JP2012135113A - Voltage adjusting device, voltage adjusting system, program and voltage adjusting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voltage adjusting device improving precision of voltage adjustment while suppressing the number of times of tap switching.SOLUTION: A voltage adjusting device comprises: an auto-transformer for voltages Vtp0-3 according to a target voltage of a secondary-side voltage V1 of a loaded tap switch transformer; a program controller for selecting one of the voltages Vtp0-3 according to a selection signal to output the voltage as a voltage V4; a voltage adjustment relay for accumulating a first time when the voltage V4 exceeds an upper limit of a dead zone (a second time when it is lower than a lower limit), and, when the first (second) time reaches an operation time, outputting a tap switch command for decreasing (increasing) the voltage V1; and a clock control section for outputting the selection signal for selecting a voltage according to the changed target voltage from the voltages Vtp0-3 at a change time for changing the target voltage, and, when increasing (decreasing)the target voltage, outputting the selection signal for decreasing (increasing) the voltage V4 in a predetermined period before the change time so that a predetermined additional time is added to the second (first) time.

Description

  The present invention relates to a voltage regulator, a voltage regulation system, a program, and a voltage regulation method.

  In order to maintain and ensure the voltage quality of the power system, it is desirable to adjust the system voltage according to the power demand. For example, as indicated by a one-dot chain line in FIG. 10, the target voltage V0 is set high during a time zone where the power demand is large such as during the daytime, and the target voltage V0 is set low during a time zone where the power demand is small such as at night. .

  As a voltage adjustment system for adjusting a system voltage to a set target voltage, a system having a load tap change transformer that switches a tap of a winding in accordance with a tap change command output from a voltage adjustment relay is known. Yes. For example, in Patent Document 1, by correcting the operation determination level of the voltage regulating relay using fuzzy inference, the number of tap switching times of the on-load tap switching transformer in the lower substation and the fluctuation range of the secondary side voltage are reduced. A voltage adjustment device capable of suppressing the above is disclosed.

  In this way, it is possible to switch the tap according to the tap switching command output from the voltage adjusting relay and adjust the secondary side voltage of the on-load tap switching transformer to the set target voltage.

Japanese Patent Application Laid-Open No. 11-231949 JP 2009-177868 A

  However, the dead zone and the operating time are set for the voltage regulation relay. In the voltage regulation system using the voltage regulation relay described above, the secondary side voltage of the on-load tap switching transformer can be quickly changed when the target voltage is changed. It cannot be adjusted, and high-accuracy voltage adjustment cannot be performed even for a high voltage transition or a low voltage transition in the dead zone. For example, in FIG. 10, since the secondary voltage V1 (solid line) is within the dead zone (short dashed line) while the target voltage V0 (dashed line) is set high during the day, most of the time In the band, the secondary side voltage V1 changes at a voltage lower than the target voltage V0.

  On the other hand, the accuracy of voltage adjustment can be improved by reducing the dead zone or shortening the operation time. However, in this case, there is a trade-off relationship that leads to a shortening of the life of the tap changer due to an increase in the number of tap switching and occurrence of hunting.

  Therefore, it is difficult to improve the accuracy of the voltage adjustment of the secondary side voltage while suppressing the number of tap switching of the on-load tap switching transformer. Moreover, since the voltage regulator of patent document 1 cannot be applied to the independent control for every substation or a transformer, it will be accompanied by the extensive change of an electric power grid | system.

  Furthermore, although the voltage adjustment system of patent document 2 aims at improving the quality of voltage adjustment based on voltage fluctuation information, it is difficult to perform high-precision adjustment in the dead zone with respect to the target voltage.

  The main present invention for solving the above-mentioned problems is an instrument for detecting a first voltage which is a secondary side voltage of a load tap change transformer having a tap changer which changes taps of windings in response to a tap change command. A self-winding transformer provided with a plurality of output taps, each of which receives a second voltage output from a transformer for output and outputs a plurality of third voltages corresponding to different target voltages of the first voltage; A program controller that selects one of the plurality of third voltages according to a selection signal and outputs the selected third voltage as a fourth voltage, and a reference in which the fourth voltage is set in advance The first time that exceeds the upper limit value of the dead zone of the voltage and the second time that the fourth voltage is less than the lower limit value of the dead zone are integrated, and the first time is a preset operating time If A voltage adjusting relay that outputs the tap switching command for increasing the first voltage when the second time has reached the operating time, and outputting the tap switching command for decreasing the voltage of 1; A storage unit storing target voltage change information indicating the change time for changing the target voltage and the target voltage after the change, and the change time from the plurality of third voltages after the change The selection signal for selecting the third voltage corresponding to the target voltage is output, and when the target voltage is increased, a predetermined addition time less than the operation time is added to the second time. As described above, when the selection signal for reducing the fourth voltage is output in a predetermined period before the change time and the target voltage is reduced, the predetermined addition time is added to the first time. To be added A voltage regulator, characterized in that it comprises a and a clock control unit which outputs the selection signal to increase the fourth voltage to the predetermined period before the change time.

