CN112578205B - Line loss analysis method for correcting technical line loss rate - Google Patents
Line loss analysis method for correcting technical line loss rate Download PDFInfo
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Abstract
The invention relates to the technical field of line loss analysis, in particular to a line loss analysis method for correcting a technical line loss rate, which comprises the following steps: sa., acquiring operation data of an externally input power supply area, wherein the operation data of the externally input power supply area comprises phase A current, phase B current, phase C current, three-phase active electric quantity, three-phase reactive electric quantity, line length and line diameter; sb., calculating the influence degree of technical line loss factors on the line loss rate of the distribution room according to the operation data of the power distribution room input from the outside in the step Sa, wherein the technical line loss factors comprise three-phase load unbalance factors, reactive power compensation deficiency factors, distribution room heavy overload factors and power supply radius overlong factors; sc. outputs the conclusion of the influence degree of the technical line loss factor on the line loss rate of the transformer area. The invention quantifies the influence degree of the technical line loss factor on the line loss rate of the transformer area, provides quantitative analysis support for line loss analysis personnel, and can effectively improve the working efficiency of the line loss analysis personnel of the power grid enterprise.
Description
Technical Field
The invention relates to the technical field of line loss analysis, in particular to a line loss analysis method for correcting a technical line loss rate.
Background
The technical line loss refers to the electric energy loss of each element of the power grid, mainly comprises constant loss and variable loss, and is inevitable loss of electric energy in the process of transmission and distribution. The line loss analysis work is to search the specific reason of the line loss lifting according to the actual line loss rate, determine the reasonability of the structure operation of the power distribution system, and find out weak links in the aspects of the structure, the operation, the equipment performance, the metering device, the power consumption management and the like of the power distribution system so as to take corresponding loss reduction measures. The anomaly of the line loss of one distribution area is often caused by the superposition influence of a plurality of factors. To accurately analyze and locate the cause of the abnormality, quantitative analysis of various factors is first required, and the degree of influence of the known abnormal factors on the line loss (i.e., the line loss rate correction process) is stripped, so as to make a conclusive evaluation. At present, in the actual work of analyzing the line loss of a transformer area of a power grid enterprise, the correction of the technical line loss rate is a long-term difficult problem.
Chinese patent CN102279320A discloses a method for determining a reasonable line loss rate interval based on error analysis, which calculates a technical line loss rate according to physical parameters of a line, calculates an electrometric error caused by the accuracy of a measuring device and an error caused by measuring time, and finally accumulates the accuracy error and the measuring time error on the basis of the technical line loss rate to obtain the reasonable line loss rate interval of the line. Although the rationality of the line loss of the line can be accurately determined, the technical factors are studied in a reasonable range, correction rate calculation based on deviation values is not deduced, the practical degree is low, and the guiding function of actual work is not sufficient.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides a line loss analysis method for correcting the technical line loss rate.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
the line loss analysis method for correcting the technical line loss rate comprises the following steps:
sa., acquiring operation data of an externally input power supply area, wherein the operation data of the externally input power supply area comprises phase A current, phase B current, phase C current, three-phase active electric quantity, three-phase reactive electric quantity, line length and line diameter;
sb., calculating the influence degree of technical line loss factors on the line loss rate of the distribution room according to the operation data of the power distribution room input from the outside in the step Sa, wherein the technical line loss factors comprise three-phase load unbalance factors, reactive power compensation deficiency factors, distribution room heavy overload factors and power supply radius overlong factors;
sc. outputs the conclusion of the influence degree of the technical line loss factor on the line loss rate of the transformer area.
According to the line loss analysis method for correcting the technical line loss rate, disclosed by the invention, aiming at four technical abnormal reasons, namely three-phase load imbalance, insufficient reactive power compensation, heavy overload and overlong power supply radius, the influence degree of the technical line loss factor on the line loss rate of the transformer area is quantized by externally acquiring input parameters and a corresponding line loss rate correction algorithm, so that quantitative analysis support is provided for line loss analysis personnel, and the working efficiency of the line loss analysis personnel of a power grid enterprise can be effectively improved.
