CN102522750A - Calculating method of user permitted harmonic current emission limits for separating background harmonic - Google Patents

Abstract

The invention discloses a calculating method of user permitted harmonic current emission limits for separating background harmonic. The method comprises the steps of firstly utilizing a harmonic separation method to calculate contributions of a use side and a system side to sub-harmonic current of a public connecting point, wherein the contributions include harmonic voltage and current produced the background harmonic at the public connecting point, harmonic voltage and current produced at the at the public connecting point by remaining load at the position of a public connecting point busbar, and harmonic voltage and current produced by load to be evaluated at the public connecting point; then calculating the user permitted harmonic current emission limits; and finally calculating an hth harmonic current allowable value of an ith user at the public connecting point. The calculating method of the user permitted harmonic current emission limits for separating the background harmonic can reasonably estimate whether user harmonic emission exceeds the standard or not and further reflect influence of harmonic severity degree to electrovalence exactly.

Description

The user of separating background harmonic wave allows harmonic current emission limit computational methods

Technical field

The invention belongs to the power transmission and distribution technical field, the user who relates in particular to a kind of separating background harmonic wave allows harmonic current emission limit computational methods.

Background technology

In recent years, some have big capacity, non-linear, impact load equipment, as: electric locomotive, arc furnace etc. is connected to the grid, and has brought serious pollution for the electrical network of " pure ", and the contradiction that power quality problems such as harmonic pollution cause also becomes increasingly conspicuous.The quality of power supply is actually the electromagnetic environment that electrical network provides with respect to power customer.The same with the natural environment resource, the electromagnetic environment resource has tangible public property and public rights and interests characteristic.It similarly is the environmental pollution in the daily life that the quality of power supply worsens, and not only influences the safety and economic operation of electrical network, and the quality of its quality directly affect user side equipment can operate as normal.The electromagnetic pollution meeting causes that other users suffer economic loss in the electrical network.

At present; Restriction and the measure that improves harmonic pollution still rest on the policy aspect, though formulated the relevant technologies measure, such as: before harmonic pollution source inserts electrical network; Its controlling device should be deferred to " Synchronization Design, synchronized construction, put into operation synchronously " principle; The principle of " who pollutes, and who administers " etc. is deferred in the improvement of the quality of power supply inferior, makes the user of generation " pollutant " when decision-making, consider the quality of power supply is worsened the influence that causes but still lack corresponding incentive mechanism.Day by day the power quality problem that worsens has had influence on a lot of users' ordinary production, and it is imperative that control is carried out in the electromagnetic pollution that practicable more drastic measure produces " pollutant sources " user.

In China, harmonic wave is a power quality problem the most outstanding at present and in the long duration from now on, and the harmonic pollution user is imposed suitable surcharge, helps the improvement of harmonic pollution, purifies electric circumstance.Aspect the research of harmonic wave electricity price, it is foundation with the harm that harmonic wave causes that the expert is arranged, and proposes the computation model that a kind of harmonic wave injects marginal electricity price, but the harmonic wave cost of considering is comprehensive not enough; The somebody proposes a kind of power factor correction incentive mechanism that is used for the harmonic wave inhibition, but this method makes the user ignore the improvement to self harmonic current emission level easily.

When whether the judges harmonic wave exceeds standard; Present foundation be quality of power supply national standard " the GB/T14549-1993. quality of power supply. the utility network harmonic wave "; Stipulated the emission limit of PCC (Point of Common Coupling, points of common connection) each harmonic electric current in this standard.But because at present the harmonic source in the electric power system is seen everywhere, make that the background harmonics problem is comparatively outstanding in the electric power system, at some PCC point even occupy bigger ratio, the existing in recent years for this reason expert that is correlated with has carried out the research work of background harmonics separation aspect.Be the harmonics level in the control electric power system, the influence of definite considered background harmonics of the emission limit of PCC each harmonic electric current after the influence of removal background harmonics, is carried out the distribution between the user with the remaining discharge index of gained then again.Equally; The influence that when also including all the other the nonlinear-load work of background harmonics and same power supply buses in the user's of actual measurement the each harmonic electric current test subscriber of institute is produced, therefore, when considering whether user's harmonic current exceeds standard; Be necessary to remove the influence of all the other loads and system side background harmonics; Obtain the actual each harmonic electric current that produces of user itself, its index with distribution is compared, the corresponding subharmonic of the judges situation that exceeds standard.

