JP4072961B2 - Control device with system interconnection protection function of SOG switch - Google Patents

Description

  The present invention relates to a control device that receives a supply of power from a power receiving system and controls a switch of a consumer that includes a distributed power source on the premises.

  Conventionally, this type of switch control device is shown in FIGS. FIG. 6 is a block diagram of a conventional switch control device, FIG. 7 is an SO operation timing chart associated with a ground fault in the conventional switch control device shown in FIG. 6, and FIG. 8 is shown in FIG. It is a SO operation | movement timing chart accompanying the overcurrent accident in the control apparatus of the conventional switch.

  In each of the drawings, the conventional switch control device receives power from the power receiving system of the distribution line 200 via the extra high power substation 8 and the distribution substation 7 on the power company side, and is connected to the power receiving system. Controlling a load switch 2 installed in a consumer equipped with a private power generator 3 capable of a system, an overcurrent detection relay OCR (not shown) disposed in the load switch 2 Based on the output, an overcurrent caused by a short-circuit accident is detected by the overcurrent detection means 130, and overload lock and overcurrent storage trip operations are performed on the load switch 2 based on the detected overcurrent. The control unit 110 executes the configuration.

  In addition, the private power generation device 3 detects that the output power is overpower supply exceeding the predetermined value by the power generation controller 4, and when the overcurrent supply is detected, the power generation controller 4 detects the connection breaker ( CB) 5 is cut off.

  Next, the operation of the conventional switch control device based on the above-described configuration is described with reference to the load switch 2 as a demarcation point and the cause of each power outage on the customer side (secondary side) and the power company side (primary side). Separately described.

  First, in the event of a short circuit accident spreading from a ground fault accident, a ground fault occurs at point B on the customer's premises, and timer integration is started from the occurrence of the ground fault and set in advance. It is determined that there is an integration time t1 (t1 <t) within the set operation time limit t. When a short circuit accident occurs, an overcurrent is supplied from the primary side to this short circuit point. If an overcurrent (or short circuit current) exceeding the set value occurs on the customer side, the load switch 2 is locked and an overcurrent is generated. Prevent opening while flowing. The protective relay of the distribution substation 7 operates to select and shut off the anomaly section, and a power failure occurs when the distribution line 200 is disconnected. After the overcurrent disappears due to the power failure, The load switch 2 is opened. Next, when the circuit breaker of the substation is closed again, electric power is supplied to consumers other than the customer having the cause of the accident, and the service distribution line of the customer having the cause of the accident remains open from the load switch 2. Therefore, power outages will continue in the customer premises. The cause of the accident is removed, and the load switch 2 is manually turned on to recover.

On the other hand, when the power distribution line 200, which is point A on the power company side (primary side), fails, a current equal to or greater than the lock current value flows from the private power generator 3 to the load switch 2 in a reverse power flow. The overcurrent detection OCR (not shown) in the device 2 operates. An overcurrent detection signal is output from the overcurrent detection OCR to the SO (overcurrent lock / overcurrent storage trip) control means 110 of the switching controller 10, and the SO control means 110 indicates that “overcurrent has flowed”. And the power generation controller 4 of the private power generator 3 detects the overcurrent supply and opens the interconnection breaker (CB) 5.
When this interconnection CB5 is opened, the control power supply of the SO control means 110 is lost, so an SO (overcurrent lock / overcurrent storage trip) operation is executed, and the load switch 2 is opened.

  After the load switch 2 is opened, the distribution line 200 is restored, and the load switch 2 is turned on again on the condition that the cause of the accident on the customer premises is investigated and it is determined that there is no abnormality. Electric power from the electric power company is fed from the distribution line 200 restored by the introduction of the load switch 2 to the load 6 installed on the customer side.

In addition, even when a short circuit accident occurs at point A of the distribution line 200 on the power company side (primary side), the SOG control unit executes the SO operation to open the load switch 2. Further, even after the load switch 2 is opened, if the cause of the accident on the customer's premises is investigated and it is determined that there is no abnormality as in the case described above, the load switch 2 is turned on and restored. It can be in an electric state.
JP 2003-158820 A

  Since the conventional switch control device is configured as described above, when a short circuit accident occurs in the distribution line 200 on the electric power company side (primary side), the distribution line 200 on the electric power company side fails. As a result, the load switch 2 is in an open state, and the open state is maintained even after the distribution line 200 is restored.

  In order to set the open state of the load switch 2 to the input state, it is confirmed that there is no abnormality in the electrical equipment in the customer premises, and it is determined that the short circuit accident has occurred in the distribution line 200 on the power company side. After that, since the load switch 2 is manually turned on, it takes a long time from power restoration of the distribution line 200 to power supply to the customer side by turning on the load switch 2. Was.

