CN105548750A - Substation current secondary loop state evaluation method based on multi-data processing - Google Patents

Abstract

The invention relates to a substation current secondary loop state evaluation method based on multi-data processing, comprising the following steps: acquiring the substation current secondary loop heating correction coefficient under different environment temperatures; detecting the substation current secondary loop temperature and the installation environment temperature, and constructing a substation current secondary loop heating value correction function; constructing a heating calculation model of the current secondary loop in a good state; determining the difference, increase ratio coefficient and evaluation coefficient of the detected heating value of the secondary loop and the assumed heating value of the secondary loop in a good state in unit time; and determining the state of the substation current secondary loop according to an evaluation grade creditability function. The method of the invention effectively makes up the defects of simple temperature detection methods, improves the accuracy of substation current secondary loop state evaluation, and has an extensive application prospect in the smart grid.

Description

Based on transformer station's electric current secondary loop state evaluating method of many data processings

Technical field

The invention belongs to power system automation technology field, be specifically related to a kind of transformer station's electric current secondary loop state evaluating method based on many data processings.

Background technology

Transformer station's electric current secondary loop state estimation can not only detect secondary current loop in the moment, Timeliness coverage fault and potential faults, so that reasonable arrangement personnel overhaul, the generation of effective less fault, has great importance to raising intelligent substation and the aspect such as the reliability of operation of power networks and the work efficiency of raising staff simultaneously.

The difficulty of current transformer station electric current secondary loop state estimation mainly contains: (1) affects the many factors of transformer station's electric current secondary loop state estimation, in these factors, the state of some and electric current secondary loop has quantitative relationship, some has qualitative relationships, has concurrently both some; (2) state estimation is subject to the restriction of multi objective, not only depends on available data analysis, will consider the impact of the factor such as historical data and installation environment simultaneously.

Existing state evaluating method is mainly divided into two classes, and a kind of is the subjective judgement of evaluator of placing one's entire reliance upon, and because the subjective judgement of evaluator affects, uncertain factor is more; Another kind relies on a certain detection data completely, ignores the importance of other useful information in operation maintenance.The assessment accuracy of this two classes appraisal procedure all has much room for improvement.

Summary of the invention

The object of the present invention is to provide a kind of transformer station's electric current secondary loop state evaluating method based on many data processings.

The technical scheme realizing the object of the invention is:

Based on transformer station's electric current secondary loop state evaluating method of many data processings, step is as follows:

Transformer station's electric current secondary loop heating correction factor at step 1, acquisition varying environment temperature;

Step 2, detection transformer station's electric current secondary loop temperature and installation environment temperature, build transformer station's electric current secondary loop thermal value correction function;

Heating computation model under step 3, structure electric current secondary loop kilter;

Step 4, determine secondary circuit in the unit interval detect thermal value under thermal value and hypothesis secondary circuit kilter difference, increase than coefficient and metewand;

Step 5, determine transformer station's electric current secondary loop state according to evaluation grade trusted function.

Compared with prior art, remarkable advantage of the present invention is:

(1) the invention provides a kind of transformer station's electric current secondary loop state evaluating method based on many data processings, Evaluation accuracy is high, and appraisal procedure is simple, has higher practical value, for the state-maintenance realizing substation equipment provides objective basis;

(2) the present invention can make up the defect of simple temperature checking method effectively, and utilize current data, environmental data and a large amount of historical data and improve the accuracy of transformer station's electric current secondary loop state estimation in conjunction with operation of power networks structure, be with a wide range of applications in intelligent grid.

Accompanying drawing explanation

Fig. 1 is the transformer station's electric current secondary loop state evaluating method process flow diagram that the present invention is based on many data processings.

Fig. 2 is evaluating system structured flowchart of the present invention.

Fig. 3 is corrected parameter lab diagram of the present invention.

Embodiment

Composition graphs 1, a kind of transformer station's electric current secondary loop state evaluating method based on many data processings of the present invention, by transformer station's electric current secondary loop and installation environment temperature detection thereof, transformer station's electric network data collects and analytical calculation, historical data base, transformer station's electric current secondary loop state estimation etc. partly form; As shown in Figure 2, appraisal procedure step is as follows for evaluating system structure:

Transformer station's electric current secondary loop heating correction factor under step 1, by experiment acquisition varying environment temperature

Because transformer station's electric current secondary loop is being to produce heat by electric current, and dispel the heat through external environment condition.Therefore, only calculating its thermal value by measuring tempeature has error, therefore needs to revise.Experiment obtains the method for correction factor as shown in Figure 3; In experiment, often kind of situation is through many experiments, deleting unrelidble data, and other data show that coefficient is repaiied in relevant heating after treatment.Heating correction factor related data b at varying environment temperature is as shown in table 1:

