JP2024011168A - System monitoring control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system monitoring control device which constitutes a single operation system of a sound zone by opening a circuit breaker of a prescribed place when a system accident occurs and can transmit a time that can maintain the signal operation system to a power generation company and users.

SOLUTION: A system monitoring control device for forming a plurality of sections A₁ to A₅ between a system power source 40 and a distributed power source 10 through circuit breakers 21 to 26, and monitoring and controlling a power system having loads 31 to 35 connected to the sections A₁ to A₅ includes a function for monitoring a power generation amount of the distributed power source 10, a reception function of accident information, an opened/closed state monitoring function and an opening/closing control function of the circuit breakers, a function for monitoring load amounts of the loads, and a function for transmitting the constitution of a single operation system to the loads in a corresponding system and the distributed power source 10 when accident information is received, and controls the opening/closing of the circuit breakers 21 to 26 so as to constitute the single operation system on the basis of at least the power generation amount and the load amount of the distributed power source 10.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention monitors the power generation amount, load amount, state of circuit breakers, etc. of distributed power sources connected to the power grid, and based on the monitoring results, the distributed power sources are used in a predetermined section when an accident occurs in the power system. The present invention relates to a system monitoring and control device that is capable of configuring an isolated operation system.

For example, Patent Document 1 discloses a technique for stabilizing the system by adjusting the supply and demand balance of an isolated system when an accident occurs in a power system to which distributed power sources are interconnected.
In Patent Document 1, when the interconnection line is cut off due to the occurrence of a grid fault and multiple generators are in standalone operation, the adjustment amount necessary for grid stabilization is determined from the power flow immediately before the interconnection line. (difference between total power generation amount and total load amount). If the deviation rate between the total power generation amount and the total load amount is more than a predetermined value, and the total power generation amount exceeds the total load amount, the load is cut off starting from the load with the highest priority to be cut off, and the total power generation amount is If the amount is less than the amount, the adjustment amount is divided proportionally between the outputs of each generator and the output of each generator is limited, making it possible to stably maintain an isolated system while adjusting the supply and demand balance through simple processing. ing.

Furthermore, in Patent Document 2, in an electric power system in which a first generator and a second generator are connected in parallel to a commercial power source, in the event of a power outage, the power is selected to be sent to each of a plurality of rooms within the range of the total amount of power generated by each generator. It also states that the selection criteria for each room is to consider the priority of the load and whether it is unnecessary or non-urgent.

Furthermore, Patent Document 3 discloses that when a system fault occurs, multiple circuit breakers on the system side are opened, generators of multiple units are operated, and the substation is switched to standalone operation, and the life consumption is minimized via the busbar. It is stated that the individual operation of the units that carries the common load will continue until the grid is restored, and that the power supply will continue to be supplied to units other than the unit with the minimum life consumption until a certain time limit has elapsed.

JP 2020-5336 ([0010] to [0026], Figures 1 to 3, etc.) Patent No. 6474174 ([0038] to [0061], Fig. 3, Fig. 4, etc.) JP-A-63-138103 (Page 2, lower right column, line 4 to page 3, upper left column, line 9, Figures 1, 2, etc.)

The above-mentioned Patent Documents 1 to 3 disclose that when an accident occurs in the power system, each facility (power generation company, consumer) in the power system calculates the time during which standalone operation can be maintained by distributed power sources. There is no disclosure of technology for stably continuing independent operation while transmitting data to the other side.
For this reason, it is difficult for power generation companies and consumers to predict the start time of limiting power generation or load shedding, and depending on the configuration of the power system, it may be difficult to configure an islanding system. there were.

Here, FIG. 4 is a configuration diagram showing an example of a power system in which distributed power sources are interconnected, where 10 is a distributed power source including a solar power generation device PV and a power conditioner system PCS, and 21 to 26 are Circuit breakers A ₁ to A ₅ provided in the power system are sections divided by circuit breakers 21 to 26, and 31 to 35 are loads connected to the sections A ₁ to A ₅ , respectively. Although not shown, the power conditioner system PCS is assumed to include a power storage device such as a storage battery as a power source when the output of the solar power generation device PV decreases.

