JP2007189821A - Output voltage regulator of distribution line in substation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an output voltage regulator capable of preventing unnecessary switching operation of a tap switching unit caused by the fact that reactive-power regulation and output voltage regulation are separately performed, especially, at the time zone when demand for a power load demand is rapidly changed. <P>SOLUTION: The output voltage controller of the distribution line in a substation is composed of: a control part issuing a tap switching command to the tap switching unit under a fixed condition based on an on-load tap changer provided with the tap switching unit, a phase modifier connected to the load in parallel through a switch in the secondary side of the on-load tap changer, an instrument transformer for reducing a secondary voltage of the changer to output it as an output voltage signal, and the output voltage signal, and a timer part issuing a voltage change command to the control part in a predetermined target voltage switching timing. The control part issues an opening and closing operation command to the switch based on the voltage change command, thus supplying or cutting-off the phase modifier. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides an unnecessary tap changeover operation of a tap changer in a substation where a tap changeover transformer with a tap changer for adjusting a sending voltage and a phase adjuster for adjusting a reactive power are installed in a distribution system. The present invention relates to a transmission voltage adjusting device that can be suppressed.

  In the power distribution system, the voltage drop fluctuates due to load fluctuations in demand areas. Usually, the system voltage becomes inductive load during the day, and the system voltage decreases. At night, the system voltage becomes a capacitive load and the system voltage increases. For this reason, in distribution substations, etc., in order to keep the received voltage at the demand area constant and stabilize the quality of the supplied power, the substation is compensated to compensate for the influence of the voltage drop in the distribution system. It is necessary to adjust the output voltage from the station. This adjustment of the transmission voltage is usually based on a preset target voltage schedule, and the secondary voltage (transmission voltage) of the on-load tap switching transformer connected in series to the distribution system of the substation is set for each time zone. This is done by switching the tap changer so as to approach the target voltage. In the present specification, hereinafter, “target voltage” is used to mean the target value of the transmission voltage from the substation, and is sometimes referred to as “target transmission voltage”.

  FIG. 5 is a diagram illustrating an example of such a target voltage schedule. In this figure, the horizontal axis indicates time (hour), and the vertical axis indicates target voltage (kV). In the power distribution system, the target voltage is normally changed in stages at predetermined time intervals based on this target voltage schedule (hereinafter, the time at which the target voltage is changed is referred to as “target voltage switching time”). According to the illustrated schedule, the target voltage is about 6530V from 1 am to 6 am, 6600 V from 6 am to 7 am, about 6660 V from 7 am to 8 am, and about 6720 V from 8 am to 12 am Each is set. In the time zone other than the above, as shown in FIG. 5, the above four types of target voltages are similarly set for each time zone.

  On the other hand, since the reactive power cannot be compensated only by adjusting the transmission voltage as described above and the power loss becomes large, it is necessary to reduce the power loss by reducing the reactive power flow in the distribution system and to save energy. is there. For this reason, in distribution substations, phase adjusters such as power capacitors and shunt reactors are connected in parallel to the distribution system load via switches, and a 24-hour timer that sets the switching operation time of the switches is used. The reactive power is reduced and the voltage is maintained at a constant value by opening and closing the switch and shutting off or turning on the phase adjuster.

  FIG. 6 is a conceptual diagram showing a configuration of a transmission voltage adjusting device of a distribution substation including such a load tap change transformer and a phase adjuster. In this figure, electric power is transformed in a load tap switching transformer 11 connected in series to the power distribution system 10, and a power demand place (load) (not shown) via a power distribution bus 12 provided on the secondary side thereof. Power distribution. An instrument transformer 13 is connected to the distribution bus 12 in parallel with the load, and the output voltage is detected by the instrument transformer 13, and the reduced output voltage signal is voltage-adjusted via the signal line 14. Input to the container 20.

  The voltage regulator 20 includes a timer unit 21 and a control unit 22. The timer unit 21 issues a voltage change command to the control unit 22 at a certain target voltage switching time of the day based on a target voltage schedule, which will be described later, and continues the external contact for the time from the time to the next target voltage switching time. Have the function of operating. The timer unit 21 may be provided with a plurality of timers having such external contact outputs. Further, the control unit 22 continuously monitors the voltage signal input via the signal line 14, and the upper limit value of the dead zone centered on the voltage signal and a reference voltage set in advance corresponding to the target voltage. And the lower limit value are compared, and if the dead zone is not within the range, a switching command for raising or lowering one tap is output to the tap changer 111. The tap changer 111 performs an operation of raising or lowering one tap in response to this tap change command.

