JP2002281669A - Compensator for variation in distribution line voltage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distribution line voltage variation compensator which reduces the size of a static var compensator, and facilitates its assembling. SOLUTION: A step voltage regulator (SVR) 3 for a line and a static var compensator (SVC) 4 are connected to a distribution line 2. The SVR is caused to perform adjustment operation, so as to make distribution line voltage within a dead zone. The upper limit value for a control target voltage larger than the upper limit of the dead zone of the SVR, and a lower limit value for the control target voltage smaller than the lower limit value of the dead zone of the SVR, are set for the SVC. When the distribution line voltage of the installation point of the SVC is increased and decreased, adjustment operation is performed, which returns the distribution line voltage to the upper limit value and the lower limit value instantaneously, by injecting reactive current from the SVC to the distribution line, respectively. With the progress of the voltage adjustment operation by the SVR, a quantity of voltage compensation is transferred from the SVC to the SVR, and the output of the SVC is made zero, before the compensation operation is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distribution line voltage fluctuation compensating device for compensating for a voltage fluctuation of a distribution line.

[0002]

2. Description of the Related Art At present, in a distribution line, a voltage of the distribution line (hereinafter also referred to as a distribution line voltage) is adjusted by using a line voltage regulator (SVR). SVR (Step Voltage
Regulator) includes at least a tapping adjustment transformer for adjusting the voltage of the distribution line, a tap selector for selecting the tap of the adjustment transformer, and a control unit for controlling the tap selector. By switching the taps of the adjusting transformer, the distribution line voltage is adjusted so as to be within a dead zone including an appropriate reference value. The voltage adjustment by the tap switching is performed in steps in minutes. Therefore, when the distribution line voltage instantaneously decreases or increases due to sudden change of large capacity load connected to the distribution line or disconnection of large capacity distributed power supply,
The instantaneous voltage fluctuation cannot be compensated by SVR. Even if the fluctuation of the distribution line voltage is instantaneous,
If the fluctuation width is large, problems such as malfunction of home electric appliances and computers occur. In order to solve these problems, a voltage fluctuation compensator for compensating for instantaneous fluctuations in distribution line voltage is required. The components of the voltage fluctuation compensating device for compensating for fluctuations in the distribution line voltage are desirably small and lightweight so that they can be mounted on ordinary power poles, and must have as large a compensation capacity as possible. It is.

As a distribution line voltage fluctuation compensator for compensating for instantaneous voltage fluctuations, a static type reactive power compensator (S) for compensating for voltage fluctuations by supplying reactive power to distribution lines.
VC) has been put to practical use. SVC (Static Var Compe)
nsator) is also called a parallel compensator, and includes a reactive current generator that generates an arbitrary reactive current, a voltage detector that detects a distribution line voltage, and a current detector that detects an output current of the reactive power generator. And a control unit that controls the output (reactive current) of the reactive current generating unit so as to maintain the distribution line voltage at a reference value by using the output of the voltage detection unit and the output of the current detection unit as inputs. By controlling the reactive current injected into the distribution line when the fluctuation occurs, the voltage of the distribution line is instantaneously adjusted so as to be maintained at the reference value.

In order to compensate for fluctuations in distribution line voltage using only SVC, it is necessary to provide the SVC with a very large compensation capacity, and it is inevitable that the compensator becomes large. Therefore, in Japanese Patent Application Laid-Open No. 4-317523, when the fluctuation of the distribution line voltage occurs, the voltage fluctuation is first instantaneously compensated by the SVC, and then the compensation amount is adjusted for the existing line provided with the tapped adjustment transformer. The SVC and the SVC are shifted so as to gradually shift to the voltage regulator (SVR).
A voltage fluctuation compensating device has been proposed that reduces the required capacity of the SVC by operating the VR in cooperation.

In this proposed voltage fluctuation compensator, when a voltage fluctuation occurs, the voltage at the installation point is first controlled by SVC so as to be equal to a preset reference value (constant), and a predetermined time elapses. After that, by issuing a tap position change command to the SVR, the SVC compensation amount is shifted to the SVR.

FIG. 15 shows the operation of the proposed voltage fluctuation compensating apparatus. FIG. 15 (A) shows the distribution line voltage at the installation point of the SVC, and FIG. 15 (B) shows the distribution line voltage at the installation point of the SVC. It shows the amount of voltage compensation for each device (SVC and SVR). Further, ΔV in FIG. 6A indicates the tap width (voltage for one tap) of the SVR. The solid line a in FIG. 15A shows the distribution line voltage at the SVC installation point when voltage compensation is performed by SVR and SVC, and the broken line b shows the distribution line voltage when compensation is performed only by SVR. I have. FIG.
The solid line a in (B) shows the amount of voltage compensation by SVC for the distribution line voltage at the installation point of SVC, and the broken line b shows the amount of voltage compensation by SVR.

In the example shown in FIG. 15, when the distribution line voltage decreases at time t1, the SVC first adjusts the voltage so that the distribution line voltage instantaneously returns to the reference value Vo. Voltage adjustment has started. SVR
Is performed stepwise by one tap width.
In the voltage fluctuation compensator already proposed, the amount of compensation by SVR is increased at regular time intervals, and the amount of compensation by SVC is decreased, so that the amount of compensation is shifted from SVC to SVR.

In this method, since the SVC operates so as to always maintain the distribution line voltage at the installation point at a set voltage (constant), when the distribution line voltage fluctuates, the SVC compensates for all fluctuations. Needs the necessary capacity.

Further, since the SVR can only adjust the voltage stepwise, the total voltage compensation amount cannot be shifted to the SVR, and the SVC is the tap width ΔV and the reference value of the distribution line voltage at the SVC installation point. It is necessary to output the reactive power for compensating the deviation from the above even when there is no voltage fluctuation.
Therefore, depending on the voltage fluctuation, S
It is necessary to make SVC bear a compensation amount close to one tap width of VR.

[0010]

As described above, in the conventional voltage fluctuation compensator, when the voltage fluctuation occurs, the SV
Since C was performing a compensation operation for returning the distribution line voltage to the reference value, it was necessary to provide the SVC with a large compensation capacity. In the conventional voltage fluctuation compensator, SVR
It was necessary to always output reactive power from the SVC so that the deviation between the tap width and the reference value became zero. Therefore, it was necessary to configure the SVC using a large and expensive device with a continuous rating. There was a problem of becoming large.

Furthermore, in the conventional voltage fluctuation compensating device, the SV
C and SVR are operated in cooperation to control the voltage compensation amount by SVC to shift to SVR.
It was necessary to exchange control signals between the control unit of C and the control unit of SVR. Therefore, there is a problem that communication equipment is required to perform communication between the SVC and the SVR, and equipment cost is increased. Further, in the conventional voltage fluctuation compensating apparatus, control is hindered when a communication error occurs, and thus there is a problem in reliability.

An object of the present invention is to provide a distribution line voltage fluctuation compensating device capable of compensating for fluctuations in distribution line voltage without increasing the size of the reactive power compensating device.

Another object of the present invention is to compensate for fluctuations in distribution line voltage without communication between the control unit of the reactive power compensator and the control unit of the line voltage regulator. To provide a distribution line voltage fluctuation compensating device.

