CN104393605B - The idle Continuous Compensation control method of thyristor switched filter - Google Patents

Abstract

The idle Continuous Compensation control method of thyristor switched filter, belong to power electronics and applied technical field that utility power quality control combines, the present invention solves that in prior art, thyristor switched filter reactive-load compensation is discontinuous, it is easy to the problem causing idle overcompensation. The inventive method adopts the switching of thyristor switched filter that system is carried out the control of reactive power compensating, system is provided with three 5 subharmonic and filters passage TSF1, TSF2, TSF3 and 7 subharmonic filter passage TSF4, and the method comprises the following steps: step one, gather three-phase voltage signal u_a,u_b,u_cWith three-phase current signal i_a,i_b,i_c; Send into after step 2, signal condition in DSP control chip; Step 3, in DSP control chip, obtain 7 subharmonic currents and 5 subharmonic currents; Step 4, the switching state of each harmonic filtration passage of determining.

Description

The idle Continuous Compensation control method of thyristor switched filter

Technical field

The present invention relates to a kind of idle continuous print thyristor switched filter (TSF, thyristorswitchedfilter) and control technology, belong to power electronics and applied technical field that utility power quality control combines.

Background technology

Thyristor switched filter is a kind of power electronic equipment for dynamic harmonic wave, compensating reactive power. It can impact load, time varying duty carry out monitoring and dynamic compensation in real time, filter harmonic wave, keep optimum power factor at any time, significant for reducing grid loss, saves energy, the raising quality of power supply.

Conventional thyristor switched filter adopts " operating passing zero " mode, namely puts into when parallel thyristors voltage zero-cross, automatically excises when electric current is zero. Although this mode can accomplish that the change according to load accurately controls the switching time, but the reactive capability of switching is certain, idle overcompensation easily occurs during load consecutive variations, cause that supply voltage is too high, make circuit and equipment overcurrent, higher hamonic wave harm is big, can damage equipment time serious. For this problem, conventional way is that certain subharmonic passage is divided into two or 3 passages in parallel, and disassembly principle meets 8_��4_��2_��The ratio of 1. By the reactive power needed for these parallel branch compensating system for both. But this mode reactive-load compensation is classification, discontinuous, easily occur without merits and demerits benefit.

Summary of the invention

The invention aims to solve thyristor switched filter reactive-load compensation in prior art discontinuous, it is easy to the problem causing idle overcompensation, it is provided that the idle Continuous Compensation control method of a kind of thyristor switched filter.

The idle Continuous Compensation control method of thyristor switched filter of the present invention, the method adopts the switching of thyristor switched filter that system is carried out the control of reactive power compensating, system is provided with three 5 subharmonic and filters passage TSF1, TSF2, TSF3 and 7 subharmonic filter passage TSF4

It is characterized in that, the method comprises the following steps:

Step one, three-phase voltage signal u to network load side, described thyristor switched filter place_a, u_b, u_cWith three-phase current signal i_a, i_b, i_cSample;

Step 2, three-phase voltage signal u step one obtained by signal conditioning circuit_a, u_b, u_cWith three-phase current signal i_a, i_b, i_cProcess, and the signal after processing is sent in DSP control chip;

Step 3, in DSP control chip, instantaneous reactive power theory calculate reactive power Q and analysis of harmonic spectrum and obtain harmonic component i_ah, i_bh, i_ch, by described harmonic component i_ah, i_bh, i_chCarry out Fourier conversion, obtain 7 subharmonic currents and 5 subharmonic currents;

Step 4, the filter capacity that can not can bear more than branch road according to harmonic current principle, simultaneously consider branch road reactive-load compensation capacity, determine the switching state of each harmonic filtration passage; And inquire about the angle of flow and reactive compensation capacity data base, choose the turn on thyristors angle �� in the harmonic filtration passage of input state.

