JPH1146445A - Phase modifying facility control method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phase modifying facility control method which can raise the power factor without being accompanied with abnormal rise of circuit voltage. SOLUTION: A device is provided with a fussy inference part 10, which performs fussy inference using a plurality of fussy rules, where at least one hand out of the circuit voltage detected from power distribution line 2 and the content of higher harmonic waves, and the reactive power, are made former case parameters, and the sensitivity correction factor used for settling the dead zone to the reactive power is made a latter case parameter. The power factor is raised without elevating circuit voltage abnormally and also while suppressing the content of higher harmonics by making the fussy inference part 10 output the value of the sensitivity correction factor corresponding to the detected value of the reactive power detected on occasion from the distribution line 2 and the detected value of the circuit voltage or the content of higher harmonic waves, and settling the dead zone of the reactive power, using this sensitivity correction factor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for controlling the input and release of a power capacitor of a phase adjustment facility provided in a power receiving and distribution facility, and to a control device used to execute the method. .

[0002]

2. Description of the Related Art In a power receiving and distributing facility, a phase modulating facility is installed in order to improve a load power factor, improve a transformer utilization rate and reduce a power loss. Generally, the phase adjustment equipment installed in the power receiving and distribution equipment includes a power capacitor, a switchgear for supplying the power capacitor to the distribution line and opening the distribution line, and an automatic power factor adjuster. Then, when the reactive power detected from the distribution line exceeds a predetermined dead zone, the automatic power factor adjuster gives a switching command or an open circuit command to the switching device to turn on or open the capacitor.

[0003]

When a power capacitor is inserted into a distribution line, the circuit voltage changes due to the influence of the reactance of the power supply. However, in the conventional phase adjustment equipment, the capacitor is used only for the purpose of improving the power factor. Since the control of turning on and off of the capacitor is performed, the circuit voltage may be excessively increased or decreased depending on the amount of opening or closing of the capacitor, which may adversely affect the load.

[0004] That is, if the voltage supplied to the load equipment becomes excessive, depending on the type of load, the power consumption increases, and at the same time, the temperature of the load itself increases, and the life of the load may be shortened. Conversely, when the voltage supplied to the load is too low, the performance of the load cannot be sufficiently exhibited.

[0005] The power capacitor has a function of absorbing harmonics generated from load equipment or the like. Conventionally, however, the turning on and off of the capacitor is controlled solely for the purpose of improving the power factor. No consideration was given to suppressing the waves, so that the effect of reducing the content of harmonics contained in the circuit voltage could not be expected from the phase adjustment equipment.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for controlling a phase adjustment facility and a control apparatus for a phase adjustment facility used for implementing the control method, wherein the power factor can be improved while suppressing a change in circuit voltage. Is to provide.

Another object of the present invention is to provide a method for controlling a phase adjustment facility and a control method capable of improving the power factor and reducing the content of harmonics in a circuit voltage. It is to provide a control device.

Still another object of the present invention is to improve the power factor while suppressing the change in the circuit voltage, and to reduce the content of harmonics in the circuit voltage. An object of the present invention is to provide a control method and a control device for implementing the control method.

[0009]

SUMMARY OF THE INVENTION According to the present invention, when the reactive power detected from a distribution line changes from a dead zone to a lag side or an advancing side, the electric power of a phase adjustment facility connected to the distribution line is changed. The present invention relates to a method for controlling a phase adjustment facility for controlling a reactive power to fall within a dead zone by turning on or off a capacitor for use, and a control device used for implementing the method.