  The distribution bus 12 is also provided with a power capacitor (phase regulator) 17 in parallel with the load via a switch 16, and a switching operation signal is sent to the switch 16 at a predetermined set time by a 24-hour timer 30. Then, by opening and closing this, the power capacitor 17 is cut off or turned on. It is known that the output voltage also changes when the power capacitor 17 is cut off or turned on (see FIG. 7).

  Thus, conventionally, the transmission voltage and reactive power of the substation distribution system have been separately controlled by the voltage regulator 20 and the 24-hour timer 30, respectively. Therefore, when the power capacitor 17 is turned on or off during a time period when the fluctuation of the power load is large, the output voltage changes, and the target voltage is out of the dead band range. As a result, the output voltage must be adjusted by tap switching. There were cases where it was not possible. On the other hand, when the target voltage is changed by the voltage regulator 20, there is a case where the fluctuation of the transmission voltage is large and it may fall outside the dead band range of the target voltage, and in order to prevent unnecessary tap switching operation, 17 may need to be turned on or off.

  An example of the above phenomenon in the apparatus of FIG. 6 will be described with reference to FIG. In FIG. 7, the target voltage from 6 am to 7 am is set to 6600 V, and after 7 am, it is set to 6700 V. The width of the dead zone centered on these target voltages is set to the target voltage ± 100V. That is, taking the 6am range as an example, the target voltage is 6600V, the upper limit value of the dead zone centered on this is 6700V, and the lower limit value is 6500V. The inductive load increases with the sudden increase in load demand from the 6 am range, and as a result, the transmission voltage starts to decrease (the reactive power increases), and from 24 hours timer 30 to the switch 16 around 6:55 am An opening / closing operation command is sent, and the power capacitor 17 is turned on (indicated as “SC turned on” in FIG. 7). As a result, the system voltage rises by about 60 V and exceeds the upper limit of the dead zone of 6700 V. Therefore, the voltage regulator 20 that detects the change in the sending voltage returns the tap voltage to the tap switch 111 so that the sending voltage is returned to the dead zone. A one-tap lowering operation command is issued. In response to this operation command, the tap changer 111 performs a one-tap lowering operation, and as a result, the delivery voltage is rapidly reduced.

  At 7 am, the voltage regulator 20 sends a command to the tap switch 111 to change the target voltage from 6600 V to 6700 V separately based on the target voltage schedule. As a result, as shown in FIG. 7, since the output voltage falls below the lower limit value 6600 V after the target voltage change and is out of the dead band range, the voltage regulator 20 again instructs the tap switch 111 to raise one tap. And the tap changer 111 operates to raise one tap. When the voltage adjustment and the reactive power adjustment are performed separately as in the case of this example, a phenomenon has occurred in which the tap switch 111 performs the tap switching operation many times in a short time.

  In recent years, in order to improve the above situation, voltage deviation and reactive power deviation on the secondary side of the transformer are detected in response to fluctuations in reactive power loss due to fluctuations in load demand and rises and drops in system voltage. There has been proposed a VQ control method that controls tap switching of a distribution transformer (see, for example, Patent Document 1). However, when this control method is introduced, many control devices must be installed, which causes a problem that the device configuration becomes complicated and costs increase.

  As another transmission voltage control method, a dead zone based on the target value is stored in the storage unit, and a time limit weight is set so that the adjustment range is divided into a plurality of regions and each region has a stepwise inverse time limit characteristic. Store the time weight for each area and the count of the time that the input voltage was for each area by the arithmetic processing unit, and when this value reaches the operation time limit, the arithmetic processing unit A method has been proposed in which an operation command is sent out and control is performed to continuously adjust the input voltage until it falls within the dead zone (see Patent Document 2). In this control method, when the tap position reaches the upper and lower limits, the phase adjuster is turned on or off for the first time. In other cases, voltage adjustment is performed by tap switching of the on-load tap switching transformer. Without change, it is difficult to reduce the number of tap switching.

Japanese Patent Laid-Open No. 5-19873 JP 56-146210 A

  In view of the above circumstances, the present invention has a demand for power load particularly in a substation in which a load tap change transformer provided with a tap changer for sending voltage adjustment and a phase adjuster for reactive power adjustment are installed in a distribution system. To provide a transmission voltage adjusting device capable of preventing an unnecessary switching operation of a tap changer due to the reactive power adjustment and the transmission voltage adjustment being performed independently and independently in a time zone where sudden change occurs, and fluctuations in the transmission voltage caused thereby. With the goal.

