CN102810856A - Phase correction method for arbitrary impulse converter transformer current difference - Google Patents

Abstract

The invention relates to a phase correction method for arbitrary impulse converter transformer current difference. When a converter transformer is at a no-load status, a phase difference theta exists in positive sequence current of a line side winding and a valve side winding, and the theta is any angle. The phase correction method comprises the following steps: selecting a side winding of the converter transformer as a reference winding, and performing phase correction to the other side winding current towards the reference winding current; using a phase relationship of three-phase current sequence components on the two sides of the converter transformer, and a conversion method of the sequence components and the phase components to calculate differential current. Due to the adoption of the phase correction method, the differential current of any impulse converter transformer can be calculated, so that a high-voltage direct-current power transmission system safely and stably operates for a long time; the method has the advantages of easily applying and preventing the generation of false differential current. Moreover, according to the phase correction method, a problem that the phase correction is only achieved when the same-phase current phase difference on the two sides of the converter transformer is 30 N (N is an integral number) as the current phase correction method adopts the adding and subtracting of the three-phase current vectors on certain side can be solved.

Description

The bearing calibration of a kind of any pulse conversion time-dependent current differential phae

Technical field

The invention belongs to technical field of power systems, method for correcting phase when the phase current phase of the same name phasic difference of particularly a kind of converter transformer both sides is arbitrarily angled.

Background technology

High voltage direct current transmission is because its distinctive advantage, such as: long distance, high-power, asynchronous networking, power quick adjustment property, trend controllability, the economy of transmitting electricity etc. are applied more and more widely.For reducing the harmonic component of system; Utilize the difference of Transformer Winding to connect method; High voltage DC engineering adopts 12 flutter valve set of connections modes mostly at present; As shown in Figure 1, its two transformers for serial connection provide that two groups of amplitudes equate, three symmetrical commutation voltages of phase phasic difference 30 ° (first-harmonic electrical degrees), to realize 12 pulse conversions.

For reflecting the inner phase fault of 12 pulse conversion transformers (be called for short: the change of current becomes), net side single-line to ground fault and turn-to-turn layer short circuit fault; The normal biased differential protection that adopts; The protection range of this protection is that T1 among Fig. 1, the T2 change of current become, and its operation equation is difference stream I _dGreater than certain threshold definite value of floating.Because becoming between phase current of the same name, the T2 change of current do not have phase difference, so the change of current becomes T2 difference stream I _dComputing formula be (suppose that the change of current becomes the net side, the current on valve side amplitude has been accomplished correction, amplitude is equal when guaranteeing normal operation or external fault, below all with)

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_A3}\\ {\stackrel{.}{I}}_{d\_B3}\\ {\stackrel{.}{I}}_{d\_C3}\end{array}\right]=\left[\begin{array}{c}{\stackrel{.}{I}}_{a3}+{\stackrel{.}{I}}_{a4}\\ {\stackrel{.}{I}}_{b3}+{\stackrel{.}{I}}_{b4}\\ {\stackrel{.}{I}}_{c3}+{\stackrel{.}{I}}_{c4}\end{array}\right]$ Formula (1)

In the formula, I _A3, I _B3, I _C3And I _A4, I _B4, I _C4Be respectively the T2 change of current and become the electric current of netting side and current on valve side instrument transformer three-phase, I _{D_A3}, I _{D_B3}, I _{D_C3}Be respectively the T2 change of current and become the three-phase differential current.

Fig. 2 becomes the both sides winding connection for the T1 change of current, and the phase difference between phase current of the same name is 30 °, and is as shown in Figure 3, and it is opposite with mark that the change of current becomes the current on valve side actual direction, i.e. I _A1With-I _A2Between angle ,-I _A2Be actual winding current direction just often, shown in θ among Fig. 3.

For the electric current that flows into differential relay when normal operation or the external fault is zero, phasing and amplitude rectification (amplitude rectification is claimed current balance type adjustment usually, and the present invention does not relate to amplitude rectification, suppose all amplitude rectifications all accomplish) should be arranged.Among the figure, I _A1, I _B1, I _C1And I _A2, I _C2, I _C2Be respectively the T1 change of current and become the electric current of netting side and current on valve side instrument transformer three-phase.