[0014]

SUMMARY OF THE INVENTION A distribution line voltage fluctuation compensating apparatus according to the present invention comprises an adjusting transformer with a tap for adjusting the voltage of a distribution line, a tap selector for selecting a tap of the adjusting transformer, and a distribution line. A line voltage regulator having a tap switching control unit that controls a tap selector so that the voltage of the line falls within a dead zone including a reference value, and a line connected to a distribution line on the load side of the line voltage regulator. When the reactive current generator that supplies reactive current to the distribution line and the voltage of the distribution line exceed the control target voltage upper limit set to a value greater than the upper limit of the dead band, the voltage of the distribution line is controlled to the target voltage upper limit. The reactive current required to equalize the value is supplied from the reactive current generator to the distribution line, and the distribution is performed when the voltage of the distribution line is lower than the control target voltage lower limit set to a value lower than the lower limit of the dead zone. Control the voltage of the wire It composed of a reactive power compensator having a reactive current controller for controlling the reactive current generator to supply the distribution line reactive current required to be equal to the voltage limit value from the reactive current generator.

The control target voltage upper limit value is set to be equal to or less than the minimum value among the voltage upper limit values allowed to operate the load connected to the distribution line without any trouble. It is preferable that the voltage is set to be equal to or greater than the maximum value among the lower limit values of the voltage allowed to operate the load connected to the electric wire without any trouble.

The reactive current control section includes a current detection section for detecting an output current of the reactive current generation section, a voltage detection section for detecting a voltage of the distribution line, and a voltage detected by the voltage detection section for controlling a control target voltage upper limit. A compensation start command is issued when the voltage becomes higher than the control target voltage and when the voltage detected by the voltage detector becomes lower than the control target voltage lower limit, and the voltage detected by the voltage detector becomes the control target voltage upper limit. When the voltage detected by the voltage detection unit is equal to or higher than the control target voltage lower limit value, the voltage compensation start determination unit that generates a compensation stop command and the output of the reactive current generation unit maintain the same polarity. Compensation operation completion judgment unit that generates a compensation completion command when a compensation continuation command is issued and the polarity of the output of the reactive current generator changes, and controls when the voltage of the distribution line exceeds the control target voltage upper limit value A target voltage command value selector for selecting the target voltage upper limit value as the target voltage command value, and selecting the control target voltage lower limit value as the target voltage command value when the voltage of the distribution line is lower than the control target voltage lower limit value; A target reactive current calculation unit that calculates a target reactive current that needs to be supplied to the distribution line in order to reduce the deviation between the target voltage command value selected by the voltage command value selection unit and the voltage value detected by the voltage detection unit to zero When,
When the voltage compensation start determination unit generates a compensation start command and the compensation operation completion determination unit generates a compensation continuation command, the target output calculated from the reactive current generation unit by the target reactive current calculation unit is calculated. The current output from the reactive current generating unit to zero when the compensating operation completion determining unit generates the compensation completion command or when the voltage compensation start determining unit generates the compensation stop command. And a current command selection unit for generating a current command for instructing the current detection unit, and an operation amount of an output current of the reactive current generation unit necessary for matching the current detected by the current detection unit with the current specified by the current command. A configuration may be provided that includes an operation amount calculation unit that performs the calculation.

In this case, the reactive current generator is configured to adjust the output current in accordance with the manipulated variable obtained by the manipulated variable calculator to make the reactive current supplied to the distribution line coincide with the target reactive current.

With the above-described configuration, the reactive power compensator can be configured such that when there is a large voltage fluctuation, the line voltage regulator changes the tap to change the voltage of the distribution line to the control target voltage upper limit value and the control target voltage. Since voltage compensation is performed only for a short time until the voltage falls below the lower limit value, a reactive power compensator can be configured using components rated for a short time. Therefore, the variation of the distribution line voltage can be compensated without increasing the size of the reactive power compensator, and the mounting of the reactive power compensator can be facilitated.

Further, with the above configuration, the line voltage adjusting device and the reactive power compensating device perform the adjusting operation individually, so that the control unit of the reactive power compensating device and the control unit of the line voltage adjusting device are different from each other. Thus, fluctuations in the distribution line voltage can be compensated without performing communication.

In the above configuration, the voltage fluctuation is instantaneously compensated by the reactive power compensator when the distribution line voltage exceeds the control target voltage upper limit value and when the distribution line voltage becomes lower than the control target voltage lower limit value. However, if the distribution line configuration does not cause the distribution line voltage to be significantly lower than the lower limit of the dead zone, or if the voltage can be slightly lower than the lower limit of the dead zone, the present invention Of the distribution line voltage fluctuation compensating device according to the present invention, an adjustment transformer with a tap for adjusting the voltage of the distribution line, a tap selector for selecting the tap of the adjustment transformer, and the voltage of the distribution line within a dead zone including a reference value. Voltage regulator provided with a tap switching control unit for controlling the tap selector, and a reactive power supply connected to the distribution line on the load side of the line voltage regulator and supplying a reactive current to the distribution line Reactive current required to make the distribution line voltage equal to the control target voltage upper limit when the voltage of the generator and the distribution line exceeds the control target voltage upper limit set to a value larger than the upper limit of the dead zone And a reactive current control unit that controls the reactive current generation unit so that the reactive power is supplied from the reactive current generation unit to the distribution line.

In this case, it is preferable that the control target voltage upper limit value is set to be equal to or less than the minimum value of the voltage upper limit values allowed to operate the load connected to the distribution line without any trouble.

In this case, the reactive current control section includes a current detecting section for detecting an output current of the reactive current generating section, a voltage detecting section for detecting the voltage of the distribution line, and a voltage detected by the voltage detecting section for controlling the target voltage. A voltage compensation start determining unit that generates a compensation start command when the voltage is higher than the voltage upper limit, and generates a compensation stop command when the voltage detected by the voltage detector is equal to or lower than the control target voltage upper limit; A compensation operation completion determining unit that generates a compensation continuation command when the output of the generator maintains the same polarity, and generates a compensation completion command when the polarity of the output of the reactive current generator changes, and a control target voltage upper limit value Reactive current calculation unit that calculates the target reactive current that needs to be supplied to the distribution line to reduce the deviation between the voltage value detected by the voltage detection unit and the voltage detection unit, and the voltage compensation start determination unit generates a compensation start command And supplement When the operation completion determination unit is issuing the compensation continuation command, the current output from the reactive current generation unit is instructed to be the target reactive current calculated by the target reactive current calculation unit, and the compensation operation completion determination unit compensates. A current command selection unit that generates a current command to instruct the current output from the reactive current generation unit to be zero when a completion command is generated or the voltage compensation start determination unit is generating a compensation stop command, An operation amount calculation unit that calculates an operation amount of the output current of the reactive current generation unit necessary for matching the current detected by the current detection unit with the current specified by the current command can be provided. .

Also in this case, the reactive current generator is configured to adjust the output current in accordance with the manipulated variable obtained by the manipulated variable calculator to match the reactive current supplied to the distribution line with the target reactive current. I do.

In addition, when the distribution line voltage does not greatly exceed the upper limit of the dead band, or when the distribution line voltage slightly exceeds the upper limit of the dead band, there is no problem with the present invention. Of the distribution line voltage fluctuation compensating device according to the present invention, an adjustment transformer with a tap for adjusting the voltage of the distribution line, a tap selector for selecting the tap of the adjustment transformer, and the voltage of the distribution line within a dead zone including a reference value. Current regulator that is connected to the distribution line on the load side of the line voltage adjustment device and has a tap switching control unit that controls the tap selector, and supplies a reactive current to the distribution line. Invalid the reactive current required to make the distribution line voltage equal to the control target voltage lower limit when the voltage of the section and the distribution line is lower than the control target voltage lower limit set to a value smaller than the lower limit of the dead zone. Current It can be constituted by a reactive power compensator having a reactive current controller for controlling the reactive current generator to supply the distribution line from the raw part.

In this case, it is preferable that the control target voltage lower limit value is set to be equal to or more than the maximum value among the voltage lower limit values allowed to operate the load connected to the distribution line without any trouble.

