JP6457855B2 - Reactive power cooperative control device and power control system - Google Patents

Description

  The present invention relates to a power control system effective for power control in a distributed power generation system and the like, and a reactive power cooperative control device constituting the power control system.

  In a distribution system in which a large number of distributed power sources such as solar power generation are connected, a voltage increase in the distribution line occurs with an increase in reverse power flow. In order to suppress this voltage increase, reactive power adjustment type voltage control equipment such as a power conditioner (PCS (Power Conditioning System)) is introduced in the distribution system. The reactive power adjustment type voltage control device suppresses the voltage increase of the distribution line by adjusting the reactive power. However, there is a limit to the amount of reactive power that can be adjusted individually, and there is a limit to the suppression by itself. Therefore, in order to suppress a further increase in voltage, the output itself of solar power generation or the like has to be limited.

  Therefore, a distribution system voltage control system capable of realizing coordinated voltage control among a plurality of voltage control devices in order to suppress further voltage rise without limiting the output itself of photovoltaic power generation or the like. It has been proposed (see, for example, Patent Document 1). This distribution system voltage control system adjusts the reactive power of the voltage control device so that the voltage measurement value measured by the voltage control device is maintained within a preset target voltage range, and measures the voltage. Configured to issue target voltage change request information for requesting other voltage control devices to change the target voltage range when the voltage moving average value calculated using the value deviates from the appropriate voltage range Has been.

Japanese Patent No. 5389303

Patent Document 1 states that “the electric power company is required to maintain the voltage at the power receiving end of a general consumer within an appropriate range (for example, in the case of 100 V power reception, the voltage is maintained at 95 V to 107 V). "" Therefore, the “appropriate” voltage range is a specified voltage range specified by the Electricity Business Law, etc., and the system described in Patent Document 1 has a voltage moving average value of 95 V to 107 V in the case of receiving 100 V, for example. It is understood that it is configured to issue the target voltage change request information when deviating from.
However, when the voltage moving average value deviates from the specified voltage range, that is, when the reactive power cannot be adjusted any more, the target voltage change request information is issued. Since the target voltage range of another voltage control device is changed after it has already deviated from the specified voltage range, it is lost later.

  The present invention has been made in view of the above circumstances, and a reactive power cooperative control device capable of issuing target voltage change request information at an appropriate timing, and a power provided with the reactive power cooperative control device The object is to provide a control system.

In order to solve the above-mentioned problem, the reactive power cooperative control device of the present invention includes:
A reactive power coordination control device provided in a system comprising a plurality of voltage control devices that are connected to a distribution line and adjust reactive power so that the measured voltage value of the terminal is maintained within a preset target voltage range. There,
Information generating means for generating target voltage change request information for requesting to change the target voltage range of a voltage control device other than the voltage control device when the voltage control device satisfies a predetermined condition;
Information transmitting means for transmitting the target voltage change request information generated by the information generating means,
The predetermined condition is configured to be satisfied while the voltage control device is in a state where the reactive power can be adjusted.

  Therefore, the target voltage change request information can be issued at an appropriate timing. That is, since the target voltage change request information is issued while the voltage control device is able to adjust the reactive power, the voltage of the distribution line has already deviated from the specified voltage range, and another voltage control A situation in which the target voltage range of the device is changed can be avoided.

Preferably,
When the moving average value of the voltage calculated using the voltage measurement value deviates from an allowable voltage range that is within a specified voltage range and narrower than the specified voltage range, the information generating means It is possible to determine that the predetermined condition is satisfied and generate the target voltage change request information.

  With this configuration, the target voltage change request information can be issued while the voltage control device can adjust the reactive power, so that the distribution line voltage has already deviated from the specified voltage range. Then, a situation in which the target voltage range of another voltage control device is changed can be avoided.

More preferably,
When the information generation means determines that the predetermined condition is satisfied,
Calculate the maximum reactive power that the voltage control device can output based on the power factor constraint of the voltage control device and the current active power of the voltage control device,
Based on the calculated maximum reactive power and the current reactive power of the voltage control device, calculate the current reactive power remaining capacity of the voltage control device,
Based on the calculated reactive power margin and sensitivity coefficient, calculate the voltage control margin of the voltage control device,
Calculate the voltage change request amount to be included in the target voltage change request information based on the calculated voltage control reserve, the required voltage change amount, and the safety factor,
The sensitivity coefficient is a voltage width that varies depending on a unit control amount of reactive power,
The safety factor can be configured to be set in consideration of at least one of communication delay and control delay.

  With this configuration, it is possible to calculate the voltage change request amount in consideration of not only reactive power remaining capacity but also communication delay and control delay, so that the voltage of the distribution line has already deviated from the specified voltage range. Then, a situation in which the target voltage range of another voltage control device is changed can be reliably avoided.

Or
When the information generation means determines that the predetermined condition is satisfied,
Calculate the maximum reactive power that the voltage control device can output based on the power factor constraint of the voltage control device and the current active power of the voltage control device,
Based on the calculated maximum reactive power and safety factor, the reactive power for cooperation that leaves the control capacity of the voltage control device is calculated, and the necessary reactive power change is based on the required voltage change amount and sensitivity coefficient Calculate the amount
Based on the calculated reactive power for cooperation and the calculated required reactive power change amount, the change request reactive power is calculated,
Calculate a voltage change request amount to be included in the target voltage change request information based on the calculated change request reactive power and the sensitivity coefficient,
The sensitivity coefficient is a voltage width that varies depending on a unit control amount of reactive power,
The safety factor can be configured to be set in consideration of at least one of communication delay and control delay.

  With this configuration, the voltage change request amount can be calculated in consideration of not only the maximum reactive power but also communication delay and control delay, so the voltage of the distribution line has already deviated from the specified voltage range. Then, a situation in which the target voltage range of another voltage control device is changed can be reliably avoided.

Or
The information generating means
Calculate the maximum reactive power that the voltage control device can output based on the power factor constraint of the voltage control device and the current active power of the voltage control device,
Based on the calculated maximum reactive power and the current reactive power of the voltage control device, calculate the current reactive power remaining capacity of the voltage control device,
When the ratio of the calculated reactive power surplus to the calculated maximum reactive power is equal to or less than a predetermined value, it is possible to determine that the predetermined condition is satisfied and generate the target voltage change request information. is there.

  With this configuration, the target voltage change request information can be issued while the voltage control device can adjust the reactive power, so that the distribution line voltage has already deviated from the specified voltage range. Then, a situation in which the target voltage range of another voltage control device is changed can be avoided.

More preferably,
When the information generation means determines that the predetermined condition is satisfied,
Based on the calculated reactive power margin and the sensitivity coefficient, calculate the voltage control margin of the voltage control device,
Calculate the voltage change request amount to be included in the target voltage change request information based on the calculated voltage control reserve, the required voltage change amount, and the safety factor,
The sensitivity coefficient is a voltage width that varies depending on a unit control amount of reactive power,
The safety factor can be configured to be set in consideration of at least one of communication delay and control delay.

  With this configuration, it is possible to calculate the voltage change request amount in consideration of not only reactive power remaining capacity but also communication delay and control delay, so that the voltage of the distribution line has already deviated from the specified voltage range. Then, a situation in which the target voltage range of another voltage control device is changed can be reliably avoided.

The power control system of the present invention is
With a plurality of reactive power cooperative control devices,
The plurality of voltage control devices;
A communication network that connects the plurality of reactive power cooperative control devices so that they can communicate with each other, and
The reactive power cooperative control device and the voltage control device are connected one-to-one,
The information generating means included in the reactive power cooperative control device generates the target voltage change request information when a voltage control device connected to the reactive power cooperative control device satisfies the predetermined condition,
The information transmitting means included in the reactive power cooperative control device is configured to transmit the target voltage change request information to the reactive power cooperative control device connected to the other voltage control device via the communication network. .

  Therefore, the target voltage change request information can be issued at an appropriate timing. That is, since the target voltage change request information is issued while the voltage control device is able to adjust the reactive power, the voltage of the distribution line has already deviated from the specified voltage range, and another voltage control A situation in which the target voltage range of the device is changed can be avoided.