Summary of the invention

The objective of the invention is to, the user who proposes a kind of separating background harmonic wave allows harmonic current emission limit computational methods, allows the harmonic current emission limit thereby calculate the user more exactly.

For realizing above-mentioned purpose, technical scheme provided by the invention is that a kind of user of separating background harmonic wave allows harmonic current emission limit computational methods, it is characterized in that said method comprises:

Step 1: utilize the harmonic separation method to calculate user and the system side contribution amount to points of common connection each harmonic electric current, its detailed process is,

Step 11: calculate harmonic voltage and electric current that background harmonics produces at points of common connection, its computing formula is respectively ${\stackrel{\·}{U}}_{\mathrm{Sh}\_\mathrm{Pcc}}=\frac{Z_{\mathrm{Lh}\_\mathrm{Ref}}//Z_{{\mathrm{Lh}}^{\′}\_\mathrm{Ref}}}{Z_{\mathrm{Lh}\_\mathrm{Ref}}//Z_{{\mathrm{Lh}}^{\′}\_\mathrm{Ref}}+Z_{\mathrm{Sh}\_\mathrm{Ref}}}\·{\stackrel{\·}{U}}_{\mathrm{Sh}\_\mathrm{New}}$ With ${\stackrel{\·}{I}}_{\mathrm{Sh}\_\mathrm{Pcc}}=\frac{{\stackrel{\·}{U}}_{\mathrm{Sh}\_\mathrm{New}}}{Z_{\mathrm{Lh}\_\mathrm{Ref}}//Z_{\mathrm{Lh}\_\mathrm{Ref}}^{\′}+Z_{\mathrm{Sh}\_\mathrm{Ref}}};$ Wherein,

Be the harmonic voltage that background harmonics produces at points of common connection, Z _{Lh_ref}Be the h subharmonic reference impedance of load to be assessed, Z _{Lh ' _ ref}Be the h subharmonic reference impedance of all the other loads except load to be assessed, Z _{Sh_ref}Be the h subharmonic reference impedance of system,

Be the h time equivalent harmonic wave power supply of system side and load side,

Be the harmonic current that background harmonics produces at points of common connection, Z ' _{Lh_ref}H subharmonic reference impedance for all the other loads;

Step 12: calculate harmonic voltage and electric current that all the other loads of this points of common connection bus place produce at points of common connection, its computing formula is respectively ${\stackrel{\·}{U}}_{{\mathrm{Ch}}^{\′}\_\mathrm{Pcc}}=(Z_{\mathrm{Sh}\_\mathrm{Ref}}//Z_{{\mathrm{Lh}}^{\′}\_\mathrm{Ref}}//Z_{\mathrm{Lh}\_\mathrm{Ref}})\·{{\stackrel{\·}{I}}^{\′}}_{\mathrm{Ch}\_\mathrm{New}}$ With ${\stackrel{\·}{I}}_{\mathrm{Ch}\_\mathrm{Pcc}}=-\frac{Z_{\mathrm{Lh}\_\mathrm{Ref}}^{\′}//Z_{\mathrm{Lh}\_\mathrm{Ref}}}{Z_{\mathrm{Sh}\_\mathrm{Ref}}+Z_{\mathrm{Lh}\_\mathrm{Ref}}^{\′}//Z_{\mathrm{Lh}\_\mathrm{Ref}}}{\stackrel{\·}{I}}_{\mathrm{Ch}\_\mathrm{New}};$ Wherein,

Be the harmonic voltage that all the other loads of this points of common connection bus place produce at points of common connection, Z _{Sh_ref}Be the h subharmonic reference impedance of system, Z _{Lh ' _ ref}Be the h subharmonic reference impedance of all the other loads except load to be assessed, Z _{Lh_ref}Be the h subharmonic reference impedance of load to be assessed,

Be the Equivalent Harmonic current source of all the other loads at the corresponding levels, Be the harmonic current that all the other loads of this points of common connection bus place produce at points of common connection, Z ' _{Lh_ref}Be the h subharmonic reference impedance of all the other loads,

Equivalent Harmonic current source for load to be assessed;