Compared with the prior art, the invention has the beneficial effects that:
according to the line loss analysis method for correcting the technical line loss rate, disclosed by the invention, aiming at four technical abnormal reasons of unbalanced three-phase load, insufficient reactive power compensation, heavy overload and overlong power supply radius, the influence degree of the technical line loss factor on the line loss rate of a transformer area is quantized by externally acquiring input parameters and a corresponding line loss rate correction algorithm, so that quantitative analysis support is provided for line loss analysis personnel, and the working efficiency of the line loss analysis personnel of a power grid enterprise can be effectively improved.
Drawings
Fig. 1 is a schematic diagram of a line loss analysis method for technical line loss rate correction;
FIG. 2 is a flow chart of analysis of influence of three-phase load imbalance factors on a transformer area line loss rate;
fig. 3 is a flowchart of the impact analysis of reactive power compensation deficiency factors on the distribution room line loss rate;
fig. 4 is a flowchart of analysis of influence of heavy overload factors on the line loss rate of a distribution room;
FIG. 5 is a flow chart of analysis of influence of power supply radius overlong factors on a distribution room line loss rate;
FIG. 6 is a drawing showing
A graph is shown;
FIG. 7 is a schematic diagram of an impedance equivalent circuit of a three-phase circuit;
FIG. 8 is a schematic diagram of an equivalent circuit of a dual winding transformer;
FIG. 9 is a schematic diagram of power loss as a function of load;
FIG. 10 shows l-k l A graph is shown;
Detailed Description
The present invention will be further described with reference to the following embodiments.
Examples
Fig. 1 to 5 show an embodiment of a line loss analysis method for line loss rate correction according to the present invention, which includes the following steps:
sa., acquiring operation data of an externally input power supply area, wherein the operation data of the externally input power supply area comprises phase A current, phase B current, phase C current, three-phase active electric quantity, three-phase reactive electric quantity, line length and line diameter;
sb., calculating the influence degree of technical line loss factors on the line loss rate of the distribution room according to the operation data of the power distribution room input from the outside in the step Sa, wherein the technical line loss factors comprise three-phase load unbalance factors, reactive power compensation deficiency factors, distribution room heavy overload factors and power supply radius overlong factors;
sc. outputs the conclusion of the influence degree of the technical line loss factor on the line loss rate of the transformer area.
The influence degree of the three-phase load unbalance factor on the transformer area line loss rate is carried out according to the following steps:
s101, first operation data are obtained, wherein the first operation data comprise station area electric quantity, main outgoing line three-phase current, phase current under three-phase load balance and station area theoretical line loss values, the station area electric quantity comprises power supply quantity and power selling quantity, the main outgoing line three-phase current comprises A, B, C three-phase current Ia, Ib and Ic, and the phase current under the three-phase load balance is obtained according to historical current values which are similar to the station area electric quantity in history and are in a three-phase basic balance state;
s102, calculating according to the first operation data in the step S101 to obtain line loss electric quantity, maximum current and load unbalance;
s103, determining an adaptive algorithm of a power loss increment coefficient based on the load unbalance degree in the step S102 and the three-phase current of the main outgoing line in the step S101, and calculating to obtain the power loss increment coefficient;
s104, calculating the line loss electric quantity increased due to the three-phase load unbalance factor based on the loss increment coefficient in the step S103, and calculating the corrected line loss rate after the increased line loss electric quantity is reduced and removed;
and S105, outputting a conclusion of influence degree of the three-phase load unbalance factors on the line loss of the transformer area.
