CN104778634B - Method for acquiring random fluctuation information of tie-line power - Google Patents

Abstract

The invention discloses a method for acquiring random fluctuation information of tie-line power. The method comprises steps as follows: 1), load levels P1 and P2 of connected two-side electrical power systems are acquired, wherein the two-side electrical power systems constitute an interconnected electric power system, and a mean square error c of load deviation mean values of the interconnected electric power system is calculated according to the load levels P1 and P2 of the connected two-side electrical power systems; 2), generating capacity P1H and P2H of the connected two-side electrical power systems is acquired, then a mean square error Rho of tie-line power fluctuation of the interconnected electric power system is acquired according to the mean square error c of the load deviation mean values of the interconnected electric power system and the generating capacity P1H and P2H of the connected two-side electrical power systems, and the random fluctuation information of tie-line power is acquired according to the mean square error Rho of tie-line power fluctuation of the interconnected electric power system. By the aid of the method, the random fluctuation information of tie-line power of the interconnected electric power system can be accurately acquired.

Description

A kind of method for obtaining dominant eigenvalues random fluctuation information

Technical field

The invention belongs to field of power, is related to a kind of method for obtaining dominant eigenvalues random fluctuation information.

Background technology

For promoting new forms of energy to dissolve, reservoir integrated application plan is completed, prevent direct current locking, tackling electrical network burst accident is Target, Guo Wang northwests branch tailor《Northwest Grid control zone interconnection quantity of electricity appraisal management method (trying)》Rule It is fixed, optimize and revise Northwest Grid and save interconnection management mode between (area), dissolve transaction risk, strengthen planning management, specification electrical network Running order, it is ensured that power network safety operation.

2014, with putting into operation for blue sky treasured 750kV projects of transmitting and converting electricity, the Northwest's 750kV main grid structures were further perfect, Further strengthen with contacting for northwest major network in Shaanxi.Between province, interconnection has highly important effect for each province's operation of power networks. The random fluctuation of dominant eigenvalues is a kind of normal phenomenon, is mainly caused by the random fluctuation of both sides load, but is worked as Undulate quantity is larger may to work the mischief to system stability.Existing technology for saving between both sides power systems formed it is mutual The research of connection power system, therefore be badly in need of wanting a kind of side of the dominant eigenvalues random fluctuation information for obtaining interconnected electric power system Method.

The content of the invention

It is an object of the invention to overcome the shortcoming of above-mentioned prior art, there is provided a kind of to obtain dominant eigenvalues random wave The method of dynamic information, the method can accurately obtain the dominant eigenvalues random fluctuation information of interconnected electric power system.

For reaching above-mentioned purpose, the method for acquisition dominant eigenvalues random fluctuation information of the present invention includes following step Suddenly：

1) obtain the load level P of the both sides power system of contact₁And P₂, wherein both sides power system constitutes one mutually Connection power system, according to the load level P of the both sides power system of the contact₁And P₂Calculate interconnected electric power system load to deviate Mean square deviation c of average, wherein,

ρ₁And ρ₂The mean square deviation of the both sides power system load fluctuation respectively got in touch with；

2) obtain the generating capacity P of the both sides power system of contact_1HAnd P_2H, it is then inclined according to interconnected electric power system load From the generating capacity P of the both sides power system of mean square deviation c and contact of average_1HAnd P_2HObtain the interconnection of interconnected electric power system Mean square deviation ρ of power swing, then obtains dominant eigenvalues according to mean square deviation ρ of the interconnection tie power fluctuation of interconnected electric power system Random fluctuation information.

