CN105069707A - Normal-distribution-statistics-based bus power balance analysis method - Google Patents

Abstract

The invention provides a normal-distribution-statistics-based bus power balance analysis method. The method comprises the following steps: obtaining real-time telemetering data and real-time remote signaling data and carrying out a topological analysis of a power grid; calculating a bus power unbalance amount under a single time section; carrying out mathematical statistics on bus power unbalance amounts under multiple time sections; and evaluating a balance of a bus power according to an estimation value of a population mean and an estimation value of population standard deviation. According to the invention, in order to overcome a defect of bus power unbalance judgment under a single time section, the unbalance amount of the bus power is used as the random variable meeting the normal population distribution, the mathematical statistics analysis is carried out on the bus power unbalance amount of the calculated bus, and the balance of the bus power is evaluated from the perspective of the population mean and the population standard deviation by using the random-variable-based mathematical statistics theory, thereby reflecting problems of data measurement and thus improving accuracy and practicability of the bus power balance examination.

Description

A kind of bus power Equilibrium Analysis Method based on normal distribution statistical

Technical field

The present invention relates to a kind of analytical approach, be specifically related to a kind of bus power Equilibrium Analysis Method based on normal distribution statistical.

Background technology

The basic data of intelligent grid scheduling controlling automated system mainly comprises the metric data gathered from SCADA, by the static data manually inputted as systems generate electricity unit, transformer and line parameter circuit value etc., and plan class data.The basic data quality of electric system affects the key factor that intelligent grid Dispatching Control System applies practical level, the calculating accuracy of its precision not only left and right Power system state estimation is the basis of total system intelligent control system advanced applied software equally.

At present, the evaluation for basic data quality is mainly carried out from metric data and state estimation result two angles.Evaluation because of state estimation result is easily subject to the impact of the factors such as model, algorithm, communication, measurement, directly can not reflect the quality of basic data.In theory, it is balance that bus flows into the power flowed out, in fact in power automatic system, performance number measures the measuring value from every bar circuit measure and control device in the transformer station of a distant place, the error in measurement of measure and control device self and the time delay of transmission network, the power of inlet highway is general impermanent with the algebraic sum of the power exporting bus is zero, the statistics of bus power balance, that evaluates as state estimation result supplements, from the angle of multibreak Down Highway power-balance distribution statistics, from the quality of the angle estimator electrical network basic data of population mean and population standard deviation, reflection data measure Problems existing.

Summary of the invention

For under discontinuity surface time single to bus power amount of unbalance pass judgment on deficiency, the invention provides a kind of bus power Equilibrium Analysis Method based on normal distribution statistical, according to the estimated value of population mean and the estimated value of population standard deviation, the balance to bus power is assessed, and improves accuracy and the practicality of the examination of bus power balance.

In order to realize foregoing invention object, the present invention takes following technical scheme:

The invention provides a kind of bus power Equilibrium Analysis Method based on normal distribution statistical, said method comprising the steps of:

Step 1: obtain real-time telemetry data and real-time remote signalling data, and carry out power network topology analysis;

Step 2: bus power amount of unbalance when calculating single under discontinuity surface;

Step 3: mathematical statistics is carried out to the bus power amount of unbalance under discontinuity surface time multiple;

Step 4: the balance assessing bus power according to the estimated value of population mean and the estimated value of population standard deviation.

Described step 1 specifically comprises the following steps:

Step 1-1: obtain the real-time telemetry data of grid equipment and real-time remote signalling data from data acquisition and supervisor control;

Step 1-2: the real-time remote signalling data according to grid equipment carries out power network topology analysis.

In described step 1-1, real-time telemetry data comprise physics busbar voltage, circuit active power, circuit reactive power, transformer active power, transformer reactive power, load active power, reactive load power, genset active power, genset reactive power, zero injection active power, zero injection reactive power and capacity reactance device reactive power;

Described real-time remote signalling data comprises the on off state of disconnecting link and the on off state of isolating switch.

In described step 1-2, according to the on off state of the on off state of disconnecting link and isolating switch respectively with the annexation of grid equipment, mark off topological electrical island, the table of comparisons forming physics bus and calculate between bus.