[0010] In the control method according to the present invention, at least one of the circuit voltage detected from the distribution line and the harmonic content in the circuit voltage and the reactive power are used as state information indicating the state of the distribution line. A plurality of fuzzy rules in which the state of each variable is expressed stepwise by a plurality of fuzzy labels using the state information as a consequent part variable and a dead zone setting variable used for setting a dead zone as a consequent variable, By performing fuzzy inference using a membership function that defines the degree to which the constitutive variable conforms to each fuzzy label concept and a membership function that defines the degree to which the consequent variable conforms to each fuzzy label. Fuzzy inference means is provided for outputting the value of the consequent variable corresponding to the value of the consequent variable. The detected value of the state information detected from the distribution line at any time is input to the fuzzy inference means, and the value of the dead zone setting variable corresponding to the detected value of the detected state information is output from the fuzzy inference means. The dead zone is determined using the value of the dead zone setting variable output from the inference means.

[0011] The phase control equipment control device according to the present invention is a state control device that indicates at least one of the circuit voltage of the distribution line and the harmonic content in the circuit voltage and the reactive power flowing through the distribution line to indicate the state of the distribution line. A state information detecting section for detecting as information, a dead zone setting means for determining a dead zone of reactive power corresponding to state information obtained as needed from the state information detecting section, and a dead zone in which the reactive power detected from the state information detecting section is set. And an output control unit that outputs a command signal for instructing turning on or off of a power capacitor of the phase adjustment equipment connected to the distribution line when the phase shifts to the lagging side or the leading side due to deviation. You.

The dead zone setting means sets the state information obtained from the state information detecting unit as a consequent part variable, and sets a dead zone setting variable used for setting the dead band as a consequent part variable, and sets a plurality of states of each variable. A plurality of fuzzy rules expressed stepwise using the fuzzy labels, a membership function defining the degree to which the antecedent variable conforms to the concept of each fuzzy label, and the consequent variable being the concept of each fuzzy label A fuzzy inference unit that outputs a value of a dead zone setting variable corresponding to a detection value of state information that is input as needed by performing a fuzzy inference using a membership function that defines a degree of conformity with the fuzzy inference unit; And a calculation unit for performing at least calculation processing for determining the dead zone using the value of the dead zone setting variable output from the control unit. That.

As described above, at least one of the circuit voltage and the harmonic content and the reactive power are used as state information indicating the state of the distribution line, and the state information is used as a variable of the antecedent and a dead zone is set. Fuzzy rules with the dead zone setting variable used as the consequent variable, a membership function that defines the degree to which the antecedent variable conforms to the concept of each fuzzy label, and the consequent variable The value of the dead zone setting variable corresponding to the detected value of the state information is obtained by performing fuzzy inference using a membership function that defines the degree of conformity with the concept of the label, and the value of the dead zone setting variable is obtained. If the dead zone is set based on this, it is possible to control the reactive power to be within the dead zone while suppressing a change in the circuit voltage. It can be prevented from being lowered circuit voltage or excessively increased by performing adjustment and the.

In the case where the content of the harmonic component is adopted as the state information as the antecedent variable, the power factor is improved, and at the same time, when the content of the harmonic contained in the circuit voltage is large, the power capacitor is not used. By increasing the input amount, it is possible to reduce the amount.

In order to set the dead zone, it is necessary to determine the threshold values on the leading and trailing sides. In the present invention, the threshold values on the leading and lagging sides of the dead zone are set to values corresponding to the state of the distribution line at that time based on the result of the fuzzy inference. In determining the dead zone, the width of the dead zone may always be constant, or may be appropriately changed according to the state of the distribution line.

The dead zone setting variable may be any numerical value that can be used to determine the dead zone. This dead zone setting variable may be a numerical value representing the dead zone itself to be set, or a numerical value indirectly defining the dead zone. For example, by keeping the width of the dead zone constant, and moving the thresholds on the leading and lagging sides of the dead zone to the leading or lagging side by a predetermined reactive power value, it was possible to cope with the situation of the distribution line at that time. When setting a dead zone,
The shift amount of the dead zone is calculated by multiplying the shift amount of the dead zone as a reference by the sensitivity correction coefficient Kf, and the dead zone is shifted to the leading side or the lagging side by the calculated shift amount, so that the dead line is distributed. In this case, the sensitivity correction coefficient Kf can be used as a dead zone setting variable.