Advantages of the present invention: the present invention proposes a kind of technology controlled based on the thyristor switched filter reactive-load compensation local continuous of Repetitive controller and adjustment trigger delay angle. Adopt Repetitive Control, it is possible to system of accurately following the tracks of needs the reactive power compensated. Change the equivalent inductive reactance of wave filter thus controlling the reactive power that thyristor switched filter is put in system by regulating IGBT group delay angle, it is possible to overcome the reactive-load compensation that conventional thyristor switched filter occurs discontinuous, without problems such as merits and demerits benefits. With Hangzhou rubber plant measured data, the inventive method is tested, result proves, the inventive method has followed the tracks of the dynamic change of load well, have issued control signal in time, when there is no load current without causing false triggering, reactive-load compensation and harmonics restraint can be effectively taking place, there is high reliability and feasibility.

Thyristor switched filter is carried out mathematical modeling by the inventive method, provide a kind of based on trigger delay angle regulate realize the adjustable important channel of thyristor switched filter reactive-load compensation local continuous, to overcoming conventional thyristor switched filter reactive-load compensation overcompensation discontinuous, idle, improving system power quality has and important realistic meaning.

The present invention can real-time monitoring system harmonic current and need compensate reactive power, it is achieved thyristor switched filter accurate tracking system reactive power and reactive-load compensation local continuous are adjustable. The inventive method ensure that the power supply quality of electrical network, meets the demand providing " totally " electric energy for sensitive loads such as computer, power equipment and automatic flows. It solve the reactive-load compensation that conventional thyristor switched filter causes only with " operating passing zero " discontinuous, the problems such as idle overcompensation, reduce thyristor switched filter design complexity, save cost, for extending thyristor switched filter service life, improve the electrical safety of load, ensure its using value and DEVELOPMENT PROSPECT efficient, that safe and stable operation has extremely reality.

Accompanying drawing explanation

Fig. 1 is the thyristor switched filter system architecture diagram realizing the inventive method, including signal conditioning circuit, control chip, drive circuit, each filtering channel, the part such as load. In figure, A, B, C are three-phase alternating current in electrical network, i_a, i_b, i_cFor three-phase current signal, u_a, u_b, u_cFor three-phase voltage signal, N is the number of times of filtering channel, and M is load motor;

Fig. 2 is the thyristor switched filter controller control flow sketch realizing the inventive method. I in figure_a, i_b, i_cFor three-phase current signal, u_a, u_b, u_cFor three-phase voltage signal, i, u respectively electric current, voltage signal, i_f��u_fRespectively fundamental current, fundamental voltage, i_h��u_hRespectively harmonic current, harmonic voltage, P, Q respectively active power and reactive power, i_standardThe harmonic current standard value injecting electrical network for national regulation;

Fig. 3 is that the TSF realizing the inventive method controls system block diagram, mainly includes the parts such as operation interface, controller, main circuit;

Fig. 4 is that the TSF realizing the inventive method controls system hardware structure figure

Fig. 5 is the TSF device master control program flow chart realizing the inventive method;

Fig. 6 is that the TSF passage switching realizing the inventive method controls program flow diagram;

Fig. 7 is that TSF device zero passage puts into thyristor voltage current waveform;

Fig. 8 is that TSF device zero passage puts into capacitance voltage current waveform;

Thyristor voltage current waveform when Fig. 9 is the excision of TSF filtering channel;

Capacitance voltage current waveform when Figure 10 is the excision of TSF filtering channel;

Figure 11 is the zero passage detection signal sending into control chip;

Figure 12 is that 110 �� of delay pulses trigger signal;

Figure 13 is the thyristor voltage current waveform of 110 �� of delayed triggers;

Figure 14 is the capacitance voltage current waveform of 110 �� of delayed triggers;

Figure 15 is the TSF Repetitive controller block diagram realizing the inventive method. I, u be current and voltage signals respectively, C₃₂It is 3/2 transformation matrix of coordinates, C₂₃It is 2/3 transformation matrix of coordinates, for i_a��i_bBiphase transient current, u_a��u_bFor biphase instantaneous voltage, Q^*The reactive power of the system for detecting, i_af��i_bfBiphase instantaneous fundamental current, Q_TSFFor the reactive power that thyristor switched filter compensates, Q is the reactive power of the actual compensation of thyristor switched filter, and Q=f (a) is the relational expression between turn on thyristors angle and reactive power;