In this case, the reactive current control section includes a current detecting section for detecting an output current of the reactive current generating section, a voltage detecting section for detecting the voltage of the distribution line, and a voltage detected by the voltage detecting section. A voltage compensation start determining unit that generates a compensation start command when the voltage is lower than the target voltage lower limit, and generates a compensation stop command when the voltage detected by the voltage detector is equal to or higher than the control target voltage lower limit. A compensating operation completion determining unit that generates a compensation continuation command when the output of the current generator maintains the same polarity, and generates a compensation completion command when the polarity of the output of the reactive current generator changes, and a control target voltage lower limit A target reactive current calculation unit that calculates a target reactive current that needs to be supplied to the distribution line in order to reduce the deviation between the voltage value and the voltage value detected by the voltage detection unit to zero, and a voltage compensation start determination unit that executes the compensation start command. Occurs And instructing that the current output from the reactive current generating section be the target reactive current calculated by the target reactive current calculating section when the compensating operation completion determining section has issued the compensation continuation command. A current generating a current command for instructing the current output from the reactive current generating unit to be zero when the unit generates the compensation completion command or when the voltage compensation start determining unit generates a compensation stop command. A configuration including a command selection unit and an operation amount calculation unit that calculates an operation amount of an output current of a reactive current generation unit necessary to match a current detected by the current detection unit with a current specified by the current command. It can be.

Also in this case, the reactive current generating section adjusts the output current in accordance with the operation amount obtained by the operation amount calculating section so that the reactive current supplied to the distribution line coincides with the target reactive current. Constitute.

[0028]

FIG. 1 shows a distribution system provided with a distribution line voltage fluctuation compensator according to the present invention. In FIG. 1, 1 is a substation, 2 is a distribution line drawn from the substation, 3 is a line voltage regulator (S) connected to the distribution line 2
VR), 4 are arranged on the load side of the SVR and
Is a static reactive power compensator (SVC).

The SVR 3 is, for example, as shown in FIG. 2A, an adjusting transformer 3A with a tap for adjusting the voltage of the distribution line 2, and a tap selector 3 for switching the tap of the adjusting transformer.
B, and a tap switching control unit 3C that controls the tap selector 3B according to the distribution line voltage. When the voltage of the distribution line 2 shows a fluctuation that deviates from the reference value from the dead zone, the distribution line voltage is changed. A voltage adjustment operation for keeping the voltage within the dead zone is performed.

In FIG. 2A, 5 is a load connected to the distribution line 2, and x and r are reactance and resistance components of the line impedance of the distribution line 2, respectively.

FIG. 2 (B) shows a voltage profile (voltage distribution) of the distribution line of the distribution system of FIG. 2 (A). The distribution line voltage is changed from the substation 1 to the SVR by the voltage drop due to the line impedance. It decreases as it approaches the installation point. The voltage on the load side from the installation point of the SVR changes as shown in a to c in FIG. 2A to 2C show voltage distributions when the SVR tap is not switched, when the SVR tap is switched to the boost side, and when the SVR tap is switched to the buck side, respectively. .

That is, by switching the tap of the adjusting transformer of the SVR 3, the voltage on the load side from the installation point of the SVR can be changed to adjust the distribution line voltage. S
In VR, the voltage of one tap or more of the regulating transformer becomes a dead zone.

The tap switching control unit 3C of the SVR 3 switches the taps one by one every minute when the voltage of the distribution line 2 shows a fluctuation outside the dead zone including the reference voltage, so that the load is higher than the installation point of the SVR. A voltage adjustment operation is performed to adjust the distribution line voltage at the load center point set at an appropriate position on the side to fall within the dead zone.

The SVR 3 includes a tapped regulating transformer having a distribution line voltage applied to the primary side, and a secondary winding disposed in the load side of the regulating transformer and having a secondary winding inserted in series with the distribution line. , A series transformer in which the secondary side output of the regulating transformer is applied to the primary side, a tap selector for selecting the tap of the regulating transformer, and a tap for switching the tap of the regulating transformer according to the distribution line voltage. There is also known a device that includes a tap switching control unit that controls a selector, and applies an output voltage of an adjustment transformer to a distribution line through a series transformer.
In the present invention, any type of SVR may be used.

As shown in FIG. 3, the reactive power compensator SV
C4 is a reactive current generator 4A that generates an arbitrary reactive current.
A voltage transformer PT for constituting a voltage detecting unit 4B for detecting a distribution line voltage, a current transformer CT for constituting a current detecting unit 4C for detecting an output current of the reactive power generating unit, and a voltage detecting unit 4B. And the output of the current detector 4C as inputs, so that the reactive current generator 4 can maintain the distribution line voltage at the target value.
A reactive current control section 4D for controlling the output of A (reactive current).

As shown in FIG. 4A, the substation is set to a voltage V
s, the reactance and resistance components of the distribution line impedance are set as x and r, respectively. The distribution line voltage at the SVC installation point is Vi, and the power factor angle is When θ is set, the following equation is established.

Vi = Vs− (r + jx) × Iq (cos θ + jsin θ) (1) Since SVC outputs a reactive current, cos θ = 0, sin θ
= 1 (positive when advancing reactive current is output): Vi = Vs-(r + jx) x jIq = Vs + (x-jr) Iq (2) The reactive current generator 4B advances and becomes invalid When the current is output, the expression (2) is represented by a vector diagram as shown in FIG. Also, regarding the case where the reactive current generator 4B outputs a delayed reactive current, the expression (2) can be expressed by a vector diagram as shown in FIG.
(C). As shown in FIGS. 4B and 4C, the distribution line voltage Vi at the installation point of the SVC can be adjusted to an arbitrary value by changing the polarity and the magnitude of the reactive current output by the SVC.

The reactive current controller 4D of the SVC 4 controls the reactive current injected from the reactive current generator 4A into the distribution line when the distribution line voltage fluctuates, so that the distribution line voltage instantaneously becomes equal to the target value. Voltage adjustment operation.

FIG. 5 illustrates the voltage adjusting operation by the SVC. As shown in FIG.
In the state separated from the substation, the voltage profile of the distribution line becomes as shown in FIG. 3B, and the distribution line voltage decreases from the substation 1 toward the load side.

When the SVC 4 is connected to the distribution line as shown in FIG. 5B, the impedance Z1 << Z2 between the impedance Z1 as viewed from the power supply side as viewed from the SVC and the impedance Z2 as viewed from the load side as viewed from the SVC. Is satisfied, the reactive current Iq output from the SVC 4 is
Through to the substation side. This reactive current causes SVC
The voltage on the power supply side changes from the setting point 4. Due to the reactive current injected from the SVC 4 into the distribution line, the voltage on the power supply side from the installation point of the SVC changes as shown in FIG. FIG. 5D shows a voltage profile when the reactive current output from the SVC is set to zero, and b and c in FIG. 5D show a case where the reactive current is advanced and the delayed reactive current is output from the SVC. The voltage profile at the time of output is shown.

FIG. 5B shows an actual voltage profile of a distribution line when an SVC is connected to a distribution line having a voltage drop as shown in FIG. 5B as shown in FIG. 5E.
5D and the voltage profile of FIG. 5D are superimposed, as shown in FIG. 5F.
In FIG. 5 (F), a shows a voltage profile when the reactive current output from the SVC is set to zero, and b and c in FIG. 5 (F) respectively show a case where the reactive current is advanced from the SVC and a delayed reactive current is output. 5 shows the voltage profile of the distribution line when the output is.

