JP2011182483A - Phase modifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately investigate an accident when energizing a distribution line by a reclosed circuit after distribution line power failure due to the accident within a phase modifier. <P>SOLUTION: The phase modifier includes phase modifying elements 4u to 4w connected to the distribution lines 1u to 1w via switches 5u to 5w and a control unit 6 for controlling the switches 5u to 5w so that a voltage of the distribution line is within a prescribed range. The control unit 6 includes a switch state storage unit 10 for storing the states of the switches immediately before detection of power failure when the distribution line power failure is detected and a switch returning means 11 at voltage recovery for restoring the states of the switches 5u to 5w to the states stored in the switch state storage unit 10 for the amount of time required for accident investigation by the reclosed circuit when detecting the recovery of the voltage in the distribution line. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a phase adjusting device that adjusts reactive power of a distribution system to adjust the voltage of the system to be within a predetermined range.

  In the distribution system, for example, as disclosed in Patent Document 1, a phase adjusting element, a switch for connecting the phase adjusting element to the distribution line, and a switch for disconnecting from the distribution line, and a switch according to the voltage of the distribution line The reactive power is adjusted so that the distribution line voltage falls within a predetermined range by controlling the input and disconnection of the phase adjustment element according to the distribution line voltage. is doing. As the phase adjusting element, a shunt reactor or a series reactor connected in series with a power capacitor is used.

JP-A-8-191019

  When an accident occurs in the distribution system to which the phase adjusting device is connected, the voltage at the distribution line disappears because the circuit breaker of the substation opens. At this time, the switch of the phase adjusting device is unconditionally opened, and the phase adjusting element is disconnected from the distribution line. At the substation, in order to investigate the accident section, reclosing is performed, and the distribution switches are sequentially turned on to restore the distribution line voltage. Remains open. Therefore, when the cause of the accident is inside the phase adjusting device, the search for the accident by the reclosing is not normally performed, and the accident section cannot be specified. After that, the control device in the phase adjuster monitors the voltage of the distribution line, and when necessary, turns on the switch to connect the phase adjustment element to the distribution line. If this happens, the accident will recur when the switch is turned on.

  An object of the present invention occurs in a phase adjusting device including a phase adjusting element connected to a distribution line via a switch and a control device that controls the switch in accordance with the voltage of the distribution line in its own device. The purpose is to provide a function that makes it possible to accurately carry out the exploration of an accident section when a system power failure occurs due to an accident.

  The present invention is directed to a phase adjusting device including a phase adjusting element connected to a distribution line via a switch and a control device that controls the switch so that the voltage of the distribution line falls within a predetermined range.

  In the present invention, when the control device detects that a power failure of the distribution line is detected, a switch state storage unit that stores the state of the switch immediately before the power failure is detected, and when the voltage of the distribution line is recovered In addition, there is provided voltage recovery switch return means for returning the switch state to the state stored in the switch state storage unit for the time required for the accident investigation at the reclosing.

  With the above configuration, when a reclosing is performed after the substation opens the circuit breaker due to an accident that occurred in the phase adjusting device, the phase adjustment is performed for the time required for the accident investigation during the reclosing. Since the switch of the device can be restored to the state immediately before the power failure and the switch that was in the on state immediately before the power failure can be returned to the on state, if the cause of the accident is inside the phase adjuster, The exploration can be performed accurately, and it is possible to prevent the accident from recurring when the phase adjusting device causing the power failure performs the voltage adjustment operation.

  The switch state storage unit includes a switch state sampling unit that samples a switch state at a constant sampling period when a voltage of the distribution line is detected, and a switch state sampling unit that samples when a power failure of the distribution line is detected. The switch state storage and holding means for storing and holding the latest switch state in the memory.

  As the memory, a rewritable nonvolatile memory is preferably used. In addition, when the control device is configured to obtain the power supply voltage from the distribution line, the power is supplied to the switch state storage unit until the memory completes the storage of the switch state when a power failure of the distribution line is detected. It is preferable to provide a backup power supply for applying a voltage.

  A volatile memory can also be used as the memory. In this case, a backup power supply that provides a power supply voltage to the switch state storage unit is provided from when a power failure of the distribution line is detected until the voltage of the distribution line is restored.