Fig. 4 is 30 ° of covert bit correction polar plots of the change of current for phase difference, and existing bearing calibration has two kinds, and a kind of is to be benchmark with the Y side, and d side electric current is carried out phase shift, makes d side current phase consistent with Y side current phase; Another kind is to be benchmark with the d side, makes Y side current phase consistent with the d side.Two kinds of methods are similar, are benchmark with d side current phase for example, carry out phase shift with Y side electric current.Can try to achieve the Y side by following formula as the three-phase current expression formula of differential calculating is:

$\left[\begin{array}{c}{\stackrel{.}{I}}_{A1}\\ {\stackrel{.}{I}}_{B1}\\ {\stackrel{.}{I}}_{C1}\end{array}\right]=\left[\begin{array}{c}{\stackrel{.}{I}}_{a1}+{\stackrel{.}{I}}_{b1}\\ {\stackrel{.}{I}}_{b1}+{\stackrel{.}{I}}_{c1}\\ {\stackrel{.}{I}}_{c1}+{\stackrel{.}{I}}_{a1}\end{array}\right]$ Formula (2)

In the formula, I _A1, I _B1, I _C1Be respectively the T1 change of current and become three-phase current after the phase shift of Y side electric current, as shown in Figure 4.(I when so normal operation and external short circuit _A2) and I _A1Current phase is identical, as long as its unsymmetrical current of longitudinal differential protection that these two electric currents of the identical use of amplitude constitute just is zero, its difference stream formula is following:

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_A1}\\ {\stackrel{.}{I}}_{d\_B1}\\ {\stackrel{.}{I}}_{d\_C1}\end{array}\right]=\left[\begin{array}{c}{\stackrel{.}{I}}_{A1}+{\stackrel{.}{I}}_{a2}\\ {\stackrel{.}{I}}_{B1}+{\stackrel{.}{I}}_{b2}\\ {\stackrel{.}{I}}_{C1}+{\stackrel{.}{I}}_{c2}\end{array}\right]$ Formula (3)

In the formula, I _{D_A1}, I _{D_B1}, I _{D_C1}Be respectively the T1 change of current and become the three-phase spill current.

Yet along with ultra high voltage ± 800kV and the more appearance of voltage levels direct current, the extra-high voltage direct-current engineering has adopted two 12 flutter valve group series wiring modes more at present, has formed two ± 400kV and more high-tension stack.For reducing the system harmonics component greatly; Utilize the difference of Transformer Winding to connect method; Possibly provide in the future that four groups of amplitudes equate for four converters of serial connection, three symmetrical commutation voltages of phase phasic difference 15 ° (first-harmonic electrical degrees), to realize 24 pulse conversions, as shown in Figure 5; If the A phase phase angle of change of current bus (net side) is 0 °, then the A phase phase angle of change of current change T1, T2, T3, T4 valve side is respectively 45 °, 30 °, 15 °, 0 °.Change of current this moment becomes the differential protection of T2, T4 and still can use formula (3) to realize; But the differential protection that the change of current becomes between T1, T3 can't adopt above-mentioned formula to realize phase current phasing of the same name; Thereby can't calculate the three-phase differential current that the change of current becomes T1, T3, promptly present method for correcting phase only is applicable to that the change of current becomes the situation of both sides phase current phase of the same name phasic difference 30N (N is integer).

Summary of the invention

The problem that the present invention will solve is to the deficiency of prior art a kind of method for correcting phase to be provided, and it is applicable to that the change of current becomes both sides phase current phase of the same name phasic difference and is situation at any angle.

For solving the problems of the technologies described above, technical scheme of the present invention is:

The present invention provides the bearing calibration of a kind of any pulse conversion time-dependent current differential phae, has phase difference θ between net side and valve side both sides winding forward-order current when said converter transformer is unloaded, and θ is arbitrarily angled, and said method for correcting phase comprises the steps:

Step 1: selected converter transformer side winding is with reference to winding, and the opposite side winding current is to carrying out phasing with reference to winding current;

Step 2: utilize the phase relation of converter transformer both sides three-phase current preface component, the method computer differential electric current that adopts preface component and phase component to change each other.