Figure 16 is TSF system structure sketch. T in figure₁��T₂For just antiparallel thyristor groups, L is inductance, and C is electric capacity;

Figure 17 is trigger delay angle a, load phase angle j_LGraph of relation with turn on thyristors angle d;

Figure 18 is angle of flow d and TSF equivalent susceptance B_LBetween graph of relation;

Detailed description of the invention

Detailed description of the invention one: present embodiment is described below in conjunction with Fig. 1 to Figure 18, the idle Continuous Compensation control method of thyristor switched filter described in present embodiment, the method adopts the switching of thyristor switched filter that system is carried out the control of reactive power compensating, and system is provided with three 5 subharmonic and filters passage TSF1, TSF2, TSF3 and 7 subharmonic filter passage TSF4.

The method comprises the following steps:

Step one, three-phase voltage signal u to network load side, described thyristor switched filter place_a, u_b, u_cWith three-phase current signal i_a, i_b, i_cSample;

Step 2, three-phase voltage signal u step one obtained by signal conditioning circuit_a, u_b, u_cWith three-phase current signal i_a, i_b, i_cProcess, and the signal after processing is sent in DSP control chip;

Step 3, in DSP control chip, instantaneous reactive power theory calculate reactive power Q and analysis of harmonic spectrum and obtain harmonic component i_ah, i_bh, i_ch, by described harmonic component i_ah, i_bh, i_chCarry out Fourier transform, obtain 7 subharmonic currents and 5 subharmonic currents;

Step 4, the filter capacity that can not can bear more than branch road according to harmonic current principle, simultaneously consider branch road reactive-load compensation capacity, determine the switching state of each harmonic filtration passage; And inquire about the angle of flow and reactive compensation capacity data base, choose the turn on thyristors angle �� in the harmonic filtration passage of input state.

The IGBT group delay angle of TSF3 range for 90 �㡫180 ��.

Reactive power Q is calculated by instantaneous reactive power theory^*And analysis of harmonic spectrum i_h, the i when harmonic content is above standard value_h> i_standard, send suppression harmonic wave instruction;

The reactive power that finally detection reality compensates, and need the reactive power compensated to compare with subsequent time system, the angle of flow repeatedly regulating IGCT makes idle infinitely the approaching compensated need the idle of compensation, and makes idle the idle of needs of always following of compensation dynamically change.

In present embodiment step one, the detection of three phase network load side voltage signal adopts voltage sensor to realize, and the detection of three phase network load-side current signal adopts current sensor to realize. The signal collected is converted into 0-3.3V signal after conditioning, is sent to the A/D port of DSP, is stored in memorizer through A/D conversion. Three-phase voltage in step 3 and in the calculating of the calculating of current effective value, reactive power and active power, the calculating of power factor, the calculating of individual harmonic current, the calculating compensating admittance and step 5 the realization of the Digital Signal Processing such as the analysis of the operating passing zero instruction of the calculating at TSF3 passage IGBT group angle and other three TSF passages all completed by dsp chip. In step 5, the triggering of TSF IGCT passage is realized by main circuit, including zero cross detection circuit, phase-locked loop circuit and frequency multiplier circuit three part. Zero cross detection circuit detection zero crossing so that the input signal of periodically continued change becomes conversion square-wave signal. Frequency and the phase place of this square-wave signal are tracked by phase-locked loop circuit, and phase-locked loop circuit is made up of phase discriminator (PD), loop filter (LPF) and voltage controlled oscillator (VCO), and wherein phaselocked loop is core. Frequency multiplier circuit realizes the N frequency multiplication that sample frequency is measured signal frequency, such as, it is achieved 128 frequencys multiplication, then when power frequency component is 50Hz, and phase locking frequency multiplying frequency is 50 �� 128=6400Hz, then have 128 sampling pulses in the cycle.

