CN104009493B - A kind of photovoltaic generation unit group equivalent modeling method of feature based distance - Google Patents

Abstract

The invention belongs to technical field of photovoltaic power generation, be specifically related to a kind of photovoltaic generation unit group equivalent modeling method of feature based distance.Steps of the method are: one, generator unit each in photovoltaic plant is numbered, reads the parameter of inverter in each generator unit; Two, calculate the trace sensitivity of inverter parameters in a generator unit and form a column vector; Three, the characteristic distance between all generator units is calculated; Four, using each generator unit successively as master unit, calculate the characteristic distance sum between each master unit and all the other all generator units respectively; Five, the master unit selecting characteristic distance sum minimum is as leading generator unit; Six, using the parameter of the parameter of inverter in leading generator unit as the equivalent machine of photovoltaic generation unit group, and the rated capacity of this equivalent machine is revised as the rated capacity sum of each generator unit in group.Equivalent modeling method clear physics conception of the present invention, improves the precision of equivalent modeling.

Description

A kind of photovoltaic generation unit group equivalent modeling method of feature based distance

Technical field

The invention belongs to technical field of photovoltaic power generation, be specifically related to a kind of photovoltaic generation unit group equivalent modeling method of feature based distance.

Background technology

In recent years, the grid-connected solar power generation of China presents great-leap-forward development.According to national new forms of energy development plan, by 2015, China's grid-connected photovoltaic power generation installed capacity will reach 3,500 ten thousand kilowatts.In west area, the hours of daylight is long and dry short of rain, and solar energy resources is very abundant, and oneself has built many large-scale photovoltaic power stations.After large-scale photovoltaic plant access electrical network, the fluctuation of photovoltaic generation power output will have an impact to power network safety operation.In order to analyze the impact of grid-connected photovoltaic power station on electrical network, in the urgent need to setting up suitable photovoltaic plant model.

Large-sized photovoltaic power station floor space is large, and be usually formed in parallel to hundreds of photovoltaic generation units by tens of, the installed capacity in power station can reach hundreds of megawatt.When setting up photovoltaic plant model, a kind of method is to the modeling respectively of each photovoltaic generation unit, then forms complete power station detailed model according to electric connecting relation.This modeling method and actual power unit one_to_one corresponding, model One's name is legion, power station model will become very complicated.When carrying out large-scale power system analytical calculation, if adopt detailed model computational efficiency very low, emulating length consuming time, and the accuracy of computational convergence variation influence result of calculation may be caused.

Another kind method is the thinking adopting equivalent modeling, first hives off to photovoltaic plant, generator unit close for several dynamic response characteristics is formed a photovoltaic generation unit group.For photovoltaic generation unit group, the electrical structure of each generator unit is similar, is made up of photovoltaic arrays, inverter and unit step-up transformer.If the response characteristic of all generator units in group can be simulated by an Equivalent Model, equivalent generator unit model so just can be utilized to carry out alternative detailed model, equivalent depression of order is carried out to photovoltaic generation unit group model, improve simulation efficiency.The key of modeling is just to carry out modeling accurately to photovoltaic generation unit group.

Summary of the invention

In order to overcome the defect of prior art, the object of the invention is to the photovoltaic generation unit group equivalent modeling method proposing a kind of feature based distance for simplifying photovoltaic generation unit group model.

Equivalent modeling method of the present invention is achieved by the following technical solution:

A photovoltaic generation unit equivalent modeling method for feature based distance, the method comprises the steps:

Step one, generator unit each in photovoltaic plant to be numbered, to read the parameter of inverter in each generator unit;

Step 2, calculate inverter parameters in a generator unit trace sensitivity and form a column vector;

Step 3, calculate characteristic distance between all generator units;

Step 4, using each generator unit successively as master unit, calculate the characteristic distance sum between each master unit and all the other all generator units respectively;

Step 5, select characteristic distance sum minimum master unit as leading generator unit;

Step 6, using the parameter of the parameter of inverter in leading generator unit as the equivalent machine of photovoltaic generation unit group, and the rated capacity of this equivalent machine is revised as the rated capacity sum of each generator unit in group, namely complete the foundation of photovoltaic generation unit group Equivalent Model.

In described step one, in each generator unit, the parameter of inverter includes the direct voltage PI controller parameter K of inverter _pv, K _ivwith reactive power PI controller parameter K _pq, K _iq.