Table 1 generates heat correction factor related data b

Temperature (DEG C)	-30	-29	-28	-27	-26	-25	-24	-23	-22	-21
											Correction factor b	1.32	1.30	1.24	1.21	1.18	1.16	1.14	1.15	1.13	1.11
Temperature (DEG C)	-20	-19	-18	-17	-16	-15	-14	-13	-12	-11
											Correction factor b	1.08	1.06	1.05	1.03	1.01	0.99	0.97	0.96	0.94	0.92
Temperature (DEG C)	-10	-9	-8	-7	-6	-5	-4	-3	-2	-1
											Correction factor b	0.90	0.89	0.87	0.86	0.84	0.82	0.81	0.79	0.77	0.76
Temperature (DEG C)	0	1	2	3	4	5	6	7	8	9
											Correction factor b	0.74	0.72	0.71	0.69	0.68	0.66	0.65	0.64	0.63	0.62
Temperature (DEG C)	10	11	12	13	14	15	16	17	18	19

Correction factor b	0.61	0.59	0.58	0.56	0.55	0.53	0.52	0.51	0.50	0.49
											Temperature (DEG C)	20	21	22	23	24	25	26	27	28	29
Correction factor b	0.48	0.47	0.46	0.45	0.43	0.42	0.41	0.4	0.39	0.38
											Temperature (DEG C)	30	31	32	33	34	35	36	37	38	39
Correction factor b	0.37	0.36	0.35	0.35	0.34	.34	0.34	0.33	0.33	0.33

The scale-up factor CM of revised thermal value and electric current is such as formula shown in (1):

CM＝I ²R/(θ ₁-θ ₂)(1+b)(1)

In formula, I is the electric current of input, and R is the equivalent resistance of analog loopback, θ ₁, θ ₂be respectively wire and experimental situation temperature;

Step 2, detection transformer station's electric current secondary loop temperature and installation environment temperature, build transformer station's electric current secondary loop thermal value correction function;

Utilize the measurement of wireless temperature detecting device realization to each main portions temperature of transformer station's electric current secondary loop, utilize wireless environment detection device to realize the isoparametric measurement of temperature of Substation Station electric current secondary loop installation environment; By the mode of Wireless Data Transmission, transformer station's electric current secondary loop temperature and environment measuring data are carried out centralized collection, arrangement and classification;

Utilize above-mentioned detection data and table 1, calculate transformer station electric current secondary loop thermal value Q _c:

$Q_c=\underset{0}{\overset{t}{\∫}}CM({\mathrm{\α}}_1-{\mathrm{\α}}_2)(1+b)dt---\left(2\right)$

α in formula ₁, α ₂be respectively electric current secondary loop monitoring point temperature and environment temperature, the value of b is by measured value α ₂to table look-up 1 acquisition, work as α ₂during for non integer value, try to achieve corresponding b value by method of interpolation, t is the time of a sense cycle.

Heating computation model under step 3, structure electric current secondary loop kilter, its computing formula is such as formula shown in (3):

$Q_j=\underset{0}{\overset{t}{\∫}}(I^{2}R+\mathrm{\ω}\·c\·U^2\·tg\mathrm{\δ})dt---\left(3\right)$

In formula, Q _jfor the unit interval thermal value calculated value under secondary circuit kilter, ω=2 π f=100 π, I is the current value of real-time collecting, and R is secondary circuit equivalent resistance, U is loop voltage-to-ground, and c is secondary circuit ground capacitance, tg δ is secondary circuit insulation loss factor.

Step 4, determine secondary circuit in the unit interval detect thermal value under thermal value and hypothesis secondary circuit kilter difference, increase than coefficient and metewand;

Δ Q is calculated by formula (4);

$\left\{\begin{array}{cc}\mathrm{\&Delta;}Q=Q_c-Q_j& Q_c\&GreaterEqual;Q_j\\ \mathrm{\&Delta;}Q=0& Q_c<Q_j\end{array}\right.---\left(4\right)$

Draw the change curve of Δ Q, and obtain increasing than coefficient k compared with history curve, the Δ Q change curve that described history curve obtained for the same secondary circuit former moment;

Detect n secondary circuit temperature oc of identical electrical network primary side ₁~ α _n, find out α ₁~ α _nin minimum value α _k, then ask α respectively ₁~ α _nwith α _kratio cc ' ₁~ α ' _n, during measurement, will the corresponding ratio in loop be chosen as metewand α '.