The dsp chip that dsp chip can adopt model to be MS320F2812, DSP2812 is the upgraded version of TMS320LF2407A, speed rises to 150M, process data bits and rise to 32 fixed points, have EVA, EVB task manager and the AD data acquisition of supporting 12 16 passages, there is powerful calculation function and higher sample frequency, be fully able to the real-time and precision that meet algorithm. The AD sample frequency of MS320F2812 chip is 10KHz.

Detailed description of the invention two: embodiment one is described further by present embodiment, obtains harmonic component i in step 3_ah, i_bh, i_chProcess be:

Step 31, by three-phase current signal i_a, i_b, i_cBy formula

$\left[\begin{array}{c}{i}_{\mathrm{\α}}\\ i_{\mathrm{\β}}\end{array}\right]=C_{3/2}\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right]$

It is transformed to the biphase orthogonal coordinates of alpha-beta and fastens transient current i_��, i_��;

In formula, C_3/2Represent 3/2 transformation matrix of coordinates;

Step 32, biphase for alpha-beta orthogonal coordinates are fastened transient current i_��, i_��By formula

$\left[\begin{array}{c}p\\ q\end{array}\right]=\sqrt{\frac{3}{2}}{E}_m\left[\begin{array}{c}{i}_p\\ i_q\end{array}\right]=\sqrt{\frac{3}{2}}{E}_m\left[\begin{array}{cc}\sin \mathrm{\ωt}& -\cos \mathrm{\ωt}\\ -\cos \mathrm{\ωt}& -\sin \mathrm{\ωt}\end{array}\right]\left[\begin{array}{c}{i}_{\mathrm{\α}}\\ i_{\mathrm{\β}}\end{array}\right]$

Obtain instantaneous active power p and instantaneous reactive power q;

In formula: E_mRepresent system voltage peak value;

Step 33, instantaneous active power p and instantaneous reactive power q is obtained its DC component p, q through low pass filter;

Step 34, according to formula

$\left[\begin{array}{c}{i}_{\mathrm{af}}\\ i_{\mathrm{bf}}\\ i_{\mathrm{cf}}\end{array}\right]=C_{2/3}{C_{\mathrm{pq}}}^{-1}\left[\begin{array}{c}\stackrel{\‾}{p}\\ \stackrel{\‾}{q}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{cc}1& 0\\ -\frac{1}{2}& \frac{\sqrt{3}}{2}\\ -\frac{1}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{cc}-\sin \mathrm{\ωt}& \cos \mathrm{\ωt}\\ \cos \mathrm{\ωt}& \sin \mathrm{\ωt}\end{array}\right]\left[\begin{array}{c}\stackrel{\‾}{p}\\ \stackrel{\‾}{q}\end{array}\right]$

Obtain three-phase fundamental current i_af, i_bf, i_cf;

Step 35, according to formula

$\left\{\begin{array}{c}{i}_{\mathrm{ah}}=i_{\mathrm{af}}-i_a\\ i_{\mathrm{bh}}=i_{\mathrm{bf}}-i_b\\ i_{\mathrm{ch}}=i_{\mathrm{cf}}-i_c\end{array}\right.$

Obtain harmonic component i_ah, i_bh, i_ch��

Present embodiment adopts the i based on instantaneous reactive power theory_p-i_qHarmonic detection. It is little that this Harmonic detection not only detects time delay, and real-time is good, it is possible to detects harmonic and reactive currents simultaneously, and still can measure higher harmonic current when line voltage is distorted exactly.

Completing mains by harmonics current detecting by the method and need the reactive power compensated to calculate, harmonics restraint and reactive power compensation for next step lay the first stone.

Detailed description of the invention three: embodiment one is described further by present embodiment, in step 4, the angle of flow with the process of setting up of reactive compensation capacity data base is: the size of the turn on thyristors angle �� in change thyristor switched filter, the reactance X of thyristor switched filter during collection difference turn on thyristors angle ��_L, load power factor angleAnd according to formulaObtain corresponding reactive power Q, set up the data base of turn on thyristors angle �� and reactive power Q corresponding relation.