In described step 2, by the column vector described in the trace sensitivity formula composed as follows of inverter parameters in a generator unit

$\stackrel{\text{\→}}{S}=\left[\begin{array}{c}{S}_1\\ S_2\\ S_3\\ S_4\end{array}\right]$

In formula, s ₁-s ₄the trace sensitivity of inverter parameters in a generator unit respectively.

In described step 3, the step calculating characteristic distance between all generator units comprises:

Step 31, the parameter of inverter in each generator unit is formed a row vector;

Step 32, according to a column vector and each row vector, calculate the characteristic distance between every two generator units.

In described step 31, formed as shown in the formula described row vector by the parameter of inverter in each generator unit

$\stackrel{\→}{V}=[K_{\mathrm{pv}},K_{\mathrm{iv}},K_{\mathrm{pq}},K_{\mathrm{iq}}]$

In formula, K _pv, K _iv, K _pq, K _iqfor the parameter of inverter.

In described step 32, calculate the characteristic distance between every two generator units by following formula:

$\begin{array}{c}{L}_{V_1-V_2}=|{({\stackrel{\→}{V}}_1-{\stackrel{\→}{V}}_2)}^T\×\stackrel{\→}{s}|\\ =|{[\left[\begin{array}{c}{K}_{\mathrm{pv}1}\\ K_{\mathrm{iv}1}\\ K_{\mathrm{pq}1}\\ K_{\mathrm{iq}1}\end{array}\right]-\left[\begin{array}{c}{K}_{\mathrm{pv}2}\\ K_{\mathrm{iv}2}\\ K_{\mathrm{pq}2}\\ K_{\mathrm{iq}2}\end{array}\right]]}^T\×\left[\begin{array}{c}{s}_1\\ s_2\\ s_3\\ s_4\end{array}\right]|\end{array}$

In formula, be the row vector of inverter parameters composition in first generator unit, K _pv1, K _iv1, K _pq1, K _iq1it is the parameter of inverter in first generator unit; be the row vector of inverter parameters composition in second generator unit, K _pv2, K _iv2, K _pq2, K _iq2it is the parameter of inverter in second generator unit.

In described step 4, calculate the characteristic distance sum between each master unit and all the other all generator units by following formula:

$C_i=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{L}_{i-j}$

In formula, C _ibe the characteristic distance sum between i-th master unit and all the other n-1 generator unit, L _i-jbe the characteristic distance between i-th master unit and a jth generator unit, n is the sum of generator unit in photo-voltaic power generation station.

In described step 6, by following formula, the rated capacity of this equivalent machine is revised as the rated capacity sum of each generator unit in group:

$S_{\mathrm{eql}}=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{S}_j$

In formula, S _eq1for the rated capacity of equivalent machine, S _jfor the rated capacity of generator unit j, n is the sum of generator unit in photo-voltaic power generation station.

Compared with prior art, beneficial effect of the present invention is:

Equivalent modeling method of the present invention, based on the characteristic distance between each generator unit, is selected leading generator unit, and then is built the Equivalent Model of photovoltaic generation unit group, clear physics conception, improve the precision of equivalent modeling.

Accompanying drawing explanation

Fig. 1 is the structural representation of photovoltaic plant in embodiment.

Fig. 2 is the schematic flow sheet of equivalent modeling method of the present invention.

Specific embodiment

Below in conjunction with accompanying drawing, the photovoltaic generation unit group equivalent modeling method that the present invention is based on characteristic distance is described in further detail.

Photovoltaic plant shown in Fig. 1 comprises 3 photovoltaic generation unit groups altogether, below according to the equivalent modeling method shown in Fig. 2, carries out equivalent modeling, comprise the steps: photovoltaic generation unit group 1

Step one, generator unit group 1 include 10 generator units, to each photovoltaic generation unit according to the called after generator unit 1 respectively of order from small to large, and generator unit 2, generator unit 3 ..., generator unit 10; Read the parameter of inverter in each generator unit respectively, in each generator unit, inverter parameters includes the direct voltage PI controller parameter K of inverter _pv, K _ivwith reactive power PI controller parameter K _pq, K _iq;

Select generator unit 1 in step 2, this example and calculate its inverter parameters K _pv1, K _iv1, K _pq1, K _iq1trace sensitivity, the trace sensitivity of generator unit 1 is formed a column vector

$\stackrel{\text{\→}}{S}=\left[\begin{array}{c}{S}_1\\ S_2\\ S_3\\ S_4\end{array}\right]---\left(1\right)$

In formula (1), s ₁, s ₂, s ₃, s ₄four parameter K respectively _pv1, K _iv1, K _pq1, K _iq1trace sensitivity;