In the such scheme, said step 1 is:

The net side winding of selected converter transformer is with reference to winding, and with reference to the current phase rotation 0o of winding, valve side winding current is to aliging with reference to winding, and the anglec of rotation is θ;

Said step 2 is:

The positive sequence component I of converter transformer three-phase differential current _{D_ps}, negative sequence component I _{D_ns}, zero-sequence component I _{D_zs}For:

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_\mathrm{zs}}\\ {\stackrel{.}{I}}_{d\_\mathrm{ps}}\\ {\stackrel{.}{I}}_{d\_\mathrm{ns}}\end{array}\right]=\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{zs}\_1}\\ {\stackrel{.}{I}}_{\mathrm{ps}\_1}\\ {\stackrel{.}{I}}_{\mathrm{ns}\_1}\end{array}\right]+\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{zs}\_2}\\ e^{\mathrm{j\θ}}{\stackrel{.}{I}}_{\mathrm{ps}\_2}\\ e^{-\mathrm{j\θ}}{\stackrel{.}{I}}_{\mathrm{ns}\_2}\end{array}\right]$

In the formula, I _{Ps_1}, I _{Ns_1}, I _{Zs_1}Be respectively positive sequence, negative phase-sequence and the zero-sequence component of converter transformer current on line side instrument transformer three-phase current, I _{Ps_2}, I _{Ns_2}, I _{Zs_2}Be respectively positive sequence, negative phase-sequence and the zero-sequence component of converter transformer current on valve side instrument transformer three-phase current;

According to three-phase ABC component in the electric power system and relation positive and negative, zero-sequence component, draw the phase component of differential current from the preface component of following formula:

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_A}\\ {\stackrel{.}{I}}_{d\_B}\\ {\stackrel{.}{I}}_{d\_C}\end{array}\right]=A\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_\mathrm{zs}}\\ {\stackrel{.}{I}}_{d\_\mathrm{ps}}\\ {\stackrel{.}{I}}_{d\_\mathrm{ns}}\end{array}\right]$

In the formula, I _{D_A}, I _{D_B}, I _{D_C}Be respectively converter transformer three-phase differential current;

And use:

$A=\left[\begin{array}{ccc}1& 1& 1\\ 1& {\mathrm{\α}}^2& \mathrm{\α}\\ 1& \mathrm{\α}& {\mathrm{\α}}^2\end{array}\right]$ With

$A^{-1}=\frac{1}{3}\·\left[\begin{array}{ccc}1& 1& 1\\ 1& \mathrm{\α}& {\mathrm{\α}}^2\\ 1& {\mathrm{\α}}^2& \mathrm{\α}\end{array}\right]$

Finally obtain:

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_A}\\ {\stackrel{.}{I}}_{d\_B}\\ {\stackrel{.}{I}}_{d\_C}\end{array}\right]=A\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{zs}\_1}\\ {\stackrel{.}{I}}_{\mathrm{ps}\_1}\\ {\stackrel{.}{I}}_{\mathrm{ns}\_1}\end{array}\right]+A\left[\begin{array}{ccc}1& 0& 0\\ 0& e^{\mathrm{j\θ}}& 0\\ 0& 0& e^{-\mathrm{j\θ}}\end{array}\right](A^{-1}\×A)\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{zs}\_2}\\ {\stackrel{.}{I}}_{\mathrm{ps}\_2}\\ {\stackrel{.}{I}}_{\mathrm{ns}\_2}\end{array}\right]$

$=\left[\begin{array}{c}{\stackrel{.}{I}}_{a1}\\ {\stackrel{.}{I}}_{b1}\\ {\stackrel{.}{I}}_{c1}\end{array}\right]+A\left[\begin{array}{ccc}1& 0& 0\\ 0& e^{\mathrm{j\θ}}& 0\\ 0& 0& e^{-\mathrm{j\θ}}\end{array}\right]A^{-1}\left[\begin{array}{c}{\stackrel{.}{I}}_{a2}\\ {\stackrel{.}{I}}_{b2}\\ {\stackrel{.}{I}}_{c2}\end{array}\right]$

I _A1, I _B1, I _C1, and I _A2, I _B2, I _C2Be respectively the electric current of converter transformer net side and current on valve side instrument transformer three-phase.