As a method of fuzzy inference, an evaluation value ri of the antecedent part of each rule is obtained by taking a logical product (MIN) of variables of the antecedent part of each fuzzy rule, and the same rule as the evaluation value ri is obtained. The fuzzy set obtained by ANDing the fuzzy set of the consequent variable with the fuzzy set is determined as the conclusion of each rule, and the logical sum (MAX) of the conclusions obtained for all the fuzzy rules is calculated as the fuzzy set of the conclusion of the rule group. Value (ri) of the antecedent part of each rule is obtained by taking the logical product (MIN) of the antecedent variable of each fuzzy rule and the same rule as the evaluation value ri The fuzzy set obtained by taking the algebraic product of the consequent variable with the fuzzy set is taken as the conclusion of each rule, and the logical sum (MAX) of the conclusions of all fuzzy rules is taken as the fuzzy And a method of a set, various methods are known, in carrying out the present invention may be used to select how the proper results are obtained.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of the configuration of a phase adjustment facility to which the control method of the present invention is applied and a control device for implementing the control method of the present invention. In FIG. vessel,
Reference numeral 2 denotes a distribution line connected to the secondary side of the transformer 1, and reference numeral 3 denotes a plurality of capacitor banks. Each capacitor bank 3 basically includes a power capacitor C and a series reactor Ls connected in series to the power capacitor C.
When the adjustment request amount of the late-phase reactive power is large, a parallel reactor (not shown) may be further provided. Each capacitor bank 3 is connected to the distribution line 2 via a switch SW, and by turning on and off each switch SW, each capacitor bank 3 is input to the distribution line 2 or is connected to the distribution line 2. It is designed to be open. The switches SW, SW,... Provided between the series of capacitor banks 3, 3,.

Reference numeral 5 denotes a reactive power detector for detecting the reactive power of the distribution line 2, reference numeral 6 denotes a voltage detector for detecting a circuit voltage of the distribution line 2, and reference numeral 7 denotes a harmonic detector for detecting a harmonic content of the circuit voltage. The outputs of the current transformer 8 and the instrument transformer 9 attached to the distribution line 2 are input to the reactive power detector 5, and the instrument transformer is connected to the voltage detector 6 and the harmonic detector 7. 9 is input.

The outputs of the reactive power detector 5, voltage detector 6, and harmonic detector 7 are input to a fuzzy inference unit 10,
The output of the fuzzy inference unit 10 is input to the calculation unit 11 together with the output of the reactive power detection unit 5. The output of the arithmetic unit 11 is input to the output control unit 12, and a closing command and an opening command are given from the output control unit 12 to a predetermined switch SW of the switching device 4.

The fuzzy inference unit 10 includes a reactive power detection unit 5
The reactive power detected by the above, the circuit voltage detected by the voltage detector 6 and the harmonic content detected by the harmonic detector 7 are used as variables in the antecedent part, and a dead zone used for setting a dead zone of the reactive power. A plurality of fuzzy rules that use a setting variable as a consequent variable, a membership function that specifies the relationship between the antecedent variable and the fuzzy label, and a membership function that specifies the relationship between the consequent variable and the fuzzy label By performing fuzzy inference using the above, it is possible to suppress the abnormal change of the circuit voltage and to reduce the harmonic content in the circuit voltage, and to insert the capacitor or In order to perform the opening, the values of the dead zone setting variables corresponding to the detected values of the reactive power, the circuit voltage, and the harmonic content that are input as needed are calculated.

The calculation unit 11 performs a calculation process necessary for determining a dead zone using the value of the dead zone setting variable given from the fuzzy inference unit 10. When the value of the dead zone setting variable is changed, , A process for changing the threshold values on the leading and trailing sides of the dead zone is performed. For example, in a case where the width of the dead zone is fixed and a method of appropriately changing the dead zone by moving the threshold values on the leading side and the lagging side is used, the fuzzy inference unit 10 sends a reference shift of each threshold value of the dead zone. The value of the sensitivity correction coefficient Kf by which the amount is multiplied is output, and the calculation unit 11 performs a calculation by multiplying the sensitivity correction coefficient Kf by the reference movement amount to calculate the movement amount of each threshold of the dead zone. The calculation unit 11 also determines whether the reactive power detected by the reactive power detection unit 5 deviates from the set dead zone (changed as needed).