  The present invention was made in order to solve the above-described problem, and prevents erroneous SO operation associated with a power outage accident that occurred outside the premises of a customer equipped with a private power generation device that can be interconnected with a power receiving system, An object of the present invention is to provide a control device having a system interconnection protection function of an SOG switch that can shorten the power failure time due to a power failure accident as much as possible.

A control device having a system interconnection protection function for an SOG switch according to the present invention is installed in a customer who is supplied with electric power from a power receiving system and has a private power generator capable of being connected to the power receiving system. A control device having a system interconnection protection function for an SOG switch that controls a load switch, comprising a current transformer disposed on a load-side distribution line in the load switch, and a current value flowing through the distribution line Current detecting means for outputting a ground fault, ground fault direction judging means for judging a ground fault direction of a ground fault based on a phase difference between zero phase current and zero phase voltage flowing through the load switch, and output from the current detecting means Overcurrent detection means for detecting an overcurrent when a current value to be generated is equal to or greater than a threshold value set between the maximum output current of the private power generator and the maximum output current of the power receiving system; and the ground fault direction And load switch based on overcurrent And a SO control means for executing the operation of the overcurrent lock and overcurrent energizing trip for the overcurrent detection means, over by comparing the detected current and SO operating threshold from the current detecting means A lock current threshold value, which is a determination criterion for executing an overcurrent lock operation that determines an SO operation based on a current and prevents an open operation when an overcurrent occurs for a load switch, is smaller than the SO operation threshold value. When the current value output from the current detection means is higher than the lock current threshold value, an overcurrent lock signal is output to the SO control means, and the SO control means detects that the lock current threshold value is higher than the lock current threshold value. If the current value is less than or equal to the SO operation threshold value, the overcurrent lock operation is executed, while the overcurrent accumulator trip SO operation is not executed, and the detected current value is greater than or equal to the SO operation threshold value. In some cases, it is to perform the SO operation of overcurrent prestressing trip.

As described above, in the present invention, the current value flowing through the distribution line is detected by the current detection means including the current transformer disposed in the distribution line on the load side of the switch, and this current value is set to a predetermined threshold. When the value is equal to or greater than the value, the overcurrent detection means detects an overcurrent, and the SO control means performs an overcurrent lock operation of the switch based on the detected overcurrent and the ground fault direction determined by the ground fault direction determination means. or since the way to perform any of the overcurrent prestressing trip operation, to prevent the opening of Oite unnecessary load switch in the event of a power failure caused by the accident other than an accident occurring in the customer premises, condensate Immediately after electricity is supplied, power can be supplied to the customer's premises electrical equipment, the power outage time on the customer side can be shortened as much as possible , and it is not necessary to determine abnormality of the electrical equipment in the customer premises.

(First embodiment of the present invention)
Hereinafter, the control apparatus provided with the system interconnection protection function of the SOG switch according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a block diagram of a control device having a system interconnection protection function of the SOG switch according to the present embodiment, and FIG. 2 is a control device having a system interconnection protection function of the SOG switch shown in FIG. The operation | movement timing chart of is shown.

In each of the drawings, the control device 1 having the system interconnection protection function of the SOG switch according to the present embodiment includes a power receiving system of the distribution line 200 via the extra high power substation 8 and the distribution substation 7 on the power company side. Which controls the load switch 2 installed in a consumer having a private power generation device 3 that can be connected to the power receiving system, and flows through the load switch 2. A ground fault direction judging means 12 for judging the ground fault direction of the ground fault accident based on the phase difference between the current and the zero phase voltage, and an over current detecting means 13 for detecting an over current caused by a short-circuit fault spreading from the ground fault accident. And an SO control means 11 for executing respective operations of overcurrent lock and overcurrent storage trip for the load switch based on the ground fault direction and overcurrent.
The private power generation device 3 is provided with a power generation controller 4, which detects an overcurrent supply from the private power generation device 3 and is connected in series with the load switch 2 on the customer premises wiring path 300. It is the structure which interrupts | blocks the circuit breaker (CB) 5 arrange | positioned.

  Next, the SO operation of the control device having the system interconnection protection function of the SOG switch according to the present embodiment based on the above configuration will be described. First, when a ground fault occurs at time S1 at either point A of the distribution line 200 or point B of the premise wiring path 300 (see FIG. 2A), it is disposed in the load switch 2. Depending on the phase difference between the zero-phase current and zero-phase voltage output from the zero-phase current transformer ZCT (not shown) and zero-phase capacitor ZPC (not shown) And point A and B of the ground fault are specified (see FIGS. 2E and 2F).