Alternatively, the power control system of the present invention includes:
With one reactive power cooperative control device,
The plurality of voltage control devices;
A communication network that connects the reactive power cooperative control device and the voltage control device so that they can communicate with each other;
The information generating means included in the reactive power cooperative control device generates the target voltage change request information when any of the plurality of voltage control devices satisfies the predetermined condition,
The information transmitting means included in the reactive power cooperative control device is configured to transmit the target voltage change request information to the other voltage control device via the communication network.

  Therefore, the target voltage change request information can be issued at an appropriate timing. That is, since the target voltage change request information is issued while the voltage control device is able to adjust the reactive power, the voltage of the distribution line has already deviated from the specified voltage range, and another voltage control A situation in which the target voltage range of the device is changed can be avoided.

  According to the present invention, target voltage change request information can be issued at an appropriate timing.

It is a figure which shows an example of a structure of the distributed power generation system to which the power control system of 1st Embodiment is applied. It is a figure which shows an example of a structure of the reactive power cooperative control apparatus of 1st Embodiment. It is a flowchart which shows the target voltage change request issue process by the reactive power cooperative control apparatus of 1st Embodiment. It is a flowchart which shows an example of the target voltage change process by the reactive power cooperative control apparatus which received the target voltage change request. It is a figure for demonstrating the difference between the case where the target voltage change request information is not issued, and the case where it is issued. It is a flowchart which shows the modification of the target voltage change request issue process by the reactive power cooperative control apparatus of 1st Embodiment. It is a figure which shows an example of a structure of the distributed power generation system to which the power control system of 2nd Embodiment is applied. It is a figure which shows an example of a structure of the reactive power cooperative control apparatus of 2nd Embodiment. It is a flowchart which shows the target voltage change request issue process by the reactive power cooperative control apparatus of 2nd Embodiment. It is a flowchart which shows the modification of the target voltage change request issue process by the reactive power cooperative control apparatus of 2nd Embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments of a reactive power cooperative control device and a power control system according to the present invention will be described with reference to the drawings. The embodiments described below are given various technically preferable limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

[First Embodiment]
The configurations of the reactive power cooperative control device 50 and the power control system 1 according to the first embodiment will be described.
First, the configuration of the power control system 1 of the first embodiment will be described.
FIG. 1 is a diagram illustrating an example of a configuration of a distributed power generation system to which the power control system 1 of the first embodiment is applied. In the present invention, a power generation system 1 is a power generation system obtained by removing a power generation source (PV) from a distributed power generation system.

In the power control system 1, a high voltage distribution line 11 is connected to a distribution transformer 10 installed in a substation. The high-voltage distribution line 11 is a high-voltage distribution line having a voltage level of, for example, 3300V to 6600V. A plurality of high-voltage distribution lines 11 may be connected to the distribution transformer 10.
A plurality of (three in the example shown in FIG. 1) measuring devices 12 that measure the voltage and phase at the connection location (own end) are connected to the high-voltage distribution line 11. The measuring device 12 may measure the current and phase at the connection location (own end), or may measure the voltage, current, and phase at the connection location (self end). .

The high-voltage distribution line 11 is connected to a low-voltage distribution line 31 having a lower voltage than the high-voltage distribution line 11 via a transformer 30. The low voltage distribution line 31 is a low voltage distribution line having a voltage level of, for example, 100V to 200V. In the present embodiment, two low-voltage distribution lines 31 are connected to the high-voltage distribution line 11, but the number of low-voltage distribution lines 31 connected to the high-voltage distribution line 11 may be three or more. . Moreover, the voltage levels of the low-voltage distribution lines 31 connected to the high-voltage distribution line 11 may all be the same or at least partially different.
The low voltage distribution line 31 is connected to a power conditioner (PV-PCS) 32 for photovoltaic power generation as a voltage control device. In addition, although illustration is abbreviate | omitted in drawing (FIG. 1 etc.), the load etc. are connected to the distribution line.

A reactive power cooperative control device 50 and a power generation source (PV) are connected to the PV-PCS 32. The reactive power cooperative control device 50 can be integrated with or provided with the PV-PCS 32, for example. The reactive power cooperative control device 50 is connected to the communication network N via a network cable 33, for example.
The PV-PCS 32 measures the voltage and current at the connection location (own end) of the low-voltage distribution line 31 in addition to the inverter function that converts the DC power generated by the power generation source (PV) into AC power. The control amount of the PCS 32 is adjusted, specifically, by adjusting the reactive power output of the PV-PCS 32, the voltage of the low-voltage distribution line 31 (for example, voltage increase) is suppressed.

In the PV-PCS 32, a target voltage range that is a control target of the PV-PCS 32 is stored in advance. The PV-PCS 32 adjusts the reactive power output so that the voltage value at its own end falls within the target voltage range.
Specifically, for example, the PV-PCS 32 determines whether or not the voltage measurement value measured at every predetermined period is within the target voltage range, and determines that the voltage measurement value is not within the target voltage range (deviates). The voltage is controlled by outputting reactive power so that the voltage is maintained within the target voltage range.

  Here, the PV-PCS 32 which is a reactive power adjustment type voltage control device uniformly raises and lowers the voltage on the distribution system load side (downstream side) by changing the reactive power amount, and on the distribution system power supply side (upstream side) The voltage control characteristic increases and decreases the voltage in proportion to the line impedance from the distribution transformer 10. For this reason, in the reactive power adjustment type voltage control device, the closer to the distribution transformer 10 (upstream side), the smaller the voltage change width with respect to the same reactive power change.

Next, the configuration of the reactive power cooperative control device 50 according to the first embodiment will be described.
FIG. 2 is a diagram illustrating an example of the configuration of the reactive power cooperative control device 50 according to the first embodiment.

The reactive power cooperative control device 50 collects, edits, and monitors voltage measurement values from the PV-PCS 32 connected to the reactive power cooperative control device 50 (hereinafter referred to as “own PV-PCS 32”). In addition, the reactive power cooperative control device 50 has a function of making a target voltage change request.
Here, the collection is to acquire the voltage value of the own end measured by the own location PV-PCS 32 from the own location PV-PCS 32, for example, at regular intervals. The editing is, for example, calculating a voltage moving average value for a certain period based on the collected voltage measurement values. Monitoring is to monitor voltage fluctuations and the like. The target voltage change request is issued when the latest voltage moving average value deviates from the allowable voltage range (described later).
Specifically, the reactive power cooperative control device 50 includes a voltage monitoring unit 51, a calculation processing unit 52, a target voltage change command unit 53, a storage unit 54, and a communication unit 55.

The voltage monitoring unit 51 monitors the voltage (V) measured by the local PV-PCS 32, acquires a voltage measurement value at, for example, a certain period, and sends it to the arithmetic processing unit 52.
In addition, the voltage monitoring unit 51 acquires the current active power of the local site PV-PCS 32, the current reactive power of the local site PV-PCS 32, and the like from the local site PV-PCS 32, and sends them to the arithmetic processing unit 52. Send it out.

The arithmetic processing unit 52 executes various arithmetic processes.
Specifically, the arithmetic processing unit 52 stores the voltage measurement value output from the voltage monitoring unit 51 in the storage unit 54 for a certain period, for example.
Further, each time the arithmetic processing unit 52 acquires the latest voltage measurement value from the voltage monitoring unit 51, the voltage moving average is calculated using the past voltage measurement value and the latest voltage measurement value already stored in the storage unit 54. A value is calculated, and this voltage moving average value is stored in the storage unit 54 for a certain period, for example.
Here, the allowable voltage range is stored in the storage unit 54 in advance. The allowable voltage range is within a specified voltage range of the local PV-PCS 32 specified by the Electricity Business Law (for example, a range of 95V to 107V in the case of 100V power reception) and is narrower than the specified voltage range. is there. The allowable voltage range can be set to be variable in time.

Further, the arithmetic processing unit 52 generates target voltage change request information when the latest voltage moving average value deviates from the allowable voltage range stored in advance in the storage unit 54. The arithmetic processing unit 52 transmits the target voltage change request information to another predetermined reactive power cooperative control device 50 via the communication unit 55 and the communication network N.
The target voltage change request information is composed of information related to the voltage change request amount and the voltage change request direction (voltage increasing direction or decreasing direction). For example, when the voltage moving average value exceeds the allowable voltage range, the voltage is decreased. Issue a request. The reason why the voltage moving average value is used to determine the deviation from the allowable voltage range is to avoid issuing unnecessary target voltage change request information due to a saddle-like voltage change in seconds.