  Other features of the present invention will become apparent from the accompanying drawings and the description of this specification.

  ADVANTAGE OF THE INVENTION According to this invention, in the independent control for every tap switching transformer at the time of load, the precision of the voltage adjustment of a secondary side voltage can be improved, suppressing the frequency | count of tap switching.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit block diagram illustrating a schematic configuration of a whole voltage regulation system and a configuration of a voltage regulation device according to an embodiment of the present invention. In one Embodiment of this invention, it is a figure explaining operation | movement of the voltage adjustment system of the front | former stage which raises a target voltage. In one Embodiment of this invention, it is a figure explaining operation | movement of the voltage adjustment system of the front | former stage which reduces a target voltage. In one Embodiment of this invention, it is a figure explaining operation | movement of the voltage regulation system when the secondary side voltage of a tap switching transformer at the time of load falls within a dead zone. In one Embodiment of this invention, it is a figure explaining operation | movement of the voltage adjustment system in case the secondary side voltage of a tap switching transformer at the time of load rises within a dead zone. FIG. 6 is a diagram for explaining the operation of the voltage adjustment system when the upper dead zone reduction function is operated when raising the target voltage in an embodiment of the present invention. FIG. 6 is a diagram for explaining the operation of the voltage adjustment system when the lower dead zone reduction function is operated when lowering the target voltage in the embodiment of the present invention. It is a circuit block diagram which shows the other structural example of a voltage adjustment system. In the voltage adjustment system in one Embodiment of this invention, it is a figure which shows an example of the change of the secondary voltage of a target voltage and a load time tap switching transformer, and a voltage adjustment signal. In a general voltage regulation system, it is a figure which shows an example of the change of the secondary voltage of a target voltage and a tap switching transformer at the time of a load.

  At least the following matters will become apparent from the description of this specification and the accompanying drawings.

=== Overall Configuration of Voltage Adjustment System and Configuration of Voltage Adjustment Device ===
Hereinafter, with reference to FIG. 1, the outline of the structure of the whole voltage regulation system in one Embodiment of this invention and the structure of a voltage regulator are demonstrated.

  The voltage adjustment system shown in FIG. 1 is a system that adjusts the secondary side voltage V1 of the on-load tap switching transformer 2 to a set target voltage V0. For example, from about several tens to hundreds of tens kV Used in distribution substations that convert to several kV. Moreover, the secondary side voltage V1 is supplied to the primary side of the instrument transformer 3, and the detection voltage V2 is output from the secondary side. The detected voltage V2 is input to the voltage adjusting device 1, and a tap switching command SW is supplied from the voltage adjusting device 1 to the on-load tap switching transformer 2.

  The voltage regulator 1 is configured to include an autotransformer 11, a program controller 12, a storage unit 13, a timepiece control unit 14, and a voltage regulation relay 15.

  A detection voltage V2 is supplied to the primary side of the autotransformer 11, and the secondary side includes four output taps that output tap voltages Vtp0 to Vtp3, respectively. Further, the target voltage change information Vsw and the voltage fluctuation information Vfl are input from the storage unit 13 to the timepiece control unit 14, and the selection signal SEL is output from the timepiece control unit 14. Further, tap voltages Vtp0 to Vtp3 and a selection signal SEL are input to the program controller 12, and a selection voltage V4 is output from the program controller 12.

  The voltage adjustment relay 15 includes a dead zone reduction circuit 151 that can reduce the width of the dead zone (for example, 1.5% → 1.0%). The dead zone reduction circuit 151 receives an upper reduction signal from the timepiece control unit 14. HR and lower reduction signal LR are input. The voltage adjustment relay 15 is supplied with a selection voltage V4. A tap switching command SW is output from the voltage adjusting relay 15.

=== Outline of operation of voltage regulation system ===
Next, an outline of the operation of the voltage adjustment system in the present embodiment will be described.
The on-load tap switching transformer 2 is, for example, a distribution transformer installed in a distribution substation, and includes, as an example, a tap switching device that switches the tap of the primary winding in response to a tap switching command SW. . Further, the secondary side voltage V1 (first voltage) of the on-load tap switching transformer 2 is adjusted according to the switching of the tap. Further, the instrument transformer 3 is a part of a grounded instrument transformer excluding, for example, open delta, and detects the secondary side voltage V1 and outputs it as a detection voltage V2 (second voltage). Then, the autotransformer 11 transforms the detection voltage V2 to generate tap voltages Vtp0 to Vtp3 (third voltage), and outputs them from the four output taps.