Further, in the such scheme, define M (θ) as follows:

$M\left(\mathrm{\θ}\right)=A\left[\begin{array}{ccc}1& 0& 0\\ 0& e^{\mathrm{j\θ}}& 0\\ 0& 0& e^{-\mathrm{j\θ}}\end{array}\right]A^{-1}$

And use:

$A=\left[\begin{array}{ccc}1& 1& 1\\ 1& {\mathrm{\α}}^2& \mathrm{\α}\\ 1& \mathrm{\α}& {\mathrm{\α}}^2\end{array}\right]$ With

$A^{-1}=\frac{1}{3}\·\left[\begin{array}{ccc}1& 1& 1\\ 1& \mathrm{\α}& {\mathrm{\α}}^2\\ 1& {\mathrm{\α}}^2& \mathrm{\α}\end{array}\right],$

Finally obtain:

M (0 °) is a unit matrix, so converter transformer three-phase differential current can be write as:

To sum up,

Certain side winding of selected converter transformer (like net side winding) is with reference to winding; Current phase with reference to winding is not rotated (rotating 0 ° in other words); Other side winding currents (like the valve side) of converter transformer then need be to aliging with reference to winding, and the anglec of rotation is θ.θ is the phase difference between the winding forward-order current of converter transformer both sides, the phase difference when also being simultaneously the converter transformer zero load between the winding positive sequence voltage of both sides.

Compared with prior art, the present invention has following beneficial effect:

The present invention utilizes the change of current to become the phase relation of both sides three-phase current preface component; The method that adopts preface component and phase component to change each other realizes the phasing of change of current change both sides phase current phase of the same name phasic difference when arbitrarily angled, and no matter how many amplitudes of this phase difference is; All can select the change of current and become certain side winding into reference to winding; Other side winding currents are to carrying out phasing with reference to winding current, thereby eliminate the phase difference of each side electric current, with the computer differential electric current.Adopt the present invention can calculate the differential current (minimum be not 0 be 360/ pulse number with famous prime minister's phase difference) of any pulse conversion transformer; Realize the long-term safety stable operation of HVDC transmission system, this method possesses implements simple and easy, as to prevent to produce false differential current advantage.Thereby solved present employed method for correcting phase and then adopted certain side three-phase current vector plus and minus calculation, can only realize the problem of the phasing the when change of current becomes both sides phase current phase of the same name phasic difference 30N (N is integer).

Description of drawings

Fig. 1 is the winding diagram that existing 12 pulse conversions become;

Fig. 2 is to be that 30 ° of changes of current become the both sides winding diagrams with famous prime minister's phase difference;

Fig. 3 is to be that 30 ° of changes of current become the three-phase current polar plots with famous prime minister's phase difference

Fig. 4 is that phase difference is 30 ° of covert bit correction polar plots of the change of current;

Fig. 5 is that certain relevant any pulse conversion of the embodiment of the invention becomes winding diagram;

Fig. 6 is to be that θ (arbitrarily angled) change of current becomes phase current polar plot of the same name with famous prime minister's phase difference;

Fig. 7 is to be that θ (arbitrarily angled) change of current becomes both sides forward-order current polar plots with famous prime minister's phase difference;

Fig. 8 is to be that θ (arbitrarily angled) change of current becomes both sides negative-sequence current polar plots with famous prime minister's phase difference;

Fig. 9 is to be that θ (arbitrarily angled) change of current becomes both sides zero-sequence current polar plots with famous prime minister's phase difference.

Embodiment

Below in conjunction with embodiment and accompanying drawing the present invention is carried out detailed description, following description is example with Fig. 5.

Among Fig. 5 to 9, Fig. 5 is the winding diagram that 24 pulse conversions become, and suppose phase difference θ between T1 change of current change forward-order current when arbitrarily angled, i.e. I _A1In advance-I _A2θ when being arbitrarily angled, as shown in Figure 6.Then the change of current becomes phase relation between positive sequence, negative phase-sequence and the zero sequence of A phase in the valve side respectively like Fig. 7, Fig. 8, shown in Figure 9.