If the output control unit 12 determines that the detected reactive power deviates from the dead zone to the late side as a result of the determination made by the calculation unit 11, the output control unit 12 An input command is given to turn on one switch SW, and one capacitor bank is turned on. If the detected reactive power still deviates from the dead zone to the late side after one capacitor bank is inserted, another capacitor bank is inserted. When it is detected that the detected reactive power deviates from the dead zone to the leading side, an open command is given to the switching device 4 to open one of the capacitor banks that have already been turned on. As a result, if the reactive power still deviates from the dead zone toward the leading side, the further supplied capacitor bank is opened. With these operations, control is performed so that the reactive power is within the dead zone.

In the example shown in FIG. 1, the reactive power detector 5
A state information detecting unit 13 for detecting the reactive power, the circuit voltage, and the harmonic content in the circuit voltage as state information indicating the state of the distribution line by the voltage detecting unit 6 and the harmonic detecting unit 7
Is configured by the fuzzy inference unit 10 and the arithmetic unit 11 to set a dead zone for reactive power.
4 are configured.

As described above, in order to set the dead zone, it is necessary to determine the thresholds on the leading and trailing sides of the dead zone. In the present invention, based on the result of the fuzzy inference, each of the threshold on the leading side and the threshold on the lagging side of the dead zone can be appropriately changed. By making the threshold on the leading side and the threshold on the lagging side of the dead zone according to the state of the distribution line the same reactive power value to the leading or lagging side,
A dead zone corresponding to the state of the distribution line (necessary for suppressing a change in circuit voltage and reducing the content of harmonics while keeping the reactive power within a predetermined range) is set.

In this case, the moving amount of the dead zone itself can be used as the dead zone setting variable for setting the dead band. However, in the following description, the moving amount of the dead zone to the leading side or the lagging side will be described. In order to determine, the shift amount of the dead zone is calculated by multiplying the reference shift amount Po by the sensitivity correction coefficient Kf using the sensitivity correction coefficient Kf.

The reactive power Pf is normalized based on the capacity Pc of one capacitor bank of the phase adjustment equipment (capacitor capacity to be supplied at one time in the phase adjustment equipment), and is expressed in%. That is, assuming that the actual reactive power is Px, the reactive power Pf
Is represented by Pf = (Px / Pc) × 100 [%].

Here, the dead band width of the reactive power on the leading side and the dead band width on the lagging side are + Pa [%] and -P, respectively.
In the case of a [%], a sensitivity correction coefficient Kf having a positive / negative sign and a reference moving amount Po = Pa / always having a positive sign.
Using Pf = Kf × Po, the movement amount Ps of the dead zone toward the leading side or the lagging side is calculated using Kf [%]. If the calculated Ps is positive, Ps
The dead band (having a width of ± Pa%) is shifted by [%], and when the calculated Ps is negative, Ps [%] is shifted to the late side.
Just move the dead zone.

For example, if the widths of the dead zones on the leading and lag sides are both Pa = 100 [%] (the capacity of one capacitor bank) as an initial value, the reference change amount Po of the dead zone is set to 25 ( = 100/4) [%], and when the sensitivity correction coefficient Kf obtained by fuzzy inference is 0, as shown in FIG. 2A, the moving amount of the dead zone is set to zero, and the zero point of the reactive power Pf is set. A dead zone (± 100 [%]) is set around.

In the case of Kf = + 4.0, FIG.
As shown in (B), the dead zone is set to 100 (Kf ×
Po = 25 × 4.0) [%] and Kf = −4.0.
In the case of (2), as shown in FIG. 2C, the dead zone is shifted by 100 (Kf × Po = 25 × 4.0) [%] to the late side.

