JP2005354884A - Switching controller and control method of distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide switching controller and control method of distribution system in which unnecessary opening of a load-break switch due to overcurrent of reverse power flow occurring upon service interruption of a distribution line due to some cause can be suppressed. <P>SOLUTION: When a power flow direction decision section 34 decides reverse power flow, a voltage detection signal of an incoming line 13 arranged with a load-break switch 16 is outputted artificially to an overcurrent detecting section 32 even when the voltage of the incoming line 13 (i.e. control power supply) disappears. Consequently, no-voltage state of the distribution line 11 and the incoming line 13 is not detected at the overcurrent detecting section 32 even if reverse power flow from a distributed power supply 15 is regarded as overcurrent and detected and the distributed power supply 15 is stopped. Open operation (SO operation) of the load-break switch 16 is thereby locked and throw-in state is sustained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power distribution system switching control device and a power distribution system switching control method.

  Conventionally, a control device for a load switch having an overcurrent protection function (for example, a SOG type high voltage load switch) has an overcurrent (or short circuit current) exceeding a set value (lock current value of the load switch) on the consumer side. When this occurs, the load switch is locked to prevent opening during overcurrent. After the protective relay of the substation operates and selectively cuts off the abnormal section, the power line is cut off by disconnecting the distribution line, and after the overcurrent disappears due to the power outage (that is, the distribution line is in a no-voltage state) Later, the load switch of the customer who caused the accident is opened. After a predetermined time has elapsed, the distribution line is reclosed. Since power is supplied to customers other than the customer who has the cause of the accident and the service line of the customer having the cause of the accident remains open by the load switch, the power outage continues in the customer premises. After that, the cause of the accident is removed, and the load switch is turned on manually to recover.

  By the way, in recent years, a distributed power source (in-house power generation device) is provided on the premises, and the number of consumers who use it in combination with the power supply of the commercial power source is increasing and the power generation capacity of the consumer tends to increase. In addition, since the power generation capacity of the distributed power source that can be linked to the power distribution system is defined as less than 2000 kW (kilowatts), for example, the current supplied from the distributed power source is overcurrent level (the load switch lock current value (Exceeding level) has occurred. However, the conventional load switch control device operates on the premise that the consumer only receives power from the power company. For this reason, when an accident occurs outside the customer's premises, a reverse power flow occurs from the distributed power source to the distribution line, and this reverse power flow is regarded as an overcurrent, so no accident has occurred in the customer's equipment. In some cases, the load switch was opened despite the fact that it was a large service line.

  In detail, if an accident occurs outside the customer's premises, the distribution line will be out of service due to a trip at the substation. However, current flows from a consumer having a distributed power source to the distribution line side, that is, reverse power flow occurs. This reverse power flow becomes an overcurrent level, and the control device detects this overcurrent, locks the opening operation of the load switch after a predetermined lock time (for example, 0.1 seconds), and performs the opening operation to the no-voltage state. Set to the standby state. As a facility standard, a distributed power source is required to stop within a predetermined stop time (about 2 seconds) from the occurrence of a power failure at the time of a power failure of a distribution line. In general, the stop time of the distributed power supply at the time of distribution line power failure is longer than the lock time of the load switch. For this reason, the control device detects the reverse power flow as an overcurrent, detects the non-voltage state of the distribution line by stopping the distributed power supply, and automatically opens the load switch.

  Therefore, if the circuit breaker of the substation is cut off (tripped) due to an accident in another customer or power distribution line (accident outside the customer's premises) and this circuit breaker is turned on again, an accident will occur. The load switch of the customer who installed the distributed power supply that is not used is open. For this reason, when the circuit breaker is turned on again, the power failure state continues in the customer premises even though power is supplied to the distribution line again. In addition, in order to turn on the load switch in the open state, a corresponding recovery procedure such as inspection and return operation by a qualified person is necessary, and it takes time to turn on the load switch. As described above, since the load switch restoration work on the customer side is complicated, it is preferable that the load switch in the customer premises is opened in a dark manner despite an accident outside the customer premises. There wasn't. It was desired to open the load switch only when an accident (short circuit) was detected on the customer premises.