  The storage unit 13 stores target voltage change information Vsw and voltage fluctuation information Vfl. Here, the target voltage change information Vsw is information indicating the change time for changing the target voltage V0 and the target voltage V0 after the change in association with each other. As an example, when the target voltage V0 is set as shown by the one-dot chain line in FIG. 10, the target voltage change information Vsw is changed from 6.66 kV (from 6.66 kV) to 6.72 kV and at 22:00. The content of changing V0 to 6.66 kV (from 6.72 kV) is included.

  On the other hand, the voltage fluctuation information Vfl indicates a rise time when the secondary side voltage V1 rises to a predetermined rate or more from the target voltage V0, and a fall time when the secondary side voltage V1 falls from the target voltage V0 to a predetermined rate or more. Information. The voltage fluctuation information Vfl is obtained by analyzing the measurement data of the secondary side voltage V1 and stored in the storage unit 13.

  As an example, when the secondary side voltage V1 starts to decrease before 8 o'clock and the difference (V0−V1) from the target voltage V0 tends to reach a predetermined ratio (for example, 1%) at 8 o'clock, the voltage fluctuation information Vfl Includes the content that 8 o'clock is the fall time. As an example, when the secondary side voltage V1 starts to increase before 14:00 and the difference (V1−V0) from the target voltage V0 tends to reach a predetermined ratio at 14:00, the voltage fluctuation information Vfl includes The content that 14:00 is the rising time is included.

  The timepiece control unit 14 outputs the selection signal SEL based on the target voltage change information Vsw and the voltage fluctuation information Vfl. Then, the program controller 12 selects one of the tap voltages Vtp0 to Vtp3 according to the selection signal SEL and outputs it as the selection voltage V4 (fourth voltage). In the voltage regulator 1, the functions of the clock controller 14 and the program controller 12 can be realized by a computer including the autotransformer 11, the storage unit 13, and the voltage regulator relay 15, for example. Detailed operations of the timepiece control unit 14 and the voltage adjustment relay 15 will be described later for each content of the target voltage change information Vsw and the voltage fluctuation information Vfl.

  The voltage adjustment relay 15 compares the selection voltage V4 with a preset reference voltage Vref and outputs a tap switching command SW according to the comparison result. Here, a dead zone (lower limit value VrL to upper limit value VrH) with respect to the reference voltage Vref and an operation time Top are set in advance in the voltage adjusting relay 15. The time when the selection voltage V4 deviates from the dead zone is accumulated, and the tap switching command SW is output when the accumulated time reaches the operation time Top.

  More specifically, the voltage adjustment relay 15 integrates the upper departure time Tup (first time) in which the selection voltage V4 exceeds the upper limit value VrH, and when the integration time reaches the operation time Top. The tap switching command SW for reducing the secondary side voltage V1 is output. Further, the voltage adjustment relay 15 also integrates a lower deviation time Tlow (second time) in which the selection voltage V4 is less than the lower limit value VrL, and when the integration time reaches the operation time Top, the secondary side A tap switching command SW for raising the voltage V1 is output.

  Since the reference voltage Vref of the voltage adjusting relay 15 is set in advance, the change of the target voltage V0 of the secondary side voltage V1 is performed by changing the tap voltage selected as the selection voltage V4. Therefore, the program controller 12 substantially selects the target voltage V0 according to the selection signal SEL.

  Here, assuming that the tap voltages Vtp0 to Vtp3 are Vtp0 <Vtp1 <Vtp2 <Vtp3 and the corresponding target voltages are Vtp0 to Vtp3, the target voltages Vtg0 to Vtg3 are Vtg0> Vtg1> Vtg2> Vtg3. . The upper limit value VrH and the lower limit value VrL of the dead zone for the reference voltage Vref correspond to the upper limit value V0H and the lower limit value V0L of the dead zone for the target voltage V0, respectively.

  In this way, the voltage adjustment device 1 changes the target voltage V0 of the secondary side voltage V1 in accordance with the selection signal SEL output based on the target voltage change information Vsw and the voltage fluctuation information Vfl. Hereinafter, the operation of the voltage adjustment system will be described for each content of the target voltage change information Vsw and the voltage fluctuation information Vfl. In the following description, as an example, the steps of tap voltages Vtp0 to Vtp3 are set to about 1%, and Vtg0 = 6.78 kV, Vtg1 = 6.72 kV, Vtg2 = 6.66 kV, and Vtg3 = 6.60 kV. In addition, the dead band for the reference voltage Vref and the target voltage V0 is in the range of −1.5% to + 1.5% with the reference voltage Vref and the target voltage V0 as the center.