According to filter system structure diagram, according to Kirchhoff's law row write circuit equation and solve and can obtain:

Formula one:

Formula two:

In above-mentioned two formula, I_mFor the first-harmonic peak point current of wave filter, �� is the angular frequency of first-harmonic, and �� is IGBT group delay angle, and �� is turn on thyristors angle,For load power factor angle. Formula one gives filter coefficient currents expression formula. Formula two give ��, ��,Between relation. As �� andTime known, �� can be determined by formula two, so that it is determined that the time zone that the current expression shown in formula one is set up.

According to filter coefficient currents expression formula formula one, its waveform being carried out Fourier decomposition, the equivalent susceptance that can obtain thyristor switched filter further is:

Formula three: $B_L=\frac{\sqrt{{\left(\sin \mathrm{\δ}\right)}^2+{\mathrm{\δ}}^2-\mathrm{\δ}\×\sin \mathrm{\δ}}}{2\mathrm{\π}{X}_L}=B_{L\max }\frac{\sqrt{{\left(\sin \mathrm{\δ}\right)}^2+{\mathrm{\δ}}^2-\mathrm{\δ}\×\sin \mathrm{\δ}}}{2\mathrm{\π}}$

X in formula_LFor filter system reactance, the maximum of equivalent susceptance is B_Lmax=1/X_L��

By formula three it can be seen that in the situation of different turn on thyristors angles, the equivalent susceptance of each passage of TSF differs. When IGBT group delay angle changes, cause the change of the susceptance value of TSF, owing to added alternating current is constant, so that the reactive power amount that TSF passage puts into system changes. Can obtaining further, the reactive power of electric capacity generation and thyristor switched filter system are put into the reactive power of electrical network and can be expressed as:

Formula four:

Reactive power can be obtained by formula above and follow the variation relation between IGBT group delay angle and load power factor angle. When load one timing, it is possible to calculate the numerical relation between IGBT group delay angle and reactive power, and then obtain the angle of flow and reactive compensation capacity data base.

With the concrete of reactive compensation capacity relation, the described angle of flow calculates that process is as follows:

In conjunction with Figure 16-Figure 18, TSF is the equal of the circuit of a pair just antiparallel Thyristors in series single phase filter, two positive anti-parallel thyristors therein play and are connected to the grid by capacitor or by its effect opened from grid disruption, the harmonic filtration passage of the inductance of series connection and electric capacity composition 5 times, 7 times or other number of times. According to equivalent circuit, then the solution procedure of system power is as follows:

Formula five: $e=E_m\sin \mathrm{\ωt}=\sqrt{2}E\sin \mathrm{\ωt}$

Formula six: $L\frac{\mathrm{di}}{\mathrm{dt}}+u_c=\sqrt{2}E\sin \mathrm{\ωt}$

Formula seven: $i=C\frac{d{u}_c}{\mathrm{dt}}$

Formula eight: i |_{�� t=��}=0

Formula nine: i |_{�� t=��+��}=0

Formula ten:

Wherein e is system power source voltage, E_mBeing system voltage peak value, E is system voltage virtual value, and w is the angular frequency of first-harmonic, and L is this filtering channel inductance value, and C is this filtering channel capacitance, u_cBeing capacitor voltage at both ends, i is system power, and R is system resistance. Formula seven is substituted into formula six, then with formula eight for initial condition, solution formula six can obtain formula one, obtains the expression formula of system power i. Bring formula nine into formula one, formula two can be obtained, obtain trigger delay angle ��, load power factor angleAnd the relation between the �� of turn on thyristors angle, relation curve is as shown in figure 17.