  When the arithmetic processing unit 52 receives target voltage change request information from another reactive power cooperative control device 50, the arithmetic processing unit 52 is based on the voltage change request amount and the voltage change request direction included in the target voltage change request information. A target voltage change command is generated and output to the target voltage change command unit 53. The target voltage change command unit 53 outputs this command to the local PV-PCS 32. The self location PV-PCS 32 changes the target voltage range stored in the self location PV-PCS 32 according to the target voltage change command from the target voltage change command section 53.

  The communication unit 55 is connected to the network cable 33 and executes communication processing.

Next, the operation principle of the PV-PCS 32 will be described.
The PV-PCS 32 measures the voltage value at its own end with a predetermined period (for example, 100 msec period), compares this with the target voltage range, determines whether or not there is a deviation, and deviates to the control amount when the deviation continues. Reactive power output control by PID control or the like to keep the voltage within the target voltage range when the deviation amount exceeds a predetermined threshold when the deviation amount exceeds a predetermined threshold value. I do. The PV-PCS 32 includes a reactive power attenuation mechanism (not shown) that gradually reduces the amount of reactive power to be controlled with a time constant of, for example, about 1 second, and avoids unnecessary reactive power loss.

  The initial range of the target voltage range of the PV-PCS 32 (the target voltage range in a state where there is no target voltage change request) is constant to the moving average value of the voltage measurement value at its own end (for example, the voltage moving average value for one minute). The dead band (for example, 0.5% of the voltage moving average value) is added and subtracted. Thereby, in a state where there is no request for changing the target voltage, the PV-PCS 32 operates so as to avoid a sudden voltage change at its own end.

Next, the operation principle of the reactive power cooperative control device 50 of the first embodiment will be described.
First, the target voltage change request issuing operation of the reactive power cooperative control device 50 will be described.
FIG. 3 is a flowchart illustrating an example of a target voltage change request issuing process performed by the reactive power cooperative control device 50 according to the first embodiment.

  First, the arithmetic processing unit 52 stores the voltage measurement value (voltage measurement value measured by the local PV-PCS 32) acquired by the voltage monitoring unit 51 at regular intervals (for example, every 1 second), as a storage unit. 54 is stored for a certain period (for example, 1 minute) (step S1). Since the voltage fluctuates in units of msec, the voltage measurement value is desirably an average of measurement values in units of 100 msec, for example.

  Next, each time the voltage monitoring unit 51 acquires a voltage measurement value, the arithmetic processing unit 52 calculates a voltage moving average value (for example, a voltage moving average value for one minute), and this is also stored in the storage unit 54 for a certain period (for example, Store for 1 minute (step S2).

  Next, the arithmetic processing unit 52 compares the calculated latest voltage moving average value with the allowable voltage range stored in the storage unit 54 at regular intervals (for example, every one minute cycle) (step S3). Here, since the allowable voltage range is within the specified voltage range and narrower than the specified voltage range, even if the voltage moving average value deviates from the allowable voltage range, the voltage moving average value does not exceed the specified voltage range. When not deviating, the PV-PCS 32 is in a state where the reactive power can be adjusted.

If the voltage moving average value deviates from the allowable voltage range (step S4; No), the arithmetic processing unit 52 first issues the power factor (85 of the local PV-PCS 32 in order to issue the target voltage change request information. %) Maximum reactive power that can be output by the local PV-PCS 32 according to Equation (1), based on the constraints and the current active power of the local PV-PCS 32 acquired by the voltage monitoring unit 51 Is calculated (step S5).
Maximum reactive power = (√ (1−0.85 ² ) /0.85) × current active power (1)

Next, based on the maximum reactive power calculated in step S5 and the current reactive power of the local PV-PCS 32 acquired by the voltage monitoring unit 51, the arithmetic processing unit 52 specifically uses Equation (2). Then, the present reactive power remaining capacity of the PV-PCS 32 is calculated (step S6).
Reactive power surplus = Maximum reactive power-Current reactive power ... (2)

Next, the arithmetic processing unit 52 calculates the current voltage control remaining capacity of the local PV-PCS 32 based on the reactive power remaining capacity and the sensitivity coefficient calculated in step S6, specifically, using Equation (3). (Step S7). Here, the sensitivity coefficient is a voltage width that varies depending on the unit control amount of reactive power, that is, a voltage variation width [V] that varies depending on reactive power control 1 kVar, and is determined by, for example, line impedance.
Voltage control margin = reactive power margin x sensitivity coefficient (3)

Next, the arithmetic processing unit 52 determines the voltage control margin calculated in step S7, the necessary voltage change amount (specifically, the deviation amount from the allowable voltage range of the voltage moving average value), and the safety coefficient α. Based on this, specifically, the voltage change request amount to be included in the target voltage change request information is calculated by equation (4) (step S8). Here, the safety coefficient α is a value between 0 and 1 inclusive. The control delay of the PV-PCS 32 and the reactive power cooperative control device 50 and / or the communication delay between the reactive power cooperative control devices 50, and the sensitivity coefficient error. It is set in consideration of the above.
Voltage change request amount = Necessary voltage change amount-Voltage control margin x Safety factor α (4)

  Next, the arithmetic processing unit 52 issues target voltage change request information (step S9), and proceeds to the process of step S1. Specifically, the arithmetic processing unit 52 includes information on the voltage change request amount calculated in step S8 and the voltage change request direction obtained based on the deviation direction of the voltage moving average value from the allowable voltage range. The target voltage change request information is generated, and the target voltage change request information is transmitted to another predetermined reactive power cooperative control device 50 via the communication unit 55 and the communication network N.

In step S3, the voltage moving average value and the allowable voltage range are compared. However, instead of the allowable voltage range, a target voltage range stored in the local PV-PCS 32 may be used. That is, in step S3, the voltage moving average value may be compared with the target voltage range, and the target voltage change request information may be issued when the voltage moving average value deviates from the target voltage range.
Moreover, said Formula (1)-(4) is a calculation formula of the voltage change request amount used when a voltage moving average value exceeds the allowable voltage range. When the voltage moving average value falls below the allowable voltage range, the voltage change request amount is calculated using the following formulas (5) and (6). That is, when it is determined in step S4 that the voltage moving average value has deviated (exceeded) the allowable voltage range, the process of steps S5 to S8 is performed to calculate the voltage change request amount, and the process of step S9 is performed. When it is determined in step S4 that the voltage moving average value has deviated (below) the allowable voltage range, the voltage change request amount is calculated using the following equations (5) and (6), Process.
Reactive power control voltage = current reactive power × sensitivity coefficient (5)
Voltage change request amount = necessary voltage change amount−reactive power control voltage × safety factor α (6)

The above formulas (1) to (4) are calculation formulas for the amount of voltage change request when the control delay and error are taken into account from the reactive power remaining capacity, but instead of the above formulas (1) to (4), the maximum invalidity The following formulas (7) to (11), which are calculation formulas of the voltage change request amount when considering control delay and error from electric power, may be used.
Specifically, when it is determined in step S4 that the voltage moving average value has deviated (exceeded) the allowable voltage range, the voltage change request amount is calculated using the following equations (7) to (11). The process in step S9 may be performed.