The reactive current generating section 4A is connected to a distribution line via a reactor to a self-excited inverter formed by using a self-extinguishing element such as an IGBT or GTO, and outputs an SVG (Static Var) for outputting reactive power to the distribution line. Generator) or a circuit connected to the primary side of the output transformer via a thyristor to control the reactor's delay reactive current using the thyristor, and a parallel circuit to the circuit consisting of the thyristor and the reactor A TCR (Thyristor Controlled Reactor) system in which a phase-advancing capacitor is connected to the power supply may be used.

FIG. 6 is an explanatory diagram for explaining the operation of the distribution line voltage fluctuation compensating apparatus according to the present invention. The vertical axis in FIG.
C indicates the distribution line voltage at the installation point, and ΔV indicates the dead zone of SVR. The dead zone ΔV is, for example, 1
This corresponds to the voltage of the tap, and the upper limit value V1 (102% V in the illustrated example) and the lower limit value V2 (9 in the illustrated example) of the dead zone.
8% V) and the reference voltage value Vo of the distribution line (100% V in the illustrated example).

In the distribution line voltage fluctuation compensator according to the present invention, the control target voltage upper limit V1U which is sufficiently larger than the upper limit V1 of the dead zone of SVR, and the control target voltage which is sufficiently smaller than the lower limit of the dead zone of SVR. A voltage lower limit value V2L is set in advance, and a range between the control target voltage upper limit value V1U and the control target voltage lower limit value V2L is defined as an SVC dead zone. And distribution line 2
When the voltage rises above the control target voltage upper limit value V1U, the reactive current required to return the distribution line voltage to the control target voltage upper limit value V1U is supplied to the distribution line to instantly control the distribution line voltage. Return to the target voltage upper limit value V1U, and supply the reactive current necessary for returning the distribution line voltage to the control target voltage lower limit value V2L to the distribution line when the voltage of the distribution line becomes lower than the control target voltage lower limit value V2L. Then, a voltage adjustment operation for instantaneously returning the voltage of the distribution line to the control target voltage lower limit value is performed.

On the other hand, the SVR indicates that the voltage of the distribution line is a dead band ΔV
When the variation is out of the range, a voltage adjustment operation for adjusting the voltage at the center of the load set on the distribution line so as to fall within the dead zone is performed while switching the taps one by one in a predetermined time period. The amount of voltage compensation by the SVR increases stepwise at predetermined time intervals. The SVC decreases its reactive current output every time the voltage compensation amount by the SVR increases, and the voltage adjustment operation of the SVR causes the distribution line voltage at the installation point of the SVC to become the control target voltage upper limit value V1U and the control target voltage lower limit value. When entering between V2L, the SVC zeroes its output current.

SVC for adjusting distribution line voltage as described above
FIG. 7 shows a more detailed configuration example.

In FIG. 7, reference numeral 401 denotes an effective value calculation unit for calculating the effective value Vrms of the distribution line voltage detected by the voltage detection unit 4B, and 402 denotes a value obtained from the output of the voltage detection unit 4B and the output of the current detection unit 4C. It is a reactive power calculation unit that calculates reactive power.

An upper limit value setting unit 403 sets a control target voltage upper limit value V1U, and a lower limit value setting unit 404 sets a control target voltage lower limit value V2L. Vrms and control target voltage upper limit V1U
And the control target voltage lower limit value V2L,
05 has been entered.

The voltage compensation start judging section 405 has first and second output terminals 405a and 405b, and has an effective value Vrms of the distribution line voltage detected by the voltage detecting section 4B.
Is higher than the control target voltage upper limit V1u, and when the effective value Vrms of the distribution line voltage is lower than the control target voltage lower limit V2L, the H level (high level) of the first output terminal 405a is changed. When a compensation start command is issued and the effective value Vrms of the distribution line voltage is equal to or lower than the control target voltage upper limit value V1u and equal to or higher than the control target voltage lower limit value V2L, L level (low level) compensation is performed from the first output terminal 405a. Generate a stop command.

When the effective value Vrms of the distribution line voltage becomes higher than the control target voltage upper limit value V1u, the voltage compensation start determining unit 405 issues a first selection command of the H level from the second output terminal 405b. Then, when the effective value Vrms of the distribution line voltage becomes lower than the control target voltage lower limit value V2L, a second selection command of the L level is generated from the second output terminal 405b.

Reference numeral 406 denotes a compensating operation completion determining unit to which the output of the reactive power calculating unit 402 is input.
Generates a compensation operation continuation command for maintaining the H level when the reactive powers calculated by the reactive power calculating unit 402 have the same polarity, and that the polarity of the reactive power has changed (the reactive power has advanced When a change from the reactive power to the lagging reactive power, or a change from the lagging reactive power to the leading reactive power) is detected, an L-level compensation completion command is generated. First output terminal 405 of voltage compensation start determination unit 405
The output of “a” and the output of the compensation operation completion determination unit 406 are input to the AND condition determination unit 407.

Reference numeral 408 designates a control target voltage upper limit voltage value V1U output from the upper limit value setting unit 403 and a lower limit value setting value, using a selection command output from the second output terminal 405b of the voltage compensation start determining unit 405 as a control input. A target voltage command value selection unit that selects one of the control target voltage lower limit values V2L output by the unit 404 and outputs the selected target voltage command value Vs. The selection unit 408 controls the effective value Vrms of the distribution line voltage. The voltage compensation start determination unit 405 exceeds the target voltage upper limit value V1U.
Generates the H-level first selection command, selects the control target voltage upper limit value V1U and outputs it as the target voltage command value Vs, and the effective value Vrms of the distribution line voltage is higher than the control target voltage lower limit value V2L. When the voltage compensation start determining unit 405 is generating the second selection command at the L level, the control target voltage lower limit value V2L is selected and output as the target voltage command value Vs.

Reference numeral 409 denotes an input of the effective value Vrms of the distribution line voltage and the target voltage command value Vs, and the target voltage command value Vs output by the target voltage command selection unit and the effective value Vs of the distribution line voltage.
rms is a target reactive current calculation unit that calculates a vector amount (magnitude and polarity) of a target reactive current that needs to be supplied to the distribution line 2 in order to reduce the deviation from rms to zero.
A subtraction unit 410 for calculating a deviation δV between the target voltage command value Vs and the effective value Vrms of the distribution line voltage, and a P for performing a proportional integral operation on the deviation δV to calculate the amplitude Iqamp of the target reactive current.
It comprises an I calculation unit 411 and a multiplier 412 that calculates a target reactive current (vector amount) Iqo by multiplying the amplitude amount Iqamp by a reference sine wave signal.

The target reactive current Iqo is input to the current command selector 410 together with a zero command signal Io for instructing the reactive current to be zero.

When the output of AND condition judging section 407 is at H level (voltage compensation start judging section 405 generates an H level compensation start command and compensation operation completion judging section 406 outputs H level) Is selected), a target reactive current Iqo is selected, and a current command Iqc for instructing the reactive current generator 4A to generate a reactive current equal to the target reactive current Iqo is output. When the output of the AND condition determination unit 407 is at L level (the voltage compensation start determination unit 405 has generated an L level compensation stop command, or the compensation operation completion determination unit 406 has generated an L level compensation completion command. The zero command signal Io
And outputs a current command Iqc for commanding the reactive current to be zero.

A variable 413 is a manipulated variable Iref, which is used to change the output (amount of vector) of the reactive current generator 4A necessary to make the reactive current detected by the current detector equal to the target reactive current given by the current command Iqc. The operation amount calculation unit subtracts the reactive current Iq ′ detected by the current detection unit 4C from the target reactive current given by the current command Iqc, and calculates the target reactive current as the target reactive current. A subtractor 414 for calculating a deviation δIq from the current;
The amount of change (vector amount) of the output of the reactive current generating unit 4A required for performing a proportional / integral operation on the deviation δIq and matching the current detected by the current detecting unit 4C with the target reactive current is defined as a current manipulated variable Iref. Output PI calculation unit 41
It consists of five.