In described step 2, bus power amount of unbalance when calculating single under discontinuity surface, has:

$Y_j=\underset{i=1}{\overset{n}{\Σ}}{Z}_i---\left(1\right)$

Wherein, Y _jfor jth bar under discontinuity surface time single calculates the bus power amount of unbalance of bus, j=1,2 ..., m, m represent calculating bus number; Z _ifor jth bar calculates the observed reading of lower i-th grid equipment of bus, i=1,2 ..., n, n calculate the sum of the grid equipment connected under bus for jth bar;

Jth bar calculates the actual value Z of lower i-th grid equipment of bus _tirepresent, then jth bar calculates the difference X between the observed reading of lower i-th grid equipment of bus and actual value _i=Z _i-Z _ti;

Calculating the actual value algebraic sum of all grid equipments under bus according to Kirchhoff's current law (KCL) known jth bar is 0, namely so single time discontinuity surface under jth bar calculate the bus power amount of unbalance Y of bus _jcan be expressed as:

$Y_j=\underset{i=1}{\overset{n}{\Σ}}{Z}_i=\underset{i=1}{\overset{n}{\Σ}}(X_i+Z_{Ti})=\underset{i=1}{\overset{n}{\Σ}}{X}_i+\underset{i=1}{\overset{n}{\Σ}}{Z}_{Ti}=\underset{i=1}{\overset{n}{\Σ}}{X}_i---\left(2\right)$

Due to X _ifor stochastic variable, and X _iobey average μ _ibe 0, standard deviation is σ _inormal distribution, namely and according to the additive property of stochastic variable, known Y _jobey population mean μ _jbe 0, population standard deviation is σ _jnormal distribution, namely $Y_j~N({\mathrm{\μ}}_j,{\mathrm{\σ}}_j^2)~N(0,\underset{i=1}{\overset{n}{\Σ}}{\mathrm{\σ}}_i^2)~N(0,{\mathrm{\σ}}_j^2).$

In described step 3, in setting-up time, calculate the bus power amount of unbalance of bus when adding up multiple under discontinuity surface, as statistical sample, represent total sample number with K, so by calculated population average μ _jestimated value with population standard deviation σ _jestimated value complete and mathematical statistics is carried out to the bus power amount of unbalance under discontinuity surface time multiple;

Population mean μ _jestimated value be expressed as:

With represent the kth sample value that the bus power amount of unbalance of jth bar calculating bus is corresponding, k=1,2 ..., K, for jth bar calculate bus bus power amount of unbalance K sample value according to from small to large sort after sample sequence;

Population standard deviation σ _jestimated value be expressed as:

${\widehat{\mathrm{\σ}}}_j=\sqrt{\frac{1}{K-1}\underset{k=1}{\overset{K}{\Σ}}(Y_j^k-{\widehat{\mathrm{\μ}}}_j)}---\left(4\right).$

In described step 4, assess the balance of bus power according to the estimated value of population mean and the estimated value of population standard deviation from Stability and veracity two aspects, specifically have:

Accuracy is mainly reflected in with μ _jdeviation, deviation is less, shows that accuracy is better;

Stability is mainly reflected in less, show that stability is better.

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

The present invention utilizes the mathematical statistics based on stochastic variable, for under discontinuity surface time single to bus power amount of unbalance pass judgment on deficiency, propose the amount of unbalance of bus power as the stochastic variable meeting normal population distribution, Mathematical Statistics Analysis is carried out to the bus power amount of unbalance calculating bus, from the balance of the angle estimator bus power of population mean and population standard deviation, reflection data measure Problems existing, thus the accuracy improved the examination of bus power balance and practicality.

Accompanying drawing explanation

Fig. 1 is the bus power Equilibrium Analysis Method process flow diagram based on normal distribution statistical in the embodiment of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in further detail.

The invention provides a kind of bus power Equilibrium Analysis Method based on normal distribution statistical, as Fig. 1, said method comprising the steps of:

Step 1: obtain real-time telemetry data and real-time remote signalling data, and carry out power network topology analysis;

Step 2: bus power amount of unbalance when calculating single under discontinuity surface;

Step 3: mathematical statistics is carried out to the bus power amount of unbalance under discontinuity surface time multiple;

Step 4: the balance assessing bus power according to the estimated value of population mean and the estimated value of population standard deviation.

Described step 1 specifically comprises the following steps:

Step 1-1: obtain the real-time telemetry data of grid equipment and real-time remote signalling data from data acquisition and supervisor control;

Step 1-2: the real-time remote signalling data according to grid equipment carries out power network topology analysis.

In described step 1-1, real-time telemetry data comprise physics busbar voltage, circuit active power, circuit reactive power, transformer active power, transformer reactive power, load active power, reactive load power, genset active power, genset reactive power, zero injection active power, zero injection reactive power and capacity reactance device reactive power;

Described real-time remote signalling data comprises the on off state of disconnecting link and the on off state of isolating switch.

