CN103163373B - Be applicable to the computing method of the harmonic pollution responsibility of power quality data Interchange Format - Google Patents

Abstract

The invention discloses a kind of computing method being applicable to the harmonic pollution responsibility of power quality data Interchange Format of technical field of electric power.Its technical scheme is, according to the nominal voltage of electrical network and the three-phase shortcircuit capacity of points of common connection, computing system harmonic impedance, on this basis, calculate the harmonic voltage effective value amplitude paid close attention to harmonic source and points of common connection bus is contributed, then the points of common connection place background harmonic voltage effective value amplitude that all the other harmonic sources are contributed at bus place except paying close attention to harmonic source is solved, and the included angle cosine calculated further between bus harmonic voltage effective value and the harmonic voltage effective value paying close attention to harmonic source contribution, finally can calculate the harmonic pollution responsibility paid close attention to harmonic source and produce at bus place.The invention has the beneficial effects as follows, the daily monitoring of harmonic source harmonic pollution responsibility can be realized on the basis of existing electric energy quality monitoring system, this to solving harmonic pollution problems further, to improve Power quality management level significant.

Description

Be applicable to the computing method of the harmonic pollution responsibility of power quality data Interchange Format

Technical field

The invention belongs to harmonic pollution responsibility computing method design field, particularly relate to a kind of computing method being applicable to the harmonic pollution responsibility of power quality data Interchange Format.

Background technology

Pollute for Harmonious Waves in Power Systems, China electric power law regulation: " who pollutes, and who administers ", but electric system at present lacks quantitative divisions of responsibility can to various harmonic pollution source, the unclear present situation of responsibility brings difficulty to harmonic wave control.Harmonic voltage responsibility weighs the common counter of harmonic pollution responsibility, and the method calculated about harmonic pollution responsibility both at home and abroad mainly can be divided into two classes: based on equivalent electrical circuit abbreviation method with based on data analysing method.Equivalent electrical circuit abbreviation method establishes quantitative harmonic pollution responsibility and points of common connection place harmonic voltage and electric current and the relation between grid side and user side reference impedance.The method needs to measure the harmonic voltage at points of common connection place and electric current and utilizes rational method to extract harmonic component, when grid side or user side parameter change, need adjust reference impedance, therefore be not convenient for practical application.Be different from equivalent electrical circuit abbreviation method, data analysing method avoids the foundation of equivalent model, and when grid side or user side parameter change, the method is also effective.Data analysing method mainly contains: neural net method, the method utilizing data variance characteristic, linear regression method and improvement thereof.These class methods utilize points of common connection place harmonic voltage and current value to calculate harmonic impedance, and and then calculate harmonic pollution responsibility.But, no matter be equivalent electrical circuit abbreviation method or data analysing method, be all complete on the basis of voltage and current instantaneous value, mainly provide the present situation of the statistical values such as effective value not to be inconsistent with the daily monitoring system of the current quality of power supply.Consider that the daily electric energy quality monitoring data of electrical network are often expressed as the quality of power supply and exchange the actual conditions of data layout, be necessary to design the harmonic pollution responsibility computing method that the quality of power supply exchanges points of common connection place under data layout.

Summary of the invention

For the deficiency calculating harmonic pollution responsibility based on electric current and voltage instantaneous value mentioned in above-mentioned background technology, the present invention proposes a kind of computing method being applicable to the harmonic pollution responsibility of power quality data Interchange Format.

Be applicable to computing method for the harmonic pollution responsibility of power quality data Interchange Format, it is characterized in that, specifically comprise the following steps:

Step 1: according to the nominal voltage of electrical network and the three-phase shortcircuit capacity of points of common connection, computing system harmonic impedance;

Step 2: the access points of common connection place that the system harmonic impedance obtained according to step 1 and power quality data Interchange Format provide pays close attention to the harmonic current effective value amplitude of harmonic source, calculates the harmonic voltage effective value amplitude paid close attention to harmonic source and contribute points of common connection bus;

Step 3: the harmonic voltage effective value amplitude of the points of common connection place bus that the harmonic voltage effective value amplitude of the concern harmonic source contribution obtained according to step 2 and power quality data Interchange Format provide, calculates the points of common connection place background harmonic voltage effective value amplitude that all the other harmonic sources are contributed at bus place except paying close attention to harmonic source;

Step 4: the harmonic voltage effective value amplitude of the points of common connection place bus that the background harmonic voltage effective value amplitude obtained according to step 3 and power quality data Interchange Format provide, calculates the included angle cosine between bus harmonic voltage effective value and the harmonic voltage effective value paying close attention to harmonic source contribution;

Step 5: the harmonic voltage effective value amplitude of the included angle cosine that the harmonic voltage effective value amplitude of the concern harmonic source contribution obtained according to step 2 and step 4 obtain and points of common connection place bus, calculates the harmonic pollution responsibility paying close attention to harmonic source.