  Furthermore, even though there is no distributed power supply installed, customers who use large motors (motors) as loads will experience an accident outside the customer's premises and the distribution line will be out of service due to a substation trip. In this case, a reverse power flow is generated because the electric motor tries to keep a current flowing due to regeneration. The control device detects this reverse power flow as an overcurrent and detects the non-voltage state of the distribution line by disconnecting the electric motor from the premises system, so that the load switch is automatically opened. Similar to the case where the distributed power source is installed, the load switch opens in spite of the accident outside the customer's premises, so it is desired to take the same measures. That is, it has been necessary to prevent the load switch from being opened by a current from a distributed power source or a current from a large motor during a power failure in the distribution line.

In order to solve such problems, conventionally, a load switch that uses the current flow direction of the line current as the judgment material and prohibits the opening operation of the load switch for reverse power flow from the distributed power source has been used. It has been proposed (see, for example, Patent Document 1). That is, the load switch control device detects the phase voltage and the load current when a power failure occurs, determines the flow direction from the phase difference between the detected phase voltage and the load current, and detects the flow direction and the overcurrent detection means. The overcurrent direction is detected by the signal. Since it is possible to specify whether the overcurrent accident has occurred on the premises or on the premises, the opening operation of the load switch due to the overcurrent caused by the accident on the premises is prevented. For this reason, after the circuit breaker of the substation is turned on again, electric power is smoothly supplied to the customer through the load switch that maintains the input state.
JP 2003-158820 A

  In the conventional load switch control device, based on the direction of power flow, it is determined whether the power flow is due to a short circuit accident on the premises or due to an overcurrent of a reverse power flow that occurs when the distribution line is interrupted for some reason. To do. Then, when it is determined that the control device is caused by a local short-circuit accident, the load switch is opened, while it is determined that the control device is caused by an overcurrent of a reverse power flow that occurs when the distribution line is interrupted for some reason. In such a case, the load switch is turned on and maintained. However, how to lock the opening of the load switch when it is determined that it is caused by an overcurrent of reverse power flow that occurs when the distribution line fails for some reason. Has not been fully studied.

  The present invention has been made to solve the above problems, and its purpose is to unnecessarily open a load switch due to an overcurrent of a reverse power flow that occurs when a distribution line fails for some reason. Disclosed is a distribution system switching control apparatus and a distribution system switching control method capable of suppressing the power distribution.

  The invention according to claim 1 supplies power separately from the power supplied from the distribution line to a load connected to the distribution line via a service line and a load switch provided on the service line. A distributed power source, an overcurrent detection unit for determining whether or not a load current of the lead-in line is at an overcurrent level and detecting a no-voltage state of the distribution line and the lead-in line, the load current and the lead-in line A load flow direction determining unit that determines a flow direction of the distribution line based on a phase difference from the line voltage of the distribution line, the load switch based on a determination result by the overcurrent detection unit and a determination result by the flow direction determination unit A control unit for opening or maintaining the input, and a switching control device for a distribution system comprising: a power detection unit that detects the presence or absence of the voltage of the lead-in line and outputs the detection signal to the overcurrent detection unit; Lead wire A pseudo detection signal generation unit that can pseudo-output a detection signal indicating that the voltage is present to the overcurrent detection unit, and an output line of the pseudo detection signal from the pseudo detection signal to the overcurrent detection unit A normally open contact or a normally closed contact is provided on the top, and when the reverse flow is determined to the effect that the flow direction is a reverse flow, the flow direction determination unit is inserted with the normally open contact, or The gist of the invention is that the overcurrent detector is provided with contact driving means for detecting the voltage of the lead-in line in a pseudo state by opening the normally closed contact.

According to a second aspect of the present invention, in the switching control device for a distribution system according to the first aspect, when the overcurrent is detected by the overcurrent detection unit, the load switch is within a preset preparation time. After completing the preparation for energy storage trip, after that, after the distribution line has become no voltage, the opening operation is performed after a preset standby time,
The tidal current direction determination unit performs a reverse tidal current determination that the tidal current direction is a reverse power flow after the standby time of the load switch has been prepared and the standby time has elapsed. The gist is that the normally open contact is inserted to cause the overcurrent detection unit to detect the voltage of the lead-in line in a pseudo state.