=== Operation when the target voltage of the voltage adjustment system is changed ===
First, the operation of the voltage adjustment system when the target voltage V0 is changed will be described with reference to FIGS.

  FIG. 2 shows an example in which the target voltage V0 is increased from 6.66 kV based on the target voltage change information Vsw including the content that the target voltage V0 is changed to 6.72 kV at 6 o'clock (change time). The change of the target voltage V0 and the secondary side voltage V1 is shown.

  In FIG. 2, at 5:50, the clock control unit 14 outputs a selection signal SEL for selecting the tap voltage Vtp2 as the selection voltage V4, and the program controller 12 selects the selection voltage V4 = in accordance with the selection signal SEL. Vtp2 is output. Therefore, the target voltage V0 is Vtg2 (= 6.66 kV).

  Further, in the periods T1 and T2 (predetermined period) before 6 o'clock, the clock control unit 14 outputs a selection signal SEL for reducing the selection voltage V4 to the tap voltage Vtp1, and the program controller 12 outputs the selection signal SEL. In response, the selection voltage V4 = Vtp1 is output. Therefore, the target voltage V0 is Vtg1 (= 6.72 kV), and the lower limit value V0L (≈6.62 kV) of the dead band is higher than the lower limit value V0L (≈6.56 kV) of the dead band with respect to the immediately preceding target voltage V0 = Vtg2. Become.

  Therefore, during the periods T1 and T2, the secondary side voltage V1 (≈6.61 kV) is less than the lower limit value V0L (≈6.62 kV) of the dead zone for the target voltage V0 = Vtg1, and the selection voltage V4 is equal to the reference voltage Vref. Is less than the lower limit value VrL of the dead zone. Therefore, the total time (predetermined addition time) of the periods T1 and T2 is added to the lower departure time Tlow. Note that the total time of the periods T1 and T2 is less than the operation time Top, and as an example, Top = 60 seconds and T1 = T2 = 20 seconds.

  Further, at 6 o'clock, the timepiece control unit 14 outputs a selection signal SEL for selecting the tap voltage Vtp1 as the selection voltage V4, and the program controller 12 outputs the selection voltage V4 = Vtp1 according to the selection signal SEL. Therefore, the target voltage V0 is changed to Vtg1 (= 6.72 kV).

  Then, when the integration time of the lower deviation time Tlow reaches the operation time Top, the voltage adjustment relay 15 outputs a tap switching command SW for increasing the secondary voltage V1.

  Thus, since the total time of the periods T1 and T2 is added to the lower departure time Tlow before the change time for increasing the target voltage V0, the accumulated time of the lower departure time Tlow reaches the operating time Top. The time until is shortened. Therefore, when the target voltage V0 is increased, the secondary voltage V1 can be quickly adjusted to the target voltage V0 (20 seconds in FIG. 2).

  When the secondary voltage V1 is changing at a voltage higher than the target voltage V0, the lower departure time Tlow may not be added. However, in this case, since the secondary side voltage V1 is a voltage in the vicinity of the changed target voltage V0 = Vtg1, it is not necessary to output the tap switching command SW for increasing the secondary side voltage V1. .

  FIG. 3 shows an example in which the target voltage V0 is decreased from 6.72 kV based on the target voltage change information Vsw including the content that the target voltage V0 is changed to 6.66 kV at 22:00 (change time). The change of the target voltage V0 and the secondary side voltage V1 is shown.

  In FIG. 3, at 21:50, the clock control unit 14 outputs a selection signal SEL for selecting the tap voltage Vtp1 as the selection voltage V4, and the program controller 12 selects the selection voltage V4 = in accordance with the selection signal SEL. Vtp1 is output. Therefore, the target voltage V0 is Vtg1 (= 6.72 kV).

  Further, in the periods T1 and T2 before 22:00, the timepiece control unit 14 outputs a selection signal SEL for raising the selection voltage V4 to the tap voltage Vtp2, and the program controller 12 selects the selection voltage V4 according to the selection signal SEL. = Vtp2 is output. Accordingly, the target voltage V0 is Vtg2 (= 6.66 kV), and the upper limit value V0H (≈6.76 kV) of the dead band is lower than the upper limit value V0H (≈6.82 kV) of the dead band with respect to the immediately preceding target voltage V0 = Vtg1. Become.

  Therefore, during the periods T1 and T2, the secondary voltage V1 (≈6.77 kV) exceeds the upper limit value V0H (≈6.76 kV) of the dead band for the target voltage V0 = Vtg2, and the selection voltage V4 is equal to the reference voltage Vref. It exceeds the upper limit value VrH of the dead zone for. Therefore, the total time of the periods T1 and T2 is added to the upper departure time Tup.