Step 5, determine transformer station's electric current secondary loop state according to evaluation grade trusted function

Step 5-1, by Δ Q, k, α of obtaining in step 4 ' be updated in evaluation grade trusted function (5) ~ (8) respectively, calculate respectively and there emerged a the confidence level of above-mentioned three parameters under four ranks; Wherein one, two, three, four is corresponding is respectively the kilter of transformer station's electric current secondary loop state estimation, general state, attention state and severe conditions;

Level Four:

$f\left(x\right)=\left\{\begin{array}{cc}1& x\&GreaterEqual;x_4+{\mathrm{\&epsiv;}}_4\\ \frac{x}{x_4+{\mathrm{\&epsiv;}}_4}& (x_4-0.5x_3)<x<x_4+{\mathrm{\&epsiv;}}_4\\ 0& x<x_4-0.5(x_3+x_2)\end{array}\right.---\left(5\right)$

Three grades:

$f\left(x\right)=\left\{\begin{array}{cc}1& 0.5(x_2+x_3)\&le;x<x_4+{\mathrm{\&epsiv;}}_4\\ \frac{x}{0.5(x_2+x_3)}& 0.5(x_1+x_2)<x<0.5(x_2+x_3)\\ 0& x\&le;0.5(x_2+x_1),x\&GreaterEqual;x_4+{\mathrm{\&epsiv;}}_4\end{array}\right.---\left(6\right)$

Secondary:

$f\left(x\right)=\left\{\begin{array}{cc}1& 0.5(x_1+x_2)\&le;x<0.5(x_2+x_3)\\ \frac{x}{0.5(x_2+x_3)}& 0.5x_1<x<0.5(x_1+x_2)\\ 0& x\&le;0.5x_1,x\&GreaterEqual;0.5(x_2+x_3)\end{array}\right.---\left(7\right)$

One-level:

$f\left(x\right)=\left\{\begin{array}{cc}1& 0.5x_1\&le;x<0.5(x_1+x_2)\\ \frac{x}{0.5(x_1+x_2)}& {\mathrm{\&epsiv;}}_1<x<0.5(x_1+x_2)\\ 0& x\&le;{\mathrm{\&epsiv;}}_1,x\&GreaterEqual;0.5(x_1+x_2)\end{array}\right.---\left(8\right)$

Wherein, x ₁for guaranteeing the minimum value of Δ Q, k or α under secondary circuit kilter ', x ₂for Δ Q, k or α under secondary circuit general state ' minimum value, x ₃for secondary circuit should be noted that the minimum value of Δ Q, k or α under state ', x ₄for Δ Q, k or α under secondary circuit severe conditions ' minimum value, ε ₁for x ₁divided by the value that the first safety factor obtains, ε ₄for x ₄be multiplied by the value that the second safety factor obtains, the first safety factor and the second safety factor are all greater than 1, and in present embodiment, the first safety factor gets 1.4, and the second safety factor gets 1.2 ~ 1.3; Wherein ε ₁, x ₁, x ₂, x ₃, x ₄, ε ₄value experimentally database, repair and maintenance database, history curve database and expert database obtain;

Step 5-2, calculated the Changeable weight of Δ Q, k and α ' by formula (9):

$\left\{\begin{array}{c}p\left(\mathrm{\&Delta;}Q\right)=\frac{f\left(\mathrm{\&Delta;}Q\right)}{f\left(\mathrm{\&Delta;}Q\right)+f\left(k\right)+f\left({\mathrm{\&alpha;}}^{\&prime;}\right)}\\ p\left(k\right)=\frac{f\left(k\right)}{f\left(\mathrm{\&Delta;}Q\right)+f\left(k\right)+f\left({\mathrm{\&alpha;}}^{\&prime;}\right)}\\ p\left({\mathrm{\&alpha;}}^{\&prime;}\right)=\frac{f\left({\mathrm{\&alpha;}}^{\&prime;}\right)}{f\left(\mathrm{\&Delta;}Q\right)+f\left(k\right)+f\left({\mathrm{\&alpha;}}^{\&prime;}\right)}\end{array}\right.---\left(9\right)$

The assessed value of four grades is calculated respectively by formula (10):

$\begin{array}{c}{v}_i\frac{f_i{\left(\mathrm{\&Delta;}Q\right)}^2}{p_1\left(\mathrm{\&Delta;}Q\right)+p_2\left(\mathrm{\&Delta;}Q\right)+p_3\left(\mathrm{\&Delta;}Q\right)+p_4\left(\mathrm{\&Delta;}Q\right)}+\frac{f_i{\left(k\right)}^2}{p_1\left(k\right)+p_2\left(k\right)+p_3\left(k\right)+p_4\left(k\right)}+\frac{f_i{\left({\mathrm{\&alpha;}}^{\&prime;}\right)}^2}{p_1\left({\mathrm{\&alpha;}}^{\&prime;}\right)+p_2\left({\mathrm{\&alpha;}}^{\&prime;}\right)+p_3\left({\mathrm{\&alpha;}}^{\&prime;}\right)+p_4\left({\mathrm{\&alpha;}}^{\&prime;}\right)}\\ i=1~4\end{array}---\left(10\right)$

Step 5-3, compare v ₁, v ₂, v ₃, v ₄four assessed values, wherein maximum v _icorresponding rank is final assessment result.