  The phase adjusting element may be a shunt reactor, or may be composed of a power capacitor and a series reactor connected in series to the power capacitor. A first phase adjusting element including a shunt reactor and a second phase adjusting element including a power capacitor and a series reactor connected in series to the power capacitor are provided. The present invention can also be applied to the case where the switch is provided for each of the second phase adjusting elements.

  According to the present invention, the state of the switch immediately before a power failure is detected when a power failure occurs in the distribution line is stored, and when the voltage of the distribution line is restored, the length required for the accident investigation at the reclosing time Since the switch state was restored to the state stored in the storage unit for the set time set in the above, after the substation opened the circuit breaker due to an accident that occurred in the phase adjuster, When the reclosing is executed, the switch of the phase adjusting device is returned to the state immediately before the power failure for the time required for the accident investigation at the time of reclosing, and the switch that was in the on state immediately before the power failure is returned to the on state. be able to. Therefore, when the cause of the accident is inside the phase adjuster, it is possible to accurately search for the accident, and when the phase adjuster that caused the power failure performs a voltage adjustment operation, the accident recurs. Can be prevented.

1 is a block diagram schematically showing a configuration of an embodiment of the present invention. It is the circuit diagram which showed the structural example of the switch state detection part used by embodiment of this invention. It is the block diagram which showed schematically the structure of other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the configuration of an embodiment of the present invention. In FIG. 1, 1u to 1w are U, V and W three-phase distribution lines. The distribution lines 1u, 1v and 1w are connected to the secondary side of the transformer provided in the substation 2 via a circuit breaker. In the middle of the distribution lines 1u to 1w, section switches 3u to 3w for inserting the distribution lines into a plurality of sections are inserted.

  Reference numerals 4u to 4w denote three-phase shunt reactors as phase adjusting elements, one end of which is grounded and the other end is connected to the distribution lines 1u to 1w through the switches 5u to 5w. 6 is a control device that controls the switches 5u to 5w so that the voltage of the distribution line falls within a predetermined range, and the shunt reactors 4u to 4w, the switches 5u to 5w, and the control device 6 allow the phase adjusting device 7 to be controlled. It is configured.

  The control device 6 includes a voltage detection unit 8 that detects the voltage of the distribution line, a switch control unit 9 that controls the switches 5u to 5w so that the distribution line voltage detected by the voltage detection unit 8 falls within a predetermined range, The switch state storage unit 10 stores the state of the switches 5u to 5w immediately before the power failure when the power distribution line fails, and the switch state storage unit 10 stores the state of the switches 5u to 5w when the voltage of the distribution line is restored. The switch recovery means 11 at the time of voltage recovery for returning to the current state and the backup power source 12 for supplying the power source voltage to the switch state storage unit 10 when the power distribution line fails.

  The voltage detection unit 8 includes a transformer that steps down the voltage between the two phases of the three-phase distribution lines, and detects the distribution line voltage from the output of the transformer.

  Each of the switches 5u to 5w is an electromagnetic switch having a movable contact and a fixed contact and a closing coil that is excited when the switch is turned on. An excitation current is supplied from the switch control unit 9 to the closing coil. When the movable contact is in contact with the fixed contact, the movable contact is turned on. When the supply of the excitation current to the closing coil is stopped, the movable contact is separated from the fixed contact and turned off.

 The switch control unit 9 is configured to operate by obtaining a power supply voltage from a transformer constituting the voltage detection unit 8. The switch control unit 9 monitors the voltage of the distribution lines 1u to 1w through the voltage detection unit 8, and when it is necessary to connect the shunt reactors 4u to 4w to the distribution line, an excitation current is applied to the input coil of the switches 5u to 5w. To turn these switches on, and when it is necessary to disconnect the shunt reactors 4u to 4w from the distribution line, the supply of the excitation current to the closing coil is stopped and these switches are turned off. The excitation current is supplied to the closing coils of the switches 5u to 5w by using the output voltage of the transformer provided in the voltage detector 8 as the power supply voltage. Therefore, when the power distribution lines 1u to 1w have a power failure, the switches 5u to 5w are unconditionally turned off.