  As a result of intensive studies under the above objective, the present inventor has paid attention to the fact that the system voltage changes even when the phase adjuster is turned on or off. The present inventors have found that the above-mentioned problems can be solved by turning on or off the phase adjuster in preference to voltage adjustment by tap switching at the time of target voltage switching at which a simple tap switching operation tends to occur.

  That is, according to the present invention, the above-described object is to provide a tap switching transformer with load equipped with a tap changer, a phase shifter connected to the secondary side of the transformer in parallel with a load via a switch, and the transformer. A voltage transformer that outputs a voltage signal as a voltage signal, a control unit that issues a tap change command to the tap changer under a certain condition based on the voltage signal, and a predetermined target voltage change time A substation distribution line sending voltage adjustment device comprising a timer unit that issues a voltage change command to the control unit, wherein the control unit further performs an open / close operation command to the switch based on the voltage change command. Is achieved by a transmission voltage adjusting device for a substation distribution line, wherein the phase shifter is turned on or off.

  The control unit receives the voltage change command from the timer unit, and thereby changes the voltage of the voltage signal, an output voltage from the voltage change unit, and a dead band between a preset voltage and a reference voltage. A voltage adjustment relay that issues a tap switching command after a preset non-operation time for the tap switch when the output voltage is out of the dead band range of the reference voltage. Can be included.

  The opening / closing operation command is preferably issued to the switch simultaneously with a voltage change command.

  According to the present invention, the control unit changes the target voltage at the target voltage switching time, thereby sending an opening / closing operation command signal to the switch connecting the phase adjuster regardless of whether or not the tap switching operation condition is satisfied. Therefore, it is possible to increase or decrease the output voltage by turning on or off the phase adjuster. As a result, the system voltage can be kept within a predetermined dead zone, and the control unit does not need to issue a tap switching operation command to the tap switching unit, thereby suppressing an unnecessary tap switching operation of the tap switching unit. .

  Further, according to the present invention, since the phase adjuster is turned on or off as described above, it is possible to control the reactive power flow at the same time particularly in a time zone accompanied by a rapid change in load.

  Hereinafter, a transmission voltage adjusting device for a substation distribution system according to the present invention will be described in more detail with reference to the drawings. FIG. 1 is a conceptual diagram showing an example of a transmission voltage adjusting device of the present invention.

  As shown in FIG. 1, a distribution system transmission voltage adjusting device according to the present invention includes a load tap switching transformer 11 connected in series to a power system 10, a distribution bus 12 provided on the load side, and a distribution bus. 12 includes a power capacitor 17 connected in parallel to a load via a switch 16, an instrument transformer 13 connected in parallel to the bus 12, and a voltage regulator 20. The sending voltage adjusting device 1 of the present invention controls the opening / closing operation of the switch 16 by the voltage regulator 20 so that the phase adjuster 17 is turned on or off. It is different from the adjusting device. In FIG. 1, only the power capacitor 17 is disclosed as the phase adjuster, but a phase adjuster such as a shunt reactor or a static reactive power compensation measure may be used alone, or two or more of these may be used. You may use it in combination. Furthermore, a plurality of the phase adjusters or a plurality of groups may be installed, and each group or each group may be sequentially input or shut off in stages.

  The voltage regulator 20 illustrated in FIG. 1 includes a timer unit 21 and a control unit 22. Note that the timer unit 21 and the control unit 22 are not limited to the configuration in which both units are built in the voltage regulator 20 as shown in FIG. It can also be built into the device.

  FIG. 2 shows an AC circuit diagram for one phase of the voltage regulator 20. In this figure, signal lines 121 and 122 branched from two of the 6.6 kV three-phase distribution buses 12 are respectively connected to the primary side of an instrument transformer (PT) 13. One end of each of the signal lines 141 and 142 is connected to the secondary side of the instrument transformer 13, and the other end thereof is introduced into the control unit 22.

  The control unit 22 includes a voltage changing unit 23 into which the signal lines 141 and 142 are introduced, a voltage adjusting relay 27 connected to the signal lines 261 and 262 via the signal lines 261 and 262, and a control circuit (see FIG. 3). .