I _{Ps_1}, I _{Ns_1}, I _{Zs_1}Be respectively positive sequence, negative phase-sequence and the zero-sequence component of T1 change of current change current on line side instrument transformer three-phase current, I _{Ps_2}, I _{Ns_2}, I _{Zs_2}Be respectively positive sequence, negative phase-sequence and the zero-sequence component of T1 change of current change current on valve side instrument transformer three-phase current, so I _{Ps_1}In advance-I _{Ps_2}The θ angle, I _{Ns_1}Hysteresis-I _{Ns_2}The θ angle, I _{Zs_1}With-I _{Zs_2}θ same-phase (because custom difference stream adopts additional calculation difference stream, as shown in Figure 6, it is opposite with mark that the change of current becomes the current on valve side actual direction).Therefore, when the T1 change of current became normal operation or external fault takes place, net side, current on valve side satisfied following relationship (set that the T1 change of current becomes the net side, the current on valve side amplitude rectification is accomplished, promptly net side, the current on valve side amplitude equates).

$\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{Zs}\_1}\\ {\stackrel{.}{I}}_{\mathrm{Ps}\_1}\\ {\stackrel{.}{I}}_{\mathrm{Ns}\_1}\end{array}\right]=-\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{Zs}\_2}\\ e^{\mathrm{J\θ}}{\stackrel{.}{I}}_{\mathrm{Ps}\_2}\\ e^{-\mathrm{J\θ}}{\stackrel{.}{I}}_{\mathrm{Ns}\_2}\end{array}\right]$ Formula (4)

According to formula (4), the T1 change of current becomes the positive sequence component I of three-phase differential current _{D_ps}, negative sequence component I _{D_ns}, zero-sequence component I _{D_zs}For

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_\mathrm{Zs}}\\ {\stackrel{.}{I}}_{d\_\mathrm{Ps}}\\ {\stackrel{.}{I}}_{d\_\mathrm{Ns}}\end{array}\right]=\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{Zs}\_1}\\ {\stackrel{.}{I}}_{\mathrm{Ps}\_1}\\ {\stackrel{.}{I}}_{\mathrm{Ns}\_1}\end{array}\right]+\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{Zs}\_2}\\ e^{\mathrm{J\θ}}{\stackrel{.}{I}}_{\mathrm{Ps}\_2}\\ e^{-\mathrm{J\θ}}{\stackrel{.}{I}}_{\mathrm{Ns}\_2}\end{array}\right]$ Formula (5)

According to three-phase ABC component in the electric power system and relation positive and negative, zero-sequence component, draw the phase component of differential current from the preface component of formula (5):

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_A}\\ {\stackrel{.}{I}}_{d\_B}\\ {\stackrel{.}{I}}_{d\_C}\end{array}\right]=A\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_\mathrm{Zs}}\\ {\stackrel{.}{I}}_{d\_\mathrm{Ps}}\\ {\stackrel{.}{I}}_{d\_\mathrm{Ns}}\end{array}\right]$ Formula (6)

In the formula, I _{D_A}, I _{D_B}, I _{D_C}Be respectively converter transformer three-phase differential current.

With formula (4), (5) substitution formula (6), can get formula (7):

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_A}\\ {\stackrel{.}{I}}_{d\_B}\\ {\stackrel{.}{I}}_{d\_C}\end{array}\right]=A(\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{Zs}\_1}\\ {\stackrel{.}{I}}_{\mathrm{Ps}\_1}\\ {\stackrel{.}{I}}_{\mathrm{Ns}\_1}\end{array}\right]+\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{Zs}\_2}\\ e^{\mathrm{J\θ}}{\stackrel{.}{I}}_{\mathrm{Ps}\_2}\\ e^{-\mathrm{J\θ}}{\stackrel{.}{I}}_{\mathrm{Ns}\_2}\end{array}\right])$ Formula (7)

$=A\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{zs}\_1}\\ {\stackrel{.}{I}}_{\mathrm{ps}\_1}\\ {\stackrel{.}{I}}_{\mathrm{ns}\_1}\end{array}\right]+A\left[\begin{array}{ccc}1& 0& 0\\ 0& e^{\mathrm{j\θ}}& 0\\ 0& 0& e^{-\mathrm{j\θ}}\end{array}\right]\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{zs}\_2}\\ {\stackrel{.}{I}}_{\mathrm{ps}\_2}\\ {\stackrel{.}{I}}_{\mathrm{ns}\_2}\end{array}\right]$