First, based on the power factor (85%) restriction of the own location PV-PCS 32 and the current effective power of the own location PV-PCS 32 acquired by the voltage monitoring unit 51, specifically, by the equation (7), The maximum reactive power that the local PV-PCS 32 can output is calculated.
Maximum reactive power = (√ (1−0.85 ² ) /0.85) × current active power (7)

Next, based on the calculated maximum reactive power and the safety coefficient β, specifically, the reactive power for cooperation that leaves the control margin of the local PV-PCS 32 is calculated by Expression (8). Here, the safety coefficient β is set in consideration of control delay of the PV-PCS 32 and the reactive power cooperative control device 50 and / or communication delay between the reactive power cooperative control devices 50, hunting, and the like.
Reactive power for cooperation = maximum reactive power (1-safety factor β) (8)

Further, based on the required voltage change amount (specifically, the amount of deviation of the voltage moving average value from the allowable voltage range) and the sensitivity coefficient, specifically, the necessary reactive power is obtained by Expression (9). Calculate the amount of change.
Necessary reactive power change amount = necessary voltage change amount / sensitivity coefficient (9)

Next, based on the calculated reactive power for cooperation and the calculated required reactive power change amount, specifically, the change request reactive power to the other location PV-PCS 32 is calculated by Expression (10).
Change request reactive power = required reactive power change amount−reactive power for cooperation (10)

Next, based on the calculated change request reactive power and the sensitivity coefficient, specifically, the voltage change request amount to be included in the target voltage change request information is calculated by Expression (11).
Voltage change request amount = Change request reactive power × sensitivity coefficient (11)

Next, the target voltage changing operation of the reactive power cooperative control device 50 that has received the target voltage changing request will be described.
FIG. 4 is a flowchart illustrating an example of a target voltage change process performed by the reactive power cooperative control device 50 that has received a target voltage change request.
The following processing is performed not only by the reactive power cooperative control device 50 that has received the request, but also by the reactive power cooperative control device 50 that has issued the request. The reactive power cooperative control device 50 that has received the request and the reactive power cooperative control device 50 that has issued the request instruct the local PV-PCS 32 to change the target voltage range, and each reactive power cooperative control device 50 is predetermined. The voltage cooperative control effective time (for example, 1 hour) and the target voltage range are fixed.

  First, when the communication unit 55 receives target voltage change request information from another reactive power cooperative control device 50 (step S11), the arithmetic processing unit 52 is a request that the content of the target voltage change request information decreases the voltage. Whether or not (step S12).

When the request for lowering the voltage is received (step S12; Yes), the arithmetic processing unit 52 determines a new target voltage range (step S13). Specifically, the maximum voltage moving average value is selected from a plurality of voltage moving average values stored in the storage unit 54 at that time including the latest voltage moving average value, and the maximum voltage moving average value is selected. The value obtained by subtracting the voltage change request amount is set as a new target voltage upper limit value (the upper limit value of the target voltage range). At this time, in order to keep the width of the target voltage range constant, the new target voltage lower limit value (the lower limit value of the target voltage range) is, for example, a value obtained by subtracting twice the dead zone from the new target voltage upper limit value. .
Here, when the latest voltage moving average value does not deviate (below) the allowable voltage range, the arithmetic processing unit 52 newly calculates a value obtained by subtracting the voltage change request amount from the maximum voltage moving average value. When the latest voltage moving average value is out of the allowable voltage range (below), the deviation amount is compared with the voltage change request amount, and the deviation amount If the value is larger, the value obtained by subtracting the deviation amount from the maximum voltage moving average value is set as the new target voltage upper limit value. If the voltage change request amount is larger, the voltage change request amount is subtracted from the maximum voltage moving average value. The new value is set as the new target voltage upper limit value.

However, when the new target voltage lower limit value thus determined is lower than the specified voltage lower limit value (the lower limit value of the specified voltage range) (step S14; No), the arithmetic processing unit 52 issues an instruction to change the target voltage range. Without requesting, the request is discarded (step S16). On the other hand, when the new target voltage lower limit value is greater than or equal to the specified voltage lower limit value (step S14; Yes), the calculation processing unit 52 sets the new target voltage range determined in step S13 so as to set the new target voltage range PV-PCS32. (Step S15).
In step S14, the new target voltage lower limit value and the specified voltage lower limit value are compared. However, instead of the specified voltage lower limit value, an allowable voltage lower limit value (lower limit value of the allowable voltage range) may be used. Good. That is, in step S14, the new target voltage lower limit value is compared with the allowable voltage lower limit value, and if the new target voltage lower limit value is lower than the allowable voltage lower limit value, the request is made without issuing an instruction to change the target voltage range. May be discarded, and when the new target voltage lower limit value is greater than or equal to the allowable voltage lower limit value, an instruction to change the target voltage range may be issued.

When receiving a request to increase the voltage (step S12; No), the arithmetic processing unit 52 determines a new target voltage range (step S17). Specifically, the minimum voltage moving average value is selected from the plurality of voltage moving average values stored in the storage unit 54 including the latest voltage moving average value at that time, and the minimum voltage moving average value is selected. A value obtained by adding the voltage change request amount is set as a new target voltage lower limit value. At this time, in order to keep the width of the target voltage range constant, the new target voltage upper limit value is, for example, a value obtained by adding twice the dead zone to the new target voltage lower limit value.
Here, when the latest voltage moving average value does not deviate from (or exceeds) the allowable voltage range, the arithmetic processing unit 52 newly sets a value obtained by adding the voltage change request amount to the minimum voltage moving average value. When the latest voltage moving average value deviates from (or exceeds) the allowable voltage range, the deviation amount is compared with the voltage change request amount. If the value is larger, the value obtained by adding the deviation amount to the minimum voltage moving average value is set as the new target voltage lower limit value. If the voltage change request amount is larger, the voltage change request amount is added to the minimum voltage moving average value. The new value is set as the new target voltage lower limit value.

However, when the new target voltage upper limit value thus determined exceeds the specified voltage upper limit value (the upper limit value of the specified voltage range) (step S18; No), the arithmetic processing unit 52 issues an instruction to change the target voltage range. Without requesting, the request is discarded (step S16). On the other hand, when the new target voltage upper limit value is less than or equal to the specified voltage upper limit value (step S18; Yes), the arithmetic processing unit 52 sets the new target voltage range determined in step S17 so as to set the new target voltage range PV-PCS32. (Step S15).
In step S18, the new target voltage upper limit value and the specified voltage upper limit value are compared. However, the allowable voltage upper limit value (the upper limit value of the allowable voltage range) may be used instead of the specified voltage upper limit value. Good. That is, in step S18, the new target voltage upper limit value is compared with the allowable voltage upper limit value, and if the new target voltage upper limit value exceeds the allowable voltage upper limit value, the request is made without issuing an instruction to change the target voltage range. May be discarded, and when the new target voltage upper limit value is less than or equal to the allowable voltage upper limit value, an instruction to change the target voltage range may be issued.

Then, after the voltage cooperative control effective time has elapsed after receiving the request, the arithmetic processing unit 52 instructs the local PV-PCS 32 to return the target voltage range to the initial range (default).
Further, when a new target voltage change request is generated even during the voltage cooperative control effective time, the arithmetic processing unit 52 issues a target voltage range change instruction with a post-priority, and further performs voltage cooperative control from the change instruction time point. Count valid time. However, in order to avoid congestion of the voltage cooperative operation, an overlapping operation prohibition time is determined for each reactive power cooperative control device 50. That is, the reactive power cooperative control device 50 does not issue a new request (transmit) or receive a request before the overlap operation prohibition time (for example, 1 minute) elapses from the request issuance (transmission) or request reception. The overlapping operation prohibition time is shorter than the voltage cooperative control effective time.

  Of course, the reactive power cooperative control device 50 that has received the request for changing the target voltage similarly performs the target voltage change request issuing process (FIG. 3 and the like).

As shown in the example shown in FIG. 1, when the number of reactive power cooperative control devices 50 included in the power control system 1 is two, one reactive power cooperative control device 50 is different from the other reactive power cooperative control device 50. The target voltage change request information is transmitted.
Specifically, for example, when the power control system 1 includes the “first reactive power cooperative control device” and the “second reactive power cooperative control device” as the reactive power cooperative control device 50, The “cooperative control device” transmits target voltage change request information to the “second reactive power cooperative control device”, and the “second reactive power cooperative control device” transmits to the “first reactive power cooperative control device”. Send target voltage change request information.

Further, when the number of reactive power cooperative control devices 50 included in the power control system 1 is three or more, one reactive power cooperative control device 50 is in response to any of the remaining reactive power cooperative control devices 50. The target voltage change request information may be transmitted, or the target voltage change request information may be transmitted to all the remaining reactive power cooperative control devices 50.
Specifically, for example, the power control system 1 includes a “first reactive power cooperative control device”, a “second reactive power cooperative control device”, and a “third reactive power cooperative control device” as the reactive power cooperative control device 50. If it is, the “first reactive power cooperative control device” sends target voltage change request information to one of the “second reactive power cooperative control device” and the “third reactive power cooperative control device”. The target voltage change request information may be transmitted to both the “second reactive power cooperative control device” and the “third reactive power cooperative control device”.

