CN103683278B - A kind of distribution network load calibration steps being applied to online closed loop power flow optimization analysis - Google Patents

Abstract

The invention discloses a kind of distribution network load calibration steps being applied to online closed loop power flow optimization analysis, comprise the steps: step one, all load values of power distribution network are adjusted to the rated load of distribution transformer；Step 2, obtains the current value that feeder line is fully loaded；Step 3, obtains the actual loading rate of feeder line；Step 4, calculates: Scap, S_load、Tcap、T_load1、T_load2、Tcap；Step 5, after refreshing all of distribution transformer load value in an iterative computation, recalculate the new load value obtaining feeder line head end, the newest load value is poor the most equal with the actual amount measured value of feeder line head end, if being unsatisfactory for requiring just to recalculate adjustment distribution transformer load, until meeting convergence precision requirement.Network load by the load of the amount calculating transformer of feeder line head end and is calibrated by the present invention, thus ensures that online closed loop power flow optimizes precision of analysis.

Description

A kind of distribution network load calibration steps being applied to online closed loop power flow optimization analysis

Technical field

The present invention relates to a kind of distribution network load calibration steps being applied to online closed loop power flow optimization analysis.

Background technology

For simplifying power system operating mode, suppress short circuit current level, improve the power supply reliability of electrical network, maintain the peace of electrical network Full economical operation, China 110kV and following supply and distribution net typically use looped network design, the pattern of open loop operation.When needs shift Load or overhaul complete plan when restoring electricity, general use first cyclization after the operator scheme unlinked to avoid user to have a power failure, improve The power supply reliability of user.

Owing to bigger closed loop power flow may be produced during Loop Closing Operation, cause apparatus overload or relay protection action, cause Loop Closing Operation failure or power failure.If relay fail, it is likely to result in device damage or upper level protection act, expands power failure model Enclose.Due to after cyclization the operation conditions of electrical network to scheduling operations staff be opaque, management and running personnel be difficult to the most pre- First judge the reliability of Loop Closing Operation, it is likely that cause apparatus overload or trip protection after cyclization owing to closed loop power flow is excessive, Cause Loop Closing Operation failure eventually, cause user to have a power failure or electrical equipment damage etc..Owing to closed loop power flow size is difficult to directly predict, In order to prevent device damage, being to use break-before-make principle to operate sometimes, cause user to have a power failure in short-term, this sacrifices electrical network Power supply reliability, is unacceptable in the important load power supply areas such as urban district.Therefore, before carrying out Loop Closing Operation, it should Carrying out closed loop power flow budget, the situation after involutive ring accomplishes to know what's what, it is ensured that Loop Closing Operation success, improves power supply reliability. In the case of with good conditionsi, the time dependent situation of closed loop power flow size should be followed the tracks of by the in-service monitoring of involutive ring trend, Select to carry out cyclization solution operation in the moment that closed loop power flow is less, improve the success rate of Loop Closing Operation.

There is comprehensive measurement system under power transmission network usual condition, when redundancy is existed for the electric parameters of equipment, but join Electrical network lacks monitoring means, runs electric data not enough, power distribution network is carried out more Accurate Analysis and brings difficulty, need to carry out state Estimations etc. are analyzed.

Summary of the invention

The technical problem to be solved is just to provide a kind of distribution being applied to online closed loop power flow optimization analysis Net load verification method, it is ensured that online closed loop power flow optimizes precision of analysis.

For solving above-mentioned technical problem, the present invention adopts the following technical scheme that one is applied to online closed loop power flow optimization The distribution network load calibration steps analyzed, comprises the steps:

All load values of power distribution network are adjusted to the rated load of distribution transformer by step one；

Step 2, the current value obtaining feeder line head end after carrying out Load flow calculation is exactly the fully loaded current value of feeder line；

Step 3, carries out being calculated the actual loading rate of feeder line with feeder line measured current and feeder line full-load current；

Step 4, calculates after obtaining the actual loading rate of feeder line: Scap feeder line full load head end measures load, S_loadFeedback Line is actual measures load, Tcap distribution transforming rated capacity, T_load1Distribution transforming current loads, T_load2The calculated new load of distribution transforming；

Step 5, after refreshing all of distribution transformer load value, recalculates and obtains feeder line head end in an iterative computation New load value, relatively newer load value is poor the most equal with the actual amount measured value of feeder line head end, if being unsatisfactory for just requiring Recalculate adjustment distribution transformer load, until meeting convergence precision requirement.