Step 3, calculate characteristic distance between all generator units, detailed process is as follows:

Step 31) by generator unit 1 ... in generator unit 10, the parameter group of inverter becomes row vector namely

$\begin{array}{c}{\stackrel{\→}{V}}_1=[K_{\mathrm{pv}1},K_{\mathrm{iv}1},K_{\mathrm{pq}1},K_{\mathrm{iq}1}]\\ {\stackrel{\→}{V}}_2=[K_{\mathrm{pv}2},K_{\mathrm{iv}2},K_{\mathrm{pq}2},K_{\mathrm{iq}2}]\\ \·\·\·\·\·\·\\ {\stackrel{\→}{V}}_{10}=[K_{\mathrm{pv}10,}{K}_{\mathrm{iv}10},K_{\mathrm{pq}10},K_{\mathrm{iq}10}]\end{array}---\left(2\right)$

Step 32) calculate characteristic distance between generator unit 1 and generator unit 2 parameter vector, namely

$\begin{array}{c}{L}_{V_1-V_2}=|{({\stackrel{\→}{V}}_1-{\stackrel{\→}{V}}_2)}^T\×\stackrel{\→}{s}|\\ =|{[\left[\begin{array}{c}{K}_{\mathrm{pv}1}\\ K_{\mathrm{iv}1}\\ K_{\mathrm{pq}1}\\ K_{\mathrm{iq}1}\end{array}\right]-\left[\begin{array}{c}{K}_{\mathrm{pv}2}\\ K_{\mathrm{iv}2}\\ K_{\mathrm{pq}2}\\ K_{\mathrm{iq}2}\end{array}\right]]}^T\×\left[\begin{array}{c}{s}_1\\ s_2\\ s_3\\ s_4\end{array}\right]|=|\underset{i=1}{\overset{4}{\mathrm{\Σ}}}(V_{1i}-V_{2i})\×s_i|\end{array}---\left(3\right)$

In formula (3), i=1,2,3,4, V _1ii-th parameter in generator unit 1 row vector, V _2ii-th parameter in generator unit 2 row vector, s _iit is the trace sensitivity of i-th parameter;

Step 33) repeat step 32, the characteristic distance between all generator units is calculated by formula (3), namely the distance between generator unit 1 and generator unit 2,3,4,5,6,7,8,9,10 is calculated respectively, calculate the distance between generator unit 2 and generator unit 1,3,4,5,6,7,8,9,10, the like, and supplement following table 1.

Table 1 characteristic distance

Step 4, using each generator unit successively as master unit, calculate the characteristic distance sum between each master unit and all the other all generator units respectively, detailed process is:

Step 41) first using generator unit 1 as master unit, calculate generator unit 1 and all the other generator units 2,3 by following formula ..., the characteristic distance sum C between 10 ₁:

$C_1=\underset{j=2}{\overset{10}{\mathrm{\Σ}}}{L}_{1-j}---\left(4\right)$

Step 42) repeat step 41, respectively by calculate the characteristic distance sum C of all the other all generator units ₂, C ₃..., C _n, namely calculate the distance sum C between generator unit 2 and generator unit 1,3,4,5,6,7,8,9,10 respectively ₂, calculate the distance sum C of generator unit 3 and generator unit 1,2,4,5,6,7,8,9,10 ₃, the like, and supplement following table 2.

Table 2 characteristic distance sum

Step 5, be arranged in order according to the size order of characteristic distance sum, the generator unit 3 selecting characteristic distance sum minimum is as leading generator unit;

Step 6, by the direct voltage PI controller parameter K of leading generator unit _pv3, K _iv3with reactive power PI controller parameter K _pq3, K _iq3as the equivalent machine parameter of photovoltaic generation unit group 1, the rated capacity S of equivalent machine 1 simultaneously _ep1(5) are revised as each generator unit rated capacity sum in group according to the following formula:

$S_{\mathrm{eql}}=\underset{j=1}{\overset{10}{\mathrm{\Σ}}}{S}_j---\left(5\right)$

Perform above steps, the modeling of photovoltaic generation unit group 1 can be completed, for generator unit group 2 and group 3, have similar modeling method with group 1, repeat no more herein.

Finally should be noted that: above embodiment is only in order to illustrate the technical scheme of the application but not the restriction to its protection range; although with reference to above-described embodiment to present application has been detailed description; those of ordinary skill in the field are to be understood that: those skilled in the art still can carry out all changes, amendment or equivalent replacement to the embodiment of application after reading the application; these change, amendment or equivalent to replace, and it is all within it applies for the right that awaits the reply.