Step 13: calculate harmonic voltage and electric current that load to be assessed produces at points of common connection, its computing formula does ${\stackrel{\·}{U}}_{\mathrm{Ch}\_\mathrm{Pcc}}=(Z_{\mathrm{Sh}\_\mathrm{Ref}}//Z_{{\mathrm{Lh}}^{\′}\_\mathrm{Ref}}//Z_{\mathrm{Lh}\_\mathrm{Ref}})\·{\stackrel{\·}{I}}_{\mathrm{Ch}\_\mathrm{New}}$ With ${\stackrel{\·}{I}}_{\mathrm{Ch}\_\mathrm{Pcc}}^{\′}=-\frac{Z_{\mathrm{Lh}\_\mathrm{Ref}}^{\′}//Z_{\mathrm{Lh}\_\mathrm{Ref}}}{Z_{\mathrm{Sh}\_\mathrm{Ref}}+Z_{\mathrm{Lh}\_\mathrm{Ref}}^{\′}//Z_{\mathrm{Lh}\_\mathrm{Ref}}}{\stackrel{\·}{I}}_{\mathrm{Ch}\_\mathrm{New}}^{\′};$ Wherein,

Be the harmonic voltage that load to be assessed produces at points of common connection, Z _{Sh_ref}Be the h subharmonic reference impedance of system, Z _{Lh ' _ ref}Be the h subharmonic reference impedance of all the other loads except load to be assessed, Z _{Lh_ref}Be the h subharmonic reference impedance of load to be assessed,

Be the Equivalent Harmonic current source of load to be assessed,

Be the harmonic current that load to be assessed produces at points of common connection, Z ' _{Lh_ref}Be the h subharmonic reference impedance of all the other loads,

Equivalent Harmonic current source for all the other loads at the corresponding levels;

Step 2: utilize formula $I_{\mathrm{<figure-callout\; id="1"\; label="Hp"\; filenames="HDA0000113815310000021.png,HDA0000113815310000023.png"\; state="\{\{state\}\}">Hp</figure-callout>}1}=\frac{-K_h\&CenterDot;I_{\mathrm{Hsystem}}+\sqrt{{(K_h\&CenterDot;I_{\mathrm{Hsystem}})}^2-4\&CenterDot;(I_{\mathrm{Hsystem}}^2-I_h^2)}}{2}$ Calculate the user and allow the harmonic current emission limit; Wherein, I _Hp1For the user allows harmonic current emission limit, I _HsystemBe the h subharmonic current that background harmonics produces at points of common connection, K _hBe the superposition coefficient when the phase angle is uncertain, I _hBe each harmonic electric current permissible value;

Step 3: utilize formula I _Hi=I _Hp1(S _i/ S _t) ^{1/ α}Calculate i user's of points of common connection h subharmonic current permissible value; Wherein, S _iBe i the user's electricity consumption protocol capacity, S _tBe the power supply unit capacity of points of common connection, α is a phase place superposition coefficient.

The user of a kind of separating background harmonic wave that the present invention proposes allows harmonic current emission limit computational methods; More reasonably whether the discharging of assesses user harmonic wave exceeds standard; And the harmonic wave Spot Price Model through considering that the harmonic wave cost combines with the harmonic current degree of exceeding standard, definitely reflect of the influence of the harmonic wave order of severity to electricity price.

Description of drawings

Fig. 1 adopts the harmonic separation method to calculate background harmonics and the actual system schematic of sending harmonic current of user;

Fig. 2 is the equivalent circuit diagram when calculating the harmonic current of background harmonics generation at the PCC place;

Fig. 3 be calculate all the other loads of this PCC bus place at PCC place the equivalent circuit diagram during the generation harmonic current;

Fig. 4 be calculate load to be assessed at PCC place the equivalent circuit diagram during the generation harmonic current;

Fig. 5 is the user that calculate to remove the background harmonics influence harmonic vector superposition figure when allowing the harmonic current emission limit;

Among the figure,

With

Be respectively the monitor value of PCC place bus phase voltage, bus phase current and load phase current to be assessed, Z _{Lh_ref}H subharmonic reference impedance for load to be assessed; Z ' _{Lh_ref}H subharmonic reference impedance for all the other loads; Z _{Sh_ref}Be the h of system subharmonic reference impedance;

The h time equivalent harmonic wave power supply for system side and load side;

Be the Equivalent Harmonic current source of all the other loads at the corresponding levels,

Be the Equivalent Harmonic current source of load to be assessed,

For the user who stipulates in the GB allows the harmonic current emission limit, Be the harmonic current of background harmonics in the generation of PCC place,

For the user who removes after background harmonics influences allows the harmonic current emission limit.

Embodiment

Below in conjunction with accompanying drawing, preferred embodiment is elaborated.Should be emphasized that following explanation only is exemplary, rather than in order to limit scope of the present invention and application thereof.