The reactive current generator 4A includes an operation amount calculator 41
The output current is changed in accordance with the current manipulated variable Iref given from 3 to make the reactive current Iq supplied to the distribution line equal to the target reactive current Iqo or set to zero.

In the example shown in FIG.
A reactive power calculation unit 402, an upper limit value setting unit 403,
A lower limit value setting unit 404, a voltage compensation start determination unit 405,
Compensation operation completion determination unit 406 and AND condition determination unit 407
A target voltage command selection unit 408, a target reactive current calculation unit 409, a current command selection unit 410, and a manipulated variable calculation unit 41.
3 constitute a reactive current control unit 4D.

Reactive current control section 4D of SVC shown in FIG.
Is as follows.

In FIG. 7, it is assumed that the distribution line voltage Vrms at the installation point of the SVC 4 is between the control target voltage upper limit V1U and the control target voltage lower limit V2L, and the reactive current control unit 4D is in a standby state. At this time, the voltage compensation start determination unit 405 has output an L-level compensation stop command from its first output terminal 405a, and the compensation operation completion determination unit 40
6 generates an H level compensation continuation command. At this time, since the output of AND condition determining section 407 is at L level, current command selecting section 410 selects zero command signal Io and issues current command I for instructing target reactive current to be zero.
qc is output. At this time, the manipulated variable calculation section 413 outputs the current manipulated variable Iref necessary to make the reactive current zero, so that the reactive current generating section 4A makes its output almost zero. That is, when the SVC 4 is in the standby state, its output is almost zero.

The voltage detecting section 4B constantly detects the voltage of the distribution line even when the control section 4D is in the standby state, and the effective value calculating section 401 calculates the effective value of the distribution line voltage detected by the voltage detecting section 4B. Vrms is calculated. The voltage compensation determination unit 4
05 is the effective value of the distribution line voltage Vrms even during standby
Is the control target voltage upper limit value V1U and the control target voltage lower limit value V2L.
Compared to

Now, the effective value Vrms and the control target voltage upper limit V
If the effective value Vrms of the distribution line voltage exceeds the control target voltage upper limit value V1U as a result of the comparison with 1U, the voltage compensation start determining unit 405 issues an H level compensation start command from the first output terminal 405a. And the second output terminal 4
The first selection command of H level is generated from 05b. At this time, the target voltage command selection unit 408 selects the control target voltage upper limit value V1U and gives it to the target reactive current calculation unit 409 as the target voltage command value Vs.

The target reactive current calculation unit 409 calculates a reactive current that needs to be output from the reactive current generation unit 4A in order to make the effective value Vrms of the distribution line voltage equal to the control target voltage upper limit value V1U, and calculates the target reactive current. The current (vector) Iqo is output.

At this time, the compensation operation completion determining unit 406
Since the level compensation continuation command has been generated, the AND condition is satisfied by the AND condition determination unit 407, and the output thereof becomes H level. Therefore, the current command selection unit 410 selects the target reactive current Iqo calculated by the target reactive current calculation unit 409 and gives the selected current to the manipulated variable calculation unit 413 as the current command Iqc.

At this time, the manipulated variable calculating section 413 outputs the current manipulated variable Iref necessary for setting the output of the reactive current generating section 4A to the target reactive current Iqo.
A supplies a reactive current equal to the reactive current calculated by the target reactive current calculation unit 409 to the distribution line 2. Thereby, the distribution line voltage is instantaneously adjusted so as to be equal to the control target voltage upper limit value.

The effective value Vrms and the control target voltage lower limit value V
If the effective value Vrms of the distribution line voltage is lower than the control target voltage lower limit value V2L as a result of the comparison with the control output voltage 2L, the voltage compensation start determination unit 405 issues an H level compensation start command from the first output terminal 405a. And an L-level second selection command is generated from the second output terminal 405b. At this time, the target voltage command selection unit 408 selects the control target voltage lower limit value V2L and gives it to the target reactive current calculation unit 409 as the target voltage command value Vs. The target reactive current calculation unit 409 calculates a reactive current that needs to be output from the reactive current generation unit 4A in order to make the effective value Vrms of the distribution line voltage equal to the control target voltage lower limit value V2L, and calculates the target reactive current (vector ) Output Iqo.

At this time, the current command selecting section 410 selects the target reactive current Iqo calculated by the target reactive current calculating section 409 and gives it to the manipulated variable calculating section 413 as the current command Iqc. The current manipulated variable Ire required to set the output of the current generator 4A to the target reactive current Iqo
f, and the reactive current generator 4 </ b> A supplies a reactive current equal to the reactive current calculated by the target reactive current calculator 409 to the distribution line 2. Thereby, the distribution line voltage is instantaneously adjusted so as to be equal to the control target voltage lower limit value V2L.

As described above, when the distribution line voltage at the installation point exceeds the control target voltage upper limit value V1U, the SVC 4
The voltage is adjusted so that the distribution line voltage is equal to the control target voltage upper limit value V1U. When the distribution line voltage at the installation point is lower than the control target voltage lower limit value V2L, the distribution line voltage is adjusted to the control target voltage. The voltage is adjusted so as to be equal to the lower limit value V2L. Therefore, the voltage range between the control target voltage upper limit value V1U and the control target voltage lower limit value V2L becomes the dead zone of the SVC, and the SVC 4 does not perform the voltage adjustment operation to make the distribution line voltage at the installation point equal to the retroactive value. . Therefore, SV
R3 performs tap switching one tap at a time, and adjusts the voltage so that the distribution line voltage at the load center set on the load side of the installation point falls within the dead band ΔV including the reference value.

Each time the voltage adjustment operation by the SVR 3 proceeds one step at a time and the amount of compensation increases, the amount of compensation required for the SVC 4 decreases, so that the output current of the SVC decreases.

In the process of the SVR 3 adjusting the distribution line voltage at the center of the load within the dead zone, the distribution line voltage at the installation point of the SVC 4 falls between the control target voltage upper limit value V1U and the control target voltage lower limit value V2L. (The dead zone of the SVC), the polarity of the reactive power output by the SVC is inverted. When the compensation operation completion range section 406 detects the inversion of the polarity of the reactive power, it generates an L level compensation completion command. Therefore, the current command selection section 410 selects the zero command signal Io and outputs the target invalidation signal. Current command I for commanding the current to zero
qc is given to the manipulated variable calculator 413. At this time, the manipulated variable calculating section 413 outputs the manipulated variable signal Iref necessary for making the output of the reactive current generating section 4A zero, so that the reactive current generating section 4A makes its output almost zero and makes the reactive current control section 4D
Enters a standby state.

The SVR 3 advances the voltage adjustment operation by tap switching stepwise, and stops the voltage adjustment operation when the distribution line voltage at the center of the load enters a dead zone including the reference value.

In the present embodiment, after the SVC instantaneously compensates for a sudden voltage fluctuation that deviates from the control target voltage range,
FIGS. 9 to 12 show changes in the voltage profile of the distribution line when the compensation amount is shifted to SVR. FIG.
FIG. 12 to FIG. 12 show a series of processes of shifting the compensation amount by the SVV to the SVR, separately for modes I to IV. In this example, it is assumed that the distributed power source 6 is connected to the end of the distribution line 2 on the load side.
VR3 is such that the distribution line voltage at the load center point Lo set between the installation point and the SVC4 installation point is a dead zone (V1 to V2).
, The tap is switched to perform a voltage adjusting operation for keeping the distribution line voltage at the load center point Lo within the dead zone.