  The invention according to claim 3 supplies power separately from the power supplied from the distribution line to a load connected to the distribution line via a service line and a load switch provided on the service line. A distributed power source, determining whether or not the load current of the lead-in line is at an overcurrent level and detecting a no-voltage state of the distribution line and the lead-in line; and the load current and the line of the lead-in line Determining the power flow direction of the distribution line based on the phase difference between the voltage, the determination result whether the load current is an overcurrent level and the determination result of the power flow direction of the distribution line A switching control method for a distribution system comprising: opening or maintaining a load switch; and when there is a reverse power flow determination that the power flow direction is a reverse power flow, there is a voltage of the lead-in line Detection signal By outputting artificially, and summarized in that which is adapted to lock the opening operation of the load switch.

(Function)
According to the first aspect of the present invention, when the reverse power flow from the distributed power source is detected as an overcurrent, even if the voltage of the service line in which the load switch is installed disappears, the service line A detection signal indicating that there is a voltage on the road is pseudo-output to the overcurrent detection unit. Thereby, even if the said distributed power supply stops, the no-voltage state of a distribution line and a drawing-in line is not detected by the overcurrent detection part. For this reason, the opening operation of the load switch is locked and held in the closed state. Therefore, unnecessary opening of the load switch due to the occurrence of overcurrent due to an off-site customer accident can be suppressed.

  According to a second aspect of the present invention, in addition to the operation of the first aspect of the invention, when the overcurrent is detected by the overcurrent detection unit, the load switch stores energy within a preset preparation time. After the preparation for the trip is completed, the opening operation is performed after a standby time set in advance after the distribution line becomes no voltage. Under such conditions, when the tidal direction determination unit makes a reverse tidal current determination that the tidal direction is a reverse tidal current, the standby time elapses after the load switch is ready for a storage trip. In the meantime, the normally open contact is inserted. Thus, before the voltage of the incoming line in which the load switch is installed completely drops (that is, before the distributed power supply is stopped), the pseudo detection signal with the incoming line voltage is detected as an overcurrent. By outputting to the unit, the opening operation of the load switch can be locked.

  According to the third aspect of the present invention, when the reverse power flow from the distributed power source is detected as an overcurrent, even if the voltage of the service line in which the load switch is installed disappears, the service line A detection signal indicating that the voltage of the road is present is output in a pseudo manner. Thereby, even if the said distributed power supply stops, the no-voltage state of a distribution line and a drawing-in line is not detected. For this reason, the opening operation of the load switch is locked and held in the closing state. Therefore, unnecessary opening of the load switch due to the occurrence of overcurrent due to an off-site customer accident can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the unnecessary opening | release of the load switch by overcurrent generation | occurrence | production caused by a customer off-site accident can be suppressed.

Hereinafter, an embodiment in which the present invention is embodied in an open / close control device for a distribution system interconnected with distributed power sources will be described with reference to FIG.
As shown in FIG. 1, a load 14 is connected to a distribution line 11 on the power company side via a lead-in line 13, and power from the distribution line 11 outside the customer premises is forward to the load 14 during normal power reception. Supplied as a tidal current. In addition, a distributed power source 15 is installed in the customer premises, and the power generated by the distributed power source 15 can be supplied to the load 14. In the present embodiment, the distributed power source 15 is a generator. On the lead-in line 13, a load switch 16 is provided on the power supply side of the connection point of the distributed power supply 15, and the load switch 16 is controlled to be opened and closed by the control device 17. Moreover, the load switch 16 is installed on the responsibility demarcation point. The control device 17 constitutes a switching control device for the distribution system.

<Load switch>
As shown in FIG. 1, in the load switch 16, a switching unit 20, a zero-phase current transformer 21, and a zero-phase voltage detection are provided on the lead-in line 13 of each phase composed of the R phase, the S phase, and the T phase. A capacitor 22, a control power source transformer 23, and two current transformers 24r and 24t for overcurrent detection are provided. The opening / closing unit 20 includes a plurality of switches 20r, 20s, and 20t provided in each phase of the lead-in line 13. The zero-phase current transformer 21 is provided on the power supply side of the switching unit 20 and detects the zero-phase current (ground fault current) of the R-phase, S-phase, and T-phase of the lead-in line 13. The zero-phase voltage detection capacitor 22 is provided on the load side of the switching unit 20 and detects a zero-phase voltage for selective protection between a load-side ground fault and a power-supply side ground fault.