  The switch control unit 9 monitors the distribution line voltage detected by the voltage detection unit 8, and controls the switches 5u to 5w to control the connection and disconnection of the shunt reactor so as to keep the distribution line voltage within a set range. Controls on / off. For example, when the distribution line voltage exceeds the first set value due to a Ferrant phenomenon or the like, the switch control unit 9 applies an exciting current to the input coil of the switches 5u to 5w to turn on the switches 5u to 5w. As a result, the shunt reactors 4u to 4w are connected to the distribution line, a lagging current is caused to flow through the distribution line, and the distribution line voltage is lowered. The switch control unit 9 stops supplying the excitation current to the closing coils of the switches 5u to 5w when the distribution line voltage becomes lower than the second set value set to a value lower than the first set value. Then, these switches are turned off, and the shunt reactors 4u to 4w are disconnected from the distribution line. By repeating these operations, the switch control unit 9 controls on / off of the switches 5u to 5w so that the voltage of the distribution line falls between the first set value and the second set value.

  When the switch state storage unit 10 monitors the distribution line voltage through the voltage detection unit 8 and detects that the distribution line has lost power, the switch state storage unit 10 is in the state (on state) of the switches 5u to 5w immediately before the power failure is detected. Or in an off state). For example, as shown in the figure, the switch state storage unit 10 detects the switches 5u to 20w detected by the switch state detection units 20u to 20w provided for the switches 5u to 5w, respectively, when the voltage of the distribution line is detected. When a power failure of the distribution line is detected from the switch state sampling means 13 that samples the state of 5w (whether the switches 5u to 5w are in the on state or the off state) at a constant sampling period and the output of the voltage detection unit 8 The switch state sampling unit 13 can store the latest state of the switches 5u to 5w being sampled and can hold the switch state storage and holding unit 14. The switch state storage / holding means 14 writes in the memory 15 the state of the switches 5u to 5w sampled by the switch state sampling means 13 when a power failure of the distribution line is detected from the memory 15 and the output of the voltage detection unit 8. The switch state writing means 16 can be used. In the present embodiment, the switch state sampling unit 13 and the switch state storage holding unit 14 are configured by the same microprocessor.

  Referring to FIG. 2, a configuration example of the switch state detection units 20u to 20w is shown. In this example, auxiliary switches 21u to 21w that perform an on / off operation in the same manner as the switches 5u to 5w are provided in the switches 5u to 5w, respectively, and the output voltages of the DC power sources 22u to 22w are respectively connected to the relays through the auxiliary switches 21u to 21w. Applied to both ends of the exciting coils 23u to 23w. The relay provided with the exciting coils 23u to 23w has normally open contacts 23ua to 23wa, and these contacts 23ua to 23wa constitute a microprocessor (MPU) 25 which constitutes the switch state sampling means 13 and the switch state memory holding means 14. Connected to a predetermined input port.

  In the present embodiment, the auxiliary switches 21u to 21w are turned on when the switches 5u to 5w are turned on. As a result, the exciting coils 23u to 23w are excited, and the contacts 23ua to 23wa are turned on. When the switches 5u to 5w are turned off, the auxiliary switches 21u to 21w are turned off, whereby the exciting coils 23u to 23w are demagnetized and the contacts 23ua to 23wa are turned off. The switch state sampling means 13 constituted by the microprocessor 25 goes to see the state of the contacts 23ua to 23wa every time each sample timing arrives, and the switches 5u to 5w are turned on respectively when the contact 23ua is on. It is determined that the switches 5u to 5w are in the off state when the contact 23ua is in the off state. These determination results are stored by the switch state storage holding unit 14.

  In this example, switch state detectors 20u to 20w are constituted by auxiliary switches 21u to 21w, DC power sources 22u to 22w, and relay exciting coils 23u to 23w.

  In FIG. 2, the DC power supplies 22 u to 22 w can be configured by a rectifier circuit that rectifies an AC voltage taken from the distribution line through a transformer provided in the voltage detection unit 8.

  In the example shown in FIG. 2, the DC power sources 22u to 22w are individually provided for the auxiliary switches 21u to 21w and the excitation coils 23u to 23w, respectively, but the auxiliary switches 21u to 21w and the excitation coils 23u to 23w are provided respectively. On the other hand, a single DC power supply may be provided in common.

  The auxiliary switches 21u to 21w may be electromagnetically driven by the input coils of the switches 5u to 5w, and are mechanically linked to the switches 5u to 5w and turned on when the switches 5u to 5w are turned on. It may be provided so as to be in an off state (or an on state) when the switch 5u to 5w is in an off state.

