CN103683278A - Power distribution network load calibration method applied to on-line loop closing trend optimization analysis - Google Patents

Abstract

The invention discloses a power distribution network load calibration method applied to on-line loop closing trend optimization analysis. The method comprises the following steps: step one, adjusting all load values of a power distribution network to a rated load of a distribution transformer; step two, obtaining a current value of a feed line full load; step three, obtaining an actual load rate of a feed line; step four, calculating Scap, S[load], Tcap, T[load1], T[load2] and Tcap; and step five, after all distribution transformation load values are refreshed in the same iterative computation, recalculating to obtain a new load value of the initial end of the feed line, comparing whether the new load value equals to an actual measurement value difference of the initial end of the feed line, and if requirements are not satisfied, recalculating and adjusting distribution transformation loads until the convergence precision requirements are satisfied. According to the invention, through measurement of the initial end of the feed line, the load of a transformer is calculated, and the electrical network load is calibrated, so that the accuracy of an on-line loop closing trend optimization analysis result is ensured.

Description

A kind of power distribution network load verification method that is applied to online cyclization tide optimization analysis

Technical field

The present invention relates to a kind of power distribution network load verification method that online cyclization tide optimization is analyzed that is applied to.

Background technology

For simplifying power system operating mode, suppress short circuit current level, improve the power supply reliability of electrical network, maintain the safety and economic operation of electrical network, China 110kV and following supply and distribution net generally adopt the pattern of looped network design, open loop operation.When needs transfer load or overhaul complete plan while restoring electricity, generally adopt the operator scheme of unlinking after first cyclization to avoid user to have a power failure, improve user's power supply reliability.

During due to Loop Closing Operation, may produce larger cyclization trend, cause apparatus overload or relaying protection action, cause Loop Closing Operation failure or have a power failure.If protection tripping, may cause device damage or upper level protection action, expand power failure range.Because the operation conditions of electrical network after cyclization is opaque to scheduling operations staff; management and running personnel are difficult to prejudge by rule of thumb the reliability of Loop Closing Operation; probably because cyclization trend is excessive, cause apparatus overload or trip protection after cyclization; finally cause Loop Closing Operation failure, cause user to have a power failure or electric equipment damage etc.Because cyclization trend size is difficult to direct prediction, in order to prevent device damage, be to adopt break-before-make principle to operate sometimes, cause user to have a power failure in short-term, this has sacrificed mains supply reliability, in the important load power supply areas such as urban district, is unacceptable.Therefore, before carrying out Loop Closing Operation, should carry out the budget of cyclization trend, the situation after involutive ring accomplishes to know what's what, and guarantees Loop Closing Operation success, improves power supply reliability.In situation with good conditionsi, should pass through the in-service monitoring of involutive ring trend, follow the tracks of the time dependent situation of cyclization trend size, being chosen in the moment that cyclization trend is less carries out the operation of cyclization solution, improves the success rate of Loop Closing Operation.

Under power transmission network usual condition, have comprehensive measurement system, have the situation of redundancy for the electric parameters of equipment, but power distribution network lacks monitoring means, operation electric data is not enough, power distribution network is carried out to comparatively Accurate Analysis and bring difficulty, need to carry out the analyses such as state estimation.

Summary of the invention

Technical problem to be solved by this invention is just to provide a kind of power distribution network load verification method that online cyclization tide optimization is analyzed that is applied to, and guarantees online cyclization tide optimization precision of analysis.

For solving the problems of the technologies described above, the present invention adopts following technical scheme: a kind of power distribution network load verification method that is applied to online cyclization tide optimization analysis, comprises the steps:

Step 1, is adjusted to all load values of power distribution network the rated load of distribution transformer;

Step 2, the current value that carries out obtaining after trend calculating feeder line head end is exactly the fully loaded current value of feeder line;

Step 3, calculates the actual loading rate of feeder line with feeder line measured current and feeder line full-load current;

Step 4, calculates after the actual loading rate of feeder line obtaining: Scap feeder line full load head end measures load, S _loadthe actual measurement load of feeder line, Tcap distribution transforming rated capacity, T _load1distribution transforming is as preload, T _load2the new load that distribution transforming calculates, the load of Tcap distribution transforming;

Step 5, with in an iterative computation, refreshing after all distribution transformer load values, recalculate the new load value that obtains feeder line head end, poor whether the equating of actual amount measured value of newer load value and feeder line head end, if do not met the demands, just do not recalculate adjustment distribution transformer load, until meet convergence precision requirement.

Preferably, the new load computing formula that distribution transforming calculates is:

$\mathrm{<figure-callout\; id="2"\; label="Tload"\; filenames="HDA0000407678550000011.png,HDA0000407678550000012.png"\; state="\{\{state\}\}">Tload</figure-callout>}2=T_{\mathrm{load}1}-\frac{(S_{\mathrm{load}}-S_{\mathrm{cap}})}{S_{\mathrm{cap}}}*T_{\mathrm{cap}}.$

The load of the present invention by the amount calculating transformer of feeder line head end also calibrated network load, thereby guarantees online cyclization tide optimization precision of analysis.