  The voltage changing means 23 further comprises a single-turn transformer 24 and a turn ratio switch 25. The autotransformer 24 has five taps drawn out from the secondary side series winding portion so that the winding ratio increases at a constant ratio. The turn ratio switching unit 25 includes a pair of a-contact and b-contact 251, 252, 253, and 254 connected between adjacent taps among the five taps 241 to 245. Each of the b contacts is sequentially connected in series to a tap 241 drawn from a winding portion where the turn ratio of the autotransformer is 1, and is connected to a signal line 262. Each of the a contacts has one end connected to the remaining four taps 242 to 245 and the other end connected to the b contact or the b contact or the signal line on the side of the voltage regulating relay 27 adjacent thereto. 262, respectively. Note that the turn ratio switching may be performed stepwise as shown in FIG. 2 or may be performed continuously, for example, like a slidac.

  The a-contact and b-contact pairs 251 to 254 have predetermined target voltages from the timers T1, T2, T3 and T4 arranged in the timer unit 21 at a target voltage switching time set in advance based on the target voltage schedule. A voltage change command is received at the switching time. This voltage change command is issued from only one timer at an arbitrary target voltage switching time, and is issued from a timer adjacent to the timer at the next target voltage switching time. In this way, the voltage changing means 23 increases or decreases the output voltage to the voltage adjusting relay 27 according to the voltage change command of each timer. The voltage change command is not particularly limited as long as it can operate the pair of contacts. Conveniently, each of the pairs 251 to 254 can be constituted by external contacts provided in timers T1 to T4 corresponding to the pairs. In addition, as such timers T1 to T4, each of the contacts that can be output to the outside provided at a presettable time can be closed or opened. If it can hold | maintain in that state, it will not specifically limit.

  For example, in FIG. 2, when the timer T1 is turned on at a predetermined target voltage switching time, the a contact is closed and the b contact is opened in the turn ratio switch 251 corresponding to the timer. This state is held until the timer T1 is turned off (the next target voltage switching time elapses). As a result, in FIG. 2, the tap 241 is switched from the top to the tap 242 to increase the turns ratio, and the secondary voltage (sending voltage signal) of the autotransformer 24 is increased with respect to the output voltage of the instrument transformer 13. Can be made. When the next target voltage switching time arrives in this state, the timer T1 is turned off, the timer T2 is turned on, the contact a of the contact pair 252 corresponding to the timer T2 is closed, and the contact b is opened. As a result, the tap 242 in FIG. 2 is switched to the tap 243 to increase the turn ratio, and the secondary voltage (sending voltage signal) of the autotransformer 24 can be further increased. For the remaining switchers, the secondary voltage of the autotransformer 24 can be increased in the same manner by sequentially receiving voltage change commands from the timers corresponding to them.

  Next, when the target voltage switching time arrives and the timer T2 is turned off from the above state, the closed a contact is opened, and the opened b contact is closed, so that a single turn is proportional to the turn ratio. The secondary voltage of the transformer 24 can be reduced. Similarly, when the other timers are turned off, the secondary voltage of the autotransformer 24 can be lowered.

  In this way, if the voltage changing means 23 switches to a direction in which the turns ratio is increased based on the voltage change command from the timer unit 21, the output of the autotransformer 24 with respect to the secondary voltage of the instrument transformer 13. The voltage can be increased, and conversely, if the turn ratio is reduced, the output voltage can be reduced. For example, when the output voltage of the autotransformer 24 is viewed in a span of one day, the increase and decrease are repeated stepwise at each target voltage switching time.

  In the voltage adjusting relay 27, the upper limit and the lower limit of the dead zone centering around the reference voltage corresponding to the target voltage of each time zone in the target voltage schedule are usually set in advance. These set values can be directly set by rotating a knob or the like with respect to the voltage adjusting relay 27, or can be set by receiving a remote command from a central power supply station, for example. In addition, as the voltage regulation relay 27, the conventionally well-known thing provided with the above functions can be used without a restriction | limiting.

  The voltage adjustment relay 27 receives the changed transmission voltage signal and compares it with an upper limit value or a lower limit value of a dead zone centered on a reference voltage set in advance corresponding to the target voltage. Depending on whether the sending voltage signal is larger or smaller than the range of the dead band set in advance, a one-tap up command or a one-tap down command is issued, and this tap switching command is sent to the tap changer. Adjusted. This tap change command may be sent immediately to the tap changer when the send voltage signal is out of the dead band range, or sent after a predetermined delay time. May be. In the latter case, for example, a timer is installed in the tap switching command generation circuit of the voltage adjusting relay 27, and the tap switching command is sent after being delayed by a set time (hereinafter referred to as non-operation time) of this timer. it can. This timer can be used to prevent an unnecessary tap switching operation of the tap changer, and the set time can be changed as appropriate in order to limit the number of tap switching times per day to an appropriate number of times, for example. For example, the timer starts counting the inactive time from the time when the sending voltage signal is out of the dead band range, and is reset when the sending voltage signal returns to the dead band range within the dead time. It is good to keep it.