  In the example shown in FIG. 2, the contacts 23ua to 23wa are turned on and off when the switches 5u to 5w are turned on and off. However, the contacts 23ua to 23wa are switched to the switches 5u to 5w. May be provided to take different states depending on whether the switches 5u to 5w are turned on or off, and the contacts 23ua to 23wa are turned off and turned on, respectively. You may comprise so that it may be in an ON state.

  The switch recovery means 11 at the time of voltage recovery shown in FIG. 1 has a length necessary for an accident search at reclosing when it is detected from the output of the voltage detection unit 8 that the voltage of the distribution line that has been interrupted is recovered. It is a means for returning the state of the switch to the state stored in the switch state storage unit for the set time set at the time, and when the voltage of the distribution line is recovered, the state immediately before the power failure stored in the memory 15 The state of the switches 5u to 5w is read, and the read switch state is given to the switch controller 9. At this time, the switch control unit 9 controls the supply of excitation current to the closing coils of the switches 5u to 5w so that the switches 5u to 5w are brought into the state given from the switch restoration means 11 at the time of voltage recovery. That is, when the switches 5u to 5w are turned on immediately before the power failure, the switch recovery means 11 at the time of voltage recovery turns on the switches 5u to 5w at the same time as the distribution line voltage is restored, and the switch 5u immediately before the power failure. When 5 to 5w are in the off state, the switches 5u to 5 are left in the off state when the distribution line voltage is recovered.

  The investigation of the accident at the time of reclosing is performed on the substation 2 side. When the substation detects that an accident has occurred in the system, the substation opens the circuit breaker, and after a certain period of time, reopens the circuit breaker to perform “reclosing”. When reclosing is performed, each division switch is turned on when a slave station (not shown) of each division switch provided in the distribution system detects the voltage of the distribution line on the power supply side. In this way, a series of section switches are sequentially turned on, and a voltage is applied to a section on the load side of the turned-on section switches. In the substation, in the process of sequentially closing the divisional switch of the system, the section where the accident occurred is investigated by checking whether the accident is detected again, and when the accident is detected again, the accident When an accident is detected, it is determined that an accident has occurred in the section connected to the closed section switch, and the power distribution to the distribution system is recovered with the accident section disconnected. Since the time required for the substation to conduct the accident search is known in advance, the time is set in the voltage recovery switch return means 11 as “the time required for the accident search during reclosing”. In general, at the time of turning on again, in the process of sequentially turning on a series of division switches 3u to 3w provided in the power distribution system, energization to one section is resumed and then energization to the next section is resumed. The time required to complete the accident can be defined as “time required for accident investigation during reclosing”.

  As the memory 15, either a non-volatile memory (ROM) or a volatile memory (RAM) may be used. When a non-volatile memory is used, a rewritable non-volatile memory such as an EPROM or an EEPROM is used. It is preferable to use it.

  When a rewritable nonvolatile memory is used as the memory 15, at least the power supply voltage is supplied to the switch state storage unit 10 until the memory 15 completes storing the switch state when a power failure of the distribution line is detected. A backup power supply 12 for providing

  When a volatile memory is used as the memory 15, a backup power source 12 that supplies power voltage to at least the switch state storage unit 14 is provided until the voltage is recovered after a power failure of the distribution line is detected.

  The backup power source 12 may be a battery that is charged by a voltage applied through the voltage detection unit 8, or may be a power source that is a capacitor charged by a voltage applied through the voltage detection unit 8.

  In the control device 6 shown in FIG. 1, the switch control unit 9, the switch state storage unit 10, and the voltage recovery switch return means 11 can be configured by causing a microprocessor to execute a predetermined program. In this case, the switch control unit 9, the switch state storage unit 10 and the voltage recovery switch return means 11 may be configured using a common microprocessor, and the switch control unit 9 and the switch state storage unit 10 may be configured as separate micro-processors. You may comprise using a processor. The switch recovery means 11 at the time of voltage recovery may be configured using a microprocessor configuring the switch control unit 9 or may be configured using a microprocessor configuring the switch state storage unit 10.