Here, when the dead zone is set as shown in FIG. 2A, the reactive power Pf becomes -100 [%].
(When the delayed reactive power exceeding the amount corresponding to the capacity of one capacitor bank is generated), a closing command is given to the switchgear 4 so that one capacitor bank 3
Into the distribution line. After putting in this capacitor bank,
A new sensitivity correction coefficient is calculated again by fuzzy inference,
A new dead zone is set based on the sensitivity correction coefficient.
When the detected reactive power deviates from the new dead zone to the late side, a switch-on command is given to the switchgear 4 again to turn on one capacitor bank 3.

When the detected reactive power deviates from the dead zone toward the leading side, for example, when Kf = 4.0 as shown in FIG. 2B, the reactive power exceeds 200%. When the advanced reactive power is generated, an open command is given to the switchgear 4 to disconnect one of the already supplied capacitor banks from the distribution line 2.

Hereinafter, the sensitivity correction coefficient K is calculated by fuzzy inference.
The process of obtaining f will be described by taking the case of the MIN-MAX method as an example.

In performing the fuzzy inference, a plurality of fuzzy labels having a specific concept are used in order to gradually represent the degree of the state of information to be input and the degree of the magnitude of a variable to be obtained as a conclusion. . Table 1 shows an example of a fuzzy label used to represent the magnitude of each of the reactive power Pf, the circuit voltage Vf, the harmonic content H, and the sensitivity correction coefficient Kf.

[0035]

[Table 1] In the example shown in Table 1, the fuzzy labels PB, PM, ZE, NM, and NB having five different concepts with respect to the reactive power Pf, the circuit voltage Vf, and the harmonic content H are used. Indicates degree. For the sensitivity correction coefficient Kf, PB, PM, PS, ZE, NS, NM,
The magnitude of the size is expressed using fuzzy labels of seven stages of NB. These fuzzy labels are used to represent almost the same concept, but the precise meaning of each differs for each variable used. For example,
PM used for reactive power means that reactive power is "slightly late", PM used for circuit voltage means that circuit voltage is "slightly low", and harmonic content PM used for quantities means that the harmonic content is "slightly less". The sensitivity correction coefficient Kf
PM means that the sensitivity correction coefficient is “large”.

When performing fuzzy inference, a function (referred to as a membership function) that defines the relationship between the above-mentioned variables and the degree (fitness) μ that conforms to the concept of each fuzzy label is prepared. Together with If A is
B and Cis D, and ..., then X
is Y. A plurality of fuzzy rules in If-then format are created in consideration of empirical rules.

In the fuzzy rules of the If-then format, the conditional part following If is referred to as "antecedent part" and t
The conclusion following hen is referred to as the "consequence." In the present specification, variables constituting the antecedent part are referred to as antecedent variables, and variables constituting the consequent part are referred to as consequent variable.

In the present invention, at least one of the circuit voltage and the harmonic content detected from the distribution line and the reactive power are used as state information indicating the state of the distribution line, and the state information is used as an antecedent variable. A plurality of fuzzy rules are created by expressing the state of each variable in a stepwise manner using a plurality of fuzzy labels, with the dead zone setting variable used to set the dead zone as a consequent variable.

An example of the membership function used in the present invention is shown in FIGS. FIG. 3 shows the circuit voltage Vf and the fuzzy label P expressed in% normalized to the rated voltage.
FIG. 4 shows a membership function defining the relationship between B, PM, ZE, NM and NB. FIG. 4 shows the reactive power Pf normalized with respect to the capacitance of one capacitor bank and the fuzzy labels PB, PM, ZE, NM and NB. The membership function that defines the relationship with the NB is shown. FIG. 5 shows a membership function defining the relationship between the harmonic content H and the fuzzy labels PB, PM, ZE, NM, and NB. FIG. 6 shows the sensitivity correction coefficient Kf and the fuzzy labels PB, PM, PS, Z.
9 shows a membership function indicating a relationship with E, NS, NM, and NB. In these examples, a Z-shaped function is used as the membership function of the label PB used for the reactive power, the circuit voltage and the harmonic content, and the membership function of the label NB used for the sensitivity correction coefficient Kf.
Membership function of label NB used for reactive power, circuit voltage and harmonic content, and sensitivity correction coefficient Kf
As the membership function of the label PB used for
Shape functions are used. Labels PM, ZE, NM used for reactive power, circuit voltage and harmonic content
And a membership function of a triangle as a membership function of labels PM, PS, ZE, NS, and NM used for the sensitivity correction coefficient Kf.