Formula (7) is further carried out the conversion between preface component and the phase component,, can get formula (8) like formula (6):

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_A}\\ {\stackrel{.}{I}}_{d\_B}\\ {\stackrel{.}{I}}_{d\_C}\end{array}\right]=A\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{Zs}\_1}\\ {\stackrel{.}{I}}_{\mathrm{Ps}\_1}\\ {\stackrel{.}{I}}_{\mathrm{Ns}\_1}\end{array}\right]+A\left[\begin{array}{ccc}1& 0& 0\\ 0& e^{\mathrm{J\θ}}& 0\\ 0& 0& e^{-\mathrm{J\θ}}\end{array}\right](A^{-1}\×A)\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{Zs}\_2}\\ {\stackrel{.}{I}}_{\mathrm{Ps}\_2}\\ {\stackrel{.}{I}}_{\mathrm{Ns}\_2}\end{array}\right]$ Formula (8)

$=\left[\begin{array}{c}{\stackrel{.}{I}}_{a1}\\ {\stackrel{.}{I}}_{b1}\\ {\stackrel{.}{I}}_{c1}\end{array}\right]+A\left[\begin{array}{ccc}1& 0& 0\\ 0& e^{\mathrm{j\θ}}& 0\\ 0& 0& e^{-\mathrm{j\θ}}\end{array}\right]A^{-1}\left[\begin{array}{c}{\stackrel{.}{I}}_{a2}\\ {\stackrel{.}{I}}_{b2}\\ {\stackrel{.}{I}}_{c2}\end{array}\right]$

Be that formula (8) is pulsed down for any, the computational methods of change of current transformer differential protection when promptly θ is arbitrarily angled become the method that valve side three-phase current is worth the three-phase differential current from the change of current.

To the further abbreviation of formula (8), define M (θ) as follows:

$M\left(\mathrm{\θ}\right)=A\left[\begin{array}{ccc}1& 0& 0\\ 0& e^{\mathrm{j\θ}}& 0\\ 0& 0& e^{-\mathrm{j\θ}}\end{array}\right]A^{-1}$

And use

$A=\left[\begin{array}{ccc}1& 1& 1\\ 1& {\mathrm{\α}}^2& \mathrm{\α}\\ 1& \mathrm{\α}& {\mathrm{\α}}^2\end{array}\right]$

$A^{-1}=\frac{1}{3}\·\left[\begin{array}{ccc}1& 1& 1\\ 1& \mathrm{\α}& {\mathrm{\α}}^2\\ 1& {\mathrm{\α}}^2& \mathrm{\α}\end{array}\right]$

Then

$M\left(\mathrm{\θ}\right)$ $=\frac{1}{3}\·\left[\begin{array}{ccc}1+2\mathrm{Cos}\left(\mathrm{\θ}\right)& 1-\mathrm{Cos}\left(\mathrm{\θ}\right)-\sqrt{3}\mathrm{Sin}\left(\mathrm{\θ}\right)& 1-\mathrm{Cos}\left(\mathrm{\θ}\right)+\sqrt{3}\mathrm{Sin}\left(\mathrm{\θ}\right)\\ 1-\mathrm{Cos}\left(\mathrm{\θ}\right)+\sqrt{3}\mathrm{Sin}\left(\mathrm{\θ}\right)& 1+2\mathrm{Cos}\left(\mathrm{\θ}\right)& 1-\mathrm{Cos}\left(\mathrm{\θ}\right)-\sqrt{3}\mathrm{Sin}\left(\mathrm{\θ}\right)\\ 1-\mathrm{Cos}\left(\mathrm{\θ}\right)-\sqrt{3}\mathrm{Sin}\left(\mathrm{\θ}\right)& 1-\mathrm{Cos}\left(\mathrm{\θ}\right)+\sqrt{3}\mathrm{Sin}\left(\mathrm{\θ}\right)& 1+2\mathrm{Cos}\left(\mathrm{\θ}\right)\end{array}\right]$ Formula (9)

Again formula (9) is used following triangle formula:

cos(x±y)＝cos(x)cos(y)m?sin(x)sin(y)

Then can get:

formula (10)

Because M (0 °) is a unit matrix, then formula (10) can be write as:

formula (11)