  Further, at 22:00, the clock control unit 14 outputs a selection signal SEL for selecting the tap voltage Vtp2 as the selection voltage V4, and the program controller 12 outputs the selection voltage V4 = Vtp2 according to the selection signal SEL. Therefore, the target voltage V0 is changed to Vtg2 (= 6.66 kV).

  Then, when the integrated time of the upper departure time Tup reaches the operation time Top, the voltage adjustment relay 15 outputs a tap switching command SW that decreases the secondary voltage V1.

  In this way, since the total time of the periods T1 and T2 is added to the upper departure time Tup before the change time for decreasing the target voltage V0, the accumulated time of the upper departure time Tup reaches the operation time Top. Time has been shortened. Therefore, when lowering the target voltage V0, the secondary side voltage V1 can be quickly adjusted to the target voltage V0 (20 seconds in FIG. 3).

  When the secondary side voltage V1 changes at a voltage lower than the target voltage V0, the upper departure time Tup may not be added. However, in this case, since the secondary side voltage V1 is a voltage in the vicinity of the changed target voltage V0 = Vtg2, it is not necessary to output the tap switching command SW for reducing the secondary side voltage V1. .

=== Operation of voltage regulation system when voltage changes ===
Next, the operation of the voltage adjustment system when the secondary side voltage V1 varies will be described with reference to FIGS.

  FIG. 4 shows an example in which the difference (V0−V1) between the target voltage V0 and the secondary side voltage V1 reaches 1% (predetermined ratio) at 8 o'clock, and the voltage fluctuation information Vfl has a drop time at 8 o'clock. The change of the target voltage V0 and the secondary side voltage V1 in the case where the content of being is included is shown.

  In FIG. 4, at a time before 8 o'clock, the clock control unit 14 outputs a selection signal SEL for selecting the tap voltage Vtp1 as the selection voltage V4, and the program controller 12 selects the selection voltage V4 = Vtp1 is output. Therefore, the target voltage V0 is Vtg1 (= 6.72 kV).

  At 8 o'clock, the secondary voltage V1 has dropped to a voltage (≈6.65 kV) that is 1% lower than the target voltage V0 = Vtg1. Here, the storage unit 13 stores, as the voltage variation information Vfl, a variation pattern in which the secondary side voltage V1 decreases at 8 o'clock, and the timepiece control unit 14 performs the secondary side based on the variation pattern. The selection voltage V4 is changed so that the voltage V1 becomes an appropriate voltage.

  Specifically, in the periods T1 and T2 after 8:00, the timepiece control unit 14 outputs a selection signal SEL for reducing the selection voltage V4 to the tap voltage Vtp0, and the program controller 12 selects according to the selection signal SEL. The voltage V4 = Vtp0 is output. Therefore, the target voltage V0 is Vtg0 (= 6.78 kV).

  Therefore, during the periods T1 and T2, the secondary side voltage V1 (≦ 6.65 kV) is less than the lower limit value V0L (≈6.68 kV) of the dead zone for the target voltage V0 = Vtg0, and the selection voltage V4 is the reference voltage Vref. Is less than the lower limit value VrL of the dead zone. Therefore, the total time of the periods T1 and T2 is added to the lower departure time Tlow.

  Then, when the integration time of the lower deviation time Tlow reaches the operation time Top, the voltage adjustment relay 15 outputs a tap switching command SW for increasing the secondary voltage V1.

  In this way, since the total time of the periods T1 and T2 is added to the lower departure time Tlow after the time when the secondary voltage V1 drops below the target voltage V0 by a predetermined rate or more, the lower departure time The time until the accumulated time of Tlow reaches the operating time Top is shortened. Therefore, when the secondary side voltage V1 decreases, the secondary side voltage V1 can be quickly adjusted to the target voltage V0.

  Since the voltage fluctuation information Vfl is obtained by analyzing the measurement data of the secondary side voltage V1, etc., the secondary side voltage V1 does not drop below the target voltage V0 at a predetermined rate or more at the drop time, and the lower deviation time. In some cases, Tlow is not added. However, in this case, since the secondary side voltage V1 is near the target voltage V0 = Vtg1, it is not necessary to output the tap switching command SW for increasing the secondary side voltage V1.

  FIG. 5 shows an example in which the difference (V1−V0) between the target voltage V0 and the secondary side voltage V1 reaches 1% (predetermined ratio) at 14:00, and the voltage fluctuation information Vfl includes the rise time at 14:00. The change of the target voltage V0 and the secondary side voltage V1 in the case where the content of being is included is shown.

  In FIG. 5, at a time before 14:00, the clock control unit 14 outputs a selection signal SEL for selecting the tap voltage Vtp1 as the selection voltage V4, and the program controller 12 selects the selection voltage V4 = in accordance with the selection signal SEL. Vtp1 is output. Therefore, the target voltage V0 is Vtg1 (= 6.72 kV).