Now, if the amount of power generated by the distributed power source 10 is larger than the load amount of all the loads 31 to 35, an accident will occur at a point within the section A ₁ to A ₅ (excluding the area between the circuit breaker 21 and the load 31). However, if the circuit breaker between the fault point and the system power supply 40 is opened, the distributed power supply 10 can operate independently for one or more loads. For example, if an accident such as a ground fault occurs in section _A4 ( _F4 is the fault point), the load is It is possible to configure an isolated operation system including 31 to 34 to maintain power supply.

However, if the amount of power generated by the distributed power source 10 is, for example, greater than the total load of loads 31 to 33 and smaller than the total load of loads 31 to 34, when an accident (fault point F ₃ ) occurs within section A ₃ If the circuit breakers 24 to 26 are opened and the circuit breakers 21 to 23 are kept closed, an isolated operation system including the loads 31 to 33 can be constructed, but an accident occurs within section A ₄ (fault point F ₄ ). When this occurs, the amount of power generated by the distributed power source 10 is smaller than the total load amount of the loads 31 to 34, so it becomes impossible to configure an islanding system including the loads 31 to 34.

In addition, when an accident (fault point F ₅ ) occurs in section A ₅ , the load 35 will immediately experience a power outage by opening the circuit breakers 25 and 26 , but the amount of power generated by the distributed power source 10 will be reduced by the loads 31 to 34 . If it is smaller than the total load amount, the loads 31 to 34 will experience a power outage with a slight delay, and in any case, it will be impossible to maintain an isolated operation system including the loads 31 to 34.

As mentioned above, due to the magnitude relationship between the amount of power generated by the distributed power source 10 and the load amounts of the loads 31 to 35, it becomes impossible to operate the distributed power source 10 independently, or it becomes impossible to predict the time when the load will experience a power outage. These problems could not be solved by the above-mentioned Patent Documents 1 to 3.

Therefore, the problem to be solved by the present invention is to configure an islanding system to the extent possible by controlling predetermined circuit breakers on and off when an accident occurs in a power system, and to calculate the time that an islanding state can be maintained. The object of the present invention is to provide a system monitoring and control device that can transmit information to each facility in the power system.

In order to solve the above problems, the present invention forms a plurality of sections between a grid power source and a distributed power source via circuit breakers, and monitors and controls a power system having loads connected to each of these sections. In system monitoring and control equipment for
a function of monitoring the power generation amount of the distributed power source; a function of receiving accident information in the power system; a function of monitoring the opening/closing state of the circuit breaker and a function of controlling the opening/closing; a function of monitoring the load amount of the load; a function of transmitting to the load in the islanding system and the distributed power source that an islanding system is configured by the distributed power source when receiving accident information;
The opening and closing of the circuit breaker is controlled so that the islanding system is configured based on at least the amount of power generated by the distributed power source and the amount of load of the load.

Here, the scope of configuring an islanding system using distributed power sources in the event of an accident is as follows:
(1) Comparison of the amount of power generated by a distributed power source and the load amount in multiple consecutive sections. (2) Comparison of the amount of power generated by a distributed power source and the amount of power generation adjustment surplus and the amount of load in multiple consecutive sections. Comparison (3) Comparison of the difference between the power generation amount of the distributed power source and the load amount and load adjustment surplus capacity of multiple consecutive sections (4) Comparison of the difference between the power generation amount of the distributed power source and the power generation amount adjustment surplus capacity, and the difference between the power generation amount of the distributed power source and the power generation amount adjustment surplus capacity This can be determined by comparing the difference between the load amount of multiple sections and the load adjustment reserve capacity.

