JP7161331B2 - power controller - Google Patents

Description

TECHNICAL FIELD The present invention relates to a power control apparatus that integrates power demand units and power generation units that are scattered on a network and performs power management that efficiently supplies power to consumers.

Conventionally, there has been proposed a power control device that is installed in an electric power consumer having storage equipment such as a storage battery or fuel cell, and adjusts the amount of power received from the grid according to the load and the power that can be supplied from the storage equipment. (Patent Documents 1 and 2).

Depending on the power command value from the center, these power control devices supply power from the grid to the load while charging a part of the power to the storage equipment, or supply power from the grid to the load while charging the storage equipment. also supplies (discharges) part of the power to the load.

In addition, an aggregator for performing the power management is arranged, and in this aggregator, the power demand of the power consumers 7 and 8 is bundled, and the energy resources generated or held by the power consumers 7 and 8 are bundled into one virtual Constructed as a power plant, the power supplied from the upstream side (centralized power supply section) and the power generated and held downstream (energy resource section) are matched to efficiently distribute power to each consumer. An aggregator system that performs the following control has been proposed (Patent Document 3, etc.)

Japanese Patent Application Laid-Open No. 2001-258176 JP 2012-249458 A JP 2018-033273 A

However, in the above device, the timing of charge/discharge control when the power command value is sent from the center is not clear. Therefore, in general, when a power command value is sent from a host server, aggregator, or the like, charging control and discharging control are performed according to the control timing inside the device.

In this case, when the slope of the power demand changes rapidly, for example, in the early morning, the power demand (load power) is initially less than the power command value, so the storage battery is charged with surplus power, and the power demand When the power exceeds the power command value, the shortfall is covered by the discharge from the storage battery.

FIG. 1 shows this situation.

The figure shows a power command value C at a power receiving point to which power is input from an external power system, a power receiving point power curve D indicating a predicted value of the power at the power receiving point, and charge/discharge control details for the storage battery. The vertical axis indicates the power at the receiving point, and the horizontal axis indicates the elapsed time since the power command value C was received. In FIG. 1, the measured value of the power at the receiving point is omitted. The power command value C is a value that instructs the actual measured value of the power at the receiving point to match this value. Also, the power command value C is received from an aggregator or the like every period T1 (30 minutes). The power control device measures the actual power at the receiving point and performs charging/discharging control at each measurement cycle (for example, 1 minute) shorter than this period T1 (30 minutes).

A power receiving point curve D indicates a change in the current power receiving point predicted from the past power receiving point. The receiving point power curve D is sent from a host server (aggregator or the like).

At time t1 at 10:30 in the morning, when the power command value C and the receiving point power curve D are sent from the host server (aggregator, etc.) via the network, etc., the power control circuit detects the actual receiving point power is the power command value C. Specifically, from time t1 to time t3, it is determined whether charging or discharging is performed from the power receiving point power curve D and the power command value C, and the charging and discharging of the storage battery is controlled. The charge/discharge amount is controlled so that the actual power at the power receiving point matches the power command value C based on the actual value of the power at the power receiving point measured every (one minute). The host server (aggregator or the like) determines whether the actual power at the receiving point matches the power command value C at time t3 after the period T1 (30 minutes) has elapsed.

At time t1, the value of the power receiving point power curve D, which is the predicted current power at the power receiving point, is smaller than the power command value C, so the surplus power that is the difference is used to charge the storage battery. After time t2, the value of the power receiving point power curve D, which is the predicted current power at the power receiving point, becomes equal to or greater than the power command value C, so the power command value C alone is insufficient. Therefore, the storage battery is discharged from time t2, and the shortfall is covered by the electric power from the storage battery. During this time, the charge/discharge amount is controlled based on the actual measurement value of the power at the power receiving point, which is measured at each measurement cycle. At time t3 at 11:00 in the morning, the next power command value comes from the host server. If the power command value C newly received at time t3 is the same as the previous power command value C, or is changed to a value greater than that, discharging continues.