In described step 1-2, according to the on off state of the on off state of disconnecting link and isolating switch respectively with the annexation of grid equipment, mark off topological electrical island, the table of comparisons forming physics bus and calculate between bus.

In described step 2, bus power amount of unbalance when calculating single under discontinuity surface, has:

$Y_j=\underset{i=1}{\overset{n}{\Σ}}{Z}_i---\left(1\right)$

Wherein, Y _jfor jth bar under discontinuity surface time single calculates the bus power amount of unbalance of bus, j=1,2 ..., m, m represent calculating bus number; Z _ifor jth bar calculates the observed reading of lower i-th grid equipment of bus, i=1,2 ..., n, n calculate the sum of the grid equipment connected under bus for jth bar;

Jth bar calculates the actual value Z of lower i-th grid equipment of bus _tirepresent, then jth bar calculates the difference X between the observed reading of lower i-th grid equipment of bus and actual value _i=Z _i-Z _ti;

Calculating the actual value algebraic sum of all grid equipments under bus according to Kirchhoff's current law (KCL) known jth bar is 0, namely so single time discontinuity surface under jth bar calculate the bus power amount of unbalance Y of bus _jcan be expressed as:

$Y_j=\underset{i=1}{\overset{n}{\Σ}}{Z}_i=\underset{i=1}{\overset{n}{\Σ}}(X_i+Z_{Ti})=\underset{i=1}{\overset{n}{\Σ}}{X}_i+\underset{i=1}{\overset{n}{\Σ}}{Z}_{Ti}=\underset{i=1}{\overset{n}{\Σ}}{X}_i---\left(2\right)$

Due to X _ifor stochastic variable, and X _iobey average μ _ibe 0, standard deviation is σ _inormal distribution, namely and according to the additive property of stochastic variable, known Y _jobey population mean μ _jbe 0, population standard deviation is σ _jnormal distribution, namely $Y_j~N({\mathrm{\μ}}_j,{\mathrm{\σ}}_j^2)~N(0,\underset{i=1}{\overset{n}{\Σ}}{\mathrm{\σ}}_i^2)~N(0,{\mathrm{\σ}}_j^2).$

In described step 3, in setting-up time, calculate the bus power amount of unbalance of bus when adding up multiple under discontinuity surface, as statistical sample, represent total sample number with K, so by calculated population average μ _jestimated value with population standard deviation σ _jestimated value complete and mathematical statistics is carried out to the bus power amount of unbalance under discontinuity surface time multiple;

Population mean μ _jestimated value be expressed as:

With represent the kth sample value that the bus power amount of unbalance of jth bar calculating bus is corresponding, k=1,2 ..., K, for jth bar calculate bus bus power amount of unbalance K sample value according to from small to large sort after sample sequence;

Population standard deviation σ _jestimated value be expressed as:

${\widehat{\mathrm{\σ}}}_j=\sqrt{\frac{1}{K-1}\underset{k=1}{\overset{K}{\Σ}}(Y_j^k-{\widehat{\mathrm{\μ}}}_j)}---\left(4\right).$

In described step 4, assess the balance of bus power according to the estimated value of population mean and the estimated value of population standard deviation from Stability and veracity two aspects, specifically have:

Accuracy is mainly reflected in with μ _jdeviation, deviation is less, shows that accuracy is better;

Stability is mainly reflected in less, show that stability is better.

Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit; those of ordinary skill in the field still can modify to the specific embodiment of the present invention with reference to above-described embodiment or equivalent replacement; these do not depart from any amendment of spirit and scope of the invention or equivalent replacement, are all applying within the claims of the present invention awaited the reply.

Claims (7)

1., based on a bus power Equilibrium Analysis Method for normal distribution statistical, it is characterized in that: said method comprising the steps of:

Step 1: obtain real-time telemetry data and real-time remote signalling data, and carry out power network topology analysis;

Step 2: bus power amount of unbalance when calculating single under discontinuity surface;

Step 3: mathematical statistics is carried out to the bus power amount of unbalance under discontinuity surface time multiple;

Step 4: the balance assessing bus power according to the estimated value of population mean and the estimated value of population standard deviation.