Claims (6)

1., based on transformer station's electric current secondary loop state evaluating method of many data processings, it is characterized in that, step is as follows:

Transformer station's electric current secondary loop heating correction factor at step 1, acquisition varying environment temperature;

Step 2, detection transformer station's electric current secondary loop temperature and installation environment temperature, build transformer station's electric current secondary loop thermal value correction function;

Heating computation model under step 3, structure electric current secondary loop kilter;

Step 4, determine secondary circuit in the unit interval detect thermal value under thermal value and secondary circuit kilter difference, increase than coefficient and metewand;

Step 5, determine transformer station's electric current secondary loop state according to evaluation grade trusted function.

2. the transformer station's electric current secondary loop state evaluating method based on many data processings according to claim 1, is characterized in that, obtains heating correction factor b and CM under difficult environmental conditions in step 1 by experiment:

CM＝I ²R/(θ ₁-θ ₂)(1+b)(1)

In formula, CM is the scale-up factor of revised thermal value and electric current, and I is the electric current of input, and R is the equivalent resistance of analog loopback, θ ₁, θ ₂be respectively wire and experimental situation temperature.

3. the transformer station's electric current secondary loop state evaluating method based on many data processings according to claim 2, is characterized in that, in step 2, transformer station's electric current secondary loop thermal value correction function is;

$Q_c=\underset{0}{\overset{t}{\&Integral;}}CM({\mathrm{\&alpha;}}_1-{\mathrm{\&alpha;}}_2)(1+b)dt---\left(2\right)$

In formula, Q _cfor transformer station's electric current secondary loop thermal value, α ₁, α ₂be respectively electric current secondary loop monitoring point temperature and environment temperature, the value of b is by measured value α ₂to table look-up 1 acquisition, work as α ₂during for non integer value, try to achieve corresponding b value by method of interpolation, t is a sense cycle time.

4. the transformer station's electric current secondary loop state evaluating method based on many data processings according to claim 3, it is characterized in that, the heating computation model in step 3 under electric current secondary loop kilter is

$Q_j=\underset{0}{\overset{t}{\&Integral;}}(I^{2}R+\mathrm{\&omega;}\&CenterDot;c\&CenterDot;U^2\&CenterDot;tg\mathrm{\&delta;})dt---\left(3\right)$

In formula, Q _jfor the unit interval thermal value calculated value under secondary circuit kilter, ω=2 π f=100 π, I is the current value of real-time collecting, R is secondary circuit equivalent resistance, U is loop voltage-to-ground, and c is secondary circuit ground capacitance, and tg δ is secondary circuit insulation loss factor.

5. the transformer station's electric current secondary loop state evaluating method based on many data processings according to claim 4, is characterized in that, in the unit interval, secondary circuit detection thermal value with the difference DELTA Q of thermal value under hypothesis secondary circuit kilter is:

$\left\{\begin{array}{cc}\mathrm{\&Delta;}Q=Q_c-Q_j& Q_c\&GreaterEqual;Q_j\\ \mathrm{\&Delta;}Q=0& Q_c<Q_j\end{array}\right.---\left(4\right)$

Draw the change curve of Δ Q, and obtain increasing than coefficient k compared with history curve, the Δ Q change curve that described history curve obtained for the same secondary circuit former moment;

Detect n secondary circuit temperature oc of identical electrical network primary side ₁~ α _n, find out α ₁~ α _nin minimum value α _k, then ask α respectively ₁~ α _nwith α _kratio cc ' ₁~ α ' _n, during measurement, will the corresponding ratio in loop be chosen as metewand α '.