In the said process, the net side winding that the change of current becomes is chosen as with reference to winding, does not rotate (rotating 0 ° in other words) with reference to the current phase of winding, and the winding current of valve side then need be to aliging with reference to winding, and the anglec of rotation is θ.θ is that the change of current becomes the phase difference between the winding forward-order current of both sides, and the phase difference when also becoming unloaded for the change of current simultaneously between the winding positive sequence voltage of both sides is determined by the manufacturing firm and the mode of connection in essence.As shown in Figure 6, when from proofreading and correct the winding direction of rotation when being counter-clockwise direction to need with reference to winding, θ get on the occasion of, otherwise θ gets negative value.It is that will net the side winding current carries out phasing with reference to winding that method for correcting phase also can be got the valve side, and this moment, the middle θ of M (θ) of corresponding net side should be negative value.

Rotation is according to being: when when the change of current becomes unloaded, netting the leading valve side of side winding forward-order current winding forward-order current θ; The change of current becomes the positive sequence component θ angle of the leading change of current change of the positive sequence component valve side winding three-phase electric current of net side winding three-phase electric current; The change of current becomes the negative sequence component θ angle of the negative sequence component hysteresis change of current change valve side winding three-phase electric current of net side winding three-phase electric current, and the change of current becomes the zero-sequence component of net side winding three-phase electric current and the zero-sequence component same-phase that the change of current becomes valve side winding three-phase electric current.Therefore; Proofread and correct for realizing any pulse conversion time-dependent current differential phae; Need that at first the change of current is become each side three-phase current phase component and convert positive and negative zero-sequence current component into; Next realizes the positive and negative zero-sequence current component of each side to the rotation with reference to the positive and negative zero-sequence current component of winding, utilizes the change of current to become the positive and negative zero-sequence current component of the positive and negative zero-sequence current component computer differential of each side electric current once more, at last the change of current is become the positive and negative zero sequence differential current of each side component and converts the three-phase differential current into.

Above embodiment only is used to explain technical scheme of the present invention, but not to its restriction; Although the present invention has been carried out detailed explanation with reference to preferred embodiment; The those of ordinary skill in affiliated field is to be understood that; Still can specific embodiments of the invention make amendment or the part technical characterictic is equal to replacement; And not breaking away from the spirit of technical scheme of the present invention, it all should be encompassed in the middle of the technical scheme scope that the present invention asks for protection.

Claims (3)

1. any pulse conversion time-dependent current differential phae bearing calibration is characterized in that: have phase difference θ between net side and valve side both sides winding forward-order current when said converter transformer is unloaded, θ is arbitrarily angled, and said method for correcting phase comprises the steps:

Step 1: selected converter transformer side winding is with reference to winding, and the opposite side winding current is to carrying out phasing with reference to winding current;

Step 2: utilize the phase relation of converter transformer both sides three-phase current preface component, the method computer differential electric current that adopts preface component and phase component to change each other.

2. any pulse conversion time-dependent current differential phae according to claim 1 bearing calibration, it is characterized in that: said step 1 is:

The net side winding of selected converter transformer is with reference to winding, rotates 0 ° with reference to the current phase of winding, and valve side winding current is to aliging with reference to winding, and the anglec of rotation is θ;

Said step 2 is:

The positive sequence component I of converter transformer three-phase differential current _{D_ps}, negative sequence component I _{D_ns}Zero-sequence component I _{D_zs}For:

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_\mathrm{zs}}\\ {\stackrel{.}{I}}_{d\_\mathrm{ps}}\\ {\stackrel{.}{I}}_{d\_\mathrm{ns}}\end{array}\right]=\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{zs}\_1}\\ {\stackrel{.}{I}}_{\mathrm{ps}\_1}\\ {\stackrel{.}{I}}_{\mathrm{ns}\_1}\end{array}\right]+\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{zs}\_2}\\ e^{\mathrm{j\θ}}{\stackrel{.}{I}}_{\mathrm{ps}\_2}\\ e^{-\mathrm{j\θ}}{\stackrel{.}{I}}_{\mathrm{ns}\_2}\end{array}\right]$