In step 1, the formula of computing system harmonic impedance is:

$Z_{\mathrm{hX}}=\frac{{\mathrm{hU}}_N^2}{S_k}$

Wherein, Z _hXit is the equivalent system h subharmonic impedance of the system of bus X place except user D and other user; U _nrepresent the nominal voltage of electrical network, unit: kilovolt; S _kfor the three-phase shortcircuit capacity of points of common connection, unit, megavolt-ampere; H represents overtone order.

In step 2, paying close attention to the computing formula of harmonic source to the harmonic voltage effective value amplitude that points of common connection bus is contributed is:

U _hX,D=|Z _hX|I _hD

Wherein, U _{hX, D}pay close attention to the h subharmonic voltage effective value amplitude that harmonic source D contributes points of common connection bus X; | Z _h|| represent Z _hXamplitude; I _hDfor the h subharmonic current effective value amplitude of the access points of common connection place concern harmonic source D that power quality data Interchange Format provides.

In step 3, the computing formula of points of common connection place background harmonic voltage effective value amplitude that all the other harmonic sources are contributed at bus place except paying close attention to harmonic source is:

$U_{\mathrm{hX},0}=\frac{{-K}_h{U}_{\mathrm{hX},D}+\sqrt{K_h^2{U}_{\mathrm{hX},D}^2+4\left(U_{\mathrm{hX},D}^2{U}_{\mathrm{hX},D}^2\right)}}{2}$

Wherein, U _{hX, 0}represent the points of common connection place background harmonic voltage effective value amplitude that all the other harmonic sources are contributed at bus place except paying close attention to harmonic source; U _{hX, D}pay close attention to the h subharmonic voltage effective value amplitude that harmonic source D contributes points of common connection bus X; U _hXit is the harmonic voltage effective value amplitude of the points of common connection place bus that power quality data Interchange Format provides; K _hbe experience factor, value is as shown in table 1.

Table 1 experience factor K _hvalue

In step 4, the computing formula of the included angle cosine between bus harmonic voltage effective value and the harmonic voltage effective value paying close attention to harmonic source contribution is:

$\cos \mathrm{\α}=\frac{U_{\mathrm{hX}}^2{U}_{\mathrm{hX},D}^2-U_{\mathrm{hX},0}^2}{{2U}_{\mathrm{hX}}{U}_{\mathrm{hX},D}}$

Wherein, α is the angle between bus harmonic voltage effective value and the harmonic voltage effective value paying close attention to harmonic source contribution; U _hXit is the harmonic voltage effective value amplitude of the points of common connection place bus that power quality data Interchange Format provides; U _{hX, D}pay close attention to the h subharmonic voltage effective value amplitude that harmonic source D contributes points of common connection bus X; U _{hX, 0}represent the points of common connection place background harmonic voltage effective value amplitude that all the other harmonic sources are contributed at bus place except paying close attention to harmonic source.

In step 5, the harmonic pollution responsibility computing formula paying close attention to harmonic source is:

${\mathrm{\μ}}_h=\frac{U_{\mathrm{hX},D}\cos \mathrm{\α}}{U_{\mathrm{hX}}}\×100\%$

Wherein, μ _hpay close attention to the harmonic pollution responsibility of harmonic source at points of common connection place; U _hXit is the harmonic voltage effective value amplitude of the points of common connection place bus that power quality data Interchange Format provides; U _{hX, D}pay close attention to the h subharmonic voltage effective value amplitude that harmonic source D contributes points of common connection bus X; Cos α is the included angle cosine between bus harmonic voltage effective value and the harmonic voltage effective value paying close attention to harmonic source contribution.

The invention has the beneficial effects as follows, the harmonic pollution responsibility computing method being applicable to power quality data Interchange Format can realize the daily monitoring of harmonic source harmonic pollution responsibility on the basis of existing electric energy quality monitoring system, this to solving harmonic pollution problems further, to improve Power quality management level significant.