  Here, the “first reactive power cooperative control device” is one of “second reactive power cooperative control device” and “third reactive power cooperative control device”, for example, “second reactive power cooperative control device”. When the target voltage change request information is transmitted to the PV-PCS 32 connected to the “second reactive power cooperative control device” in accordance with the received target voltage change request information. To change the target voltage range. Then, as a result of changing the target voltage range according to the instruction, when the voltage moving average value of the PV-PCS 32 deviates from the allowable voltage range, the “second reactive power cooperative control device” It is preferable to transmit the target voltage change request information to reactive power cooperative control devices 50 other than “cooperative control device” (in this example, “third reactive power cooperative control device”).

In addition, when transmitting target voltage change request information with respect to the some reactive power cooperative control apparatus 50, the sum total of the voltage change request amount included in each target voltage change request information is the voltage change request amount calculated by step S8. If it becomes.
Specifically, for example, a value obtained by dividing the voltage change request amount calculated in step S8 by the number of the reactive power cooperative control devices 50 at the transmission destination may be used as the voltage change request amount (in this case, the transmission destination). Regardless of the voltage change request amount, the voltage change request amount may be the same). The value corresponding to the transmission destination is, for example, a value corresponding to the voltage moving average value of the transmission destination (that is, the voltage moving average value stored in the storage unit 54 of the reactive power cooperative control device 50 of the transmission destination). .

Here, when a request to lower the voltage is received, a value obtained by subtracting the voltage change request amount from the maximum voltage moving average value is set as a new target voltage upper limit value, and a new target voltage calculated from the new target voltage upper limit value is obtained. When the lower limit value is lower than the specified voltage lower limit value (step S14; No), the target voltage range is not changed (step S16). Therefore, when making a request to lower the voltage to the plurality of reactive power coordination control devices 50, the larger the maximum voltage moving average value of the transmission destination is, the larger the voltage change request amount is. The occurrence of inconvenience that the target voltage range is not changed in any or all of the control devices 50 can be suppressed.
In addition, when a request to increase the voltage is received, a value obtained by adding the voltage change request amount from the minimum voltage moving average value is set as a new target voltage lower limit value, and a new target voltage upper limit calculated from the new target voltage lower limit value. When the value exceeds the specified voltage upper limit value (step S18; No), the target voltage range is not changed (step S16). Therefore, when making a request to increase the voltage to a plurality of reactive power coordination control devices 50, the smaller the minimum voltage moving average value of the transmission destination is, the larger the voltage change request amount is, so that the plurality of reactive power coordinations are increased. The occurrence of inconvenience that the target voltage range is not changed in any or all of the control devices 50 can be suppressed.

Here, the difference between the case where the target voltage change request information is not issued by the reactive power cooperative control device 50 of the first embodiment and the case where it is issued will be described using the actually measured values shown in FIG.
The voltage is higher at point B (see FIG. 1) on the downstream side than point A (see FIG. 1) on the upstream side. That is, the voltage is higher at points farther from the substation (distribution transformer 10). Even when the reactive power is not adjusted by the PV-PCS 32a (see FIG. 1) (“no voltage control”), the voltage at the point A is within the specified voltage range (6400V to 6600V). In a state where the reactive power is not adjusted by the PCS 32b (see FIG. 1) (“no voltage control”), the voltage at the point B is out of the specified voltage range.

When the reactive power is adjusted by the PV-PCS 32a (“single voltage control”), the voltage at the point A decreases, and when the reactive power is adjusted by the PV-PCS 32b (“single voltage control”), the voltage at the point B However, the voltage at point B is still outside the specified voltage range.
Thus, since there is a limit to the amount of reactive power that can be individually adjusted and there is a limit to voltage suppression alone, in the case of single voltage control, in order to keep the voltage at point B within the specified voltage range, PV− There is no choice but to limit the output of the power generation source (PV) connected to the PCS 32b.

On the other hand, when the reactive power cooperative control device 50b (see FIG. 1) connected to the PV-PCS 32b issues target voltage change request information to the reactive power cooperative control device 50a (see FIG. 1) connected to the PV-PCS 32a ( “Collaborative voltage control”), the voltage at the point A further decreases, so that not only the voltage at the point A but also the voltage at the point B falls within the specified voltage range.
As described above, the PV-PCS 32a and the PV-PCS 32b adjust the reactive power amount in cooperation with each other, without restricting the output of the power source (PV) connected to the PV-PCS 32a, 32b. Can be kept within the specified voltage range. Therefore, it is possible to reduce the output (active power) limit of the power generation source by the cooperative voltage control of the present invention, that is, the reactive voltage is coordinated at a plurality of points and the voltage of the distribution line is controlled. Become.

<Modification 1>
Next, a modification of the first embodiment will be described.
In the first embodiment, when the voltage moving average value deviates from the allowable voltage range, the target voltage change request information is issued. However, the timing for issuing the target voltage change request information is the own PV-PCS 32. Can be arbitrarily changed as long as reactive power can be adjusted.
For example, the target voltage change request information when the ratio of the reactive power remaining power of the local PV-PCS 32 to the maximum reactive power of the local PV-PCS 32 (= 100 × reactive power remaining / maximum reactive power) is equal to or less than a predetermined value. Can also be configured to issue That is, the reactive power cooperative control device 50 can be configured to execute the target voltage change request issuing process shown in FIG. 6 instead of the target voltage change request issuing process shown in FIG.

In the target voltage change request issuance process shown in FIG. 6, the arithmetic processing unit 52 performs the processes of step S5 and step S6 after performing the processes of step S1 and step S2.
Next, the arithmetic processing unit 52 compares the reactive power surplus calculated in step S6 with the maximum reactive power calculated in step S5 (step S21). Here, when the present reactive power remaining capacity of the PV-PCS 32 is not 0, the PV-PCS 32 is in a state where the reactive power can be adjusted.

  When the reactive power surplus is 50% or less of the maximum reactive power (step S22; Yes), that is, when the ratio of the reactive power surplus to the maximum reactive power is 50% or less, the arithmetic processing unit 52 performs step The process of S7, step S8, and step S9 is performed.

  According to the reactive power coordination control device 50 of the first embodiment described above, the measured voltage value of the own end connected to the distribution line (in the case of the present embodiment, the low-voltage distribution line 31) is within a preset target voltage range. A reactive power cooperative control device provided in a system (distributed power generation system or the like) having a plurality of voltage control devices (PV-PCS32) for adjusting reactive power so as to be maintained at In the case of the embodiment, when the local location PV-PCS 32) satisfies a predetermined condition, target voltage change request information for requesting to change the target voltage range of the voltage control device other than the voltage control device is generated. Information generating means (arithmetic processing unit 52) for transmitting and information transmitting means (arithmetic processing unit 52 and communication unit 55) for transmitting the target voltage change request information generated by the information generating means. Matter, while the voltage control device is an adjustable state reactive power, and is configured to be judged satisfies a.

  Therefore, the target voltage change request information can be issued at an appropriate timing. That is, since the target voltage change request information is issued (generated / transmitted) while the voltage control device (in the case of the present embodiment, the local PV-PCS 32) can adjust the reactive power, It is possible to avoid a situation in which the target voltage range of another voltage control device is changed after the voltage has already deviated from the specified voltage range.

  In addition, according to the reactive power cooperative control device 50 of the first embodiment, the information generating means (calculation processing unit 52) has a voltage moving average value (voltage moving average value) calculated by using the voltage measurement value, It can be configured to generate target voltage change request information by determining that a predetermined condition has been satisfied when the voltage deviates from an allowable voltage range that is within the specified voltage range and narrower than the specified voltage range. It is.

  By configuring in this way, the voltage control device (local PV-PCS 32) can issue the target voltage change request information while the reactive power can be adjusted. It is possible to avoid a situation in which the target voltage range of another voltage control device is changed after deviating from the voltage range.