Embodiment 1

The user of separating background harmonic wave provided by the invention allows the practical implementation process of harmonic current emission limit computational methods to be:

Step 1: utilize harmonic separation method calculating user and system side contribution amount to points of common connection each harmonic electric current.

To system shown in Figure 1, the harmonic current of PCC place (points of common connection) is to be caused by whole user's actings in conjunction that system is connected with PCC.Assess the harmonic effects of a certain load, just need removal system and all the other effects of load, calculate the harmonic current that only produces in the PCC place certainly by load to be assessed to system.Not all load branch circuit all has monitoring device in the practical power systems, and therefore with points of common connection, all the other the load equivalences except that load to be assessed are a synthetic load, and are as shown in Figure 1.

The user of separating background harmonic wave allows its detailed process of harmonic current emission limit computational methods to be,

Step 11: calculate harmonic voltage and electric current that background harmonics produces at points of common connection, its computing formula is respectively

${\stackrel{\&CenterDot;}{U}}_{\mathrm{sh}\_\mathrm{pcc}}=\frac{Z_{\mathrm{lh}\_\mathrm{ref}}//Z_{{\mathrm{lh}}^{\&prime;}\_\mathrm{ref}}}{Z_{\mathrm{lh}\_\mathrm{ref}}//Z_{{\mathrm{lh}}^{\&prime;}\_\mathrm{ref}}+Z_{\mathrm{sh}\_\mathrm{ref}}}\&CenterDot;{\stackrel{\&CenterDot;}{U}}_{\mathrm{sh}\_\mathrm{new}}---\left(1\right)$

${\stackrel{\&CenterDot;}{I}}_{\mathrm{sh}\_\mathrm{pcc}}=\frac{{\stackrel{\&CenterDot;}{U}}_{\mathrm{sh}\_\mathrm{new}}}{Z_{\mathrm{lh}\_\mathrm{ref}}//Z_{\mathrm{lh}\_\mathrm{ref}}^{\&prime;}+Z_{\mathrm{sh}\_\mathrm{ref}}}---\left(2\right)$

Wherein,

is the harmonic voltage that background harmonics produces at points of common connection;

is the h time equivalent harmonic wave power supply of system side and load side, be the harmonic current that background harmonics produces at points of common connection;

Step 12: calculate harmonic voltage and electric current that all the other loads of this points of common connection bus place produce at points of common connection, its computing formula is respectively

${\stackrel{\&CenterDot;}{U}}_{{\mathrm{ch}}^{\&prime;}\_\mathrm{pcc}}=(Z_{\mathrm{sh}\_\mathrm{ref}}//Z_{{\mathrm{lh}}^{\&prime;}\_\mathrm{ref}}//Z_{\mathrm{lh}\_\mathrm{ref}})\&CenterDot;{{\stackrel{\&CenterDot;}{I}}^{\&prime;}}_{\mathrm{ch}\_\mathrm{new}}---\left(3\right)$

${\stackrel{\&CenterDot;}{I}}_{\mathrm{ch}\_\mathrm{pcc}}=-\frac{Z_{\mathrm{lh}\_\mathrm{ref}}^{\&prime;}//Z_{\mathrm{lh}\_\mathrm{ref}}}{Z_{\mathrm{sh}\_\mathrm{ref}}+Z_{\mathrm{lh}\_\mathrm{ref}}^{\&prime;}//Z_{\mathrm{lh}\_\mathrm{ref}}}{\stackrel{\&CenterDot;}{I}}_{\mathrm{ch}\_\mathrm{new}}---\left(4\right)$

Wherein, is the harmonic voltage that all the other loads of this points of common connection bus place produce at points of common connection;

is the Equivalent Harmonic current source of all the other loads at the corresponding levels;

is the harmonic current that all the other loads of this points of common connection bus place produce at points of common connection, and

is the Equivalent Harmonic current source of load to be assessed;

Step 13: calculate harmonic voltage and electric current that load to be assessed produces at points of common connection, its computing formula does

${\stackrel{\&CenterDot;}{U}}_{\mathrm{ch}\_\mathrm{pcc}}=(Z_{\mathrm{sh}\_\mathrm{ref}}//Z_{{\mathrm{lh}}^{\&prime;}\_\mathrm{ref}}//Z_{\mathrm{lh}\_\mathrm{ref}})\&CenterDot;{\stackrel{\&CenterDot;}{I}}_{\mathrm{ch}\_\mathrm{new}}---\left(5\right)$