Formula 11: $i=\underset{n=\mathrm{1,3,5},...}{\overset{\∞}{\mathrm{\Σ}}}(a_{\mathrm{in}}\cos \mathrm{n\ωt}+b_{\mathrm{in}}\sin \mathrm{n\ωt})$

Formula 12: $I_1=\frac{1}{\sqrt{2}}\sqrt{a_{i1}^2+b_{i1}^2}$

Formula 13: $I_1=\frac{\sqrt{{\left(\sin \mathrm{\δ}\right)}^2+{\mathrm{\δ}}^2-\mathrm{\δ}\×\sin \left(\mathrm{\δ}\right)}}{2\mathrm{\π}{X}_L}E$

Formula 14: Q=E²/B_L��sin��₁

Formula 15: ��₁=arctan (a_i1/b_i1)

Electric current i represented by formula one is carried out Fourier decomposition and can obtain formula 11. Decomposed the Fourier coefficient obtained by Fourier, load current first-harmonic virtual value I can be obtained further₁. Take load power factor angleFormula two and formula 11 are brought in formula 12 and can obtain fundamental current I₁And the relation between the d of turn on thyristors angle, such as formula 13, and then the expression formula formula three of the equivalent susceptance of TSF can be obtained.The reactive power of electric capacity generation and TSF put into reactive power such as formula 14 of electrical network, the wherein calculating of the initial phase angle of load current first-harmonic such as formula 15. Finally, it is possible to the reactive power obtaining being represented by load phase angle expresses formula formula four.

Detailed description of the invention four: present embodiment is described below in conjunction with Fig. 6, embodiment one is described further by present embodiment, and in step 4, the judge process of the switching state of each harmonic filtration passage is:

Step 1, judge that whether 7 subharmonic currents are more than 7 subharmonic current setting values; Judged result is yes, performs step 2; Judged result is no, performs step 4;

Step 2, judge that whether reactive power Q filters the reactive compensation capacity rated value Q of passage more than or equal to 7 subharmonic₇; Judged result is yes, puts into TSF4, carries out 7 subharmonic and filter, and then performs step 3; Judged result is no, performs step 3;

Step 3, judge that whether reactive power Q filters the reactive compensation capacity rated value Q of passage less than 7 subharmonic₇; Judged result is yes, excises TSF4, then performs step 4; Judged result is no, performs step 4;

Step 4, judge that whether 5 subharmonic currents are more than 5 subharmonic current setting values; Judged result is yes, performs step 5; Judged result is no, performs step 9;

Step 5, judge relational expression (Q-Q₇)��Q₅Whether set up, wherein Q₅It is the 5 subharmonic reactive compensation capacity rated values that filter passage; Judged result is yes, performs step 6; Judged result is no, performs step 7;

Step 6, currently whether to put into TSF1; If so, then put into TSF1, then perform step 7; If it is not, then put into TSF2, then perform step 7;

Step 7, judge relational expression (Q-Q₇) <-Q₅Whether set up; Judged result is yes, excises TSF2, then performs step 8; Judged result is no, performs step 8;

Step 8, judge relational expression (Q-Q₇) < Q₅Whether set up; Judged result is yes, excises TSF1, then performs step 9; Judged result is no, performs step 9;

Step 9, judge relational expression (Q-Q₅-Q₇) whether > 0 set up; Judged result is yes, performs step 10; Judged result is no, returns step 1 and re-starts judgement;

Step 10, inquiry data base choose the angle of flow of IGCT; Then step 11 is performed;

Step 11, intervalometer is carried out assignment; Then step 12 is performed;

Step 12, timer interruption trigger, and are then back to step 1 and re-start judgement.

Claims (3)

1. the idle Continuous Compensation control method of thyristor switched filter, the method adopts the switching of thyristor switched filter that system is carried out the control of reactive power compensating, system is provided with three 5 subharmonic and filters passage TSF1, TSF2, TSF3 and 7 subharmonic filter passage TSF4

It is characterized in that, the method comprises the following steps:

Step one, three-phase voltage signal u to network load side, described thyristor switched filter place_a, u_b, u_cWith three-phase current signal i_a, i_b, i_cSample;

Step 2, three-phase voltage signal u step one obtained by signal conditioning circuit_a, u_b, u_cWith three-phase current signal i_a, i_b, i_cProcess, and the signal after processing is sent in DSP control chip;