  Further, according to the reactive power cooperative control device 50 of the first embodiment, when the information generating means (the arithmetic processing unit 52) determines that the predetermined condition is satisfied, the voltage control device (in the case of the present embodiment, the local location) PV-PCS32) calculates the maximum reactive power that the voltage control device can output based on the power factor constraint of the voltage control device and the current active power of the voltage control device, the calculated maximum reactive power, and the voltage control device Current reactive power of the voltage control device is calculated based on the current reactive power, and the voltage control remaining power of the voltage control device is calculated based on the calculated reactive power remaining power and the sensitivity coefficient. Calculate the voltage change request amount to be included in the target voltage change request information based on the calculated voltage control reserve, the required voltage change amount, and the safety factor, and the sensitivity coefficient is a voltage that varies depending on the unit control amount of reactive power In width Any safety factor may be configured to be set in consideration of at least one of the communication delay and control delay.

  With this configuration, it is possible to calculate the voltage change request amount in consideration of not only reactive power remaining capacity but also communication delay and control delay, so that the voltage of the distribution line has already deviated from the specified voltage range. Then, a situation in which the target voltage range of another voltage control device is changed can be reliably avoided.

  Further, according to the reactive power cooperative control device 50 of the first embodiment, when the information generating means (the arithmetic processing unit 52) determines that the predetermined condition is satisfied, the voltage control device (in the case of the present embodiment, the local location) PV-PCS32) calculates the maximum reactive power that the voltage control device can output based on the power factor constraint of the voltage control device and the current active power of the voltage control device, the calculated maximum reactive power, the safety factor, Based on the above, the reactive power for cooperation that leaves the control capacity of the voltage control device is calculated, and the necessary reactive power change amount is calculated based on the required voltage change amount and the sensitivity coefficient. The change request reactive power is calculated based on the power and the calculated necessary reactive power change amount, and the voltage change request amount to be included in the target voltage change request information based on the calculated change request reactive power and the sensitivity coefficient Calculate The sensitivity coefficient is a voltage width that varies depending on the unit control amount of the reactive power, and the safety coefficient can be configured to be set in consideration of at least one of communication delay and control delay. .

  With this configuration, the voltage change request amount can be calculated in consideration of not only the maximum reactive power but also communication delay and control delay, so the voltage of the distribution line has already deviated from the specified voltage range. Then, a situation in which the target voltage range of another voltage control device is changed can be reliably avoided.

  Further, according to the reactive power cooperative control device 50 of the first embodiment, as in the modified example, the information generating means (arithmetic processing unit 52) is a voltage control device (in the case of the present embodiment, the local PV-PCS 32). The maximum reactive power that can be output by the voltage control device is calculated based on the power factor constraint of the voltage control device and the current active power of the voltage control device. The current reactive power surplus of the voltage control device is calculated based on the power, and when the ratio of the calculated reactive power surplus to the calculated maximum reactive power is equal to or less than a predetermined value, it is determined that the predetermined condition is satisfied. The target voltage change request information can be generated.

By configuring in this way, the voltage control device (local PV-PCS 32) can issue the target voltage change request information while the reactive power can be adjusted. It is possible to avoid a situation in which the target voltage range of another voltage control device is changed after deviating from the voltage range.
Note that the “predetermined value” of “when the ratio of the calculated reactive power surplus to the calculated maximum reactive power is less than or equal to the predetermined value” is not limited to 50% and may be greater than 0% and smaller than 100%. If necessary, it can be arbitrarily changed. As the ratio of the reactive power remaining capacity to the maximum reactive power increases, the reactive power remaining capacity (reactive power adjustment capacity) remains. Therefore, if the "predetermined value" is too large, the target voltage change request information is issued wastefully. It will end up. On the other hand, if the “predetermined value” is too small, the target voltage change request information is issued in a state where the reactive power reserve is low, so the target voltage range of other voltage control devices changes due to a sudden change in the output of the power source. Before being done, there is a risk that the voltage of the distribution line will deviate from the specified voltage range. Therefore, the “predetermined value” is preferably about 30% to 70%.

  Further, according to the reactive power cooperative control device 50 of the first embodiment, as in the modification, when the information generating unit (arithmetic processing unit 52) determines that the predetermined condition is satisfied, the calculated reactive power remaining power and The voltage control margin of the voltage control device (in this embodiment, the PV-PCS 32 in the present embodiment) is calculated based on the sensitivity coefficient, the calculated voltage control margin, the necessary voltage change amount, the safety factor, The voltage change request amount to be included in the target voltage change request information is calculated based on the sensitivity, the sensitivity coefficient is a voltage width that varies depending on the unit control amount of reactive power, and the safety coefficient is at least one of communication delay and control delay It is possible to configure so as to take into account.

  With this configuration, it is possible to calculate the voltage change request amount in consideration of not only reactive power remaining capacity but also communication delay and control delay, so that the voltage of the distribution line has already deviated from the specified voltage range. Then, a situation in which the target voltage range of another voltage control device is changed can be reliably avoided.

  According to the power control system 1 of the first embodiment described above, a plurality of reactive power cooperative control devices 50 are provided, and a plurality of voltage control devices (PV-PCS 32) and a plurality of reactive power cooperative control devices 50 communicate with each other. The reactive power cooperative control device 50 and the voltage control device are connected in a one-to-one relationship, and information generating means (calculation processing unit 52) provided in the reactive power cooperative control device 50 is provided. ) Generates target voltage change request information when the voltage control device (own PV-PCS 32) connected to the reactive power cooperative control device 50 satisfies a predetermined condition, and the reactive power cooperative control device 50 includes information. The transmission means (arithmetic processing unit 52 and communication unit 55) is a reactive power cooperative that is connected to another voltage control device (other PV-PCS 32) via communication network N. It is configured to send the target voltage change request information to the control unit 50.

  Therefore, the target voltage change request information can be issued at an appropriate timing. That is, since the target voltage change request information is issued (generated / transmitted) while the voltage control device (in the case of the present embodiment, the local PV-PCS 32) can adjust the reactive power, It is possible to avoid a situation in which the target voltage range of another voltage control device is changed after the voltage has already deviated from the specified voltage range.

[Second Embodiment]
Next, the reactive power cooperative control device 50 and the power control system 1 of the second embodiment will be described.
In the first embodiment, the power control system 1 includes a plurality of reactive power cooperative control devices 50 and a plurality of PV-PCSs 32, and one reactive power cooperative control device 50 controls one PV-PCS 32. In the second embodiment, the power control system 1 includes one reactive power cooperative control device 50 and a plurality of PV-PCSs 32, and the single reactive power cooperative control device 50 performs centralized control of the plurality of PV-PCSs 32. Different from the first embodiment. Therefore, description of portions having the same configuration as in the first embodiment is omitted, and different portions are mainly described.

FIG. 7 is a diagram illustrating an example of a configuration of a distributed power generation system to which the power control system 1 of the second embodiment is applied.
In the power control system 1 of the second embodiment, the PV-PCS 32 is not directly connected to the reactive power cooperative control device 50 but is connected to the reactive power cooperative control device 50 via the network cable 33 and the communication network N. Yes.

FIG. 8 is a diagram illustrating an example of the configuration of the reactive power cooperative control device 50 according to the second embodiment.
The reactive power cooperative control device 50 according to the second embodiment includes an arithmetic processing unit 52, a storage unit 54, and a communication unit 55. In the second embodiment, the communication unit 55 has the same functions as the voltage monitoring unit 51, the target voltage change command unit 53, and the communication unit 55 in the first embodiment.
FIG. 9 is a flowchart illustrating an example of a target voltage change request issuing process performed by the reactive power cooperative control device 50 according to the second embodiment.

  First, the arithmetic processing unit 52 stores each voltage measurement value (voltage measurement value measured by each PV-PCS 32) received by the communication unit 55 at regular intervals (for example, every 1 second) in the storage unit 54 for a certain period. Save (for example, for 1 minute) (step S31).

  Next, every time the communication unit 55 receives a voltage measurement value, the arithmetic processing unit 52 calculates a voltage moving average value (for example, a voltage moving average value for one minute), and this is also stored in the storage unit 54 for a certain period (for example, 1). Save for a minute (step S32).

  Next, for each of the plurality of PV-PCSs 32, the arithmetic processing unit 52 calculates the latest voltage moving average value calculated for each fixed period (for example, every one minute period), and the allowable voltage range stored in the storage unit 54. Are compared (step S33).