${\stackrel{\&CenterDot;}{I}}_{\mathrm{ch}\_\mathrm{pcc}}^{\&prime;}=-\frac{Z_{\mathrm{lh}\_\mathrm{ref}}^{\&prime;}//Z_{\mathrm{lh}\_\mathrm{ref}}}{Z_{\mathrm{sh}\_\mathrm{ref}}+Z_{\mathrm{lh}\_\mathrm{ref}}^{\&prime;}//Z_{\mathrm{lh}\_\mathrm{ref}}}{\stackrel{\&CenterDot;}{I}}_{\mathrm{ch}\_\mathrm{new}}^{\&prime;}---\left(6\right)$

Wherein,

is the harmonic voltage that load to be assessed produces at points of common connection;

is the Equivalent Harmonic current source of load to be assessed;

is the harmonic current that load to be assessed produces at points of common connection,

be the Equivalent Harmonic current source of all the other loads at the corresponding levels.

In above-mentioned formula (1)-(6), Z _{Sh_ref}Be the h subharmonic reference impedance of system, Z _{Lh ' _ ref}Be the h subharmonic reference impedance of all the other loads except load to be assessed, Z _{Lh_ref}Be the h subharmonic reference impedance of load to be assessed, Z ' _{Lh_ref}H subharmonic reference impedance for all the other loads.

Utilize said method, can obtain the each harmonic electric current that system and each user produce at the PCC place respectively, its Chinese style (2) is the system side background harmonics, below will utilize its user who carries out the separating background harmonic effects to allow the calculating of harmonic current; Formula (6) is the harmonic current that load to be assessed produces in the PCC place certainly, below will utilize it to carry out the correlation computations of harmonic wave electricity price.

Step 2: calculate the user and allow the harmonic current emission limit.

2-25 total allowable harmonic current that has provided in the quality of power supply national standard " GB/T14549-93 " that the whole users in PCC place inject to this point and the distribution method between different user thereof; But do not consider the contribution amount of background harmonics to PCC place harmonic current; For strict guarantee PCC place each harmonic electric current in limit value; Be necessary background correction influence of harmonic before distributing to user's discharge index, below will in GB, provide the modification method that following user allows the harmonic current emission limit in the basis for establishing:

Required symbol is done as giving a definition:

S _kThe minimum capacity of short circuit of the three-phase of-points of common connection, unit is megavolt-ampere (MVA);

S _K2The benchmark capacity of short circuit that provides in-the GB, unit is megavolt-ampere (MVA);

I _HpH subharmonic current permissible value in the-GB, unit are ampere (A);

I _h-capacity of short circuit is S _kThe time h subharmonic current permissible value.

When the minimum capacity of short circuit at public tie point place was different from the benchmark capacity of short circuit, the each harmonic electric current permissible value of stipulating in the GB need be done following conversion:

$I_h=\frac{S_k}{S_{k2}}{I}_{\mathrm{hp}}---\left(7\right)$

The h subharmonic current that the background harmonics of supposing to be calculated by formula (2) produces at the PCC place is I _Hsystem, deduction I _HsystemAfter the user to allow the harmonic current emission limit be I _Hp1, can get following formula by harmonic vector superposition figure among Fig. 5:

$I_h=\sqrt{I_{\mathrm{<figure-callout\; id="1"\; label="hp"\; filenames="HDA0000113815310000021.png,HDA0000113815310000023.png"\; state="\{\{state\}\}">hp</figure-callout>}1}^2+I_{\mathrm{hsystem}}^2+K_h\&CenterDot;I_{\mathrm{<figure-callout\; id="1"\; label="hp"\; filenames="HDA0000113815310000021.png,HDA0000113815310000023.png"\; state="\{\{state\}\}">hp</figure-callout>}1}\&CenterDot;I_{\mathrm{hsystem}}}---\left(8\right)$

Find the solution:

$I_{\mathrm{<figure-callout\; id="1"\; label="hp"\; filenames="HDA0000113815310000021.png,HDA0000113815310000023.png"\; state="\{\{state\}\}">hp</figure-callout>}1}=\frac{-K_h\&CenterDot;I_{\mathrm{hsystem}}+\sqrt{{(K_h\&CenterDot;I_{\mathrm{hsystem}})}^2-4\&CenterDot;(I_{\mathrm{hsystem}}^2-I_h^2)}}{2}---\left(9\right)$

Wherein, I _Hp1For the user allows harmonic current emission limit, K _hBe the superposition coefficient when the phase angle is uncertain, in the GB it had clearly regulation.