In addition, if an accident occurs in the power system, the loads and distributed power sources that make up the islanding system will be in islanding state, and at least the time schedules for the amount of power generation and the amount of load will be affected. It is desirable to send the calculated islanding system maintenance time.
In addition, during normal times before an accident occurs in the power system, the time that the islanding system can be maintained for all the assumed accident points is calculated and memorized in advance, and when an accident actually occurs, the islanding system can be maintained in advance. The system maintenance possible time may be transmitted to each facility.

According to the present invention, the amount of power generated, the amount of load, the status of the circuit breaker, etc. of the distributed power source are constantly monitored, and when an accident occurs in the power system, the amount of power generated, the amount of load, and the fault point (interruption section) are By controlling on/off of predetermined circuit breakers, it is possible to configure and maintain an islanding system to the extent possible. In addition, by communicating to the loads in the power system that they are in islanding mode and the amount of time that islanding can be maintained, customers can prevent unexpected power outages and achieve their load operation plans without any problems. can.

1 is a configuration diagram of a power system to which an embodiment of the present invention is applied. 2 is a flowchart illustrating a process of calculating and transmitting the time during which an isolated operation system can be maintained in an embodiment of the present invention. 2 is a flowchart illustrating a process of calculating and transmitting the time during which an isolated operation system can be maintained in an embodiment of the present invention. FIG. 1 is a configuration diagram of a power system for explaining a conventional technique.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram of a power system to which a system monitoring device 100 of this embodiment is applied, and the power system includes a solar power generation device PV and a power conditioner system (hereinafter abbreviated as PCS), as in FIG. ), circuit breakers 21 to 26, and loads 31 to 35 in sections A ₁ to A ₅ .

Note that the PCS in the distributed power source 10 includes a power storage device such as a storage battery as a power source when the output of the solar power generation device PV decreases. In addition, the power generation equipment may be a wind power generation device in addition to the solar power generation device PV. In that case, the PCS converts the AC output of the wind power generation device into DC power, and then converts it into AC power. It can be supplied to the power grid.

The system monitoring device 100 receives information such as the current power generation amount (including the power generation amount based on the storage capacity (SOC) of a storage battery (not shown)) and the power generation amount adjustment surplus from the PCS of the distributed power source 10, and Accident information indicating that an accident such as a ground fault has occurred in any of A ₁ to A ₅ , opening/closing information of circuit breakers 21 to 26, current loads of loads 31 to 35, load adjustment capacity, etc. are received. It controls the output of the PCS and the opening/closing of the breakers 21 to 26, and also controls the output of the PCS and the opening/closing of the circuit breakers 21 to 26. It is equipped with a function to transmit information on whether or not the system is in islanding mode and the amount of time that the system can maintain islanding mode.

Next, the operation of this embodiment will be explained.
In FIG. 1, when all circuit breakers 21 to 26 are on and loads 31 to 35 are being supplied with power from the distributed power source 10 or the grid power source 40, an accident such as a ground fault occurs in section _A4 . If this happens ( _F4 is set as the accident point), the accident information is transmitted to the system monitoring and control device 100.
In this case, the system monitoring and control device 100 includes the following range based on the current power generation amount of the distributed power source 10, the power generation amount adjustment surplus capacity, the current load amount of the loads 31 to 35, the load amount adjustment surplus capacity, etc. The on/off state of each circuit breaker 21 to 26 is controlled so as to configure an islanding system for the load.

(1) Range where the current power generation amount of the distributed power source 10≧the current load amount For example, if an accident occurs in section _A4 , the current power generation amount of the distributed power source 10 is within the range of consecutive sections A1 to _A4 . If the current total load of the loads 31 to 33 in A ₃ is greater than or equal to the current total load, it is possible to supply power to the loads 31 to 33 from the distributed power source 10, and it is possible to configure an isolated operation system including these loads 31 to 33. .
Therefore, the system monitoring and control device 100 issues a command to each circuit breaker to turn off the circuit breakers 24 and 25 on both sides of the load 34 (fault point F ₄ ) and to keep the other circuit breakers 21 to 23 and 26 on. and configures an islanding system including loads 31 to 33.