  The control power transformer 23 is provided on the load side with respect to the zero-phase voltage detection capacitor 22 on the lead-in line 13. Both ends of the primary side winding of the control power transformer 23 are connected to the S phase and T phase of the lead-in line 13, respectively. The secondary side winding of the control power transformer 23 includes a primary side winding and An electromotive voltage is generated according to the turn ratio. The current transformers 24 r and 24 t are arranged between the zero-phase voltage detection capacitor 22 and the control power transformer 23 on the lead-in line 13. Both current transformers 24r and 24t are provided in the R phase and the T phase of the lead-in line 13, respectively.

  In addition, a trip coil 25 for automatically tripping (opening) the switching unit 20 is provided in the load switch 16. Incidentally, the automatic trip operation includes a ground fault trip operation and an overcurrent trip operation. The ground fault trip operation means that when a ground fault current flows through the lead-in line 13 due to a ground fault occurring on the load side, when the ground fault current is detected and the set value is exceeded, the trip coil 25 is excited. In this operation, the opening / closing part 20 is automatically opened. The overcurrent trip operation means that when an overcurrent exceeding a certain set value is detected in a short circuit accident, the switching unit 20 is locked so as not to automatically open, and the circuit breaker of the substation trips to cause the distribution line 11 and the incoming line 13. Is the operation of exciting the trip coil 25 and automatically opening and closing the opening / closing part 20 instantly after the no-voltage state.

<Control device>
The control device 17 includes a trip power supply P, a ground fault current detection unit 31, an overcurrent detection unit 32, a phase difference calculation unit 33, a power flow direction determination unit 34, and a control unit 35.

  The trip power source P is a capacitor, for example, and supplies power for exciting the trip coil 25. A power supply line L1 is connected between the trip power supply P and the trip coil 25, and a normally open contact MS1 is provided on the power supply line L1.

  The ground fault current detection unit 31 detects the zero phase current (ground fault current) output from the zero phase current transformer 21 and the zero phase voltage output from the zero phase voltage detection capacitor 22, and outputs the detection results. Output to the control unit 35.

  The overcurrent detector 32 detects the load current (more precisely, the load current flowing through the R phase and T phase of the lead-in line 13) output from the current transformers 24r and 24t, and the detected load current is the overcurrent. It is determined whether or not it is level (that is, whether or not the lock current value of the load switch 16 is exceeded), and the determination result is output to the control unit 35. Further, the overcurrent detection unit 32 detects the presence / absence of the voltage of the distribution line 11 and the lead-in line 13 (that is, whether or not it is in a no-voltage state), and sends the detection result to the control unit 35.

  The phase difference calculation unit 33 includes a line voltage (in this embodiment, a voltage between the S phase and the T phase) detected by the control power transformer 23 and a load current detected by the current transformers 24r and 24t. Based on each value, the phase difference from the load current is calculated based on the line voltage, and the calculation result is sent to the power flow direction determination unit 34.

  The power flow direction determination unit 34 is based on the phase difference between the line voltage and the load current calculated by the phase difference calculation unit 33 (more precisely, based on the phase change of the load current vector with respect to the line voltage vector). And the determination result is sent to the control unit 35. Moreover, the tidal current direction determination unit 34 includes an exciting coil 34a. When the power flow direction determination unit 34 determines that the power flow direction is reverse power flow, the power flow direction determination unit 34 excites the excitation coil 34a and closes a normally-open contact 43 described later.

  When the ground fault current is detected by the ground fault current detector 31, the controller 35 excites the trip coil 25 to automatically open the opening / closing part 20. When the overcurrent detection unit 32 detects an overcurrent that is equal to or greater than a set value (the load switch 16 lock current value), the control unit 35 opens and closes the load based on the flow direction determined by the flow direction determination unit 34. The vessel 16 is kept open or charged.