Just can obtain the deduction I of PCC place thus _HsystemH subharmonic current permissible value after the influence is considered the variation characteristic and the complexity of Harmonious Waves in Power Systems problem, I _HsystemShould be the mean value of system's long term monitoring statistics gained, the emission limit of user's harmonic current has stability in the GB of therefore obtaining in the long term.

Step 3: the h subharmonic current permissible value that calculates i user of points of common connection.Its computing formula is:

I _hi＝I _hp1(S _i/S _t) ^1/α (10)

Wherein, S _i-the i user's electricity consumption protocol capacity, unit are megavolt-ampere (MVA);

S _tThe power supply unit capacity of-points of common connection, unit are megavolt-ampere (MVA);

α-phase place superposition coefficient has clearly regulation to it in the GB.

In the actual production life; Use the user of the separating background harmonic wave of said method calculating to allow the harmonic current emission limit; Can be used for the harmonic wave Spot Price Model of considering that the harmonic wave cost harmonic electric current degree of exceeding standard combines; Calculate the harmonic wave electricity price of separating background harmonic effects, calculate inaccurate problem because of not considering the electricity price that the background harmonics influence causes in order to solve electricity price computational methods commonly used.

Embodiment 2

Consider the background harmonics influence, the detailed process of calculating electricity price is:

Step 21: the separating background influence of harmonic, calculate the electricity charge of harmonic wave cost electricity price harmonic electric weight.Introduce the Harmonic Interference coefficient k ₁For:

${\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="HDA0000113815310000021.png,HDA0000113815310000023.png"\; state="\{\{state\}\}">k</figure-callout>}}_1=\frac{{\&Integral;}_T\underset{h}{\mathrm{\&Sigma;}}{U}_{\mathrm{ch}\_\mathrm{pcc}}\left(t\right)\&CenterDot;I_h\left(t\right)d_t}{{\&Integral;}_T{p}_1\left(t\right)d_t}=\frac{S_h}{P}---\left(11\right)$

In the formula, S _hUnder the situation for the separating background harmonic wave, during a charging in the T, the mean value sum of user's each harmonic apparent power; U _{Ch_pcc}(t) suc as formula shown in (5), be the result of calculation based on the system monitoring instantaneous value, I _h(t) be the transient measurement value of the each harmonic electric current of load to be assessed.P is user's an average fundamental active power; p ₁(t) in the T during chargeing, the real-time measurement values of user's fundamental active power.

In order to weigh the electricity price under this Harmonic Interference level, introduce harmonic wave electricity price correction factor k _Re(k _ReValue should with k ₁Value irrelevant) and define the harmonic wave electricity price:

C _h1＝k _reC ₁ (12)

Wherein, C _H1Be the harmonic wave electricity price; C ₁Be the unit quantity of electricity electricity price.At this moment, in a metering period charging T, the harmonic wave electric weight electricity charge M that should collect to the user _H1For:

${\mathrm{<figure-callout\; id="1"\; label="M\; h"\; filenames="HDA0000113815310000021.png,HDA0000113815310000023.png"\; state="\{\{state\}\}">M</figure-callout>}}_h=k_{\mathrm{re}}{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000113815310000021.png,HDA0000113815310000023.png"\; state="\{\{state\}\}">C</figure-callout>}}_1{\&Integral;}_T\underset{n}{\mathrm{\&Sigma;}}{U}_{\mathrm{ch}\_\mathrm{pcc}}\left(t\right)\&CenterDot;I_h\left(t\right)\mathrm{dt}=k_{\mathrm{re}}{k}_1{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000113815310000021.png,HDA0000113815310000023.png"\; state="\{\{state\}\}">C</figure-callout>}}_1\mathrm{PT}---\left(13\right)$

Step 22: calculate the harmonic excess punishment electricity price and the electricity charge.

On the basis of background harmonics influence,, confirm the harmonic excess punishment electricity price and the electricity charge to the user that harmonic current exceeds standard.

In a metering period, as the CP95 value (I of the h time steady harmonic current of i user of surveying _Hcp95) greater than the revised GB limit value I shown in the formula (10) _Hi, think that then this user's i subharmonic exceeds standard, introduce single harmonic component hyperscaling k _2hi, and definition:

$k_{2\mathrm{hi}}=\frac{I_{\mathrm{hcp}95}}{I_{\mathrm{hi}}}\&times;100\%---\left(14\right)$

Under the situation of taking into account 25 subharmonic, introduce user's harmonic excess coefficient k ₂, and be defined as:

$k_2=\frac{1}{24}\&times;\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}(k_{2\mathrm{hi}}-1)+\frac{n}{24}--\left(15\right)$

In the formula, k _2hiBe the single harmonic component hyperscaling; N is total harmonic excess number of times.