Step 2) in the expression formula of mean square deviation ρ of interconnection tie power fluctuation of interconnected electric power system be：

If ρ_1∏And ρ_2∏The both sides power system load fluctuation respectively got in touch with brings the mean square of interconnection tie power fluctuation amount Difference, wherein,

Wherein, k_f1、k_f2The slope of the static frequency characteristic of the both sides power system respectively got in touch with, then have interconnecting electric power The expression formula of mean square deviation ρ of the interconnection tie power fluctuation of system is：

If the Relative slope of the static frequency thermoelectricity of the both sides power system of contact is identical, then have：

IfThen have

If P_1H=P₁、P_2H=P₂, then have

The invention has the advantages that：

It is inclined that the method for obtaining dominant eigenvalues random fluctuation information of the present invention first obtains interconnected electric power system load From the mean square deviation of average, then the generating capacity P for obtaining the both sides power system of contact_1HAnd P_2H, then according to interconnected electric power system Load deviates the interconnection work(that the generating capacity of the both sides power system of the mean square deviation of average and contact obtains interconnected electric power system The mean square deviation of rate fluctuation, in practical application, the mean square deviation of the interconnection tie power fluctuation of interconnected electric power system and two side systems The static frequency characteristic of generating capacity, load level, unit and load, load deviation size under normal circumstances have relation, Therefore the information of dominant eigenvalues random fluctuation is obtained by the mean square deviation of the interconnection tie power fluctuation of interconnected electric power system.

Specific embodiment

The present invention is described in further detail with reference to embodiment：

The method for obtaining dominant eigenvalues random fluctuation information of the present invention is comprised the following steps：

1) obtain the load level P of the both sides power system of contact₁And P₂, wherein both sides power system constitutes one mutually Connection power system, according to the load level P of the both sides power system of the contact₁And P₂Calculate interconnected electric power system load to deviate Mean square deviation c of average, wherein,

ρ₁And ρ₂The mean square deviation of the both sides power system load fluctuation respectively got in touch with, the both sides power system load of contact The mean square deviation of fluctuation is described with normal distribution, if stochastic variable X₁And X₂The load fluctuation amount of A sides and B side systems is represented respectively, Then have

2) obtain the generating capacity P of the both sides power system of contact_1HAnd P_2H, it is then inclined according to interconnected electric power system load From the generating capacity P of the both sides power system of mean square deviation c and contact of average_1HAnd P_2HObtain the interconnection of interconnected electric power system Mean square deviation ρ of power swing, then obtains dominant eigenvalues according to mean square deviation ρ of the interconnection tie power fluctuation of interconnected electric power system Random fluctuation information.

The generating capacity P of the both sides power system wherein got in touch with_1HAnd P_2HCan be with just being distributed to represent very much, if random become Amount Y₁And Y₂Represent that A sides and B side system load fluctuations bring the undulate quantity of dominant eigenvalues, then have respectively

Step 2) in the expression formula of mean square deviation ρ of interconnection tie power fluctuation of interconnected electric power system be：

If ρ_1∏And ρ_2∏The both sides power system load fluctuation respectively got in touch with brings the mean square of interconnection tie power fluctuation amount Difference, wherein,

Wherein, k_f1、k_f2The slope of the static frequency characteristic of the both sides power system respectively got in touch with, then have interconnecting electric power The expression formula of mean square deviation ρ of the interconnection tie power fluctuation of system is：

If the Relative slope of the static frequency thermoelectricity of the both sides power system of contact is identical, i.e.,

Then have：

IfThen have

If P_1H=P₁、P_2H=P₂, then have

Embodiment one

Shown in, the year two thousand twenty Xinjiang and northwest major network load level in 2010 in 2015 and generating capacity statistical table 1.

Table 1

The mean square deviation of interconnection tie power fluctuation is represented with symbol ρ, symbol M is used_95% M_99%Represent that 95% and 99% puts respectively Dominant eigenvalues maximum fluctuation amount under letter level.According to formula, Xinjiang-Northwest Grid under different c value conditions is calculated Dominant eigenvalues random wave momentum, as shown in table 2.

Table 2

Analysis understands：

1) c values may be considered the inherent attribute of system, reflect the relation between load deviation and load level.Together Under the load level of sample, load deviation is bigger, then c values are bigger, and the mean square deviation of the interconnection tie power fluctuation amount for obtaining is also bigger. Give the interval of c values in table, using when c values can be modified according to practical situation.