  Further, at 14:00, the secondary side voltage V1 has increased to a voltage (≈6.79 kV) that is 1% higher than the target voltage V0 = Vtg1. Here, the storage unit 13 stores, as the voltage variation information Vfl, a variation pattern in which the secondary side voltage V1 rises at 14:00, and the timepiece control unit 14 performs the secondary side based on the variation pattern. The selection voltage V4 is changed so that the voltage V1 becomes an appropriate voltage.

  Specifically, in the periods T1 and T2 after 14:00, the timepiece control unit 14 outputs a selection signal SEL for raising the selection voltage V4 to the tap voltage Vtp2, and the program controller 12 selects according to the selection signal SEL. The voltage V4 = Vtp2 is output. Therefore, the target voltage V0 is Vtg2 (= 6.66 kV).

  Therefore, during the periods T1 and T2, the secondary side voltage V1 (≧ 6.79 kV) exceeds the upper limit value V0H (≈6.76 kV) of the dead band for the target voltage V0 = Vtg2, and the selection voltage V4 is set to the reference voltage Vref. It exceeds the upper limit value VrH of the dead zone for. Therefore, the total time of the periods T1 and T2 is added to the upper departure time Tup.

  Then, when the integrated time of the upper departure time Tup reaches the operation time Top, the voltage adjustment relay 15 outputs a tap switching command SW that decreases the secondary voltage V1.

  In this way, since the total time of the periods T1 and T2 is added to the upper departure time Tup after the rising time when the secondary voltage V1 rises above the target voltage V0 by a predetermined rate or more, the upper departure time Tup The time until the accumulated time reaches the operating time Top is shortened. Therefore, when the secondary side voltage V1 rises, the secondary side voltage V1 can be quickly adjusted to the target voltage V0.

  Since the voltage fluctuation information Vfl is obtained by analyzing the measurement data of the secondary side voltage V1, etc., the secondary side voltage V1 does not rise above the target voltage V0 at a predetermined rate at the rising time, and the upper side deviation time Tup May not be added. However, in this case, since the secondary side voltage V1 is a voltage in the vicinity of the target voltage V0 = Vtg1, it is not necessary to output the tap switching command SW for reducing the secondary side voltage V1.

=== Dead band reduction function of voltage regulation system ===
In FIG. 4, during the periods T1 and T2 after 8:00, the timepiece control unit 14 outputs the selection signal SEL with the selection voltage V4 = Vtp0 to raise the target voltage V0. However, during this period, the upper limit value V0H of the dead zone also increases, and there is a risk that the response will be delayed when the voltage increases rapidly. On the other hand, in FIG. 5, during the periods T1 and T2 after 14:00, the timepiece control unit 14 outputs the selection signal SEL with the selection voltage V4 = Vtp2 to lower the target voltage V0. However, during this period, the lower limit value V0L of the dead zone is also low, and there is a risk that the response will be delayed when the voltage drops rapidly.

  The voltage regulation system according to the present embodiment includes a dead band reduction circuit 151 in the voltage regulation relay 15 so that it can quickly cope with a sudden voltage rise or voltage drop as described above. FIG. 6 shows, as an example, the target voltage V0 and the secondary side voltage V1 when the dead zone reduction circuit 151 reduces the upper dead zone (target voltage V0 to upper limit value V0H of the dead zone) during voltage fluctuations similar to FIG. Shows changes.

  Specifically, the timepiece control unit 14 outputs the upper reduced signal HR together with the selection signal SEL that sets the selection voltage V4 = Vtp0. Then, the dead zone reduction circuit 151 reduces the width of the upper dead zone from 1.5% (V0H≈6.88 kV) to 1.0% (V0H≈6.85 kV) based on the upper side reduction signal HR. Therefore, the upper limit value V0H of the dead band is substantially equal to the upper limit value V0H (≈6.82 kV) of the dead band in the case of the target voltage V0 = Vtg1 (= 6.72 kV). Can do.

  On the other hand, FIG. 7 shows, as an example, the target voltage V0 and the secondary when the dead zone reduction circuit 151 reduces the lower dead zone (the target voltage V0 to the lower limit value V0L of the dead zone) in the same voltage variation as FIG. The change of the side voltage V1 is shown.

  Specifically, the timepiece control unit 14 outputs the lower reduction signal LR together with the selection signal SEL for setting the selection voltage V4 = Vtp2. The dead zone reduction circuit 151 reduces the width of the lower dead zone from 1.5% (V0L≈6.56 kV) to 1.0% (V0L≈6.59 kV) based on the lower side reduction signal LR. Therefore, the lower limit value V0L of the dead zone is substantially equal to the lower limit value V0L (≈6.62 kV) of the dead zone when the target voltage V0 = Vtg1 (= 6.72 kV), and promptly responds to sudden voltage drops. Can do.