In the mode I shown in FIG. 9, when the distributed power supply 6 is connected to the system, the distribution line voltage profile becomes as shown by the broken line, and the distribution power supply 6 is distributed from the installation point of the SVR due to the presence of the distributed power supply. The distribution line voltage increases toward the load end of the line. At this time, the distribution line voltage at the installation point of the SVC is lower than the control target voltage upper limit value,
SVC has stopped outputting the reactive current because it is in the dead zone of C.

If the dispersed power source 6 is disconnected from this state, the voltage profile becomes as shown by the thin line.
The distribution line voltage at the SVC installation point is the control target voltage lower limit value V2L
, And the distribution line voltage at the load center point Lo adjusted by the SVR becomes lower than the lower limit value V2 of the dead zone. This means that the SVC immediately outputs the leading reactive current so as to make the voltage at the installation point equal to the control target voltage lower limit value V2L, so that the voltage profile becomes as shown by the thick line.

In the mode II shown in FIG. 10, since the distributed power source is disconnected and the distribution line voltage is lowered, the SVC outputs a leading reactive current and the voltage at the installation point is set to the control target voltage lower limit value V2L. Since the SVR changed the tap position by one tap from the state of equality, the load center point Lo was changed.
Voltage rises and the voltage profile becomes
In order to make the voltage at the installation point of the SVC equal to the lower limit value of the control target voltage, the leading fast reactive current output by the SVC decreases.
Then, when the SVR further changes the tap position, the voltage profile becomes as follows, and the leading reactive current output by the SVC further decreases.

In the mode III shown in FIG. 11, the voltage profile changes to the state shown in FIG. 10 by further changing the tap position of the SVR from the state shown in FIG. At this time, in order to maintain the voltage at the installation point of the SVC at the control target voltage lower limit value, the polarity of the reactive current output by the SVC is inverted, and the SVC is a late-phase reactive current. At this time, since the compensation operation completion determination unit 406 of FIG. 7 generates a compensation completion command, the SVC stops outputting the reactive current. As the SVR switches the tap position further, the voltage profile becomes:

Next, in the mode IV shown in FIG. 12, since the tap position of the SVR is further changed from the state shown in FIG. 11, the voltage profile becomes as follows, and the distribution line at the load center point Lo is obtained. The voltage is in the dead zone V1 to V2. At this time, the voltage adjustment operation of the SVR stops,
The voltage fluctuation compensation operation of the distribution line voltage fluctuation compensator according to the present invention is completed.

FIGS. 13A and 13B show a state where the compensation amount of the SVC shifts to the SVR in the course of the above series of operations. FIG. 13A shows the installation point of the SVC. (B) shows the SVR and the amount of voltage compensation of the SVC at the installation point of the SVC. The process indicated by circles in FIG.
12 corresponds to the steps indicated by circled numbers in FIG.

In the distribution line voltage fluctuation compensator according to the present invention, the control target voltage upper limit value V1U that defines the upper limit of the dead zone of the SVC is allowed to operate the load connected to the distribution line 2 without any trouble. The control target voltage lower limit value V2L, which is set to be equal to or less than the minimum value of the voltage upper limit value and defines the lower limit of the dead zone of the SVC, is a voltage lower limit value that allows the load connected to the distribution line 2 to operate without any trouble. It is preferable to set the value equal to or larger than the maximum value.

FIG. 14 shows the resistance to instantaneous voltage drop of home electric appliances connected to distribution lines. The horizontal axis of the figure indicates the duration of the voltage drop, and the vertical axis indicates the supply voltage of the device (rated voltage: 100 [V]). Reference numerals a to s shown in the drawing denote devices a to s listed at the right end of the drawing, and reference numerals a to s denote each device.
The inverted L-shaped symbol attached to s indicates the boundary between the supply voltage that has an effect on the operation of each device and the supply voltage that has no effect. The region inside the inverted L-shaped symbol attached to each device indicates the supply voltage that affects the operation of each device, and the region outside the inverted L-shaped symbol indicates the supply voltage range that does not affect the operation of the device. Is shown. Also, the symbol a
Parentheses written at the end of each device indicated by ｓs indicate contents of malfunction or abnormality of the device when the voltage is reduced.

In the example shown in FIG. 14, the maximum value of the supply voltage which affects the operation of the device is 90 [V]. Therefore, in this example, the control target voltage lower limit value V2L is set to be equal to or higher than this voltage.

The reactive current controller 4D shown in FIG. 7 can be realized by causing a computer to execute a predetermined program. FIG. 8 shows an example of an algorithm of a program when the reactive current control unit 4D of FIG. 7 is realized using a computer.

In the case of the algorithm shown in FIG. 8, first, in step 1, it is determined whether or not the distribution line voltage V at the installation point of the SVC is higher than the control target voltage upper limit value V1U.
When V> V1U, the process proceeds to step 2 and the target voltage is set to the upper limit value V1U.

Then, the program proceeds to a step 3, wherein a control for controlling the reactive current generating section 4A so as to keep the target voltage constant is started. In this control, the reactive current generator 4A is controlled so that the reactive current necessary to make the voltage at the installation point of the SVC equal to the target value is output from the SVC. Next, in step 4, the process waits for the polarity of the reactive power output by the SVC to be inverted.
The compensation operation by C is completed, and the process returns to step 1.

When it is determined in step 1 that V <V1U, the process proceeds to step 6 to determine whether or not the distribution line voltage V is lower than the control target voltage lower limit value V2L. When it is determined that there is, the target voltage is set to the control target voltage lower limit value V2L. Thereafter, the process proceeds to steps 3, 4, and 5. When the polarity of the reactive power output from the SVC is inverted, the compensation operation by the SVC is completed. If it is determined in step 6 that V> V2L, the process returns to step 1 without doing anything.

In the example shown in FIG. 8, step 1 and step 6 constitute a voltage compensation start determining section 405.
Step 4 constitutes the compensation operation completion determination unit 406. Steps 2 and 7 constitute the target voltage command selection unit 408.

In step 3, the target reactive current calculator 409, the current command selector 410, and the manipulated variable calculator 413
And so on.

With the above configuration, when there is a large voltage fluctuation, the reactive power compensator SVC changes the tap by the line voltage adjuster SVR to change the voltage of the distribution line to the control target voltage upper limit value. Since voltage compensation is performed only for a short time until the voltage falls below the control target voltage lower limit value, the reactive power compensator can be configured using small components rated for a short time. Therefore, the variation of the distribution line voltage can be compensated without increasing the size of the reactive power compensator, and the mounting of the reactive power compensator can be facilitated.

Further, with the above-described configuration, the line voltage regulator SVR and the reactive power compensator SVC perform the respective adjusting operations individually. Therefore, the control unit of the reactive power compensator and the control unit of the line voltage regulator are different from each other. It is possible to compensate for fluctuations in the distribution line voltage without performing communication between them.

In the above example, when the distribution line voltage exceeds the control target voltage upper limit V1U, and when the control target voltage lower limit V2L
The reactive power compensator SV
Although the voltage fluctuation is instantaneously compensated by C, the distribution line configuration prevents the distribution line voltage from being significantly lower than the lower limit of the dead zone, or slightly lower than the lower limit of the dead zone. If there is no problem, the distribution line voltage fluctuation compensator according to the present invention may be provided with an adjustment transformer with a tap for adjusting the voltage of the distribution line, a tap selector for selecting a tap of the adjustment transformer, and a distribution line. Voltage regulator SVR having a tap switching control unit for controlling a tap selector so as to keep the voltage of the tap within a dead zone including a reference value.
The voltage of the reactive current generator 4A, which is connected to the distribution line on the load side of the line voltage regulator and supplies the reactive current to the distribution line, and the voltage of the distribution line 2 are set to values larger than the upper limit of the dead zone. When the voltage exceeds the control target voltage upper limit value V1U, the reactive current required to make the voltage of the distribution line equal to the control target voltage upper limit value is supplied from the reactive current generator to the distribution line. When the voltage of the distribution line 2 is lower than the control target voltage lower limit set to a value smaller than the lower limit, the reactive current required to make the voltage of the distribution line 2 equal to the control target voltage lower limit is supplied from the reactive current generator to the distribution line. And a reactive current compensator SVC provided with a reactive current controller for controlling the reactive current generator.