2), when c values are identical, the load level of the mean square deviation of interconnection tie power fluctuation amount and two side systems, generating are held Amount, the active power static frequency characteristic of system (including unit and load) have relation.According to approximate formula (2-29), both sides The capacity of system is bigger and capacity ratio is closer to 1, and the mean square deviation of interconnection tie power fluctuation amount is bigger.From 2010 to 2015 Year, then to the Northwest Grid of the year two thousand twenty, the mean square deviation presentation ascendant trend of interconnection tie power fluctuation amount.To the year two thousand twenty, when c takes Be worth for 1.05 when, the mean square deviation of interconnection tie power fluctuation amount reaches 182.7MW or so, the maximum fluctuation under 95% confidence level Value reaches 301.46MW, more than 300MW, it means that interconnection tie power fluctuation reaches 5% or so more than the situation of 300MW.This Shi Keneng needs to take certain measure to prevent due to the excessive harm to system stability of random power fluctuation amount.

Claims (1)

1. it is a kind of obtain dominant eigenvalues random fluctuation information method, it is characterised in that comprise the following steps：

1) obtain the load level P of the both sides power system of contact₁And P₂, wherein both sides power system constitute one interconnection electricity Force system, according to the load level P of the both sides power system of the contact₁And P₂Calculate interconnected electric power system load and deviate average Mean square deviation c, wherein,

$\frac{{\mathrm{\ρ}}_1}{\sqrt{P_1}}=\frac{{\mathrm{\ρ}}_2}{\sqrt{P_2}}=c$

ρ₁And ρ₂The mean square deviation of the both sides power system load fluctuation respectively got in touch with；

2) obtain the generating capacity P of the both sides power system of contact_1HAnd P_2H, deviate average further according to interconnected electric power system load The generating capacity P of the both sides power system of mean square deviation c and contact_1HAnd P_2HObtain the interconnection tie power fluctuation of interconnected electric power system Mean square deviation ρ, dominant eigenvalues random fluctuation is obtained according to mean square deviation ρ of the interconnection tie power fluctuation of interconnected electric power system then Information；

Step 2) in the expression formula of mean square deviation ρ of interconnection tie power fluctuation of interconnected electric power system be：

$\mathrm{\ρ}=c\sqrt{\frac{P_{1H}{P}_{2H}}{P_{1H}+P_{2H}}}$

If ρ_1ΠAnd ρ_2ΠThe both sides power system load fluctuation respectively got in touch with brings the mean square deviation of interconnection tie power fluctuation amount, its In,

${\mathrm{\ρ}}_{1\Π}=\frac{{\mathrm{\ρ}}_1{k}_{f2}}{k_{f1}+k_{f2}}$

${\mathrm{\ρ}}_{2\Π}=\frac{{\mathrm{\ρ}}_2{k}_{f1}}{k_{f1}+k_{f2}}$

Wherein, k_f1、k_f2The slope of the static frequency characteristic of the both sides power system respectively got in touch with, then have interconnected electric power system The expression formula of mean square deviation ρ of interconnection tie power fluctuation is：

${\mathrm{\ρ}}^2={\mathrm{\ρ}}_{1\Π}^2+{\mathrm{\ρ}}_{2\Π}^2=\frac{{\mathrm{\ρ}}_1^2{k}_{f2}^2+{\mathrm{\ρ}}_2^2{k}_{f1}^2}{{(k_{f1}+k_{f2})}^2}$

If the Relative slope of the static frequency thermoelectricity of the both sides power system of contact is identical, then have：

${\mathrm{\ρ}}^2=\frac{{\mathrm{\ρ}}_1^2{P}_{2H}^2+{\mathrm{\ρ}}_2^2{P}_{1H}^2}{{(P_{1H}+P_{2H})}^2}$

IfThen have

$\mathrm{\ρ}=c\sqrt{\frac{P_1+P_2{\mathrm{\β}}^2}{{(1+\mathrm{\β})}^2}}$

If P_1H=P₁、P_2H=P₂, then have

$\mathrm{\ρ}=c\sqrt{\frac{P_{1H}{P}_{2H}}{P_{1H}+P_{2H}}}.$