Table 2 shows an example of a rule matrix defining the fuzzy rules used in the present invention.

[0041]

[Table 2] In the example shown in Table 2, in order to simplify the description, the reactive power Pf and the circuit voltage Vf are used as state information indicating the state of the distribution line. In Table 2, r1, r2,.
25 means Rule 1, Rule 2,... Rule 25, respectively, and Kf = P described under each of r1 to r25.
B,... Indicate the conclusions constituting the consequent part. In this rule matrix, “low, PB”, “slightly low, PM”,... Described in the first row indicate propositions of the antecedent part regarding the circuit voltage, and “low, PB” described in the first column. The description such as “Slow phase, PB”, “Slightly late, PM”,... Indicates the proposition of the antecedent part regarding the reactive power. At the intersection of each row and each column, the conclusion of the consequent part of the rule with the proposition shown at the left end of each row and the proposition shown at the top end of each column as the antecedent part is shown. . A series of fuzzy rules shown in the rule matrix of Table 2 is defined as If to then.
It is as follows when written down in the sentence of the form.

Rule 1: If Vf is PB and Pf is PB then Kf is PB. Rule 2: If Vf is PM and Pf is PB then Kf is PB. Rule 3: If Vf is ZE and Pf is PB then Kf is PM. Rule 4: If Vf is NM and Pf is PB then Kf is PS. Rule 5: If Vf is NB and Pf is PB then Kf is ZE. Rule 6: If Vf is PB and Pf is PM then Kf is PB. Rule 7: If Vf is PM and Pf is PM then Kf is PM. Rule 8: If Vf is ZE and Pf is PM then Kf is PS. Rule 9: If Vf is NM and Pf is PM then Kf is ZE. Rule 10: If Vf is NB and Pf is PM then Kf is NS. ............ Rule 25: If Vf is NB and Pf is NB then Kf is NB. As described above, when a fuzzy rule is created with the two variables of the circuit voltage and the reactive power as the antecedent variables and the sensitivity correction coefficient Kf as the consequent variable, as shown in FIG. When the voltage Vf is fuzzy labels PB, PM, ZE,
A membership function defining the degree of conformity with each concept of NM and NB, and, as shown in FIG. And a membership function defining the degree to which the sensitivity correction coefficient Kf conforms to each concept of the fuzzy labels NB, NM, NS, ZE, PS, PM and PB, as shown in FIG. And the sensitivity correction coefficient Kf is obtained by applying the MIN-MAX method.

Assuming that the circuit voltage Vf is about 98%, as shown in FIG. 3, the degree of conformity μ of the circuit voltage to the concept of the fuzzy label PM is 0.6, and the concept of the fuzzy label ZE is 0.6. Is 0.35. The fitness of the circuit voltage to other fuzzy label concepts is all zero.

Assuming that the reactive power Pf is -25 [%], as shown in FIG. 4, the degree of conformity of Pf with respect to the concept of fuzzy label PM is 0.5 and that of Pf with respect to the concept of fuzzy label ZE. The fitness is also 0.5. The degree of conformity of the reactive power to other fuzzy label concepts is zero.
It is.

Here, for each of rules 1 to 25, the minimum value of the degree of conformity of the antecedent variable to the concept of the fuzzy label is determined as the antecedent part evaluation value ri. The rule indicating that the evaluation value ri of the antecedent part is a value other than 0 is rule 7,
In other rules, the evaluation value ri of the antecedent part is 0.