Preferably, the calculated new carry calculation formula of distribution transforming is:

$Tload2=T_{load1}-\frac{(S_{load}-S_{cap})}{S_{cap}}*T_{cap}.$

Network load by the load of the amount calculating transformer of feeder line head end and is calibrated by the present invention, thus ensures Line closed loop power flow optimizes precision of analysis.

Accompanying drawing explanation

The invention will be further described with detailed description of the invention below in conjunction with the accompanying drawings:

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

Fig. 2 is feeder line trend scattergram；

Fig. 3 is load verification current distributing figure.

Detailed description of the invention

Power distribution network has to carry out the necessary data of Load flow calculation: 3 phase active reactive values of the load of each distribution transforming Busbar voltage, the electric parameter of all elements of circuit with feeder line outlet.

The exact load value actual power distribution network being gathered to all loads is highly difficult thing, and for power distribution network institute The outlet having feeder line measures all collection, i.e. meritorious, idle, power factor, the feeder current of feeder line outlet.Accordingly, it would be desirable to it is logical Cross the load of the amount calculating transformer of feeder line head end.

The power of feeder line head end (meritorious, idle) be equal on feeder line all load powers and line loss power thereof it With, it may be assumed that

Wherein S: for apparent energy S=P+jQ；I is the plural number of electric current, has amplitude and phase angle.

Process and the result of distribution network load calibration are described below as a example by Fig. 1.

The data measured have: every phase P+jQ=200+j100 of load of distribution transforming 2#；The electric current of feeder line outlet measurement and power Factor is I=96.18A (being converted into power), COS=0.9, feeder line busbar voltage U=10.5kV；Distribution transforming 1# load is unknown；Root Carry out state estimation according to these data load and obtain feeder line trend scattergram as shown in Figure 2.

From the load verification current distributing figure shown in Fig. 3 it can be seen that the load of 1# distribution transforming is automated and is adjusted to 319+ J140, and the active power of feeder line head end is equal to load power and line loss power sum.

When specifically calculating, the first all load values by power distribution network are adjusted to the rated load of distribution transformer, so enter The current value of the feeder line head end obtained after row Load flow calculation is exactly the current value that feeder line is fully loaded, full with feeder line with feeder line measured current Carry electric current and carry out being calculated the actual loading rate of feeder line.

The load factor reflection of feeder line is whole piece feeder line distribution transforming load factor situation, in the case of not having other data, presses It is implied terms according to distribution transformer load factor equilibrium on whole piece feeder line, carries out state estimation.

Calculate after obtaining load factor:

Scap feeder line full load head end measures load；

S_loadFeeder line actual measurement load；

Tcap distribution transforming rated capacity；

T_load1Distribution transforming current loads；

T_load2The calculated new load of distribution transforming.

Note: the most all of load value is all plural form.

The formula calculating a certain distribution transforming after learning feeder line full load and actual measurement load is:

$Tload2=T_{load1}-\frac{(S_{load}-S_{cap})}{S_{cap}}*T_{cap}$

After refreshing all of distribution transformer load value in an iterative computation, recalculate new the bearing obtaining feeder line head end Charge values, the newest load value poor with the actual amount measured value of feeder line head end the most equal (difference is less than convergence precision), if discontented Foot requires just to recalculate adjustment distribution transformer load, until meeting convergence precision requirement.

Claims (1)

1. one kind is applied to the distribution network load calibration steps that online closed loop power flow optimization is analyzed, it is characterised in that include walking as follows Rapid:

All load values of power distribution network are adjusted to the rated load of distribution transformer by step one；

Step 2, the current value obtaining feeder line head end after carrying out Load flow calculation is exactly the fully loaded current value of feeder line；

Step 3, carries out being calculated the actual loading rate of feeder line with feeder line measured current and feeder line full-load current；

Step 4, calculates after obtaining the actual loading rate of feeder line: Scap feeder line full load head end measures load, S_loadFeeder line is real Border measures load, Tcap distribution transforming rated capacity, T_load1Distribution transforming current loads, T_load2The calculated new load of distribution transforming；

$Tload2=T_{load1}-\frac{(S_{load}-S_{cap})}{S_{cap}}*T_{cap},$

Step 5, after refreshing all of distribution transformer load value, recalculates and obtains the new of feeder line head end in an iterative computation Load value, relatively newer load value is the most equal with the actual amount measured value of feeder line head end, if being unsatisfactory for requiring the most again to count Calculate and adjust distribution transformer load, until meeting convergence precision requirement；

The calculated new carry calculation formula of distribution transforming is:

$Tload2=T_{load1}-\frac{(S_{load}-S_{cap})}{S_{cap}}*T_{cap}.$