  As shown in FIG. 1, the control device 17 includes a series circuit C1 including a normally open contact 41, a protective resistor 46, and a DC power source 42, and a series circuit C2 including a normally open contact 43, a protective resistor 47, and a DC power source 44. It has. The series circuits C1 and C2 are connected in parallel to each other. One end of the normally open contact 41 side of the series circuit C1 and one end of the normally open contact 43 of the series circuit C2 are connected to the overcurrent detection unit 32 through the signal output line L2, respectively, and the other end on the DC power sources 42 and 44 side is also used. Are each grounded.

  Excitation coils 45 are provided between both ends of the secondary winding of the control power transformer 23. The excitation coil 45 is always excited in a normal time when a current flows through the distribution line 11 and keeps the normally open contact 41 closed. Then, the voltage of the DC power supply 42 is output to the overcurrent detection unit 32 as the control power supply detection signal S. When the distribution line 11 and the lead-in line 13 are brought into a no-voltage state due to a short circuit accident or the like, the exciting coil 45 is demagnetized and the normally open contact 41 is opened, and the control power supply detection signal S is output to the overcurrent detection unit 32. Is stopped. On the other hand, the normally open contact 43 is closed when the reverse flow is determined by the flow direction determination unit 34 and the excitation coil 34a of the flow direction determination unit 34 is excited. Then, the voltage of the DC power supply 44 is output to the overcurrent detection unit 32 as a pseudo power detection signal Sg of the control power supply, that is, the voltage of the lead-in line 13.

  In the present embodiment, the exciting coil 34 a constitutes a contact driving means for inserting the normally open contact 43. The series circuit C1 detects the presence or absence of the voltage of the control power source of the control device 17, that is, the lead-in line 13 in which the load switch 16 is installed, and sends the detection signal (control power source detection signal S) to the overcurrent detection unit 32. The power supply detection part which outputs to is comprised. Further, the series circuit C2 detects a detection signal (that is, a pseudo signal indicating that the voltage of the control power supply, that is, the lead-in line is present) when the power flow direction determination unit 34 performs a reverse power flow determination that the power flow direction is a reverse power flow. A pseudo detection signal generation unit is configured that can pseudo-output the detection signal Sg) to the overcurrent detection unit.

<Operation of Embodiment>
Next, a description will be given of the operation in the event of an internal short circuit accident of the switching control device for the distribution system configured as described above and when the distribution line 11 is interrupted due to some cause and an overcurrent of reverse power flow occurs.

  Now, in the event of a short circuit accident inside or outside the customer premises, or when a reverse power flow occurs when the distribution line 11 fails for some reason, a short circuit current (the lock current of the load switch 16 is applied to the lead-in line 13). Overcurrent level current exceeding the value) flows. This short-circuit current is detected by the overcurrent detection unit 32. Further, one of the R-phase and T-phase load currents detected by the current transformers 24r and 24t (in this embodiment, the R-phase load current) and the control power transformer 23 detect the load current. Based on the line voltage between the S phase and the T phase, the phase difference calculator 33 calculates the phase difference between the load current and each line voltage. Based on the phase difference calculated by the phase difference calculator 33, the tidal direction determination unit 34 determines the tidal direction.

  If the tidal direction determining unit 34 determines that the tidal direction is on the premises (the load side of the load switch 16), the control unit 35 turns on the normally open contact MS1. Then, the power from the trip power supply P is supplied to the trip coil 25 via the power supply line L1. As a result, the trip coil 25 is excited and the opening / closing part 20 of the load switch 16 is opened.

  When the reverse flow determination is made by the flow direction determination unit 34, the flow direction determination unit 34 closes the normally open contact 43 by exciting the excitation coil 34a. More specifically, when an overcurrent is detected by the overcurrent detection unit 32, the load switch 16 completes preparation for a storage trip within a preset preparation time (for example, 0.1 seconds or less), and then An opening operation is performed after a preset standby time (for example, 0.5 seconds or more) has elapsed since the distribution line 11 has no voltage due to the tripping of the circuit breaker of the substation. Even if the distribution line 11 is in a no-voltage state, the control power from the distributed power source 15 is supplied while the distributed power source 15 is in the single operation state. However, when a predetermined time elapses after detection of the single operation state of the distributed power source 15, the distributed power source 15 is stopped, and as a result, the control power source is completely shut off. Incidentally, the no-voltage state of the distribution line 11 and the lead-in line 13 is detected by the overcurrent detector 32 when the normally open contact 41 is opened.