In this case, the lower limit value setting section 404 shown in FIG.
The target voltage command selection unit 408 is omitted, and the control target voltage upper limit V1U is provided to the target reactive current calculation unit 409.

In addition, when the distribution line voltage does not greatly exceed the upper limit of the dead zone, or when the distribution line voltage slightly exceeds the upper limit of the dead band, there is no problem with the present invention. Of the distribution line voltage fluctuation compensating device according to the present invention, an adjustment transformer with a tap for adjusting the voltage of the distribution line, a tap selector for selecting the tap of the adjustment transformer, and the voltage of the distribution line within a dead zone including a reference value. Current adjusting device SVR provided with a tap switching control unit for controlling a tap selector as described above, and a reactive current connected to the distribution line on the load side of the line voltage adjusting device and supplying a reactive current to the distribution line When the voltage of the generator and the distribution line is lower than the control target voltage lower limit set to a value lower than the lower limit of the dead zone, the reactive current necessary to make the distribution line voltage equal to the control target voltage lower limit is determined. Nothing It can be constituted by a var compensator SVC having a reactive current controller for controlling the reactive current generator to supply the distribution line from the current generator.

In this case, the upper limit value setting section 403 and the target voltage command selecting section 408 in FIG.
The target control voltage lower limit value V2L output by the control unit 04 is supplied to the target reactive current calculation unit 409.

The upper limit or lower limit of the control target voltage is
A specific load may be selected from the loads connected to the distribution line, and set for the selected load.

[0095]

As described above, according to the present invention, the dead band defined by the control target voltage upper limit value and the control target voltage lower limit value is set for the reactive power compensating device, and the distribution line voltage becomes invalid. When a fluctuation that deviates from the dead band of the power compensator is shown, the reactive power compensator performs a compensating operation to instantaneously compensate the distribution line voltage to the upper limit value or the lower limit value of the dead band of the reactive power compensator, and thereafter for the line With the progress of the adjustment operation by the voltage adjusting device, the amount of compensation by the reactive power compensating device was gradually shifted to the line voltage adjusting device, and finally the output of the reactive power compensating device was reduced to zero. The reactive power compensator performs voltage compensation only for a short time until the line voltage adjuster changes the tap to bring the voltage of the distribution line between the control target voltage upper limit value and the control target voltage lower limit value. Just do it Therefore, the reactive power compensator can be configured by using components rated for a short time, the compensator can be downsized, and the mounting of the reactive power compensator can be facilitated.

Further, according to the present invention, since the line voltage adjusting device and the reactive power compensating device individually perform the adjusting operation, the control section of the reactive power compensating device and the control section of the line voltage adjusting device need to be operated separately. Variations in distribution line voltage can be compensated without performing communication.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a distribution system to which a distribution line voltage fluctuation compensator according to the present invention is connected.

FIG. 2A is a connection diagram illustrating a configuration example of an SVR;
(B) is a diagram for explaining the operation of the SVR.

FIG. 3 is a configuration diagram illustrating a configuration example of a reactive power compensator.

FIG. 4A is a circuit diagram showing an equivalent circuit of the reactive power compensator. (B) and (C) are vector diagrams for explaining the voltage compensation operation of the reactive power compensator of (A).

5A and 5B are a configuration diagram showing a configuration of a distribution system in which a reactive power compensator is separated and a voltage profile in which a voltage drop due to distribution line impedance of the distribution system is taken into account. FIG. (C) and (D) respectively show a configuration diagram showing the configuration of the distribution system to which the reactive power compensator is connected, and reflect only the compensation operation by the reactive power compensator without considering the voltage drop due to the distribution line impedance. FIG. 3 is a diagram showing the applied voltage profile. (D) and (E) are a configuration diagram showing the configuration of the distribution system to which the reactive power compensator is connected, and a voltage profile of the system obtained by superimposing the voltage profiles of (B) and (D). FIG.

FIG. 6 is an explanatory diagram showing an example of a relationship between a dead zone of the voltage regulator and a control target voltage upper limit value and a control target voltage lower limit value set for the reactive power compensator in the voltage fluctuation compensator according to the present invention. is there.

FIG. 7 is a block diagram showing a configuration example of a reactive power compensator used in the distribution line voltage fluctuation compensator according to the present invention.

8 is a flowchart illustrating an example of a control algorithm when the reactive current control unit of the reactive power compensator illustrated in FIG. 7 is implemented on software.

FIG. 9 is an explanatory diagram for explaining the operation of the distribution line voltage fluctuation compensator according to the present invention.

FIG. 10 is an explanatory diagram for explaining the operation of the distribution line voltage fluctuation compensator according to the present invention.

FIG. 11 is an explanatory diagram for explaining the operation of the distribution line voltage fluctuation compensator according to the present invention.

FIG. 12 is an explanatory diagram for explaining the operation of the distribution line voltage fluctuation compensator according to the present invention.

FIG. 13 is a diagram showing a voltage change when a voltage drop occurs in a distribution line in the distribution line voltage fluctuation compensating device according to the present invention, and the amount of compensation of the reactive power compensating device shifts to the line voltage adjusting device. FIG. 3 is a diagram for explaining how to go.

FIG. 14 is a diagram showing the tolerance of instantaneous voltage drop of various home appliances connected to the distribution line.

FIG. 15 is a diagram for explaining the operation of a conventional distribution line voltage fluctuation compensator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substation, 2 ... Distribution line, 3 ... Line voltage regulator (S
VR), 4 ... reactive power compensator (SVC), 4A ... reactive current generator, 4B ... voltage detector, 4C ... current detector, 4
D: reactive current control unit, 401: effective value calculation unit, 402:
Reactive power calculation unit, 403: upper limit value setting unit, 404: lower limit value setting unit, 405: voltage compensation start determination unit, 406: compensation operation completion determination unit, 407: AND condition determination unit, 408 ...
Target voltage command selector, 409 ... Target reactive current calculator, 4
10: current command selector, 413: manipulated variable calculator.