Accompanying drawing explanation

Below in conjunction with the drawings and specific embodiments, the invention will be further described:

Fig. 1 is process and the result figure of power distribution network load verification;

Fig. 2 is feeder line trend distribution map;

Fig. 3 is load verification current distributing figure.

Embodiment

In power distribution network, in order to carry out trend, calculate necessary data and have: 3 meritorious idle value and the busbar voltage of feeder line outlet, the electric parameters of all elements of circuit mutually of the load of each distribution transforming.

The accurate load value that gathers all loads for actual power distribution network is very difficult thing, and measure for the outlet of all feeder lines of power distribution network, all has collection, i.e. meritorious, idle, the power factor of feeder line outlet, feeder current.Therefore, need to pass through the load of the amount calculating transformer of feeder line head end.

The power of feeder line head end (meritorious, idle) just equals all load powers and line loss power sum thereof on feeder line, that is:

S wherein: be apparent power S=P+jQ; I is the plural number of electric current, has amplitude and phase angle.

Take process and the result of Fig. 1 as the load verification of example explanation power distribution network below.

The data that measure have: the every phase P+jQ=200+j100 of load of distribution transforming 2#; Electric current and power factor that feeder line outlet measures are that I=96.18A(is converted into power), COS=0.9, feeder line busbar voltage U=10.5kV; Distribution transforming 1# loads unknown; According to these data load, carry out state estimation and obtain feeder line trend distribution map as shown in Figure 2.

From the load verification current distributing figure shown in Fig. 3, can find out: the load of 1# distribution transforming has been adjusted into 319+j140 by automation, and the active power of feeder line head end equals load power and line loss power sum.

During concrete calculating, first all load values of power distribution network are adjusted to the rated load of distribution transformer, the current value that carries out like this feeder line head end that obtains after trend calculating is exactly the fully loaded current value of feeder line, calculates the actual loading rate of feeder line with feeder line measured current and feeder line full-load current.

What the load factor of feeder line reflected is whole piece feeder line distribution transforming load factor situation, in the situation that there is no other data, according to distribution transformer load factor equilibrium on whole piece feeder line, is implied terms, carries out state estimation.

After obtaining load factor, calculate:

scap feeder line full load head end measures load;

s _loadthe actual measurement load of feeder line;

tcap distribution transforming rated capacity;

t _load1preload is worked as in distribution transforming;

t _load2the new load that distribution transforming calculates;

the load of Tcap distribution transforming.

Note: all load values are all plural forms here.

The formula that calculates a certain distribution transforming after learning the fully loaded load of feeder line and actual measurement load is:

$\mathrm{<figure-callout\; id="2"\; label="Tload"\; filenames="HDA0000407678550000011.png,HDA0000407678550000012.png"\; state="\{\{state\}\}">Tload</figure-callout>}2=T_{\mathrm{load}1}-\frac{(S_{\mathrm{load}}-S_{\mathrm{cap}})}{S_{\mathrm{cap}}}*T_{\mathrm{cap}}$

With in an iterative computation, refreshing after all distribution transformer load values, recalculate the new load value that obtains feeder line head end, poor whether the equating of actual amount measured value of newer load value and feeder line head end (the poor convergence precision that is less than), if do not met the demands, just do not recalculate adjustment distribution transformer load, until meet convergence precision requirement.

Claims (2)

1. be applied to the power distribution network load verification method that online cyclization tide optimization is analyzed, it is characterized in that comprising the steps:

Step 1, is adjusted to all load values of power distribution network the rated load of distribution transformer;

Step 2, the current value that carries out obtaining after trend calculating feeder line head end is exactly the fully loaded current value of feeder line;

Step 3, calculates the actual loading rate of feeder line with feeder line measured current and feeder line full-load current;

Step 4, calculates after the actual loading rate of feeder line obtaining: Scap feeder line full load head end measures load, S _loadthe actual measurement load of feeder line, Tcap distribution transforming rated capacity, T _load1distribution transforming is as preload, T _load2the new load that distribution transforming calculates, the load of Tcap distribution transforming;

Step 5, with in an iterative computation, refreshing after all distribution transformer load values, recalculate the new load value that obtains feeder line head end, poor whether the equating of actual amount measured value of newer load value and feeder line head end, if do not met the demands, just do not recalculate adjustment distribution transformer load, until meet convergence precision requirement.

2. a kind of power distribution network load verification method that online cyclization tide optimization is analyzed that is applied to according to claim 1, is characterized in that: the new load computing formula that distribution transforming calculates is:

$\mathrm{Tload}2=T_{\mathrm{load}1}-\frac{(S_{\mathrm{load}}-S_{\mathrm{cap}})}{S_{\mathrm{cap}}}*T_{\mathrm{cap}}.$

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