In step S102, the load unbalance B is calculated as follows:
in the formula I max The current value of the largest phase of the load, I cp The phase current value is the phase current value when the three-phase load is balanced;
in step S104, the method for calculating the line loss Δ F increased by the three-phase load imbalance factor includes:
ΔF＝F(1-1/K)
wherein F represents the line loss amount described in step S102, and K represents the power loss increment coefficient calculated in step S103;
corrected line loss rate A after rejecting increased line loss electric quantity S % is expressed as:
wherein Δ A represents the line loss before correction, and A 1 Representing the power supply amount of the platform area;
in step S105, the influence degree of the three-phase load imbalance factor on the distribution room line loss is represented as:
ΔA S1 ％＝A S1 ％-A S ％
in the formula, A S1 % represents the actual finished line loss value; delta A S1 % is the result value of the output.
In step S103, the power loss increment coefficient K is calculated according to different conditions and different methods:
(a) one-phase heavy load and two-phase light load
Assuming that the A phase is loaded with a heavy load and the B, C phase is loaded with a light load
Current I of neutral line when three-phase is symmetrical O ＝32BI cp ；
Power loss Δ P per unit length line 1 Comprises the following steps:
calculating a power loss increment coefficient K1:
wherein Δ P is the current I of the neutral line with completely balanced three-phase load O The power loss per unit length of line is 0,
r is the resistance of the circuit with unit length;
(b) one phase is loaded with heavy load, one phase is loaded with light load, and the load of the third phase is the average load
Assuming that the A phase is loaded with a heavy load, the B phase is loaded with a light load, and the C phase is loaded with an average value, then I a ＝(1+B)I cp ，I b ＝(1-B)I cp ，I c ＝I cp (ii) a In the case of three-phase symmetry, the power loss per unit length of line is:
calculating the increment coefficient of the power loss, wherein the value of the increment coefficient of the power loss is K2:
(c) one phase load is heavy and two phase load is light
Let I a ＝(1-2B)I cp ，I b ＝I c ＝(1+B)I cp In the case of three-phase symmetry, the current I of the neutral line o ＝3B I cp The power loss per unit length of line is:
calculating the increment coefficient of the power loss, wherein the value of the increment coefficient of the power loss is K3:
the influence degree of the reactive power compensation deficiency factor on the line loss rate of the transformer area is carried out according to the following steps:
s201, obtaining second operation data, wherein the second operation data comprise active power P, reactive power Q, apparent power S and a theoretical line loss value of a transformer area;
s202, calculating the power factor according to the second operation data in the step S201
S203, calculating and analyzing a relation curve between the power factor and the line loss electric quantity in the step S202;
s204, calculating a corrected line loss rate after the line loss electric quantity is reduced and removed;
and S205, outputting a conclusion of the influence degree of the reactive power compensation deficiency factors on the line loss of the transformer area.
In step S202, the power factor
Calculated as follows:
wherein the power factor varies between 0 and 1, i.e.
In step S203, when the power factor is decreased
Is improved to
The reactive load reduced in the process is:
in the formula, Q zd To reduce reactive load; p is pj Is the average active load; then it can be deduced that:
setting the power factor
For every 0.01 increase, the following formula is obtained:
thus, the power grids can be drawn differently
In the case of the above-described situation,
increase by 0.01 to obtain
The curves are shown in fig. 6. As can be seen from FIG. 6, K is the actual power factor of the grid over 0.9 i The linear increase shows that the actual power factor exceeds more than 0.9 in the power grid with the average active load unchanged
For every 0.01 improvement, more and more reactive compensation capacity needs to be increased. Therefore, it isIt is necessary to reduce the line loss and improve the power factor.
The calculation formula of the line loss rate is as follows:
wherein the line loss is equal to
In inverse proportion. When the power factor is from
Is improved to
And active power loss is reduced.