In the formula, I _{Ps_1}, I _{Ns_1}, I _{Zs_1}Be respectively positive sequence, negative phase-sequence and the zero-sequence component of converter transformer current on line side instrument transformer three-phase current, I _{Ps_2}, I _{Ns_2}, I _{Zs_2}Be respectively positive sequence, negative phase-sequence and the zero-sequence component of converter transformer current on valve side instrument transformer three-phase current;

According to three-phase ABC component in the electric power system and relation positive and negative, zero-sequence component, draw the phase component of differential current from the preface component of following formula:

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_A}\\ {\stackrel{.}{I}}_{d\_B}\\ {\stackrel{.}{I}}_{d\_C}\end{array}\right]=A\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_\mathrm{zs}}\\ {\stackrel{.}{I}}_{d\_\mathrm{ps}}\\ {\stackrel{.}{I}}_{d\_\mathrm{ns}}\end{array}\right]$

In the formula, I _{D_A}, I _{D_B}, I _{D_C}Be respectively converter transformer three-phase differential current;

And use:

$A=\left[\begin{array}{ccc}1& 1& 1\\ 1& {\mathrm{\α}}^2& \mathrm{\α}\\ 1& \mathrm{\α}& {\mathrm{\α}}^2\end{array}\right]$ With

$A^{-1}=\frac{1}{3}\·\left[\begin{array}{ccc}1& 1& 1\\ 1& \mathrm{\α}& {\mathrm{\α}}^2\\ 1& {\mathrm{\α}}^2& \mathrm{\α}\end{array}\right]$

Finally obtain:

$\left[\begin{array}{c}{\stackrel{.}{I}}_{d\_A}\\ {\stackrel{.}{I}}_{d\_B}\\ {\stackrel{.}{I}}_{d\_C}\end{array}\right]=A\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{zs}\_1}\\ {\stackrel{.}{I}}_{\mathrm{ps}\_1}\\ {\stackrel{.}{I}}_{\mathrm{ns}\_1}\end{array}\right]+A\left[\begin{array}{ccc}1& 0& 0\\ 0& e^{\mathrm{j\θ}}& 0\\ 0& 0& e^{-\mathrm{j\θ}}\end{array}\right](A^{-1}\×A)\left[\begin{array}{c}{\stackrel{.}{I}}_{\mathrm{zs}\_2}\\ {\stackrel{.}{I}}_{\mathrm{ps}\_2}\\ {\stackrel{.}{I}}_{\mathrm{ns}\_2}\end{array}\right]$

$=\left[\begin{array}{c}{\stackrel{.}{I}}_{a1}\\ {\stackrel{.}{I}}_{b1}\\ {\stackrel{.}{I}}_{c1}\end{array}\right]+A\left[\begin{array}{ccc}1& 0& 0\\ 0& e^{\mathrm{j\θ}}& 0\\ 0& 0& e^{-\mathrm{j\θ}}\end{array}\right]A^{-1}\left[\begin{array}{c}{\stackrel{.}{I}}_{a2}\\ {\stackrel{.}{I}}_{b2}\\ {\stackrel{.}{I}}_{c2}\end{array}\right]$

I _A1, I _B1, I _C1, and I _A2, I _B2, I _C2Be respectively the electric current of converter transformer net side and current on valve side instrument transformer three-phase.

3. any pulse conversion time-dependent current differential phae according to claim 2 bearing calibration is characterized in that: define M (θ) as follows:

$M\left(\mathrm{\θ}\right)=A\left[\begin{array}{ccc}1& 0& 0\\ 0& e^{\mathrm{j\θ}}& 0\\ 0& 0& e^{-\mathrm{j\θ}}\end{array}\right]A^{-1}$

And use:

$A=\left[\begin{array}{ccc}1& 1& 1\\ 1& {\mathrm{\α}}^2& \mathrm{\α}\\ 1& \mathrm{\α}& {\mathrm{\α}}^2\end{array}\right]$ With

$A^{-1}=\frac{1}{3}\·\left[\begin{array}{ccc}1& 1& 1\\ 1& \mathrm{\α}& {\mathrm{\α}}^2\\ 1& {\mathrm{\α}}^2& \mathrm{\α}\end{array}\right],$

Finally obtain:

M (0 °) is a unit matrix, so converter transformer three-phase differential current can be write as:

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