6. the transformer station's electric current secondary loop state evaluating method based on many data processings according to claim 5, it is characterized in that, step 5 detailed process is:

Step 5-1, by Δ Q, k, α of obtaining in step 4 ' be updated in evaluation grade trusted function (5) ~ (8) respectively, calculate respectively and there emerged a the confidence level of above-mentioned three parameters under four ranks; Wherein one, two, three, four is corresponding is respectively the kilter of transformer station's electric current secondary loop state estimation, general state, attention state and severe conditions;

Level Four:

$f\left(x\right)=\left\{\begin{array}{cc}1& x\&GreaterEqual;x_4+{\mathrm{\&epsiv;}}_4\\ \frac{x}{x_4+{\mathrm{\&epsiv;}}_4}& (x_4-0.5x_3)<x<x_4+{\mathrm{\&epsiv;}}_4\\ 0& x<x_4-0.5(x_3+x_2)\end{array}\right.---\left(5\right)$

Three grades:

$f\left(x\right)=\left\{\begin{array}{cc}1& 0.5(x_2+x_3)\&le;x<x_4+{\mathrm{\&epsiv;}}_4\\ \frac{x}{0.5(x_2+x_3)}& 0.5(x_1+x_2)<x<0.5(x_2+x_3)\\ 0& x\&le;0.5(x_2+x_1),x\&GreaterEqual;x_4+{\mathrm{\&epsiv;}}_4\end{array}\right.---\left(6\right)$

Secondary:

$f\left(x\right)=\left\{\begin{array}{cc}1& 0.5(x_1+x_2)\&le;x<0.5(x_2+x_3)\\ \frac{x}{0.5(x_2+x_3)}& 0.5x_1<x<0.5(x_1+x_2)\\ 0& x\&le;0.5x_1,x\&GreaterEqual;0.5(x_2+x_3)\end{array}\right.---\left(7\right)$

One-level:

$f\left(x\right)=\left\{\begin{array}{cc}1& 0.5x_1\&le;x<0.5(x_1+x_2)\\ \frac{x}{0.5(x_1+x_2)}& {\mathrm{\&epsiv;}}_1<x<0.5(x_1+x_2)\\ 0& x\&le;{\mathrm{\&epsiv;}}_1,x\&GreaterEqual;0.5(x_1+x_2)\end{array}\right.---\left(8\right)$

Wherein, x ₁for guaranteeing the minimum value of Δ Q, k or α under secondary circuit kilter ', x ₂for Δ Q, k or α under secondary circuit general state ' minimum value, x ₃for secondary circuit should be noted that the minimum value of Δ Q, k or α under state ', x ₄for Δ Q, k or α under secondary circuit severe conditions ' minimum value, ε ₁for x ₁divided by the value that the first safety factor obtains, ε ₄for x4 is multiplied by the value that the second safety factor obtains, the first safety factor and the second safety factor are all greater than 1;

Step 5-2, calculated the Changeable weight of Δ Q, k and α ' by formula (9):

$\left\{\begin{array}{c}p\left(\mathrm{\&Delta;}Q\right)=\frac{f\left(\mathrm{\&Delta;}Q\right)}{f\left(\mathrm{\&Delta;}Q\right)+f\left(k\right)+f\left({\mathrm{\&alpha;}}^{\&prime;}\right)}\\ p\left(k\right)=\frac{f\left(k\right)}{f\left(\mathrm{\&Delta;}Q\right)+f\left(k\right)+f\left({\mathrm{\&alpha;}}^{\&prime;}\right)}\\ p\left({\mathrm{\&alpha;}}^{\&prime;}\right)=\frac{f\left({\mathrm{\&alpha;}}^{\&prime;}\right)}{f\left(\mathrm{\&Delta;}Q\right)+f\left(k\right)+f\left({\mathrm{\&alpha;}}^{\&prime;}\right)}\end{array}\right.---\left(9\right)$

The assessed value of four grades is calculated respectively by formula (10):

$v_i=\frac{f_i{\left(\mathrm{\&Delta;}Q\right)}^2}{p_1\left(\mathrm{\&Delta;}Q\right)+p_2\left(\mathrm{\&Delta;}Q\right)+p_3\left(\mathrm{\&Delta;}Q\right)+p_4\left(\mathrm{\&Delta;}Q\right)}+\frac{f_i{\left(k\right)}^2}{p_1\left(k\right)+p_2\left(k\right)+p_3\left(k\right)+p_4\left(k\right)}+\frac{f_i{\left({\mathrm{\&alpha;}}^{\&prime;}\right)}^2}{p_1\left({\mathrm{\&alpha;}}^{\&prime;}\right)+p_2\left({\mathrm{\&alpha;}}^{\&prime;}\right)+p_3\left({\mathrm{\&alpha;}}^{\&prime;}\right)+p_4\left({\mathrm{\&alpha;}}^{\&prime;}\right)}---\left(10\right)$

In formula, i=1 ~ 4;

Step 5-3, compare v ₁, v ₂, v ₃, v ₄four assessed values, wherein maximum v _icorresponding rank is final assessment result.