The method for calculating the line loss electric quantity delta F increased due to the reactive power compensation deficiency factor comprises the following steps:
Δ F ═ supply amount ═ line loss rate ═ Δ P
Calculating the corrected line loss rate after eliminating the increased line loss electric quantity:
the influence degree of the reactive compensation deficiency factor on the line loss of the transformer area is expressed as follows:
ΔA S ％＝A S1 ％-A S ％
in the formula, A S1 % represents the actual finished line loss value; delta A S % is the result value of the output.
The influence degree of the heavy overload factor of the transformer area on the line loss rate of the transformer area is carried out according to the following steps:
s301, third operation data are obtained, wherein the third operation data comprise head end voltage U 1 Terminal voltage U 2 Current flowing through the line
Maximum load rate of transformer in transformer area and three-phase active power P at tail end of line in same time period 2 And reactive power Q 2 Calculating an equivalent impedance R + jX according to the theoretical line loss value of the transformer area;
s302, calculating power loss generated in impedance of a three-phase power supply line of a distribution room;
s303, solving apparent power loss S of the transformer during heavy load operation according to the maximum load rate of the transformer in the transformer area in the step S301 T Obtaining rated capacity S of the transformer according to the type of the transformer N Impedance loss value delta P of transformer k Impedance voltage percent U k % and percent impedance current I 0 ％；
S304, calculating power loss generated in the three-phase transformer of the transformer area;
s305, analyzing the load condition of the distribution room after line loss correction of the distribution room heavy overload factor technology, and restoring the corrected line loss rate after eliminating the increased line loss electric quantity;
and S306, outputting a conclusion of the influence degree of the heavy overload factors of the transformer area on the line loss of the transformer area.
In step S301, the calculation is performed as follows:
according to
Obtaining Δ a, Δ P ═ 3I, can be obtained 2 R l Then R can be obtained l ，
So as to solve to obtain the equivalent power supply radius l of the distribution room line, according to
Solving equivalent impedance X of the line;
the three-phase line impedance equivalent line is shown in fig. 7. In step S302, the power loss is calculated according to the following formula:
in the formula: r + jX is the impedance of one phase of the line; p is 2 、Q 2 Three-phase active power and reactive power flowing through the tail end of the line impedance; u shape 2 The line end line voltage of the line end power can be expressed by the rated voltage of the line when the line end line voltage is approximately calculated;
referred to as the active power loss in the line resistance,
referred to as reactive power loss in line reactance; d M The geometric mean distance between the three-phase wires; and r is the calculated radius of the wire.
Therefore, when the load current flows through the impedance of the line, active power is generated on the resistor, reactive power is generated on the reactance, and the active power P flowing through the line can be obtained through formula decomposition 2 Reactive power Q 2 The larger the power is, the larger the active power delta P and the reactive power delta Q of the line are; returning to the low-voltage distribution network line, when the electrical load of a user is larger, the load current can be understood to be larger, and the power flowing through the three-phase line can be understood to be larger, so that when the load of a transformer area is larger or the transformer area runs in an overload mode, the loss of the line is higher; when the load is too low, the losses in the three-phase supply line are significantly smaller.
In step S303, the maximum load rate of the transformer in the transformer area is obtained according to the metering automation system, and S is obtained T The parameter S can be obtained according to the type of the transformer N Impedance loss value delta P of transformer k Impedance voltage percent U k % impedance current percent I 0 ％。
In step S304, the power loss generated in the three-phase transformer (for the double-winding transformer, the equivalent circuit of the double-winding transformer is shown in fig. 8) is calculated according to the following formula:
in the formula (I), the compound is shown in the specification,
the total loss of the three-phase transformer; r T +jX T Impedance for one phase of the transformer; p is T 、Q T Is the active and reactive power on the impedance of the transformer; u shape 2 The voltage at the tail end of the equivalent circuit of the transformer is obtained;
or as:
considering that the voltage of the transformer is close to the rated voltage during normal operation, i.e. U ≈ U N Then, the power loss calculation formula of the dual winding transformer can be expressed as:
the power loss of the transformer during operation varies with the load as shown in fig. 9, and when the load of the transformer is larger, the power loss of the transformer increases exponentially with the increase of the load. Wherein, Δ P 0 、ΔQ 0 Is the no-load loss, i.e., the iron loss, of the transformer, which is fixed and unchangeable; the other is short-circuit loss Δ P k I.e. copper loss, which is the loss produced when current flows through the transformer winding, has an equivalent resistance value to that of the windingClosing; when the load carried by the transformer is small, the line loss value calculated by the line loss rate can be approximately equal to the loss of the transformer. Therefore, when the transformer is lightly loaded, the total power input by the transformer area is small, the loss of the transformer is large, and the line loss value is high compared with the line loss value.