  In the distribution system to which the phase adjusting device 7 is connected, when an accident occurs, the circuit breaker of the substation 2 is opened, so that the voltages of the distribution lines 1u to 1w are lost. The switches 5u to 5w of the phase adjusting device are turned on when an excitation current is passed through the input coil using the voltage of the distribution line as a power source. Therefore, when the voltage of the distribution line is lost, the switches 5u to 5w are unconditional. The shunt reactor (phase adjusting element) 4u to 4w is disconnected from the distribution line by being turned off. In the substation, in order to investigate the accident section, reclosing is executed, and the distribution switches are sequentially turned on to restore the distribution line voltage. The switches 5u to 5w remain open. Therefore, when the cause of the accident is inside the phase adjusting device 7, the accident search by the reclosing is not normally performed, and the accident section cannot be specified. Thereafter, the control device 6 in the phase adjusting device 7 monitors the voltage of the distribution line, and when it becomes necessary, turns on the switches 5u to 5w to connect the shunt reactor to the distribution line. Is in the phase adjusting device, the accident will recur when the switches 5u to 5w are turned on.

  On the other hand, when configured as in the above embodiment, when the reclosing is executed after the substation 2 opens the circuit breaker due to an accident occurring in the phase adjusting device 7, the reclosing is performed. The switch 5u to 5w of the phase adjusting device 7 can be returned to the state immediately before the power failure for the time required for the accident investigation at the time, and the switch that was in the on state immediately before the power failure can be returned to the on state. If the cause of the fault is inside the phase adjuster, the accident can be accurately investigated, and the accident can reoccur when the phase adjuster that caused the power failure performs voltage regulation. Can be prevented.

  In the above embodiment, the shunt reactor is used as the phase adjusting element for adjusting the reactive power flowing through the distribution system. However, as shown in FIG. 3, the power capacitors 18u to 18w and these capacitors are respectively connected in series. The present invention can also be applied to the case where the connected series reactors 19u to 19w are used as the phase adjusting elements.

  The shunt reactor is a first phase adjusting element, the power capacitor and the series reactor connected in series to the power capacitor is a second phase adjusting element, and the first phase adjusting element and the second phase adjusting element are used. The present invention can also be applied to a case where switches corresponding to the switches 5u to 5w are provided for each element.

1u to 1w Distribution line 2 Substation 3u to 3w Division switch 4u to 4w Shunt reactor 5u to 5w Switch 6 Controller 7 Phase adjuster 8 Voltage detector 9 Switch controller 10 Switch state storage 11 Switch recovery at voltage recovery Means 12 Backup power supply 13 Switch state sampling means 14 Switch state storage holding means 15 Memory 16 Switch state writing means 18u to 18w Power capacitor 19u to 19w Series reactor 20u to 20w Switch state detector 21u to 21w Auxiliary connection switch 22u to 22w DC power supply 23u to 23w Relay exciting coil 23ua to 23wa Relay contact

Claims (7)

In a phase adjusting device comprising a phase adjusting element connected to a distribution line via a switch, and a control device for controlling the switch so that the voltage of the distribution line falls within a predetermined range,
The controller is
A switch state storage unit that stores a state of the switch immediately before a power failure is detected when a power failure of the distribution line is detected;
When detecting that the voltage of the distribution line has recovered, the switch at the time of voltage recovery that returns the state of the switch to the state stored in the switch state storage unit for the time required for the accident search at the time of reclosing Return means;
A phase adjusting device comprising: The switch state storage unit is a switch state sampling unit that samples the state of the switch at a constant sampling period when a voltage of the distribution line is detected, and the switch state when a power failure of the distribution line is detected. Switch state storage holding means for storing and holding the state of the latest switch sampled by the sampling means in a memory;
The phase adjusting device according to claim 1. The memory comprises a rewritable nonvolatile memory,
The backup power supply which provides a power supply voltage to the said switch state memory | storage part until the said memory completes the memory | storage of a switch state when the power failure of the said distribution line is detected is provided. The phase adjusting apparatus as described. The memory comprises volatile memory,
The control power supply according to claim 2, wherein a backup power supply for supplying a power supply voltage to the switch state storage unit is provided from when a power failure of the distribution line is detected to when the voltage of the distribution line is recovered. Phase device.   The phase adjusting device according to claim 1, 2, 3, or 4, wherein the phase adjusting element is a shunt reactor.   5. The phase adjusting device according to claim 1, wherein the phase adjusting element is a power capacitor and a series reactor connected in series to the capacitor. As the phase adjusting element, a first phase adjusting element consisting of a shunt reactor and a second phase adjusting element consisting of a power capacitor and a series reactor connected in series to the power capacitor are provided.
The switch is provided for each of the first phase adjusting element and the second phase adjusting element;
The phase adjusting device according to claim 1, 2, 3, or 4.

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