Continued on the front page (72) Inventor Naoaki Fukatsu 1-3-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Electric Power Company (72) Inventor Yasuhiko Fukuda 2-1-1-11 Tagawa, Yodogawa-ku, Osaka-shi, Osaka Daihen Co., Ltd. (72) Inventor Koichi Harada 2-1-1-11 Tagawa, Yodogawa-ku, Osaka City, Osaka F-Term Co., Ltd. F-term (reference) 5G066 DA01 DA04 DA08

Claims (9)

[Claims] 1. An adjusting transformer with a tap for adjusting a voltage of a distribution line, a tap selector for selecting a tap of the adjusting transformer, and a voltage range of the distribution line so as to be within a dead zone including a reference value. A line voltage adjustment device including a tap switching control unit that controls the tap selector; and an invalid supply that is connected to the distribution line on the load side of the line voltage adjustment device and supplies a reactive current to the distribution line. A current generator, and when the voltage of the distribution line exceeds a control target voltage upper limit value set to a value larger than the upper limit value of the dead zone, equalizes the voltage of the distribution line to the control target voltage upper limit value. The reactive current necessary for supplying to the distribution line from the reactive current generating unit, when the voltage of the distribution line is lower than the control target voltage lower limit set to a value smaller than the lower limit of the dead zone, Distribution line voltage A reactive current control unit that controls the reactive current generation unit so as to supply a reactive current necessary for equalizing the control target voltage lower limit value to the distribution line from the reactive current generation unit. And a distribution line voltage fluctuation compensator characterized by comprising: 2. The control target voltage upper limit value is set to be equal to or less than a minimum value among voltage upper limit values allowed to operate a load connected to the distribution line without any trouble. 2. The distribution line voltage fluctuation compensator according to claim 1, wherein the value is set to be equal to or more than a maximum value among lower limit values of a voltage allowed to operate the load connected to the distribution line without any trouble. 3. The reactive current control unit includes: a current detection unit that detects an output current of the reactive current generation unit; a voltage detection unit that detects a voltage of the distribution line; and a voltage detected by the voltage detection unit. Generates a compensation start command when the voltage is higher than the control target voltage upper limit and when the voltage detected by the voltage detector is lower than the control target voltage lower limit, and is detected by the voltage detector. A voltage compensation start determining unit that issues a compensation stop command when the detected voltage is equal to or less than the control target voltage upper limit value or when the voltage detected by the voltage detection unit is equal to or greater than the control target voltage lower limit value; A compensating operation completion determining unit that generates a compensation continuation command when the output of the generation unit maintains the same polarity, and generates a compensation completion command when the polarity of the output of the reactive current generation unit changes; When the voltage of the distribution line exceeds the control target voltage upper limit value, the control target voltage upper limit value is selected as a target voltage command value, and when the voltage of the distribution line is lower than the control target voltage lower limit value, A target voltage command value selecting unit that selects a control target voltage lower limit value as a target voltage command value; and zeroing a deviation between the target voltage command value selected by the target voltage command value selecting unit and the voltage value detected by the voltage detecting unit. A target reactive current calculation unit that calculates a target reactive current that needs to be supplied to the distribution line in order to generate the compensation start command,
And the compensation operation completion determination unit instructs the current output from the reactive current generation unit to be the target reactive current calculated by the target reactive current calculation unit when the compensation continuation command is being issued, A current command selection unit that generates a current command that instructs the current output from the reactive current generation unit to be zero when the compensation operation completion determination unit generates the compensation completion command; A manipulated variable computing unit that computes a manipulated variable of the output current of the reactive current generating unit necessary to match the current to the current instructed by the current command, the reactive current generating unit includes: 3. The system according to claim 1, wherein an output current is adjusted according to an operation amount calculated by the operation amount calculation unit so that a reactive current supplied to the distribution line matches the target reactive current. Mains voltage fluctuation compensator according. 4. An adjusting transformer with a tap for adjusting the voltage of a distribution line, a tap selector for selecting a tap of the adjusting transformer, and a voltage range of the distribution line within a dead zone including a reference value. A line voltage adjustment device including a tap switching control unit that controls the tap selector; and an invalid supply that is connected to the distribution line on the load side of the line voltage adjustment device and supplies a reactive current to the distribution line. A current generating unit, to make the voltage of the distribution line equal to the control target voltage upper limit value when the voltage of the distribution line exceeds a control target voltage upper limit value set to a value larger than the upper limit value of the dead zone. A reactive current compensator comprising: a reactive current control unit that controls the reactive current generation unit so as to supply a reactive current necessary for the reactive current generation unit to the distribution line. Fluctuation compensator. 5. The control target voltage upper limit value according to claim 4, wherein the control target voltage upper limit value is set to be equal to or less than a minimum value of the voltage upper limit values allowed to operate the load connected to the distribution line without any trouble. The distribution line voltage fluctuation compensator according to the above. 6. The reactive current control unit, a current detection unit that detects an output current of the reactive current generation unit, a voltage detection unit that detects a voltage of the distribution line, and a voltage detected by the voltage detection unit. Generates a compensation start command when the voltage is higher than the control target voltage upper limit, and generates a compensation stop command when the voltage detected by the voltage detection unit is equal to or less than the control target voltage upper limit. A judging unit, compensating operation completion judging that generates a compensation continuation command when the output of the reactive current generating unit keeps the same polarity, and generates a compensation completion command when the polarity of the output of the reactive current generating unit changes. And a target reactive current calculation unit that calculates a target reactive current that needs to be supplied to the distribution line in order to make the deviation between the control target voltage upper limit value and the voltage value detected by the voltage detection unit zero. The electric The pressure compensation start determination unit generates the compensation start command,
And the compensation operation completion determination unit instructs the current output from the reactive current generation unit to be the target reactive current calculated by the target reactive current calculation unit when the compensation continuation command is being issued, A current command selection unit that generates a current command that instructs the current output from the reactive current generation unit to be zero when the compensation operation completion determination unit generates the compensation completion command; A manipulated variable computing unit that computes a manipulated variable of the output current of the reactive current generating unit necessary to match the current to the current instructed by the current command, the reactive current generating unit includes: 6. The system according to claim 4, wherein an output current is adjusted according to an operation amount calculated by the operation amount calculation unit, and a reactive current supplied to the distribution line is made to match the target reactive current. Mains voltage fluctuation compensator according. 7. An adjusting transformer with a tap for adjusting a voltage of a distribution line, a tap selector for selecting a tap of the adjusting transformer, and a voltage range of the distribution line so as to be within a dead zone including a reference value. A line voltage adjustment device including a tap switching control unit that controls the tap selector; and an invalid supply that is connected to the distribution line on the load side of the line voltage adjustment device and supplies a reactive current to the distribution line. A current generating unit, to make the voltage of the distribution line equal to the control target voltage lower limit when the voltage of the distribution line is lower than a control target voltage lower limit set to a value smaller than the lower limit of the dead zone. A reactive current compensator comprising: a reactive current control unit that controls the reactive current generation unit so as to supply a reactive current necessary for the reactive current generation unit to the distribution line. Fluctuation compensation device 8. The control target voltage lower limit value is set to be equal to or more than a maximum value among voltage lower limit values allowed to operate a load connected to the distribution line without trouble. The distribution line voltage fluctuation compensator according to the above. 9. The reactive current control unit includes: a current detection unit that detects an output current of the reactive current generation unit; a voltage detection unit that detects a voltage of the distribution line; and a voltage detected by the voltage detection unit. Generates a compensation start command when the voltage becomes lower than the control target voltage lower limit, and generates a compensation stop command when the voltage detected by the voltage detector is equal to or higher than the control target voltage lower limit. A judging unit, compensating operation completion judging that generates a compensation continuation command when the output of the reactive current generating unit keeps the same polarity, and generates a compensation completion command when the polarity of the output of the reactive current generating unit changes. And a target reactive current calculation unit that calculates a target reactive current that needs to be supplied to the distribution line to reduce the deviation between the control target voltage lower limit value and the voltage value detected by the voltage detection unit to zero. The electric The pressure compensation start determination unit generates the compensation start command,
And the compensation operation completion determination unit instructs the current output from the reactive current generation unit to be the target reactive current calculated by the target reactive current calculation unit when the compensation continuation command is being issued, A current command selection unit that generates a current command that instructs the current output from the reactive current generation unit to be zero when the compensation operation completion determination unit generates the compensation completion command; A manipulated variable computing unit that computes a manipulated variable of the output current of the reactive current generating unit necessary to match the current to the current instructed by the current command, the reactive current generating unit includes: 9. The system according to claim 7, wherein an output current is adjusted in accordance with an operation amount calculated by the operation amount calculation unit so that a reactive current supplied to the distribution line matches the target reactive current. Mains voltage fluctuation compensator according.