Step 3, in DSP control chip, instantaneous reactive power theory calculate reactive power Q and analysis of harmonic spectrum and obtain harmonic component i_ah, i_bh, i_ch, by described harmonic component i_ah, i_bh, i_chCarry out Fourier transform, obtain 7 subharmonic currents and 5 subharmonic currents;

Step 4, the filter capacity that can not can bear more than branch road according to harmonic current principle, simultaneously consider branch road reactive-load compensation capacity, determine the switching state of each harmonic filtration passage; And inquire about the angle of flow and reactive compensation capacity data base, choose the turn on thyristors angle �� in the harmonic filtration passage of input state;

In step 4, the judge process of the switching state of each harmonic filtration passage is:

Step 1, judge that whether 7 subharmonic currents are more than 7 subharmonic current setting values; Judged result is yes, performs step 2; Judged result is no, performs step 4;

Step 2, judge that whether reactive power Q filters the reactive compensation capacity rated value Q of passage more than or equal to 7 subharmonic₇; Judged result is yes, puts into TSF4, carries out 7 subharmonic and filter, and then performs step 3; Judged result is no, performs step 3;

Step 3, judge that whether reactive power Q filters the reactive compensation capacity rated value Q of passage less than 7 subharmonic₇; Judged result is yes, excises TSF4, then performs step 4; Judged result is no, performs step 4;

Step 4, judge that whether 5 subharmonic currents are more than 5 subharmonic current setting values; Judged result is yes, performs step 5; Judged result is no, performs step 9;

Step 5, judge relational expression (Q-Q₇)��Q₅Whether set up, wherein Q₅It is the 5 subharmonic reactive compensation capacity rated values that filter passage; Judged result is yes, performs step 6; Judged result is no, performs step 7;

Step 6, currently whether to put into TSF1; If so, then put into TSF1, then perform step 7; If it is not, then put into TSF2, then perform step 7;

Step 7, judge relational expression (Q-Q₇) <-Q₅Whether set up; Judged result is yes, excises TSF2, then performs step 8; Judged result is no, performs step 8;

Step 8, judge relational expression (Q-Q₇) < Q₅Whether set up; Judged result is yes, excises TSF1, then performs step 9; Judged result is no, performs step 9;

Step 9, judge relational expression (Q-Q₅-Q₇) whether > 0 set up; Judged result is yes, performs step 10; Judged result is no, returns step 1 and re-starts judgement;

Step 10, inquiry data base choose the angle of flow of IGCT; Then step 11 is performed;

Step 11, intervalometer is carried out assignment; Then step 12 is performed;

Step 12, timer interruption trigger, and are then back to step 1 and re-start judgement.

2. the idle Continuous Compensation control method of thyristor switched filter according to claim 1, it is characterised in that obtain harmonic component i in step 3_ah, i_bh, i_chProcess be:

Step 31, by three-phase current signal i_a, i_b, i_cBy formula

It is transformed to the biphase orthogonal coordinates of alpha-beta and fastens transient current i_��, i_��;

In formula, C_3/2Represent 3/2 transformation matrix of coordinates;

Step 32, biphase for alpha-beta orthogonal coordinates are fastened transient current i_��, i_��By formula

Obtain instantaneous active power p and instantaneous reactive power q;

In formula: E_mRepresent system voltage peak value;

Step 33, instantaneous active power p and instantaneous reactive power q is obtained its DC component through low pass filter

Step 34, according to formula

Obtain three-phase fundamental current i_af, i_bf, j_cf;

Step 35, according to formula

Obtain harmonic component i_ah, i_bh, i_ch��

3. the idle Continuous Compensation control method of thyristor switched filter according to claim 1, it is characterized in that, in step 4, the angle of flow with the process of setting up of reactive compensation capacity data base is: the size of the turn on thyristors angle �� in change thyristor switched filter, the reactance X of thyristor switched filter during collection difference turn on thyristors angle ��_L, load power factor angleAnd according to formulaObtain corresponding reactive power Q, set up the data base of turn on thyristors angle �� and reactive power Q corresponding relation.