In addition, if the current power generation amount of the distributed power source 10 is less than the current load amount of the loads 31 to 33 and greater than the current load amount of the loads 31 and 32, the circuit breakers 23 to 25 are turned off and other A command to keep the circuit breakers 21, 22, and 26 on is transmitted to each circuit breaker, and an isolated operation system including the loads 31, 32 in the sections _A1 and _A2 is configured.
Furthermore, if the current power generation amount of the distributed power source 10 is less than the current load amount of the loads 31 and 32 and is greater than or equal to the current load amount of the load 31, the circuit breakers 22 to 25 are turned off and other circuit breakers are switched off. 21 and 26 are sent, and an isolated operation system including only the load 31 in section _A1 is configured.

(2) (Current power generation amount of distributed power source 10 + remaining capacity for power generation amount adjustment) ≧ Range where current load amount is satisfied If distributed power source 10 is performing output suppression operation, cancel this output suppression operation and output The maximum possible power is (current power generation amount of distributed power source 10 + power generation amount adjustment surplus), so in this case, (current power generation amount of distributed power source 10 + power generation amount adjustment surplus) ≧ current load amount A command is sent to each circuit breaker to turn off a predetermined circuit breaker and keep the remaining circuit breakers on so as to configure an islanding system within the range where .
That is, the (current power generation amount of the distributed power source 10) in the above (1) is replaced with (the current power generation amount of the distributed power source 10 + power generation amount adjustment surplus), and the magnitude relationship with the load amount is compared, and the result is The on/off state of each circuit breaker may be controlled according to the situation.

(3) The range in which the current power generation amount of the distributed power source 10 ≧ (current load amount - load amount adjustment surplus) If the loads 31 to 35 can execute demand response control, each load has the current amount of power generated. If a predetermined amount of load is reduced from the current amount of power generated by the distributed power source 10 to reduce the total amount of load, an islanding system can be configured for the predetermined load based on the current power generation amount of the distributed power source 10.
In this case, replace the current load amount in (1) above with (current load amount - load amount adjustment surplus capacity), compare the magnitude relationship with the current power generation amount of the distributed power source 10, and adjust according to the result. The ON/OFF state of each circuit breaker can be controlled by

(4) Range where (current power generation amount of distributed power source 10 + power generation amount adjustment surplus capacity) ≧ (current load amount - load amount adjustment surplus capacity) In this case, both (2) and (3) above apply. This is a case where the distributed power source 10 is performing output suppression operation and the loads 31 to 35 are capable of demand response control.
In this case, replace (current power generation amount of distributed power source 10) in (1) above with (current power generation amount of distributed power source 10 + remaining power generation amount adjustment capacity), and change the current load amount to (current power generation amount). (Load amount - Load amount adjustment surplus capacity), compare the magnitude relationship between the two, and control the on/off state of each circuit breaker according to the result.

In cases (1) to (4) above, if the minimum output of the distributed power source 10 is specified, the amount of power generated above the minimum output is compared with the load amount, etc., and the isolated operation system is determined. All you have to do is decide on the configurable range.
Furthermore, in the above explanation, it is assumed that an accident occurs in section _A4 , but the same situation also applies if an accident occurs in section _A3 or _A5 (accident points _F3 and _F5 , respectively). It is sufficient to control the on/off state of each circuit breaker according to the principle.

Furthermore, in the cases (1) to (4) above, the following can be considered as the power generation amount adjustment surplus capacity of the distributed power source 10.
(a) The power generation amount adjustment surplus of the distributed power source 10 is set as (rated output of the distributed power source 10 - current operating output).
(b) The power generation amount adjustment surplus of the distributed power source 10 is set as (maximum operable output of the distributed power source 10 - current operating output).
Here, when the distributed power source 10 has a solar power generation device PV, the maximum output is determined depending on the amount of solar radiation, and when it has a wind power generation device, the maximum output is determined depending on the wind speed and wind direction.
(c) The power generation adjustment surplus capacity of the distributed power source 10 is set to (maximum output of the distributed power source 10 applied in advance - current operating output). In other words, the value corresponds to the amount provided in the supply and demand adjustment market.
Note that the power generation amount adjustment surplus according to (b) and (c) above may be information possessed by the power generation company, or may be information transmitted from an outside that monitors the power system.