The total power loss of the station area is expressed as:
wherein:
the increased power consumption caused by the heavy overload factor of the transformer area is as follows:
ΔF＝(ΔS 1 -ΔS 0 )T
in the formula, the overload operation is performed when the load factor of the transformer exceeds 80%, the light-load operation is performed when the load factor of the transformer is less than 30%, and delta S is performed 0 The power loss is 80% and 30% of the load factor of the transformer.
In step S305, the corrected line loss rate after removing the increased line loss electric quantity is restored, and the specific calculation method is as follows:
the conclusion of the influence degree of the transformer heavy load overload on the transformer area line loss is represented as follows:
ΔA S ％＝A S1 ％-A S ％
in the formula, A S1 % represents the actual finished line loss value; delta A S % is the result value of the output.
The influence degree of the overlong radius factor of the power supply line on the line loss rate of the transformer area is carried out according to the following steps:
s401, fourth operation data are obtained, wherein the fourth operation data comprise the radius length of a power supply line of a transformer area and a theoretical line loss value of the transformer area;
s402, calculating a resistance value of a power supply line according to the radius length of the power supply line of the transformer area and the ambient temperature value of the equipment;
s403, calculating power loss of the line according to the resistance value calculated in the step S402 and by combining the input power and the input voltage of the line;
s404, calculating the increased line loss electric quantity caused by the factor of overlong power supply radius of the power receiving line, and calculating the line loss rate after the increased line loss electric quantity is reduced and removed;
and S405, outputting a conclusion of the influence degree of the factor of the overlong radius of the power supply line on the line loss rate of the transformer area.
In step S402, the resistance value of the power supply line is calculated according to the following formula:
in the formula, S represents the sectional area of a conductive part of a lead, rho represents the resistivity of the lead, l is the length of the lead, and gamma is the conductivity of a lead material; r is a radical of hydrogen 1 ＝r 20 [1+α(t-20)]Wherein r is 1 、r 20 Respectively representing resistance values at the temperature t and 20 ℃, wherein alpha is a resistance temperature coefficient;
in step S403, the power loss calculation formula of the line is:
in the formula, U represents three-phase line voltage, and P represents transmitted active power;
when the radius of the power supply line is from l 1 Is reduced to l 0 The power loss reduced in time is:
when l is reduced by 50 m, l 0 /1 1 ＝k 1 Then, k can be plotted when l of the power supply line is reduced by 10 meters under the condition of different power supply radiuses 1 Value curves, i.e. l-k 1 The curves are shown in fig. 10. As can be seen from FIG. 10, when the radius of the power supply line is reduced by 50 meters when the power supply radius of the power grid is between 550 meters and 600 meters, k is 1 Stabilized at about 0.91, and k is decreased by 100 m or more when the actual power supply radius is decreased 1 Shows a linear decrease when 0 And 1 1 The closer together, the less line power loss.
In step S404, the line loss caused by the technical reason that the radius of the power supply line is too long is calculated as:
in step S405, the line loss rate after the increased power loss is removed is calculated:
the influence degree of the overlong radius of the power supply line on the line loss of the transformer area is represented by the following formula:
ΔA S ％＝A S1 ％-A S ％
in the formula, S1% represents an actually completed line loss value; delta A S % is the result value of the output.