After the evaluation value ri of the antecedent of each rule is obtained in this way, the membership function for the fuzzy label that gives the conclusion of the consequent of each rule is calculated as the evaluation value of the antecedent of the rule. cutting by ri (calculating the logical product)
The upper part is removed from the evaluation value ri of the membership function to obtain a fuzzy set as the conclusion of each rule.

The above example is specifically described as follows.
Is "If Vf is PM and Pfis PM then Kf
is PM. In this case, the P of the circuit voltage Vf
The conformity to M is 0.6, and the conformity of reactive power Pf to PM is 0.5. Of these, the smaller one, 0.5, is used as the evaluation value ri of the antecedent part of rule 7, and FIG.
As shown in (A), the membership function of the label PM, which gives the conclusion of the consequent part of Rule 7, is changed to the evaluation value ri of the antecedent part.
By cutting at 0.5, the part above 0.5 is removed to obtain a fuzzy set M7 (the hatched part in FIG. 7A) as the conclusion of Rule 7.

Rule 8 states that “If Vf is ZE and P
f is PM then Kf is PS. Where the fitness of Vf to ZE is 0.35 and Pf of Pf
The fitness for M is 0.5. The smaller one of these fitness levels, “0.35”, is used as the evaluation value ri of the antecedent part of rule 8, and as shown in FIG. 7B, the membership function of the label PS that gives the conclusion of the consequent part Is the evaluation value r of the antecedent
Cutting is performed at i = 0.35 to obtain a fuzzy set M8 as the conclusion of rule 8.

Rule 12 states that “If Vf is PM and
Pf is ZE then Kf is PS. Where the conformity of Vf to PM is 0.6, and Z of Pf is Z
The degree of conformity to E is 0.5. Among the degrees of conformity, the smaller “0.5” is set as the evaluation value ri of the antecedent part of the rule 12, and as shown in FIG. 7C, the member of the label PS that gives the conclusion of the consequent part of the rule 12. The ship function is cut at the evaluation value 0.5 of the antecedent part, and a fuzzy set M12 as a conclusion of the rule 12 is obtained.

Rule 13 states that “If Vf is ZE and
Pf is ZE then Kf is ZE. Where the fitness of Vf to ZE is 0.35 and the fitness of Pf to ZE is 0.5. The smaller one of these fitness levels, "0.35", is used as the evaluation value ri of the antecedent part of the rule 13, and as shown in FIG. 7D, the membership function of the label ZE that gives the conclusion of the consequent part The evaluation value of the antecedent part is 0.35
And a fuzzy set M13 as a conclusion of the rule 13 is obtained.

In other rules, the evaluation value of the antecedent part is 0, so if the membership function that gives the conclusion of the consequent part is cut off based on the evaluation value, the fuzzy set as the conclusion of the rule becomes zero.

After obtaining a fuzzy set as a conclusion for all rules, a logical sum of the obtained fuzzy sets is obtained to obtain a fuzzy set as a conclusion. In the above example, the logical sum of the fuzzy sets M7, M8, M12, and M13 indicated by oblique lines in FIGS. 7A to 7D is obtained.
As shown by hatching in FIG. 6, a fuzzy set M is obtained as a conclusion.

Next, the center of gravity G of the fuzzy set M is obtained and defuzzified, and a sensitivity correction coefficient Kf corresponding to the center of gravity G is output as an inference result. The sensitivity correction coefficient Kf obtained in this manner is used as a reference movement amount (25 in the above example).
[%]) To obtain a moving amount of the dead zone and set a new dead zone.

In the above example, the arithmetic unit 11 determines whether or not the reactive power detected by the reactive power detection unit 5 has deviated from the set dead zone. You may.