  In the event of a short-circuit overcurrent accident from the ground fault at time S2 after the occurrence of the ground fault, see the overcurrent detection OCR (see FIG. 2B). (Not shown) starts at time S3 about 0.03 seconds later and outputs an overcurrent detection signal (see FIG. 2D). On the condition that this overcurrent detection signal is input and a ground fault direction power side signal or a ground fault direction consumer side signal is input, the SO control means 11 performs 0.05 after the output of the overcurrent detection signal. It is detected that it is in the SO state at time S4 after 2 seconds, and when the ground fault direction consumer side signal is input (that is, when a ground fault occurs at point B on the consumer side), SO The output is output to the load switch 2 (indicated by a solid line in FIG. 2 (h)). On the other hand, on the condition that the SO control means 11 is detected to be in the SO state, when the ground fault direction power side signal is input (that is, the ground fault occurs at the point A on the power company side). If it occurs, the SO output is not output to the load switch 2 (indicated by a broken line in FIG. 2 (h)).

  Therefore, the load switch 2 is opened at time S6 because the SO output is input from the SO control means 11 only when a ground fault occurs at point B on the customer side (FIG. 2 (i)). ) Is indicated by a solid line.) On the other hand, when a ground fault occurs at point A on the electric power company side, the SO output is not input from the SO control means 11, and therefore the open state is not established (indicated by a broken line in FIG. 2 (i)).

  Thus, even when a ground fault occurs at point A on the electric power company side and a reverse power flow occurs from the private power generation device 3 to the distribution line 200 on the grid side, the load switch 2 operates as an SO. Will not be executed by mistake, and as soon as the distribution line 200 on the system side recovers, power can be supplied to the electrical equipment in the customer premises.

(Second embodiment of the present invention)
A control device having a system interconnection protection function for an SOG switch according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a block diagram of a control device having a system interconnection protection function of the SOG switch according to the present embodiment, and FIG. 4 is a control device having a system interconnection protection function of the SOG switch shown in FIG. FIG. 5 shows an overcurrent detection timing chart of the overcurrent detection means in the control device having the system interconnection protection function of the SOG switch shown in FIG.

In each of the drawings, the control device having the system interconnection protection function of the SOG switch according to this embodiment is similar to the embodiment shown in FIG. 1 in that the SO control means 11, the ground fault direction judgment means 12, and the overcurrent are provided. The control device 1 provided with the system interconnection protection function of the SOG switch comprising the detection means 13, the load switch 2, the private power generation device 3, the power generation controller 4, and the connection CB5 are provided. In addition, the load switch 2 includes a current transformer CT disposed in the load-side premise wiring path 300, and includes a current detection means 20 that outputs a current value flowing through the premise wiring path 300 as a detection current i. The overcurrent detection means 13 detects the detected current i from the current detection means 20, the maximum output current value (for example, 1000 A) of the private power generation device 3, and the maximum output current supplied to the distribution line 200 as the power receiving system ( Example, if, SO operating threshold SL (e.g., which is set between 2000A), 1500A) is compared with a configuration of determining the SO operation based on the overcurrent.

  In addition to the SO operation threshold, the overcurrent detection means 13 is a lock current threshold that is a criterion for executing an overcurrent lock operation for preventing the load switch 2 from opening when an overcurrent occurs. It has a value RL (for example, 500 A) and outputs an overcurrent lock signal for executing an overcurrent lock operation to the SO control means 11 when the detection current of the current detection means 20 is higher than the lock current threshold. is there.

  Next, the SO operation of the control device having the system interconnection protection function of the SOG switch according to the present embodiment based on the above configuration will be described. First, when an overcurrent accident occurs at time S11 at either point A of the distribution line 200 or point B of the premise wiring path 300 (see the overcurrent accident in FIG. 5 (a)), the circuit breaker of the substation 7 is turned on. The power is cut off from the state to the power-off state (see the substation in FIG. 5A).

  Thus, when performing a power failure operation for an overcurrent accident, the current CT of the current detection means 20 detects the current flowing through the premise wiring path 300 and compares this detected current with the lock current threshold RL (500A). And compared with the SO operation threshold value SL (1500 A).

  For example, when the detected current i is 300 A as shown in FIG. 5A in the lock non-execution and the SO operation non-execution, the lock current threshold RL (500 A) or less and the SO operation threshold SL Since (1500A) or less, the SO operation of overcurrent lock and overcurrent storage trip is not executed.