Through the steps, the transformer area is influenced by three-phase unbalance factors, and the line loss rate is increased by delta A s1 Percent; the transformer area is influenced by the factor of insufficient reactive compensation, and the line loss rate is increased by delta A s2 Percentage points; the transformer area is influenced by heavy overload factors, and the line loss rate is increased by delta A s3 Percent; the transformer area is influenced by the factor of overlong radius of a power supply line, and the line loss rate is increased by delta A s4 And (4) percent.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. This need not be, nor should it be exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.
Claims (9)
1. A line loss analysis method for correcting a technical line loss rate is characterized by comprising the following steps:
sa. obtaining operation data of the externally input power supply area, wherein the operation data of the externally input power supply area comprises A-phase current, B-phase current, C-phase current, three-phase active electric quantity, three-phase reactive electric quantity, line length and line diameter;
sb., calculating the influence degree of technical line loss factors on the line loss rate of the distribution room according to the operation data of the power distribution room input from the outside in the step Sa, wherein the technical line loss factors comprise three-phase load unbalance factors, reactive power compensation deficiency factors, distribution room heavy overload factors and power supply radius overlong factors;
sc., outputting the conclusion of the influence degree of the technical line loss factor on the line loss rate of the transformer area;
the influence degree of the three-phase load unbalance factor on the transformer area line loss rate is carried out according to the following steps:
s101, first operation data are obtained, wherein the first operation data comprise station area electric quantity, main outgoing line three-phase current, phase current under three-phase load balance and station area theoretical line loss values, the station area electric quantity comprises power supply quantity and power selling quantity, the main outgoing line three-phase current comprises A, B, C three-phase current Ia, Ib and Ic, and the phase current under the three-phase load balance is obtained according to historical current values which are similar to the station area electric quantity in history and are in a three-phase basic balance state;
s102, calculating according to the first operation data in the step S101 to obtain line loss electric quantity, maximum current and load unbalance;
s103, determining an adaptive algorithm of a power loss increment coefficient based on the load unbalance degree in the step S102 and the three-phase current of the main outgoing line in the step S101, and calculating to obtain the power loss increment coefficient;
s104, calculating the line loss electric quantity increased due to the three-phase load unbalance factor based on the loss increment coefficient in the step S103, and calculating the corrected line loss rate after the increased line loss electric quantity is reduced and removed;
and S105, outputting a conclusion of influence degree of the three-phase load unbalance factors on the line loss of the transformer area.
2. The method for analyzing line loss according to claim 1, wherein in step S102, the load imbalance degree B is calculated according to the following formula:
in the formula I max To load the current value of the maximum phase, I cp The phase current value is the phase current value when the three-phase load is balanced;
in step S104, the method for calculating the line loss Δ F increased by the three-phase load imbalance factor includes:
ΔF＝F(1-1/K)
wherein F represents the line loss amount described in step S102, and K represents the power loss increment coefficient calculated in step S103;
corrected line loss rate A after rejecting increased line loss electric quantity S % is expressed as:
where Δ A represents the line loss before correction, and A 1 Representing the power supply amount of the platform area;
in step S105, the influence degree of the three-phase load imbalance factor on the line loss of the transformer area is represented as:
ΔA S1 ％＝A S1 ％-A S ％
in the formula, A S1 % represents the actual finished line loss value; delta A S1 % is the result value of the output.