Accompanying drawing explanation

Fig. 1 is a kind of points of common connection place electric energy quality monitoring schematic diagram being applicable to the computing method of the harmonic pollution responsibility of power quality data Interchange Format provided by the invention;

Fig. 2 is a kind of phasor relation schematic diagram being applicable to the computing method of the harmonic pollution responsibility of power quality data Interchange Format provided by the invention.

Embodiment

Below in conjunction with accompanying drawing, preferred embodiment is elaborated.It is emphasized that following explanation is only exemplary, instead of in order to limit the scope of the invention and apply.

For certain transformer station's bus, the nominal voltage of this bus is 10kV, and three-phase shortcircuit capacity is 100MVA, bus place electrical connection schematic diagram as shown in Figure 1, for 5 subharmonic, suppose that user D is the harmonic-producing load paid close attention to, calculated load D is in the harmonic pollution responsibility at bus X place.Arrange electric energy quality monitor device at monitoring point place, data layout saves as power quality data Interchange Format.Intercept bus X harmonic voltage amplitude between 0 moment in moment to 1 of evening and branch road harmonic current data as shown in table 2.With 0 time 0 point of 0 second this group data instance, calculate the harmonic pollution responsibility of this period load D at bus X place, perform following steps:

The part electric energy quality monitoring data that table 2 intercepts

Step 1: calculate the system of bus X place except user D and the equivalent system 5 subharmonic impedance of other user:

Because h=5, $U_N^2={10}^2$ , S _k=100, so $Z_{5X}=\frac{{\mathrm{hU}}_N^2}{S_k}=\frac{5\×{10}^2}{100}=5\left(\mathrm{\Ω}\right)$

Step 2: calculate the harmonic voltage effective value amplitude that harmonic-producing load D contributes bus X:

U _5X,D=|Z _5X|I _5D=5×12.3374=61.687（V）

Step 3: calculate the background harmonic voltage effective value amplitude that all the other harmonic sources are contributed at bus X place except harmonic-producing load D:

$U_{5X,0}=\frac{{-K}_h{U}_{\mathrm{hX},D}+\sqrt{K_h^2{U}_{\mathrm{hX},D}^2+4(U_{\mathrm{hX}}^2-U_{\mathrm{hX},D}^2)}}{2}$

$=\frac{{-K}_5{U}_{5X,D}+\sqrt{K_5^2{U}_{5X,D}^2+4(U_{5X}^2-U_{5X,D}^2)}}{2}$

$=\frac{-1.28\×61.687+\sqrt{1.28^2\×{61.687}^2+4({197.6744}^2-{61.687}^2)}}{2}$

$=152.4279\left(V\right)$

Step 4: calculate bus harmonic voltage effective value and pay close attention to harmonic source contribution harmonic voltage effective value between included angle cosine, angle α as shown in Figure 2:

$\cos \mathrm{\α}=\frac{U_{5X}^2+U_{5X,D}^2-U_{5X,0}^2}{{2U}_{5X}{U}_{5X,D}}$

$=\frac{{197.6744}^2+{61.687}^2-{152.4279}^2}{2\×197.6744\×61.687}$

$=0.80557$

Step 5: calculate and pay close attention to the harmonic pollution responsibility of harmonic-producing load D at bus X place.

${\mathrm{\μ}}_5=\frac{U_{5X,D}\cos \mathrm{\α}}{U_{5X}}\×100\%=\frac{61.687\×0.80557}{197.6744}\×100\%=25.139\%$

Therefore, 0 time 0 point of 0 second period load D be 25.139% in the harmonic pollution responsibility at bus X place.Corresponding to the data of table 2, evening, 0 moment to 1 time period in moment internal loading D was as shown in table 3 in all result of calculations of the harmonic pollution responsibility at bus X place.

Table 3 is for the harmonic pollution responsibility result of calculation of part Monitoring Data

Can find out that result of calculation is rational from the stationarity of table 3 result of calculation, and from computation process, method is easy to apply in engineering practice.

The above; be only the present invention's preferably embodiment, but protection scope of the present invention is not limited thereto, is anyly familiar with those skilled in the art in the technical scope that the present invention discloses; the change 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 domain of claim.