  When there is a PV-PCS 32 whose voltage moving average value has deviated from the allowable voltage range (hereinafter referred to as “deviation PV-PCS 32”) (step S34; No), the arithmetic processing unit 52 issues target voltage change request information. In order to do so, first, based on the power factor constraint of the deviation PV-PCS 32 and the current effective power of the deviation PV-PCS 32 received by the communication unit 55, specifically, the deviation PV -The maximum reactive power that can be output by the PCS 32 is calculated (step S35).

  Next, the arithmetic processing unit 52, based on the maximum reactive power calculated in step S35 and the current reactive power of the deviation PV-PCS 32 received by the communication unit 55, specifically by the above formula (2), The present reactive power remaining capacity of the deviation PV-PCS 32 is calculated (step S36).

  Next, the arithmetic processing unit 52 calculates the current voltage control remaining capacity of the deviation PV-PCS 32 based on the reactive power remaining capacity and the sensitivity coefficient calculated in step S36, specifically, the above equation (3). (Step S37).

  Next, the arithmetic processing unit 52 determines the voltage control margin calculated in step S37, the necessary voltage change amount (specifically, the deviation amount from the allowable voltage range of the voltage moving average value), and the safety coefficient α. Specifically, the voltage change request amount to be included in the target voltage change request information is calculated by the above equation (4) (step S38).

  Next, the arithmetic processing unit 52 issues target voltage change request information (step S39), and proceeds to the process of step S31. Specifically, the arithmetic processing unit 52 includes information regarding the voltage change request amount calculated in step S38 and the voltage change request direction obtained based on the deviation direction of the voltage moving average value from the allowable voltage range. Target voltage change request information is generated and the target voltage change request information is transmitted to another predetermined PV-PCS 32 via the communication unit 55 and the communication network N.

In step S33, the voltage moving average value and the allowable voltage range are compared. However, the target voltage range stored in each PV-PCS 32 may be used instead of the allowable voltage range. That is, in step S33, the voltage moving average value may be compared with the target voltage range, and the target voltage change request information may be issued when the voltage moving average value deviates from the target voltage range.
Moreover, said Formula (1)-(4) is a calculation formula of the voltage change request amount used when a voltage moving average value exceeds the allowable voltage range. When the voltage moving average value falls below the allowable voltage range, the voltage change request amount is calculated using the above formulas (5) and (6). That is, if it is determined in step S34 that there is a PV-PCS 32 whose voltage moving average value has deviated (exceeded) the allowable voltage range, the process of steps S35 to S38 is performed to calculate the voltage change request amount. When the process of S39 is performed and it is determined in step S34 that there is a PV-PCS 32 whose voltage moving average value has deviated (below) the allowable voltage range, the voltage is changed using the above equations (5) and (6). The requested amount is calculated, and the process of step S39 is performed.

The above formulas (1) to (4) are calculation formulas for the amount of voltage change request when the control delay and error are taken into account from the reactive power remaining capacity, but instead of the above formulas (1) to (4), the maximum invalidity The above formulas (7) to (11), which are formulas for calculating the voltage change request amount when considering control delay and error from the electric power, may be used.
Specifically, if it is determined in step S34 that there is a PV-PCS 32 whose voltage moving average value has deviated (exceeded) the allowable voltage range, a voltage change request is made using the above equations (7) to (11). The amount may be calculated and the process of step S39 may be performed.

  Then, the PV-PCS 32 that has received the target voltage change request information changes the target voltage range based on the voltage change request amount and the voltage change request direction included in the target voltage change request information, and for each PV-PCS 32 in advance. The target voltage range is fixed for a predetermined voltage cooperative control effective time (for example, 1 hour).

  As in the example illustrated in FIG. 7, when the number of PV-PCSs 32 included in the power control system 1 is two and one PV-PCS 32 is a deviation PV-PCS 32, the reactive power cooperative control device 50 It is comprised so that target voltage change request information may be transmitted with respect to PV-PCS32.

When the number of PV-PCSs 32 included in the power control system 1 is three or more, the reactive power cooperative control device 50 sets the target voltage for any of the remaining PV-PCSs 32 other than the departure PV-PCS 32. The change request information can be transmitted, or the target voltage change request information can be transmitted to all the remaining PV-PCSs 32.
Specifically, for example, the power control system 1 includes “first PV-PCS”, “second PV-PCS”, and “third PV-PCS” as PV-PCS 32, and “first PV-PCS” is provided. When the “PCS” is the departure PV-PCS 32, the reactive power cooperative control device 50 transmits the target voltage change request information to one of the “second PV-PCS” and the “third PV-PCS”. Alternatively, the target voltage change request information may be transmitted to both “second PV-PCS” and “third PV-PCS”.

  Here, the “first PV-PCS 32” is the departure PV-PCS 32, and the reactive power cooperative control device 50 is one of “second PV-PCS” and “third PV-PCS”, for example, “ When the target voltage change request information is transmitted to the “second PV-PCS”, the target voltage range of the “second PV-PCS” is changed. As a result, when the voltage moving average value of the “second PV-PCS 32” deviates from the allowable voltage range, the reactive power cooperative control device 50 determines a PV-PCS 32 other than the “first PV-PCS 32” (in this example, “ It is preferable to transmit the target voltage change request information to the “third PV-PCS”).

In addition, when transmitting target voltage change request information with respect to several PV-PCS32, if the sum total of the voltage change request amount included in each target voltage change request information becomes the voltage change request amount calculated by step S38. Good.
Specifically, for example, a value obtained by dividing the voltage change request amount calculated in step S38 by the number of PV-PCSs 32 of the transmission destination may be used as the voltage change request amount (in this case, the transmission destination is related). The voltage change request amount becomes the same, and the value corresponding to the transmission destination may be used as the voltage change request amount. The value corresponding to the transmission destination is, for example, a value corresponding to the voltage moving average value of the transmission destination.

  Further, the reactive power cooperative control device 50 transmits not only the target voltage change request information to the PV-PCS 32 other than the deviation PV-PCS 32 but also the target voltage change request information to the deviation PV-PCS 32. It is also possible to configure.

<Modification 2>
Next, a modification of the second embodiment will be described.
In the second embodiment, in any one of the plurality of PV-PCSs 32, when the voltage moving average value deviates from the allowable voltage range, the target voltage change request information is issued. The issuance timing can be arbitrarily changed as long as the PV-PCS 32 is in a state where the reactive power can be adjusted.
For example, in any one of the plurality of PV-PCSs 32, when the ratio of the reactive power remaining capacity to the maximum reactive power (= 100 × reactive power remaining capacity / maximum reactive power) becomes a predetermined value or less, the target voltage change request information Can also be configured to issue That is, the reactive power cooperative control device 50 can be configured to execute the target voltage change request issuing process shown in FIG. 10 instead of the target voltage change request issuing process shown in FIG.

  In the target voltage change request issuing process shown in FIG. 10, the arithmetic processing unit 52 first performs the processes of step S31 and step S32, and then receives the power factor constraint and the communication unit 55 for each of the plurality of PV-PCSs 32. Specifically, based on the current active power, the maximum reactive power that can be output is calculated by the above formula (1) (step S41).

Next, the arithmetic processing unit 52, for each of the plurality of PV-PCSs 32, based on the maximum reactive power calculated in step S41 and the current reactive power received by the communication unit 55, specifically, the above formula (2 ) To calculate the current reactive power remaining capacity (step S42).
Next, the arithmetic processing unit 52 compares the reactive power surplus calculated in Step S42 with the maximum reactive power calculated in Step S41 for each of the plurality of PV-PCSs 32 (Step S43).

  And there exists PV-PCS32 (henceforth "predetermined value or less PV-PCS32") below the predetermined value of reactive power surplus (step S44; No), ie, ratio of reactive power remaining power with respect to maximum reactive power When there is a PV-PCS 32 that is equal to or less than a predetermined value (50% in the case of the present modification), the arithmetic processing unit 52 performs specific processing based on the reactive power margin calculated in step S42 and the sensitivity coefficient. In step S45, the current voltage control margin of the PV-PCS 32 equal to or less than a predetermined value is calculated by the above equation (3).