3. The line loss analysis method for correcting the technical line loss rate as claimed in claim 2, wherein in step S103, the power loss increment coefficient K is calculated according to different conditions and different methods:
(a) one-phase heavy load and two-phase light load
Assuming that the A phase is loaded with heavy load and the B, C phase is loaded with light load, I a ＝(1+B)·I cp ，
Current I of neutral line when three phases are symmetrical O ＝32BI cp ；
Power loss Δ P per unit length line 1 Comprises the following steps:
calculating a power loss increment coefficient K1:
in the formula, Δ P is the current I of the neutral line with completely balanced three-phase load O The power loss per unit length of line is 0,
r is the resistance of the circuit with unit length;
(b) one phase load is heavy, one phase load is light, and the load of the third phase is the average load
Assuming that the A phase is loaded with a heavy load, the B phase is loaded with a light load, and the C phase is loaded with an average value, then I a ＝(1+B)I cp ，I b ＝(1-B)I cp ，I c ＝I cp (ii) a In the case of three-phase symmetry, the power loss per unit length of line is:
calculating a power loss increment coefficient, wherein the value of the power loss increment coefficient is K2:
(c) one phase load is heavy and two phase load is light
Let I a ＝(1-2B)I cp ，I b ＝I c ＝(1+B)I cp In the case of three-phase symmetry, the current I of the neutral line o ＝3BI cp The power loss per unit length of line is:
calculating the increment coefficient of the power loss, wherein the value of the increment coefficient of the power loss is K3:
4. the line loss analysis method for correcting the technical line loss rate according to claim 1, wherein the degree of the influence of the reactive power compensation deficiency factor on the line loss rate of the distribution room is performed according to the following steps:
s201, obtaining second operation data, wherein the second operation data comprise active power P, reactive power Q, apparent power S and a theoretical line loss value of a transformer area;
s202, calculating the power factor according to the second operation data in the step S201
S203, calculating and analyzing a relation curve between the power factor and the line loss electric quantity in the step S202;
s204, calculating a corrected line loss rate after the line loss electric quantity is reduced and removed;
and S205, outputting a conclusion of influence degree of reactive power compensation insufficient factors on the line loss of the transformer area.
5. The method for analyzing line loss according to claim 4, wherein the line loss correction is performed by a line loss rate correction unit,
in step S202, the power factor
Calculated as follows:
wherein the power factor varies between 0 and 1, i.e.
In step S203, when the power factor is decreased
Is improved to
The reactive load reduced in time is:
in the formula, Q zd To reduce reactive load; p pj Is the average active load;
the calculation formula of the line loss rate is as follows:
the method for calculating the increased line loss electric quantity delta F caused by the reactive power compensation insufficient factor comprises the following steps:
Δ F ═ supply amount ═ line loss rate ═ Δ P
Calculating the corrected line loss rate after eliminating the increased line loss electric quantity:
the influence degree of the reactive compensation deficiency factors on the line loss of the transformer area is expressed as follows:
ΔA S ％＝A S1 ％-A S ％
in the formula (I), the compound is shown in the specification,
represents the actual finished line loss value; delta A S % is the result value of the output.
6. The line loss analysis method for correcting the technical line loss rate according to claim 1, wherein the degree of influence of the station area heavy overload factor on the station area line loss rate is performed according to the following steps:
s301, third operation data are obtained, and the third operation data comprise head end voltage U 1 Terminal voltage U 2 Current flowing through the line
Maximum load rate of transformer in transformer area and three-phase active power P at tail end of line in same time period 2 And reactive power Q 2 Calculating an equivalent impedance R + jX according to the theoretical line loss value of the transformer area;
s302, calculating power loss generated in impedance of a three-phase power supply line of a distribution room;
s303, according to the maximum load rate of the transformer in the transformer area in the step S301, the apparent power loss S of the transformer during heavy load operation is solved T Root of Chinese scholar treeObtaining rated capacity S of transformer according to the type of the transformer N Impedance loss value delta P of transformer k Impedance voltage percent U k % and percent impedance Current I 0 ％；
S304, calculating power loss generated in the three-phase transformer of the transformer area;
s305, analyzing the load condition of the distribution room after line loss correction by the distribution room heavy overload factor technology, and reducing the corrected line loss rate after eliminating the increased line loss electric quantity;
and S306, outputting a conclusion of the influence degree of the heavy overload factors of the transformer area on the line loss of the transformer area.