Furthermore, in cases (1) to (4) above, the following can be considered as the load amount adjustment surplus capacity.
(b) The surplus capacity for load adjustment shall be the supply and demand adjustment contract amount.
(b) Set the load amount adjustment surplus capacity to the demand response capacity requested in advance.
Note that when the minimum output of the distributed power source 10 is specified, the load amount adjustment surplus power includes not only the surplus power to decrease the load amount but also the surplus power to increase the load amount.

As described above, according to the present embodiment, the system monitoring and control device 100 determines the current power generation amount and power generation amount adjustment surplus capacity of the distributed power source 10, the current load amount, the load amount adjustment surplus capacity, etc. By specifying the load that can be supplied with power from the distributed power source 10 and controlling the on/off of each circuit breaker, it is possible to maintain an islanding system for the maximum section within the power system.

In addition, in this embodiment, the system monitoring and control device 100 generates information on whether each load is in an islanding state and the time during which the islanding system can be maintained, It is desirable to have a function of transmitting the information to a power generation company having a type power source 10, and further to an aggregator.
Here, the time during which the islanding system can be maintained can be calculated and sent to each facility when an accident occurs in the power system, or it can be calculated and stored in advance according to the accident section, and this stored time can be calculated and sent to each facility. It is sufficient to adopt a method of transmitting the information to each facility when an actual accident occurs.

That is, FIG. 2 is a flowchart for calculating the time during which an isolated system can be maintained when an accident occurs in the power system and transmitting the calculated time to each facility.
In FIG. 2, the system monitoring and control device 100 identifies the section where the accident occurred and the section was cut off based on the received accident information and the on/off state of the circuit breaker (steps S1 YES, S2), and the distributed power source 10 generates electricity. Based on the time schedule of the amount of electricity and load (including these predicted values), the surplus capacity for power generation adjustment, the surplus capacity for load adjustment, etc., the time that can be maintained for the load in the remaining section is calculated and stored. (Step S3).
Then, information indicating that a predetermined load is in an islanding state and the stored islanding system maintainable time are transmitted to the loads in the islanding system and equipment such as the distributed power source 10 ( Step S4).

As a result, the loads in the isolated system and the distributed power sources 10 can confirm the future supply and demand plan, modify the load amount (including stopping the operation of non-urgent loads), etc. It is possible to prevent unforeseen power outages and ensure smooth operation.

In addition, Fig. 3 shows that the possible accident sections in normal times are assumed, and the time during which the isolated operation system can be maintained is calculated and stored in advance according to these accident sections, and this stored time is used for each equipment when an actual accident occurs. FIG.
In FIG. 3, the system monitoring and control device 100 preliminarily assumes points [i] within all sections as accident points during normal times. Then, in the case where an accident occurs at point [i] and the power is cut off, the time schedule of the power generation amount and load amount (including these predicted values) of the distributed power source 10, the power generation amount adjustment surplus capacity, the load amount adjustment surplus capacity, etc. Based on this, a process is performed to calculate and store the time during which independent operation can be maintained for the load in the remaining section (step S12), and this process is repeatedly executed for all points (steps S13, S11). ).
After that, if an accident actually occurs at point [i] (step S14 YES), information indicating that the predetermined load is in the islanding state and the pre-stored time that the islanding system can be maintained are transferred to the islanding system. The information is transmitted to the load within the building and equipment such as the distributed power source 10 (step S15).