  Under such conditions, when the reverse flow determination is made by the flow direction determination unit 34, the load flow 16 is ready for the storage trip until the standby time elapses. The direction determination unit 34 excites the exciting coil 34 a to close the normally open contact 43. As a result, the voltage of the DC power supply 44 is output to the overcurrent detection unit 32 as a pseudo detection signal Sg indicating that the voltage of the lead-in line 13 (that is, the control power supply) is present. Thereby, the overcurrent detection part 32 recognizes artificially that the distribution line 11 and the drawing-in line 13 are not in a no-voltage state (the control power supply, ie, the voltage of the drawing-in line 13 is not cut off). As a result, the load switch 16 is not locked to the SO operation (overcurrent lock operation and overcurrent storage trip operation) and is held in the locked state.

  In other words, a signal indicating no voltage detection is not output from the overcurrent detection unit 32 to the control unit 35. For this reason, the control unit 35 does not turn on the normally open contact MS1, and the power from the trip power supply P is not supplied to the trip coil 25 via the power supply line L1. Therefore, since the trip switch 25 is not excited and the load switch 16 is turned on and maintained, the load switch 16 is unnecessary due to the reverse current overcurrent that occurs when the distribution line 11 fails for some reason. Can be prevented.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) When reverse power flow is determined by the power flow direction determination unit 34, even if the voltage of the service line 13 (that is, the control power supply) in which the load switch 16 is installed disappears, there is a voltage of the service line 13 A control power supply detection signal S to the effect is output to the overcurrent detection unit 32 in a pseudo manner. Thereby, the reverse power flow from the distributed power source 15 is detected as an overcurrent, and even if the distributed power source 15 is stopped, the non-voltage state of the distribution line 11 and the incoming line 13 is detected as an overcurrent detection unit. 32 is not detected. For this reason, the opening operation (SO operation) of the load switch 16 is locked and held in the closing state. Therefore, unnecessary opening of the load switch 16 due to the occurrence of overcurrent caused by an accident outside the customer premises can be suppressed.

  (2) When an overcurrent is detected by the overcurrent detection unit, the load switch completes preparation for a storage trip within a preset preparation time, and then the distribution line becomes no-voltage. The opening operation is performed after a preset waiting time has elapsed. Under such conditions, when the tidal direction determination unit makes a reverse tidal current determination that the tidal direction is a reverse tidal current, the standby time elapses after the load switch is ready for a power storage trip. In the meantime, the normally open contact 43 is inserted. Thus, before the voltage (control power supply) of the lead-in line 13 completely drops, that is, before the distributed power supply 15 is stopped, the pseudo detection signal Sg indicating that the voltage of the lead-in line 13 is present is an overcurrent. By outputting to the detection unit 32, the opening operation of the load switch 16 can be locked.

  (3) The output line of the control power supply detection signal S from the series circuit C1 and the output line of the pseudo detection signal Sg from the series circuit C2 are shared by one signal output line L2. This simplifies the circuit configuration.

<Another embodiment>
In addition, you may implement the said embodiment as follows.
In the present embodiment, the excitation coil 34a is excited when a reverse power flow is detected by the power flow direction determination unit 34, but may be as follows. That is, an isolated operation detection unit (not shown) for detecting the isolated operation of the distributed power source 15 is provided, and an excitation coil 34a is provided in the isolated operation detection unit. Then, when the isolated operation of the distributed power source 15 is detected by the isolated operation detection unit, the excitation coil 34a is excited. Even if it does in this way, the effect similar to this embodiment can be acquired.