  As described above, in the voltage regulator 1, the selection voltage V4 is changed in the periods T1 and T2 (predetermined periods) before the change time based on the target voltage change information Vsw, and the upper departure time Tup (first Time) or the lower deviation time Tlow (second time) by adding the total time (predetermined addition time) of the periods T1 and T2 until these accumulated times reach a preset operation time Top When the target voltage V0 is changed, the accuracy of adjusting the secondary side voltage V1 to the target voltage V0 can be improved while suppressing the tap switching frequency of the on-load tap switching transformer 2. .

  Further, based on the voltage fluctuation information Vfl, the selection voltage V4 is changed in the periods T1 and T2 after the rising time or after the falling time, and the total time of the periods T1 and T2 is set to the upper departure time Tup or the lower departure time Tlow. By adding, the time until the accumulated time reaches the operating time Top is shortened, and when the secondary side voltage V1 fluctuates, the secondary side voltage V1 is set to the target voltage V0 while suppressing the number of tap switching. The accuracy of adjustment can be improved.

  Further, by dividing the period to be added to the upper departure time Tup or the lower departure time Tlow into a plurality of periods whose total time is less than the operation time Top, the accumulated time is added to the operation time Top by addition in a single period. It is possible to suppress the excessive control from reaching.

  Further, in the voltage adjustment system that is controlled independently for each load tap change transformer 2 shown in FIG. 1, the target voltage V0 of the secondary side voltage V1 is changed during the periods T1 and T2, and the upper side deviation time Tup Alternatively, by adding the total time of the periods T1 and T2 to the lower deviation time Tlow, the time until these integration times reach the operation time Top is reduced, and the secondary side voltage V1 is suppressed while suppressing the number of tap switching. Can be adjusted to the target voltage V0.

  In addition, by adjusting the secondary voltage V1 of the distribution transformer according to the tap switching command SW output from the voltage regulator 1, the voltage regulator system of the above embodiment can be used for most of the substations in the power system. It can be applied to the distribution substation that occupies it and maintain and ensure the voltage quality of the power system without extensive changes.

  Further, in a program for causing a computer to realize the functions corresponding to the clock control unit 14 and the program controller 12 of the voltage adjusting device 1, based on the target voltage change information Vsw (and the voltage fluctuation information Vfl), during the periods T1 and T2. By changing the selection voltage V4, the total time of the periods T1 and T2 can be added to the upper departure time Tup or the lower departure time Tlow.

  Further, based on the target voltage change information Vsw (and voltage fluctuation information Vfl), the selected voltage is applied to the periods T1 and T2 so that the total time of the periods T1 and T2 is added to the upper departure time Tup or the lower departure time Tlow. When V4 is changed and the accumulated time of the upper departure time Tup or the lower departure time Tlow reaches the operation time Top, a tap switching command SW for changing the secondary side voltage V1 of the on-load tap switching transformer 2 is output. By doing so, the precision which adjusts the secondary side voltage V1 to the target voltage V0 can be improved, suppressing the frequency | count of tap switching.

  In addition, the said embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof.

  In the above embodiment, the upper departure time Tup or the lower departure time Tlow is added in the periods T1 and T2 before the change time or after the rise / fall time, but the present invention is not limited to this. The period in which the upper departure time Tup or the lower departure time Tlow is added may be a total time that is less than the operation time Top, for example, a single period of T1 = 40 seconds. Moreover, you may divide | segment into 3 or more periods.

  Further, as shown in FIG. 8, a load pattern based on the secondary side current value a or the system operation information is stored in the storage unit 13, and based on the load pattern, a high operation voltage adjustment is performed when the load is large. When the load is small, the voltage adjustment for lower operation may be performed. FIG. 9 shows, as an example, a rise pulse signal for correcting a voltage drop at the time of a load increase in the morning and a decrease pulse signal for correcting a voltage rise due to a load drop at night in the same voltage change as FIG. Is shown.

DESCRIPTION OF SYMBOLS 1 Voltage regulator 2 Load tap change transformer 3 Instrument transformer 11 Self-winding transformer 12 Program controller 13 Memory | storage part 14 Clock control part 15 Voltage adjustment relay

Claims (8)