When user's harmonic current does not exceed standard, k ₂=0.Definition user harmonic excess penalty coefficient k _Rs, establishing the punishment electricity price that user's harmonic current is exceeded standard is C _H2, and have

C _h2＝k _rsk ₂C ₂ (16)

C in the formula ₂Be user's basic capacity electricity price, then user's harmonic current exceeds standard and punishes that the electricity charge are:

M _h2＝C _h2S _i＝k _rsk ₂C ₂S _i (17)

In the formula, S _iBe i user's electricity consumption protocol capacity, unit is megavolt-ampere (MVA).

Step 23: the harmonic wave electric charge calculating method of confirming the separating background harmonic effects.

Based on above analysis, the demand charge of on the basis of two system electricity prices, taking into account harmonic effects is:

M＝C ₁PT+k _rek ₁C ₁PT+C ₂S _i+k _rsk ₂C ₂S _i (18)

＝(1+k _rek ₁)M ₁+(1+k _rsk ₂)M ₂

In the formula, M ₁And M ₂Be respectively the electric weight electricity charge and electrical capacity charge that the user should pay.

The method that the present invention proposes is the basis with the harmonic wave cost analysis, and itself and harmonic current are exceeded standard to influence to combine, and through collecting the harmonic wave electricity charge, the economic loss that causes in order to compensation harmonic on the one hand is presented as harmonic wave cost electricity price; Thereby the punishment of carrying out different dynamics in order to whether user's harmonic wave is exceeded standard on the other hand supervises the user to improve the harmonic current emission level of self, is embodied in the punishment electricity price part that harmonic current exceeds standard.

The above; Be merely the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, any technical staff who is familiar with the present technique field is in the technical scope that the present invention discloses; The variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.

Claims (1)

1. the user of a separating background harmonic wave allows harmonic current emission limit computational methods, it is characterized in that said method comprises:

Step 1: utilize the harmonic separation method to calculate user and the system side contribution amount to points of common connection each harmonic electric current, its detailed process is,

Step 11: calculate harmonic voltage and electric current that background harmonics produces at points of common connection, its computing formula is respectively ${\stackrel{\&CenterDot;}{U}}_{\mathrm{Sh}\_\mathrm{Pcc}}=\frac{Z_{\mathrm{Lh}\_\mathrm{Ref}}//Z_{{\mathrm{Lh}}^{\&prime;}\_\mathrm{Ref}}}{Z_{\mathrm{Lh}\_\mathrm{Ref}}//Z_{{\mathrm{Lh}}^{\&prime;}\_\mathrm{Ref}}+Z_{\mathrm{Sh}\_\mathrm{Ref}}}\&CenterDot;{\stackrel{\&CenterDot;}{U}}_{\mathrm{Sh}\_\mathrm{New}}$ With ${\stackrel{\&CenterDot;}{I}}_{\mathrm{Sh}\_\mathrm{Pcc}}=\frac{{\stackrel{\&CenterDot;}{U}}_{\mathrm{Sh}\_\mathrm{New}}}{Z_{\mathrm{Lh}\_\mathrm{Ref}}//Z_{\mathrm{Lh}\_\mathrm{Ref}}^{\&prime;}+Z_{\mathrm{Sh}\_\mathrm{Ref}}};$ Wherein,

Be the harmonic voltage that background harmonics produces at points of common connection, Z _{Lh_ref}Be the h subharmonic reference impedance of load to be assessed, Z _{Lh ' _ ref}Be the h subharmonic reference impedance of all the other loads except load to be assessed, Z _{Sh_ref}Be the h subharmonic reference impedance of system,

Be the h time equivalent harmonic wave power supply of system side and load side,

Be the harmonic current that background harmonics produces at points of common connection, Z ' _{Lh_ref}H subharmonic reference impedance for all the other loads;