  In the present embodiment, for example, the normally open contact 43 is provided on the signal output line L2 of the pseudo detection signal Sg from the series circuit C2 to the overcurrent detection unit 32. However, a normally closed contact may be used. In this case, the tidal current direction determination unit 34 opens the normally closed contact when the forward tidal current direction is determined to indicate that the tidal current direction is a forward tidal current, or when the tidal current direction is not determined to be a reverse tidal current. Even if it does in this way, the effect similar to this embodiment can be acquired. Further, unlike the normally open contact 43, the normally closed contact does not need to consider a holding circuit after the voltage of the lead-in line 13 (that is, the control power supply) is lost. For this reason, the circuit can be simplified as compared with the normally open contact 43.

The signal output line from the power supply detection unit and the signal output line from the pseudo detection signal generation unit may be separate lines.
<Another technical idea>
The switching control device for a distribution system according to claim 1 or 2, wherein the pseudo detection signal generation unit is a DC power supply.

  The power distribution according to claim 1 or 2, wherein the output line of the signal from the power supply detection unit and the output line of the signal from the pseudo detection signal generation unit are shared by one output line (L2). System switching control device.

The block block diagram of the load switch and control apparatus in this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Distribution line, 13 ... Service line, 14 ... Consumer load, 15 ... Distributed power supply,
16 ... Load switch, 17 ... Control device (switch control device), 32 ... Overcurrent detector,
34 ... Tidal direction determination unit, 34a ... excitation coil constituting contact driving means, 35 ... control unit, 43 ... normally open contact, C1 ... series circuit constituting power source detection unit,
C2: a series circuit constituting a pseudo detection signal generation unit,
L2 ... signal output line (output line of pseudo detection signal), S ... control power supply detection signal,
Sg: pseudo detection signal.

Claims (3)

A distributed power source that supplies power separately from the power supplied from the distribution line to the load connected to the distribution line via a service line and a load switch provided on the service line;
An overcurrent detector that determines whether the load current of the lead-in line is at an overcurrent level and detects a no-voltage state of the distribution line and the lead-in line,
A tidal direction determination unit that determines a tidal direction of the distribution line based on a phase difference between the load current and a line voltage of the lead-in line;
A control unit for opening or maintaining the load switch based on a determination result by the overcurrent detection unit and a determination result by the power flow direction determination unit, and a switching control device for a distribution system comprising:
A power source detection unit that detects the presence or absence of the voltage of the lead-in line and outputs the detection signal to the overcurrent detection unit;
A pseudo detection signal generation unit capable of pseudo-outputting a detection signal indicating that there is a voltage of the lead-in line to an overcurrent detection unit; and
On the output line of the pseudo detection signal from the pseudo detection signal to the overcurrent detection unit, a normally open contact or a normally closed contact is provided,
When the reverse flow is determined that the flow direction is reverse flow, the overflow current is determined by turning on the normally open contact or opening the normally closed contact. A switching control device for a power distribution system, comprising contact driving means for causing the detection unit to detect the voltage of the lead-in line in a pseudo state. When an overcurrent is detected by the overcurrent detection unit, the load switch completes preparation for a storage trip within a preset preparation time, and then presets after the distribution line becomes no-voltage. The release operation is performed after the waiting time passed,
When the tidal current direction determination unit makes a reverse tidal current determination that the tidal current direction is a reverse tidal current between the time when the standby time elapses after the load switch is ready for the energy storage trip, 2. The switching control device for a distribution system according to claim 1, wherein the normally open contact is inserted to cause the overcurrent detection unit to detect the voltage of the lead-in line in a pseudo state. A distributed power source that supplies power separately from the power supplied from the distribution line to the load connected to the distribution line via a service line and a load switch provided on the service line,
Determining whether the load current of the lead-in line is at an overcurrent level and detecting a no-voltage state of the distribution line and the lead-in line;
Determining the flow direction of the distribution line based on the phase difference between the load current and the line voltage of the lead-in line;
Opening and closing the load switch based on a determination result of whether or not the load current is at an overcurrent level and a determination result of a flow direction of the distribution line, and a switching control method for a distribution system comprising: Because
When a reverse power flow determination is made that the power flow direction is a reverse power flow, a detection signal indicating that there is a voltage on the lead-in line is output in a pseudo manner to lock the opening operation of the load switch. Open / close control method for distribution system.

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