As in the case of FIG. 5 (a), in the overcurrent accident and substation timing charts of FIG. 5 (b), for example, as shown in FIG. 5 (b) lock execution and SO operation non-execution. When the detected current i is 600 A, the overcurrent lock operation is executed because it is equal to or greater than the lock current threshold RL (500 A), but the SO operation is not performed because it is equal to or less than the SO operation threshold SL (1500 A). .

Further, FIG. In 5 (a) in the case as well as over-current fault and the timing chart of the substation shown in FIG. 5 (c), the example as shown in the lock and SO dynamic Sakumi line shown in FIG. 5 (c) When the detected current i is 2000 A, the SO control means 11 executes the overcurrent lock operation and the SO operation because the lock current threshold RL (500 A) or more and the SO operation threshold SL (1500 A) or more are exceeded. To do.

Thus, in the consumer who installs the private power generation device 3 that can be connected to the power receiving system, the overcurrent detection means 13 detects the overcurrent in any power outage accident on the customer's premises and other than the premises. become, but by the overcurrent detection unit 13 determines the execution of each comparison to overcurrent lock operation and SO operation and detection current and lock current threshold RL and SO operating threshold SL, consumers The SO operation can be executed only in the case of a power outage accident on the premises, the power outage time on the customer side can be shortened as much as possible at the time of a power outage accident other than on the customer premises, and the abnormality of the electrical equipment in the customer premises is judged. Is unnecessary.
Note that the lock current threshold value RL and the SO operation threshold value SL are arbitrarily set according to the scale of the electrical equipment of the consumer.

It is a block block diagram in the control apparatus provided with the grid connection protection function of the SOG switch which concerns on the 1st Embodiment of this invention. It is an operation | movement timing chart of the control apparatus provided with the grid connection protection function of the SOG switch of FIG. It is a block block diagram in the control apparatus provided with the grid connection protection function of the SOG switch which concerns on the 2nd Embodiment of this invention. It is an overcurrent detection characteristic figure of the overcurrent detection means in the control apparatus provided with the system interconnection protection function of the SOG switch of FIG. It is an overcurrent detection timing chart of the overcurrent detection means in the control apparatus provided with the system interconnection protection function of the SOG switch shown in FIG. It is a block block diagram of the control apparatus provided with the grid connection protection function of the conventional SOG switch. FIG. 7 is an SO operation timing chart associated with a ground fault in the control device having the system interconnection protection function of the conventional SOG switch shown in FIG. 6. FIG. 7 is an SO operation timing chart associated with an overcurrent accident in the control device having the system interconnection protection function of the conventional SOG switch shown in FIG. 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control apparatus provided with system connection protection function of SOG switch 2 Load switch 3 Private power generator 4 Power generation controller 5 Link breaker (CB)
6 Load 7 Distribution substation 8 Extra high voltage substation 10 Switch controller 11, 110 SO control means 12 Ground fault direction judgment means 20 Current detection means 130 Overcurrent detection means 200 Distribution line 300 In-house wiring path i Detected current

Claims (1)

A control device having a system interconnection protection function of an SOG switch that controls a load switch installed in a consumer that is provided with a private power generation device that can receive power from the power reception system and connect to the power reception system. In
A current detector comprising a current transformer disposed in a load-side distribution line in the load switch, and outputting a current value flowing through the distribution line;
A ground fault direction judging means for judging a ground fault direction of a ground fault accident based on a phase difference between a zero phase current and a zero phase voltage flowing through the load switch;
Overcurrent detection means for detecting an overcurrent when the current value output from the current detection means is equal to or greater than a threshold value set between the maximum output current of the private power generator and the maximum output current of the power receiving system. When,
SO control means for performing overcurrent lock and overcurrent storage trip operations on the load switch based on the ground fault direction and overcurrent , and
The overcurrent detection means compares the detected current from the current detection means with the SO operation threshold value to determine the SO operation based on the overcurrent, and prevents the load switch from opening when an overcurrent occurs. A lock current threshold value, which is a criterion for executing overcurrent lock operation, is set to a value smaller than the SO operation threshold value, and the current value output from the current detection means is higher than the lock current threshold value. Output overcurrent lock signal to SO control means,
When the detected current value higher than the lock current threshold is equal to or less than the SO operation threshold, the SO control means executes the overcurrent lock operation, but does not execute the SO operation of the overcurrent storage trip. In addition, when the detected current value is equal to or higher than the SO operation threshold value, the control device having a system interconnection protection function for the SOG switch, which performs an SO operation of an overcurrent storage trip .

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