Step 12: calculate harmonic voltage and electric current that all the other loads of this points of common connection bus place produce at points of common connection, its computing formula is respectively ${\stackrel{\&CenterDot;}{U}}_{{\mathrm{Ch}}^{\&prime;}\_\mathrm{Pcc}}=(Z_{\mathrm{Sh}\_\mathrm{Ref}}//Z_{{\mathrm{Lh}}^{\&prime;}\_\mathrm{Ref}}//Z_{\mathrm{Lh}\_\mathrm{Ref}})\&CenterDot;{{\stackrel{\&CenterDot;}{I}}^{\&prime;}}_{\mathrm{Ch}\_\mathrm{New}}$ With ${\stackrel{\&CenterDot;}{I}}_{\mathrm{Ch}\_\mathrm{Pcc}}=-\frac{Z_{\mathrm{Lh}\_\mathrm{Ref}}^{\&prime;}//Z_{\mathrm{Lh}\_\mathrm{Ref}}}{Z_{\mathrm{Sh}\_\mathrm{Ref}}+Z_{\mathrm{Lh}\_\mathrm{Ref}}^{\&prime;}//Z_{\mathrm{Lh}\_\mathrm{Ref}}}{\stackrel{\&CenterDot;}{I}}_{\mathrm{Ch}\_\mathrm{New}};$ Wherein,

Be the harmonic voltage that all the other loads of this points of common connection bus place produce at points of common connection, Z _{Sh_ref}Be the h subharmonic reference impedance of system, Z _{Lh ' _ ref}Be the h subharmonic reference impedance of all the other loads except load to be assessed, Z _{Lh_ref}Be the h subharmonic reference impedance of load to be assessed,

Be the Equivalent Harmonic current source of all the other loads at the corresponding levels,

Be the harmonic current that all the other loads of this points of common connection bus place produce at points of common connection, Z ' _{Lh_ref}Be the h subharmonic reference impedance of all the other loads,

Equivalent Harmonic current source for load to be assessed;

Step 13: calculate harmonic voltage and electric current that load to be assessed produces at points of common connection, its computing formula does ${\stackrel{\&CenterDot;}{U}}_{\mathrm{Ch}\_\mathrm{Pcc}}=(Z_{\mathrm{Sh}\_\mathrm{Ref}}//Z_{{\mathrm{Lh}}^{\&prime;}\_\mathrm{Ref}}//Z_{\mathrm{Lh}\_\mathrm{Ref}})\&CenterDot;{\stackrel{\&CenterDot;}{I}}_{\mathrm{Ch}\_\mathrm{New}}$ With ${\stackrel{\&CenterDot;}{I}}_{\mathrm{Ch}\_\mathrm{Pcc}}^{\&prime;}=-\frac{Z_{\mathrm{Lh}\_\mathrm{Ref}}^{\&prime;}//Z_{\mathrm{Lh}\_\mathrm{Ref}}}{Z_{\mathrm{Sh}\_\mathrm{Ref}}+Z_{\mathrm{Lh}\_\mathrm{Ref}}^{\&prime;}//Z_{\mathrm{Lh}\_\mathrm{Ref}}}{\stackrel{\&CenterDot;}{I}}_{\mathrm{Ch}\_\mathrm{New}}^{\&prime;};$ Wherein,

Be the harmonic voltage that load to be assessed produces at points of common connection, Z _{Sh_ref}Be the h subharmonic reference impedance of system, Z _{Lh ' _ ref}Be the h subharmonic reference impedance of all the other loads except load to be assessed, Z _{Lh_ref}Be the h subharmonic reference impedance of load to be assessed, Be the Equivalent Harmonic current source of load to be assessed,

Be the harmonic current that load to be assessed produces at points of common connection, Z ' _{Lh_ref}Be the h subharmonic reference impedance of all the other loads,

Equivalent Harmonic current source for all the other loads at the corresponding levels;

Step 2: utilize formula $I_{\mathrm{Hp}1}=\frac{-K_h\&CenterDot;I_{\mathrm{Hsystem}}+\sqrt{{(K_h\&CenterDot;I_{\mathrm{Hsystem}})}^2-4\&CenterDot;(I_{\mathrm{Hsystem}}^2-I_h^2)}}{2}$ Calculate the user and allow the harmonic current emission limit; Wherein, I _Hp1For the user allows harmonic current emission limit, I _HsystemBe the h subharmonic current that background harmonics produces at points of common connection, K _hBe the superposition coefficient when the phase angle is uncertain, I _hBe each harmonic electric current permissible value;

Step 3: utilize formula I _Hi=I _Hp1(S _i/ S _t) ^{1/ α}Calculate i user's of points of common connection h subharmonic current permissible value; Wherein, S _iBe i the user's electricity consumption protocol capacity, S _tBe the power supply unit capacity of points of common connection, α is a phase place superposition coefficient.

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