  Here, the relationship between the transmission voltage signal to the voltage adjustment relay 27 and the tap switching operation command from the voltage adjustment relay 27 will be described. When the output voltage signal deviates from the lower limit value of the dead band centered on the reference voltage set in advance in the voltage adjustment relay 27 and a predetermined non-operation time has elapsed in this state, the voltage adjustment relay 27 increases the output voltage. A tap change command for raising one tap is issued to the tap changer. The tap changer that has received this command performs a one-tap raising operation of the on-load tap change transformer, which increases the transmission voltage of the distribution system.

  On the other hand, when the target voltage is lowered and the output voltage signal is high with respect to the reference voltage and the predetermined dead time elapses in a state where the upper limit value of the dead zone is exceeded, the voltage adjustment relay 27 is now turned on. A tap change command is issued to the tap changer to lower the send voltage by one tap. As a result, the tap of the on-load tap switching transformer 11 is lowered by one tap, and the output voltage is lowered.

  Whether the target voltage is raised or lowered, the transmission voltage signal is within the dead band range centered on the reference voltage, or once the dead band is out of the dead band range, If it returns to the range, the voltage adjusting relay 27 does not issue a tap switching command to the tap switching device. Immediately after the target voltage is changed, the send voltage signal is within the dead band range, and if the dead voltage range is exceeded due to fluctuations in the send voltage, the dead time is counted at that time. When the time has elapsed as it is started, the voltage adjusting relay 27 issues a command to raise or lower one tap to the tap changer.

  FIG. 3 is a circuit diagram of a control circuit for causing the switch of the phase adjuster to perform an opening / closing operation in the transmission voltage adjusting device of the present invention. In this figure, P, N and P1, N1 indicate control DC power supplies, respectively, but these two control power supplies are not limited to DC, and may be AC, taking into account the specifications of the equipment used. And can be selected as appropriate. In FIG. 3, the portion surrounded by the one-dot chain line in the upper left is a portion corresponding to the timer T1. In the figure, the portions corresponding to the remaining timers T2 to T4 are omitted because they have the same configuration as the portion corresponding to the timer T1. Also, the control circuit for the switch for turning on or off the phase adjuster is shown in the lower right dashed-dotted box.

  When the timer T1 is turned on at a predetermined target voltage switching time, the a contact 411 is closed and the b contact 412 associated therewith is opened in the P and N control circuit. When the a contact 411 is closed, the set coil 421 of the keep relay 42 is excited, and in the P1, N1 control circuit, the a contact 441 which is the contact output of the keep relay is closed and connected in parallel to the a contact 411. The b contact 442 associated with the contact is held in an open state. At the same time, the c-contact 43 provided on the negative electrode side of the keep relay 42 is held in a state of falling to the left from the state of falling to the right with the lower contact as a fulcrum toward the drawing. As a result, the c-contact 43 of the keep relay falls to the downstream side of the reset coil 422, and when the timer T1 is turned off, the reset coil 422 can be energized. The same control is performed when any of the other timers T2 to T4 is turned on. In addition, as shown in FIG. 3, you may connect the test terminals 451 and 452 to the negative electrode side of a contact and b contact in a P1 and N1 control circuit.

  The a contact 441 is connected to the set coil 51 of the keep relay for closing the switch 16 and turning on the phase adjuster 17 via the signal line N11, and the b contact 442 is connected to the keep relay of the keep relay via the signal line N12. When the reset coil 52 is excited and is connected to the reset coil 52, the switch 16 is opened to shut off the phase shifter 17. The signal line N11 is provided with an a contact 53 that is closed when the reset coil 52 is excited, and the signal line N12 is provided with a b contact 54 that is opened when the set coil 51 is excited. It is designed to surely switch from the state in which both are held.

  A timer (not shown) is interposed between the a contact 411 and the set coil 421 of the keep relay 42, the timer T1 is turned on and a voltage change command is issued, and thereby the a contact 411 and the b contact 412 are operated. The excitation of the set coil 421 of the keep relay 42 may be delayed by this timer for the set time. In this case, the set time of the timer (not shown) may be out of the dead band range centered on the reference voltage due to the switching of the target voltage. Need to be shorter. This timer can be incorporated in the control circuit by a conventionally known method. In this way, by allowing the excitation of the set coil 421 to be delayed, the timing of the switching operation of the switch can be appropriately determined within the time from the target voltage switching time to the tap switching operation by the tap switching device.