Claims (4)

1. be applicable to computing method for the harmonic pollution responsibility of power quality data Interchange Format, it is characterized in that, specifically comprise the following steps:

Step 1: according to the nominal voltage of electrical network and the three-phase shortcircuit capacity of points of common connection, computing system harmonic impedance;

Step 2: the access points of common connection place that the system harmonic impedance obtained according to step 1 and power quality data Interchange Format provide pays close attention to the harmonic current effective value amplitude of harmonic source, calculates the harmonic voltage effective value amplitude paid close attention to harmonic source and contribute points of common connection bus;

Step 3: the harmonic voltage effective value amplitude of the points of common connection place bus that the harmonic voltage effective value amplitude of the concern harmonic source contribution obtained according to step 2 and power quality data Interchange Format provide, calculates the points of common connection place background harmonic voltage effective value amplitude that all the other harmonic sources are contributed at bus place except paying close attention to harmonic source.The computing formula of described points of common connection place background harmonic voltage effective value amplitude that all the other harmonic sources are contributed at bus place except paying close attention to harmonic source is:

$U_{\mathrm{hX},0}=\frac{-K_h{U}_{\mathrm{hX},D}+\sqrt{K_h^2{U}_{\mathrm{hX},D}^2+4(U_{\mathrm{hX}}^2-U_{\mathrm{hX},D}^2)}}{2}$

Wherein, U _{hX, 0}represent the points of common connection place background harmonic voltage effective value amplitude that all the other harmonic sources are contributed at bus place except paying close attention to harmonic source; U _{hX, D}pay close attention to the h subharmonic voltage effective value amplitude that harmonic source D contributes points of common connection bus X; U _hXit is the harmonic voltage effective value amplitude of the points of common connection place bus that power quality data Interchange Format provides; K _hit is experience factor;

Step 4: the harmonic voltage effective value amplitude of the points of common connection place bus that the background harmonic voltage effective value amplitude obtained according to step 3 and power quality data Interchange Format provide, calculates the included angle cosine between bus harmonic voltage effective value and the harmonic voltage effective value paying close attention to harmonic source contribution.The computing formula of the included angle cosine between described bus harmonic voltage effective value and the harmonic voltage effective value paying close attention to harmonic source contribution is:

$\cos \mathrm{\α}=\frac{U_{\mathrm{hX}}^2+U_{\mathrm{hX},D}^2-U_{\mathrm{hX},0}^2}{2U_{\mathrm{hX}}{U}_{\mathrm{hX},D}}$

Wherein, α is the angle between bus harmonic voltage effective value and the harmonic voltage effective value paying close attention to harmonic source contribution; U _hXit is the harmonic voltage effective value amplitude of the points of common connection place bus that power quality data Interchange Format provides; U _{hX, D}pay close attention to the h subharmonic voltage effective value amplitude that harmonic source D contributes points of common connection bus X; U _{hX, 0}represent the points of common connection place background harmonic voltage effective value amplitude that all the other harmonic sources are contributed at bus place except paying close attention to harmonic source;

Step 5: the harmonic voltage effective value amplitude of the included angle cosine that the harmonic voltage effective value amplitude of the concern harmonic source contribution obtained according to step 2 and step 4 obtain and points of common connection place bus, calculates the harmonic pollution responsibility paying close attention to harmonic source.

2. computing method according to claim 1, is characterized in that, the formula of described computing system harmonic impedance is:

$Z_{\mathrm{hX}}=\frac{{\mathrm{hU}}_N^2}{S_k}$

Wherein, Z _hXit is the equivalent system h subharmonic impedance of the system of bus X place except user D and other user; U _nrepresent the nominal voltage of electrical network, unit: kilovolt; S _kfor the three-phase shortcircuit capacity of points of common connection, unit: megavolt-ampere; H represents overtone order.

3. computing method according to claim 1, is characterized in that, the computing formula of described concern harmonic source to the harmonic voltage effective value amplitude that points of common connection bus is contributed is:

U _hX,D＝|Z _hX|I _hD

Wherein, | Z _hX| represent Z _hXamplitude; Z _hXit is the equivalent system h subharmonic impedance of the system of bus X place except user D and other user; I _hDfor the h subharmonic current effective value amplitude of the access points of common connection place concern harmonic source D that power quality data Interchange Format provides.

4. computing method according to claim 1, is characterized in that, the harmonic pollution responsibility computing formula of described concern harmonic source is:

${\mathrm{\μ}}_h=\frac{U_{\mathrm{hX},D}\cos \mathrm{\α}}{U_{\mathrm{hX}}}\×100\%$

Wherein, μ _hpay close attention to the harmonic pollution responsibility of harmonic source at points of common connection place.