800Hz to system voltage u _a, u _bAnd u _c, load current i _La, i _LbAnd i _Lc, current i in thyristor control separate type reactor (TCR) angle _Tcra, i _TcrbAnd i _TcrcCarry out synchronized sampling;

(2) each phase susceptance of calculated load;

With the meritorious p of column count fundamental positive sequence under each numerical value substitution of aforementioned detection ₁₁With the idle q of fundamental positive sequence ₁₁Formula calculate,

$C_{\mathrm{abc}/\mathrm{\&alpha;\&beta;}}=\sqrt{2/3}\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right]---\left(d\right),$

$C_{\mathrm{pq}}=\left[\begin{array}{cc}{u}_{\mathrm{\&alpha;}}& u_{\mathrm{\&beta;}}\\ u_{\mathrm{\&beta;}}& -u_{\mathrm{\&alpha;}}\end{array}\right]---\left(e\right),$

C wherein _{Abc/ α β}, C _PqBe transformation matrix;

With the aforementioned C that obtains _PqBy low pass filter (LPF), its filtering exponent number and cut-off frequency design according to current harmonic content, and low pass filter herein generally adopts Butterworth (Butterworth is a kind of of filter, and Chinese is translated into " Butterworth ") filter;

With the meritorious p of column count first-harmonic negative phase-sequence under each numerical value substitution of aforementioned detection ₂₁With the idle q of first-harmonic negative phase-sequence ₂₁Formula calculate,

$C_{\mathrm{abc}/{\mathrm{\&alpha;}}^{\&prime;}{\mathrm{\&beta;}}^{\&prime;}}=\sqrt{\frac{2}{3}}\left[\begin{array}{c}1-1/2-1/2\\ 0-\sqrt{3/2}\sqrt{3/2}\end{array}\right]---\left(f\right),$

C wherein _{Abc/ α ' β '}Be transformation matrix;

Utilize each phase susceptance of following formula calculated load:

$\left\{\begin{array}{c}{B}_{\mathrm{ab}}^L=\frac{1}{U^2}(-\frac{1}{9}{q}_{11}-\frac{1}{3\sqrt{3}}{P}_{21}-\frac{1}{9}{q}_{21})\\ B_{\mathrm{bc}}^L=\frac{1}{U^2}(-\frac{1}{9}{q}_{11}+\frac{2}{9}{q}_{21})\\ B_{\mathrm{ca}}^L=\frac{1}{U^2}(-\frac{1}{9}{q}_{11}+\frac{1}{3\sqrt{3}}{P}_{21}-\frac{1}{9}{q}_{21})\end{array}\right.---\left(g\right),$

Wherein: B _Ab ^LThe alternate susceptance of-load ab;

B _Bc ^LThe alternate susceptance of-load bc;

B _Ca ^LThe alternate susceptance of-load ca;

U-SVC access point voltage effective value;

(3) each has exported susceptance mutually to calculate Static Type Dynamic Reactive Compensation Device (SVC);

For thyristor control separate type reactor (TCR), adopts the method identical with (2), can export susceptance in the hope of the respectively phase that thyristor is controlled separate type reactor (TCR):

$\left\{\begin{array}{c}{B}_{\mathrm{ab}}^{\mathrm{tcr}}=\frac{1}{U^2}(-\frac{1}{9}{q}_{\mathrm{tcr}11}-\frac{1}{3\sqrt{3}}{P}_{\mathrm{tcr}21}-\frac{1}{9}{q}_{\mathrm{tcr}21})\\ B_{\mathrm{bc}}^{\mathrm{tcr}}=\frac{1}{U^2}(-\frac{1}{9}{q}_{\mathrm{tcr}11}+\frac{2}{9}{q}_{\mathrm{tcr}21})\\ B_{\mathrm{ca}}^{\mathrm{tcr}}=\frac{1}{U^2}(-\frac{1}{9}{q}_{\mathrm{tcr}11}+\frac{1}{3\sqrt{3}}{P}_{\mathrm{tcr}21}-\frac{1}{9}{q}_{\mathrm{tcr}21})\end{array}\right.---\left(h\right),$

Wherein:

B _Ab ^TcrThe alternate susceptance of-TCR ab;

B _Bc ^TcrThe alternate susceptance of-TCR bc;

B _Ca ^TcrThe alternate susceptance of-TCR ca;

U-SVC access point voltage effective value;

q _Tcr11-TCR fundamental positive sequence is idle;

p _Tcr21-TCR first-harmonic negative phase-sequence is meritorious;

q _Tcr21-TCR first-harmonic negative phase-sequence is idle;