  Next, a method for adjusting the transmission voltage when the transmission voltage adjustment apparatus according to the embodiment illustrated in FIG. 1 is used will be described. FIG. 4 is a diagram showing an example of a fluctuation state of the sending voltage when the sending voltage adjusting device of the present invention is used. In this figure, the target voltage is 6600V at 6am, and 6660V after 7am. The range of the dead zone set in advance in the adjustment relay is assumed to be ± 100 V with the target voltage as the center. Therefore, the range of this dead zone is 6700V and 6500V at the upper limit at 6 o'clock, and 6760V and 6560V at the upper limit at 7 o'clock.

  Assuming that it is now 7:00 am, the control unit 22 switches the timer T4 from ON to OFF based on the target voltage schedule, and instead, the timer T3 is turned ON. As a result, a voltage signal that is lower by a smaller turn ratio from the tap 245 to the tap 244 is applied to the voltage adjustment relay 27, and as a result, the target voltage is changed from 6600V to 6660V. At the time when the target voltage is switched, the sending voltage is below the lower limit 6560V of the dead zone, so the timer for the inactive time starts counting. At the same time, as shown in FIG. 3, an opening / closing operation signal is sent to the switch, and the power capacitor is turned on by closing the switch. As a result, the system voltage rises by about 60V by inserting the power capacitor. As the system voltage rises in this way, the system voltage falls within the range of the dead zone of the target voltage, and the timer for the inactive time is reset.

  As described above, by using the transmission voltage adjustment device of the substation distribution system of the present invention, especially in a time zone where the power load fluctuation is large, prior to the transmission voltage adjustment by tap switching at a predetermined target voltage switching time. Since the phase adjuster can be turned on or off, the number of unnecessary tap switching by the tap changer is reduced, and as a result, the life of the tap changer is extended.

  The distribution system transmission voltage adjusting device of the present invention is preferably used in a substation where phase adjusting equipment is installed in the distribution system and reactive power is controlled individually or automatically together with the transmission voltage of the distribution system.

It is a conceptual diagram which shows an example of the transmission voltage adjustment apparatus of the power distribution system of this invention. It is an AC circuit diagram of the distribution system transmission voltage adjusting device of the present invention. It is a circuit diagram of the control circuit for performing operation | movement of the sending voltage adjustment apparatus of this invention. It is a figure which shows an example of the fluctuation | variation of the sending voltage at the time of using the sending voltage adjustment apparatus of this invention. It is a figure which shows an example of a target voltage schedule. It is a conceptual diagram which shows the structure of the transmission voltage adjustment apparatus of the distribution system of the conventional distribution substation. It is a figure which shows an example of the fluctuation | variation of the sending voltage by the conventional unnecessary tap switching operation | movement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Distribution system 11 Load tap change transformer 12 Distribution bus 13 Instrument transformer 4, 14, 23, 31 Signal line 16 Switch 17 Power capacitor (phase regulator)
DESCRIPTION OF SYMBOLS 20 Voltage regulator 21 Timer part 22 Control part 23 Voltage change means 24 Single voltage transformer 25 Turn ratio switch 27 Voltage adjustment relay 30 24 hour timer

Claims (3)

  A tap switching transformer equipped with a tap changer, a phase shifter connected to the secondary side of the transformer via a switch in parallel with the load, and a secondary voltage of the transformer is stepped down as a sending voltage signal An output transformer, a control unit that issues a tap switching command to the tap switch under a certain condition based on the output voltage signal, and a voltage change command to the control unit at a predetermined target voltage switching time A transmission voltage adjusting device for a substation distribution line comprising a timer unit for emitting, wherein the control unit further issues an opening / closing operation command to the switch based on the voltage change command to turn on or off the phase adjuster A substation distribution line transmission voltage adjusting device characterized by:   The control unit receives the voltage change command from the timer unit, and thereby changes the voltage of the voltage signal, an output voltage from the voltage change unit, and a dead band between a preset voltage and a reference voltage. A voltage adjustment relay that issues a tap switching command after a preset non-operation time for the tap switch when the output voltage is out of the dead band range of the reference voltage. The sending voltage adjusting device according to claim 1 including. 3. The sending voltage adjusting apparatus according to claim 1, wherein the switching operation command is issued to the switch simultaneously with a voltage change command.

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