7. The line loss analyzing method for correcting the technical line loss rate as claimed in claim 6, wherein the step S301 comprises the steps of:
according to
Obtaining Δ a, Δ P ═ 3I, can be obtained 2 R l Then R can be obtained l ，
So as to solve and obtain the equivalent power supply radius l of the distribution room line according to
Determining the equivalent impedance X, D of the line m The geometric mean distance between the three-phase wires; r is the calculated radius of the wire;
in step S302, the power loss is calculated according to the following formula:
in the formula: r + jX is the impedance of one phase of the line; p 2 、Q 2 Three-phase active power and reactive power flowing through the tail end of the line impedance; u shape 2 Approximate line end line voltage for line end powerThe time can be expressed by the rated voltage of the line;
referred to as the active power loss in the line resistance,
referred to as reactive power loss in line reactance;
in step S304, the power loss generated in the three-phase transformer is calculated according to the following formula:
in the formula (I), the compound is shown in the specification,
the total loss of the three-phase transformer; r is T +jX T Impedance for one phase of the transformer; p T 、Q T Is the active and reactive power on the impedance of the transformer; u shape 2 The voltage is the voltage at the tail end of the equivalent circuit of the transformer;
wherein:
the increased power loss caused by the heavy overload factor of the transformer area is as follows:
ΔF＝(ΔS 1 -ΔS 0 )T
in step S305, the corrected line loss rate after removing the increased line loss electric quantity is reduced, and the specific calculation method is as follows:
the conclusion of the influence degree of the transformer heavy load overload on the transformer area line loss is represented by the following formula:
ΔA S ％＝A S1 ％-A S ％
in the formula (I), the compound is shown in the specification,
represents the actual finished line loss value; delta A S % is the result value of the output.
8. The line loss analysis method for correcting the technical line loss rate according to any one of claims 1 to 7, wherein the influence degree of the power supply line radius overlong factor on the line loss rate of the transformer area is performed according to the following steps:
s401, fourth operation data are obtained, wherein the fourth operation data comprise the radius length of a power supply line of a distribution room and a theoretical line loss value of the distribution room;
s402, calculating a resistance value of a power supply line according to the radius length of the power supply line of the transformer area and the ambient temperature value of the equipment;
s403, calculating power loss of the line according to the resistance value calculated in the step S402 and by combining the input power and the input voltage of the line;
s404, calculating the increased line loss electric quantity caused by the factor of overlong power supply radius of the power receiving line, and calculating the line loss rate after the increased line loss electric quantity is reduced and eliminated;
and S405, outputting a conclusion of the influence degree of the factor of the overlong radius of the power supply line on the line loss rate of the transformer area.
9. The line loss analyzing method for correcting the technical line loss rate according to claim 8, wherein in step S402, the resistance value of the power feeding line is calculated according to the following formula:
in the formula, S represents the sectional area of a conductive part of a lead, rho represents the resistivity of the lead, l is the length of the lead, and gamma is the conductivity of a lead material; r is 1 ＝r 20 [1+α(t-20)]Wherein r is 1 、r 20 Respectively representing resistance values at the temperature t and 20 ℃, wherein alpha is a resistance temperature coefficient;
in step S403, the power loss calculation formula of the line is:
in the formula, U represents three-phase line voltage, and P represents transmitted active power;
when the radius of the power supply line is from l 1 Is reduced to l 0 The power loss reduced in time is:
in step S404, the line loss caused by the technical reason that the radius of the power supply line is too long is calculated as:
in step S405, the line loss rate after the increased power loss is removed is calculated:
the influence degree of the overlong radius of the power supply line on the line loss of the transformer area is represented by the following formula:
ΔA S ％＝A S1 ％-A S ％
in the formula, A S1 % represents the actual finished line loss value; delta A S % is the result value of the output.
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