In addition, suppose that fixed filters group and the susceptance that has dropped into thyristor switchable capacitor (TSC) are B ^cThen SVC each mutually exported susceptance and be:

$\left\{\begin{array}{c}{B}_{\mathrm{ab}}^{\mathrm{svc}}=B_{\mathrm{ab}}^{\mathrm{tcr}}+B^c\\ B_{\mathrm{bc}}^{\mathrm{svc}}=B_{\mathrm{bc}}^{\mathrm{tcr}}+B^c\\ B_{\mathrm{ca}}^{\mathrm{svc}}=B_{\mathrm{ca}}^{\mathrm{tcr}}+B^c\end{array}\right.---\left(i\right),$

Wherein:

B _Ab ^SvcThe alternate output susceptance of-SVC device ab;

B _Bc ^SvcThe alternate output susceptance of-SVC device bc;

B _Ac ^SvcThe alternate output susceptance of-SVC device ca;

B ^c-fixed filters branch road and dropped into the susceptance of thyristor switchable capacitor TSC branch road;

(4) proportion of utilization-integration (PI) adjuster calculates each susceptance that should export mutually of Static Type Dynamic Reactive Compensation Device (SVC);

Respectively needing to compensate susceptance mutually with load is reference quantity, and each actual mutually output susceptance of Static Type Dynamic Reactive Compensation Device (SVC) is a feedback quantity, and each phase of proportion of utilization-integration (PI) algorithm computation Static Type Dynamic Reactive Compensation Device (SVC) should be exported the susceptance value; Wherein the integration time constant of ratio-integration (PI) adjuster is got 100ms～300ms, the controlled range of ratio-integration (PI) adjuster be Static Type Dynamic Reactive Compensation Device (SVC) variable capacity ± 10%;

(5) control method of realization open loop+closed loop;

Wherein each phase susceptance controlled quentity controlled variable of Static Type Dynamic Reactive Compensation Device (SVC) is:

$\left\{\begin{array}{c}{B}_{\mathrm{ab}}^{\left(c\right)}=-B_{\mathrm{ab}}^L+B_{\mathrm{ab}}^{\mathrm{pi}}\\ B_{\mathrm{bc}}^{\left(c\right)}=-B_{\mathrm{bc}}^L+B_{\mathrm{ab}}^{\mathrm{pi}}\\ B_{\mathrm{ca}}^{\left(c\right)}=-B_{\mathrm{ca}}^L+B_{\mathrm{ab}}^{\mathrm{pi}}\end{array}\right.---\left(j\right),$

Wherein:

B _Ac ^(c)The alternate total compensation susceptance of-SVC device ab;

B _Bc ^(c)The alternate total compensation susceptance of-SVC device bc;

B _Ca ^(c)The alternate total compensation susceptance of-SVC device ca;

B _Ab ^Pi-alternate compensation the susceptance of ab that utilizes pi regulator to calculate;

B _Bc ^Pi-alternate compensation the susceptance of bc that utilizes pi regulator to calculate;

B _Ca ^Pi-alternate compensation the susceptance of ca that utilizes pi regulator to calculate.

2. dynamic reactive compensation control method according to claim 1, it is characterized in that described static dynamic no-power compensation device (SVC) comprises a main circuit, this main circuit comprises: filter circuit in parallel, thyristor switchable capacitor in parallel (TSC), thyristor in parallel control separate type reactor (TCR) and be serially connected in thyristor switchable capacitor in parallel (TSC) and separating thyristor in parallel is controlled thyristor valve in reactor (TCR) branch road, wherein:

Filter circuit in parallel is made up of ac filter inductance and electric capacity, and fixedly capacitive reactive power and filtering harmonic wave are provided;

Thyristor switchable capacitor (TSC) in parallel is made up of current-limiting inductance, thyristor and capacitance series, controls switching so that capacitive reactive power to be provided by thyristor;

Separating thyristor in parallel is controlled reactor (TCR), cooperates perception and capacitive reactive power so that continuous variable to be provided with filter circuit in parallel;

Thyristor valve, the thyristor right by inverse parallel is in series, be serially connected in current limiting reactor and capacitor in separating thyristor control reactor (TCR) or the thyristor switchable capacitor in parallel (TSC) between.

3. dynamic reactive compensation control method according to claim 1, when it is characterized in that described real-time detection load electric current and static dynamic no-power compensation device (SVC) access point system voltage, the sample frequency of getting 1600Hz～6400Hz at least is to system voltage u _a, u _bAnd u _c, load current i _La, i _LbAnd i _Lc, current i in thyristor control separate type reactor (TCR) angle _Tcra, i _TcrbAnd i _TcrcCarry out synchronized sampling.

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