[0055]

As described above, according to the present invention, at least one of the circuit voltage and the harmonic content and the reactive power are used as the antecedent variables of the fuzzy rule, and the dead zone used to determine the dead zone of the reactive power. The fuzzy inference is performed using the setting variable as the consequent variable of the fuzzy rule, so that the dead zone corresponding to the state of the distribution line is determined.
The power factor can be improved by adjusting the reactive power to an appropriate value while suppressing the change in the circuit voltage, so that the utilization factor of the transformer can be improved and the power loss can be reduced. In addition, the effect of suppressing the change in the circuit voltage can prevent an increase in power consumption of the load equipment, a shortened life, or a decrease in performance.

Further, in the present invention, when the harmonic content is used as the antecedent variable of the fuzzy rule together with the reactive power, the power factor can be adjusted and the harmonic component can be reduced at the same time.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a configuration of a phase adjustment facility to which the present invention is applied;
FIG. 2 is a block diagram illustrating a configuration example of a phase adjustment facility control device according to the present invention.

FIGS. 2A to 2C are explanatory diagrams illustrating a dead zone set for reactive power.

FIG. 3 is a diagram showing a membership function used when performing fuzzy inference.

FIG. 4 is a diagram showing another membership function used when performing fuzzy inference.

FIG. 5 is a diagram showing still another membership function used when performing fuzzy inference.

FIG. 6 is a diagram showing still another membership function used when performing fuzzy inference.

FIGS. 7A to 7D are explanatory diagrams illustrating a process of fuzzy inference.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transformer 2 Distribution line 3 Capacitor bank 4 Switchgear 5 Reactive power detector 6 Voltage detector 7 Harmonic detector 8 Current transformer 9 Instrument transformer C Capacitor Ls Series reactor

Claims (2)

[Claims] When a reactive power detected from a distribution line deviates from a dead zone and changes to a phase delay side or a phase advance side, a power capacitor of a phase adjustment facility connected to the distribution line is turned on or off. In the phase control equipment control method for controlling the reactive power to fall within the dead zone by performing the method, at least one of a circuit voltage detected from the distribution line and a harmonic content in the circuit voltage is invalid. The electric power is used as state information indicating the state of the distribution line, the state information is used as a consequent part variable, and a dead zone setting variable used for determining the dead band is used as a consequent part variable. A plurality of fuzzy rules expressed step by step, a membership function that defines the degree to which the antecedent variable conforms to the concept of each fuzzy label, and Fuzzy inference means for outputting a value of the consequent variable conforming to the value of the antecedent variable by performing fuzzy inference using a membership function for defining a degree of conformity with the concept of fuzzy label; The detected value of the state information detected from the electric wire at any time is input to the fuzzy inference means, and the value of the dead zone setting variable corresponding to the detected value of the detected state information is output from the fuzzy inference means. A method for controlling a phase adjustment facility, wherein the dead zone is determined using a value of a dead zone setting variable output from the means. 2. A state information detecting section for detecting at least one of a circuit voltage of a distribution line and a harmonic content in the circuit voltage and reactive power as state information indicating a state of the distribution line, and the state A dead zone setting means for determining a dead zone of reactive power corresponding to state information obtained as needed from an information detecting unit; and the reactive power detected from the state information detecting unit changes to a slow side or a fast side outside the dead zone. And an output control unit that outputs a command signal for instructing turning on or off of a power capacitor of the phase adjustment equipment connected to the distribution line, the dead zone setting unit obtains from the state information detecting unit. The state information obtained is used as the antecedent part variable, and the dead zone setting variable used for setting the dead zone is used as the consequent part variable, and the state of each variable is displayed stepwise using a plurality of fuzzy labels. A plurality of fuzzy rules, a membership function defining the degree to which the antecedent variable conforms to each fuzzy label concept, and a membership function defining the degree to which the consequent variable conforms to each fuzzy label concept. A fuzzy inference unit that outputs a value of a dead zone setting variable corresponding to a detection value of state information input as needed by performing fuzzy inference using a function, and a dead zone setting variable output from the fuzzy inference unit. And a calculating unit that performs at least a calculating process for determining the dead zone using the value of (i).