  Next, the arithmetic processing unit 52 determines the voltage control margin calculated in step S45, the necessary voltage change amount (specifically, the deviation amount from the allowable voltage range of the voltage moving average value), and the safety coefficient α. Specifically, the voltage change request amount to be included in the target voltage change request information is calculated by the above equation (4) (step S46).

  Next, the arithmetic processing unit 52 issues target voltage change request information (step S47), and proceeds to the process of step S31. Specifically, the arithmetic processing unit 52 includes information on the voltage change request amount calculated in step S46 and the voltage change request direction obtained based on the deviation direction of the voltage moving average value from the allowable voltage range. Target voltage change request information is generated and the target voltage change request information is transmitted to another predetermined PV-PCS 32 via the communication unit 55 and the communication network N.

  The reactive power cooperative control device 50 not only transmits the target voltage change request information to other PV-PCSs 32 other than the PV-PCS 32 below the predetermined value, but also sends the target voltage change request information to the PV-PCS 32 below the predetermined value. It can also be configured to transmit.

  According to the reactive power cooperative control device 50 of the second embodiment described above, the measured voltage value of the own end connected to the distribution line (in the case of the present embodiment, the low-voltage distribution line 31) is within a preset target voltage range. A reactive power cooperative control device provided in a system (distributed power generation system or the like) having a plurality of voltage control devices (PV-PCS32) for adjusting reactive power so as to be maintained at In the case of the embodiment, when any one of the plurality of PV-PCSs 32 satisfies a predetermined condition, the target voltage for requesting to change the target voltage range of another voltage control device other than the voltage control device. Information generation means (calculation processing section 52) for generating change request information, information transmission means (calculation processing section 52 and communication section 55) for transmitting target voltage change request information generated by the information generation means, With a predetermined condition, while the voltage control device is an adjustable state reactive power, and is configured to be judged satisfies a.

  Therefore, the target voltage change request information can be issued at an appropriate timing. That is, since the target voltage change request information is issued (generated / transmitted) while the voltage control device (PV-PCS32) is in a state where the reactive power can be adjusted, the voltage of the distribution line has already deviated from the specified voltage range. Then, a situation in which the target voltage range of another voltage control device is changed can be avoided.

  According to the power control system 1 of the second embodiment described above, one reactive power cooperative control device 50 is provided, a plurality of voltage control devices (PV-PCS32), a reactive power cooperative control device 50, and a voltage control device. The information generation means (arithmetic processing unit 52) included in the reactive power cooperative control device 50 includes any one of a plurality of voltage control devices satisfying a predetermined condition. The target voltage change request information is generated, and the information transmission means (the arithmetic processing unit 52 and the communication unit 55) included in the reactive power cooperative control device 50 transmits the target voltage to other voltage control devices via the communication network N. It is configured to send change request information.

  Therefore, the target voltage change request information can be issued at an appropriate timing. That is, since the target voltage change request information is issued (generated / transmitted) while the voltage control device (PV-PCS32) is in a state where the reactive power can be adjusted, the voltage of the distribution line has already deviated from the specified voltage range. Then, a situation in which the target voltage range of another voltage control device is changed can be avoided.

  In the above-described embodiments and modifications, the configurations and the like illustrated in the accompanying drawings are merely examples, and are not limited thereto, and may be appropriately changed within the scope of the effects of the present invention. Is possible. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  The voltage control device is not limited to the PV power conditioner (PV-PCS) 32, but can be used for wind power generation, geothermal power generation, wave power generation, fuel cell power generation, biomass power generation, and the like. It may be.

1 Power control system 31 Low voltage distribution line (distribution line)
32 PV-PCS (voltage control equipment)
50 reactive power cooperative control device 52 arithmetic processing unit (information generating means, information transmitting means)
55 Communication unit (information transmission means)
N communication network

Claims (8)

A reactive power coordination control device provided in a system comprising a plurality of voltage control devices that are connected to a distribution line and adjust reactive power so that the measured voltage value of the terminal is maintained within a preset target voltage range. There,
Information generating means for generating target voltage change request information for requesting to change the target voltage range of a voltage control device other than the voltage control device when the voltage control device satisfies a predetermined condition;
Information transmitting means for transmitting the target voltage change request information generated by the information generating means,
The reactive power cooperative control apparatus according to claim 1, wherein the predetermined condition is determined to be satisfied while the voltage control device is in a state where the reactive power can be adjusted.   When the moving average value of the voltage calculated using the voltage measurement value deviates from an allowable voltage range that is within a specified voltage range and narrower than the specified voltage range, the information generating means The reactive power cooperative control device according to claim 1, wherein the target voltage change request information is generated by determining that a predetermined condition is satisfied. When the information generation means determines that the predetermined condition is satisfied,
Calculate the maximum reactive power that the voltage control device can output based on the power factor constraint of the voltage control device and the current active power of the voltage control device,
Based on the calculated maximum reactive power and the current reactive power of the voltage control device, calculate the current reactive power remaining capacity of the voltage control device,
Based on the calculated reactive power margin and sensitivity coefficient, calculate the voltage control margin of the voltage control device,
Calculate the voltage change request amount to be included in the target voltage change request information based on the calculated voltage control reserve, the required voltage change amount, and the safety factor,
The sensitivity coefficient is a voltage width that varies depending on a unit control amount of reactive power,
The reactive power cooperative control apparatus according to claim 2, wherein the safety coefficient is set in consideration of at least one of communication delay and control delay. When the information generation means determines that the predetermined condition is satisfied,
Calculate the maximum reactive power that the voltage control device can output based on the power factor constraint of the voltage control device and the current active power of the voltage control device,
Based on the calculated maximum reactive power and safety factor, the reactive power for cooperation that leaves the control capacity of the voltage control device is calculated, and the necessary reactive power change is based on the required voltage change amount and sensitivity coefficient Calculate the amount
Based on the calculated reactive power for cooperation and the calculated required reactive power change amount, the change request reactive power is calculated,
Calculate a voltage change request amount to be included in the target voltage change request information based on the calculated change request reactive power and the sensitivity coefficient,
The sensitivity coefficient is a voltage width that varies depending on a unit control amount of reactive power,
The reactive power cooperative control apparatus according to claim 2, wherein the safety coefficient is set in consideration of at least one of communication delay and control delay. The information generating means
Calculate the maximum reactive power that the voltage control device can output based on the power factor constraint of the voltage control device and the current active power of the voltage control device,
Based on the calculated maximum reactive power and the current reactive power of the voltage control device, calculate the current reactive power remaining capacity of the voltage control device,
2. The target voltage change request information is generated by determining that the predetermined condition is satisfied when a ratio of the calculated reactive power surplus to the calculated maximum reactive power is equal to or less than a predetermined value. The reactive power cooperative control device described in 1. When the information generation means determines that the predetermined condition is satisfied,
Based on the calculated reactive power margin and the sensitivity coefficient, calculate the voltage control margin of the voltage control device,
Calculate the voltage change request amount to be included in the target voltage change request information based on the calculated voltage control reserve, the required voltage change amount, and the safety factor,
The sensitivity coefficient is a voltage width that varies depending on a unit control amount of reactive power,
The reactive power cooperative control apparatus according to claim 5, wherein the safety coefficient is set in consideration of at least one of communication delay and control delay. While comprising a plurality of reactive power cooperative control device according to claim 1,
The plurality of voltage control devices;
A communication network that connects the plurality of reactive power cooperative control devices so that they can communicate with each other, and
The reactive power cooperative control device and the voltage control device are connected one-to-one,
The information generating means included in the reactive power cooperative control device generates the target voltage change request information when a voltage control device connected to the reactive power cooperative control device satisfies the predetermined condition,
The information transmitting means included in the reactive power cooperative control device transmits the target voltage change request information to the reactive power cooperative control device connected to the other voltage control device via the communication network. Control system. While comprising one reactive power cooperative control device according to claim 1,
The plurality of voltage control devices;
A communication network that connects the reactive power cooperative control device and the voltage control device so that they can communicate with each other;
The information generating means included in the reactive power cooperative control device generates the target voltage change request information when any of the plurality of voltage control devices satisfies the predetermined condition,
The power control system, wherein the information transmission means included in the reactive power cooperative control device transmits the target voltage change request information to the other voltage control device via the communication network.

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