As a result, in the event that an accident actually occurs, information indicating that each piece of equipment is in islanded operation status and the length of time that the islanded system can be maintained can be quickly transmitted, allowing each piece of equipment to respond more quickly. can contribute to

A ₁ to A ₅ : Section PV: Solar power generation device PCS: Power conditioner system F ₃ , F ₄ , F ₅ : Fault point 10: Distributed power source 21 to 26: Circuit breaker 31 to 35: Load 40: System power source 100 :System monitoring and control equipment

Claims (14)

In a system monitoring and control device for monitoring and controlling a power system in which a plurality of sections are formed between a system power source and a distributed power source via circuit breakers, and loads are respectively connected to the plurality of sections,
a function of monitoring the power generation amount of the distributed power source; a function of receiving accident information in the power system; a function of monitoring the opening/closing state of the circuit breaker and a function of controlling the opening/closing; a function of monitoring the load amount of the load; a function of transmitting to the load in the islanding system and the distributed power source that an islanding system is configured by the distributed power source when receiving accident information;
A system monitoring and control device, characterized in that the circuit breaker is controlled to open and close so that the islanding system is configured based on at least the amount of power generated by the distributed power source and the amount of load of the load. In the system monitoring control device according to claim 1,
A system monitoring and control device that controls opening and closing of the circuit breaker so that the plurality of sections constitute an islanding system when the power generation amount of the distributed power source is greater than or equal to the load amount of the plurality of consecutive sections. . In the system monitoring control device according to claim 1,
Controlling the opening and closing of the circuit breaker so that the plurality of sections constitute an isolated operation system when the sum of the power generation amount and the power generation amount adjustment surplus of the distributed power source is greater than or equal to the load amount of the plurality of consecutive sections. A system monitoring and control device characterized by: In the system monitoring control device according to claim 1,
The circuit breaker is controlled to open and close so that the plurality of sections constitute an isolated operation system when the power generation amount of the distributed power source is greater than or equal to the difference between the load amount of the continuous plurality of sections and the load adjustment surplus capacity. Characteristic system monitoring and control equipment. In the system monitoring control device according to claim 1,
When the sum of the power generation amount and the power generation amount adjustment surplus capacity of the distributed power source is equal to or greater than the difference between the load amount and the load adjustment surplus capacity of the plurality of consecutive zones, the individual operation system is configured by the plurality of consecutive zones. A system monitoring and control device characterized by controlling the opening and closing of circuit breakers. In the system monitoring control device according to claim 3 or 5,
A system monitoring and control device characterized in that the power generation amount adjustment surplus capacity is a difference between a rated output and a current operating output of the distributed power source. In the system monitoring control device according to claim 3 or 5,
A system monitoring and control device, wherein the power generation amount adjustment surplus is a difference between a maximum output and a current operating output of the distributed power source. In the system monitoring control device according to claim 4 or 5,
The load amount adjustment surplus capacity is
A system monitoring and control device characterized in that the supply and demand adjustment contract amount or the demand response possible amount is predefined. In the system monitoring control device according to claim 4 or 5,
The load amount adjustment surplus capacity is
A system monitoring and control device characterized in that the supply and demand adjustment contract amount or the demand response possible amount is predefined. In the system monitoring control device according to claim 1,
With respect to the load configuring the islanding system,
the load is in an islanding state, and the islanding system maintainable time calculated based on at least the time schedules of the power generation amount and the load amount;
A system monitoring and control device characterized by being capable of transmitting. In the system monitoring control device according to claim 1,
For the distributed power source,
A system monitoring and control device characterized in that it is capable of transmitting an islanding system maintainable time calculated based on each time schedule of at least the power generation amount and the load amount. In the system monitoring control device according to claim 10 or 11,
A system monitoring and control device characterized in that the islanding system maintainable time is calculated and transmitted when an accident occurs in the power system. In the system monitoring control device according to claim 10 or 11,
The islanding system maintainable time is calculated and stored in advance before an accident occurs in the power system, and when an accident actually occurs, the islanding system maintainable time is transmitted. Characteristic system monitoring and control equipment. In the system monitoring control device according to any one of claims 1 to 5,
The system monitoring and control device is characterized in that the power generation amount includes a power generation amount using a power storage amount by a power storage device inside the distributed power source.

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