Claims (8)

1. a photovoltaic generation unit equivalent modeling method for feature based distance, it is characterized in that, the method comprises the steps:

Step one, generator unit each in photovoltaic plant to be numbered, to read the parameter of inverter in each generator unit;

Step 2, calculate inverter parameters in a generator unit trace sensitivity and form a column vector;

Step 3, calculate characteristic distance between all generator units;

Step 4, using each generator unit successively as master unit, calculate the characteristic distance sum between each master unit and all the other all generator units respectively;

Step 5, select characteristic distance sum minimum master unit as leading generator unit;

Step 6, using the parameter of the parameter of inverter in leading generator unit as the equivalent machine of photovoltaic generation unit group, and the rated capacity of this equivalent machine is revised as the rated capacity sum of each generator unit in group, namely complete the foundation of photovoltaic generation unit group Equivalent Model.

2. the photovoltaic generation unit equivalent modeling method of feature based distance according to claim 1, is characterized in that, in described step one, in each generator unit, the parameter of inverter includes the direct voltage PI controller parameter K of inverter _pv, K _ivwith reactive power PI controller parameter K _pq, K _iq.

3. the photovoltaic generation unit equivalent modeling method of feature based distance according to claim 1, is characterized in that, in described step 2, by the column vector described in the trace sensitivity formula composed as follows of inverter parameters in a generator unit

$\stackrel{\→}{s}=\left[\begin{array}{c}{s}_1\\ s_2\\ s_3\\ s_4\end{array}\right]$

In formula, s ₁-s ₄the trace sensitivity of inverter parameters in a generator unit respectively.

4. the photovoltaic generation unit equivalent modeling method of feature based distance according to claim 3, is characterized in that, in described step 3, the step calculating characteristic distance between all generator units comprises:

Step 31, the parameter of inverter in each generator unit is formed a row vector;

Step 32, according to a column vector and each row vector, calculate the characteristic distance between every two generator units.

5. the photovoltaic generation unit equivalent modeling method of feature based distance according to claim 4, is characterized in that, in described step 31, consists of as shown in the formula described row vector the parameter of inverter in each generator unit

$\stackrel{\→}{V}=\[K_{pv},K_{iv},K_{pq},K_{iq}\]$

In formula, K _pv, K _iv, K _pq, K _iqfor the parameter of inverter.

6. the photovoltaic generation unit equivalent modeling method of feature based distance according to claim 4, is characterized in that, in described step 32, calculates the characteristic distance between every two generator units by following formula:

$\begin{array}{c}{L}_{V_1-V_2}=|{({\stackrel{\→}{V}}_1-{\stackrel{\→}{V}}_2)}^T\×\stackrel{\→}{s}\\ =|{\[\left[\begin{array}{c}{K}_{pv1}\\ K_{iv1}\\ K_{pq1}\\ K_{iq1}\end{array}\right]-\left[\begin{array}{c}{K}_{pv2}\\ K_{iv2}\\ K_{pq2}\\ K_{iq2}\end{array}\right]\]}^T\×\left[\begin{array}{c}{s}_1\\ s_2\\ s_3\\ s_4\end{array}\right]|\end{array}$

In formula, be the row vector of inverter parameters composition in first generator unit, K _pv1, K _iv1, K _pq1, K _iq1it is the parameter of inverter in first generator unit; be the row vector of inverter parameters composition in second generator unit, K _pv2, K _iv2, K _pq2, K _iq2it is the parameter of inverter in second generator unit.

7. the photovoltaic generation unit equivalent modeling method of feature based distance according to claim 1, is characterized in that, in described step 4, calculates the characteristic distance sum between each master unit and all the other all generator units by following formula:

$C_i=\underset{j=1}{\overset{n}{\Σ}}{L}_{i-j}$

In formula, C _ibe the characteristic distance sum between i-th master unit and all the other n-1 generator unit, L _i-jbe the characteristic distance between i-th master unit and a jth generator unit, n is the sum of generator unit in photo-voltaic power generation station.

8. the photovoltaic generation unit equivalent modeling method of feature based distance according to claim 1, is characterized in that, in described step 6, by following formula, the rated capacity of this equivalent machine is revised as the rated capacity sum of each generator unit in group:

$S_{eq1}=\underset{j=1}{\overset{n}{\Σ}}{S}_j$

In formula, S _eq1for the rated capacity of equivalent machine, S _jfor the rated capacity of generator unit j, n is the sum of generator unit in photo-voltaic power generation station.