2. the bus power Equilibrium Analysis Method based on normal distribution statistical according to claim 1, is characterized in that: described step 1 specifically comprises the following steps:

Step 1-1: obtain the real-time telemetry data of grid equipment and real-time remote signalling data from data acquisition and supervisor control;

Step 1-2: the real-time remote signalling data according to grid equipment carries out power network topology analysis.

3. according to the bus power Equilibrium Analysis Method based on normal distribution statistical that claim 2 is stated, it is characterized in that: in described step 1-1, real-time telemetry data comprise physics busbar voltage, circuit active power, circuit reactive power, transformer active power, transformer reactive power, load active power, reactive load power, genset active power, genset reactive power, zero injection active power, zero injection reactive power and capacity reactance device reactive power;

Described real-time remote signalling data comprises the on off state of disconnecting link and the on off state of isolating switch.

4. the bus power Equilibrium Analysis Method based on normal distribution statistical according to claim 3, it is characterized in that: in described step 1-2, according to the on off state of the on off state of disconnecting link and isolating switch respectively with the annexation of grid equipment, mark off topological electrical island, the table of comparisons forming physics bus and calculate between bus.

5. the bus power Equilibrium Analysis Method based on normal distribution statistical according to claim 1, is characterized in that: in described step 2, and bus power amount of unbalance when calculating single under discontinuity surface, has:

$Y_j=\underset{i=1}{\overset{n}{\Σ}}{Z}_i---\left(1\right)$

Wherein, Y _jfor jth bar under discontinuity surface time single calculates the bus power amount of unbalance of bus, j=1,2 ..., m, m represent calculating bus number; Z _ifor jth bar calculates the observed reading of lower i-th grid equipment of bus, i=1,2 ..., n, n calculate the sum of the grid equipment connected under bus for jth bar;

Jth bar calculates the actual value Z of lower i-th grid equipment of bus _tirepresent, then jth bar calculates the difference X between the observed reading of lower i-th grid equipment of bus and actual value _i=Z _i-Z _ti;

Calculating the actual value algebraic sum of all grid equipments under bus according to Kirchhoff's current law (KCL) known jth bar is 0, namely so single time discontinuity surface under jth bar calculate the bus power amount of unbalance Y of bus _jcan be expressed as:

$Y_j=\underset{i=1}{\overset{n}{\Σ}}{Z}_i=\underset{i=1}{\overset{n}{\Σ}}(X_i+Z_{Ti})=\underset{i=1}{\overset{n}{\Σ}}{X}_i+\underset{i=1}{\overset{n}{\Σ}}{Z}_{Ti}=\underset{i=1}{\overset{n}{\Σ}}{X}_i---\left(2\right)$

Due to X _ifor stochastic variable, and X _iobey average μ _ibe 0, standard deviation is σ _inormal distribution, namely and according to the additive property of stochastic variable, known Y _jobey population mean μ _jbe 0, population standard deviation is σ _jnormal distribution, namely $Y_j~N({\mathrm{\μ}}_j,{\mathrm{\σ}}_j^2)~N(0,\underset{i=1}{\overset{n}{\Σ}}{\mathrm{\σ}}_i^2)~N(0,{\mathrm{\σ}}_j^2).$

6. the bus power Equilibrium Analysis Method based on normal distribution statistical according to claim 5, it is characterized in that: in described step 3, in setting-up time, the bus power amount of unbalance of bus is calculated under discontinuity surface when adding up multiple, as statistical sample, total sample number is represented, so by calculated population average μ with K _jestimated value with population standard deviation σ _jestimated value complete and mathematical statistics is carried out to the bus power amount of unbalance under discontinuity surface time multiple;

Population mean μ _jestimated value be expressed as:

With represent the kth sample value that the bus power amount of unbalance of jth bar calculating bus is corresponding, k=1,2 ..., K, for jth bar calculate bus bus power amount of unbalance K sample value according to from small to large sort after sample sequence;

Population standard deviation σ _jestimated value be expressed as:

${\widehat{\mathrm{\σ}}}_j=\sqrt{\frac{1}{K-1}\underset{k=1}{\overset{K}{\Σ}}(Y_j^k-{\widehat{\mathrm{\μ}}}_j)}---\left(4\right).$

7. the bus power Equilibrium Analysis Method based on normal distribution statistical according to claim 6, it is characterized in that: in described step 4, assess the balance of bus power according to the estimated value of population mean and the estimated value of population standard deviation from Stability and veracity two aspects, specifically have:

Accuracy is mainly reflected in with μ _jdeviation, deviation is less, shows that accuracy is better;

Stability is mainly reflected in less, show that stability is better.