The second voltage output from the transformer for the instrument that detects the first voltage that is the secondary voltage of the on-load tap switching transformer provided with the tap switching device that switches the tap of the winding in response to the tap switching command. A single-winding transformer comprising a plurality of output taps that respectively output a plurality of third voltages corresponding to target voltages of the first voltages different from each other.
A program controller that selects one of the plurality of third voltages according to a selection signal and outputs the selected third voltage as a fourth voltage;
Integrating a first time during which the fourth voltage exceeds the upper limit value of the dead zone of the reference voltage set in advance, and a second time during which the fourth voltage is less than the lower limit value of the dead zone; When the first time reaches a preset operation time, the tap switching command for lowering the first voltage is output, and when the second time reaches the operation time, A voltage adjusting relay for outputting the tap switching command for increasing the first voltage;
A storage unit storing target voltage change information indicating the change time for changing the target voltage and the changed target voltage;
In the case of outputting the selection signal for selecting a third voltage corresponding to the changed target voltage from the plurality of third voltages at the change time and increasing the target voltage, the second voltage The selection signal for lowering the fourth voltage is output during a predetermined period before the change time so that the predetermined addition time less than the operation time is added to the time of In this case, the clock control unit outputs the selection signal for increasing the fourth voltage during the predetermined period before the change time so that the predetermined addition time is added to the first time. When,
The voltage regulator characterized by having. The storage unit includes a voltage indicating a rise time when the first voltage rises to a predetermined rate or more from the target voltage, and a fall time when the first voltage falls from the target voltage to the predetermined rate or more. Fluctuation information is further memorized,
The clock control unit outputs the selection signal for increasing the fourth voltage so that the predetermined addition time is added to the first time during the predetermined period after the rising time, The selection signal for lowering the fourth voltage is output so that the predetermined addition time is added to the second time during the predetermined period after a decrease time. The voltage regulator described. The voltage regulation relay includes a dead zone reduction circuit that reduces the dead zone width equal to or higher than the reference voltage or the dead zone width equal to or lower than the reference voltage based on a dead zone reduction signal.
3. The voltage regulator according to claim 2, wherein the clock control unit outputs the selection signal and the dead band reduction signal during the predetermined period. 4.   4. The voltage regulator according to claim 1, wherein the predetermined period includes a plurality of periods in which a total time is less than the operation time. 5. A voltage regulator according to any one of claims 1 to 4,
The on-load tap change transformer in which the first voltage is adjusted in response to the tap change command;
The instrument transformer for detecting the first voltage and outputting as the second voltage;
A voltage regulation system comprising:   The voltage regulation system according to claim 5, wherein the on-load tap switching transformer is a distribution transformer installed in a distribution substation. The second voltage output from the transformer for the instrument that detects the first voltage that is the secondary voltage of the on-load tap switching transformer provided with the tap switching device that switches the tap of the winding in response to the tap switching command. A single-winding transformer comprising a plurality of output taps that respectively output a plurality of third voltages corresponding to target voltages of the first voltages different from each other.
The first time when the fourth voltage selected from the plurality of third voltages exceeds the upper limit value of the dead zone of the reference voltage set in advance, and the fourth voltage is less than the lower limit value of the dead zone. When a certain second time is accumulated and the first time reaches a preset operation time, the tap switching command for lowering the first voltage is output, and the second time When the operating time is reached, a voltage adjustment relay that outputs the tap switching command to increase the first voltage;
A computer to which target voltage change information indicating the change time for changing the target voltage and the changed target voltage in association with each other is input,
A function of selecting one of the plurality of third voltages according to a selection signal and outputting the selected third voltage as the fourth voltage;
In the case of outputting the selection signal for selecting a third voltage corresponding to the changed target voltage from the plurality of third voltages at the change time and increasing the target voltage, the second voltage The selection signal for lowering the fourth voltage is output during a predetermined period before the change time so that the predetermined addition time less than the operation time is added to the time of In this case, the function of outputting the selection signal for increasing the fourth voltage in the predetermined period before the change time so that the predetermined addition time is added to the first time;
A program to realize The second voltage output from the transformer for the instrument that detects the first voltage that is the secondary voltage of the on-load tap switching transformer provided with the tap switching device that switches the tap of the winding in response to the tap switching command. Are transformed by a single-winding transformer having a plurality of output taps to generate a plurality of third voltages corresponding to target voltages of the first voltages different from each other,
Based on the target voltage change information indicating the change time for changing the target voltage and the target voltage after the change in correspondence, the change time corresponds to the changed target voltage from the plurality of third voltages. When the third voltage is selected as the fourth voltage and the target voltage is lowered, the first time when the fourth voltage exceeds the upper limit value of the dead band of the reference voltage set in advance. In the case where the fourth voltage is increased during a predetermined period before the change time and the target voltage is increased so that a predetermined addition time less than the preset operation time is added to Lowering the fourth voltage during the predetermined period before the change time so that the predetermined addition time is added to a second time when the fourth voltage is less than the lower limit of the dead zone;
When the accumulated first time reaches the operating time, the tap switching command for reducing the first voltage is output, and the accumulated second time reaches the operating time. In this case, the voltage switching method is characterized in that the tap switching command for increasing the first voltage is output.

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