Thus, in the power control shown in FIG. 1, the storage battery is always charged or discharged for 30 minutes in the morning, and a charging period (t1 to t2) and a discharging period (t2 to t3) occur respectively. . Conversely, since the power demand decreases from evening to night, discharging or discharging is always performed in 30 minutes, and a discharging period (t1 to t2) and a charging period (t2 to t3) occur respectively. Become.

In such control, in both the charging period and the discharging period, charging and discharging are sequentially repeated so that the actual measurement value of the power at the receiving point and the command value C match, which causes loss in the switching element and deterioration of the storage battery. There is a problem of expediting

SUMMARY OF THE INVENTION It is an object of the present invention to provide a power control device that requires only one charging period or one discharging period in the period between receiving a power command value and receiving the next power command value.

The present invention comprises a power receiving point to which power is input from an external power system;
a communication terminal that receives a power command value of power at the power receiving point to be input to the power receiving point from a host server every period T1;
A power controller is provided to perform charge/discharge control of a storage battery so that the power at the power receiving point reaches the power command value when the period T1 has elapsed.

When the power command value of the power receiving point is input to the communication terminal from the host server, the power controller controls charging and discharging of the storage battery.

That is, the power controller sets the power receiving point power curve for the period T1 when the power command value is received at the communication terminal, and determines the difference between the power receiving point power curve and the power command value during the period T1. An integrated value is obtained, either the charge amount or the discharge amount of the storage battery is set based on the integrated value, and either charge control or discharge control is performed within the period T1.

The integrated value is a value obtained by integrating the difference for each period T2 (T2<T1) in the period T1. When the integrated value is positive, the discharge amount is obtained. set.

As for the relationship of T2<T1, for example, T1 is 30 minutes and T2 is 1 minute.

The power controller obtains the integrated value of the difference between the power receiving point power curve and the power command value during the period T1, and depending on whether the integrated value is positive or negative, the charging period or the discharging period is performed only once during the period T1. set and charge or discharge only once during this period. Also, the charging amount (charging time) or the discharging amount (discharging time) is determined based on the magnitude of the integrated value.

In the present invention, it is not necessary to sequentially perform charging and discharging during the period T1 in time periods such as early in the morning and late in the evening when the amount of power demand varies greatly. As a result, the number of charge/discharge cycles of the storage battery is reduced, and the life of the storage battery is lengthened. In addition, since no charging/discharging operation (operation by switching control) is required during a time period in which charging or discharging is not performed, power loss in the power control device can be reduced accordingly.

FIG. 10 is a diagram showing a charge/discharge control operation of a conventional power control device; 1 is a schematic diagram of a power integration system that is an embodiment of the invention; FIG. 2 is a schematic configuration diagram of power consumers 7 and 8. FIG. FIG. 4 is a diagram for explaining the operation of the power control device according to the embodiment of the present invention when only discharging to a storage battery is performed; FIG. 4 is a diagram for explaining the operation of the power control apparatus according to the embodiment of the present invention when only charging the storage battery; 4 is a flow chart showing a charge/discharge control operation of the power control device that is the embodiment of the present invention; Another embodiment in the case of performing only discharge to the storage battery is shown. Another embodiment in the case of only charging the storage battery is shown.

FIG. 2 is a schematic diagram of a power integration system comprising a virtual power plant 1 including a power control device that is an embodiment of the present invention, and a power company 2 connected to the virtual power plant 1. As shown in FIG. This power integration system is a system in which the power generated by electric power companies and power producers and the power required, generated and owned by each customer are integrated by an aggregator, and the distribution of power is managed. be.

In the power integrated system, there may be multiple power companies 2 and multiple virtual power plants 1 .

The power companies 2 include one or more power companies 3 and power companies 4 and 5 other than the power companies connected to each power company 3 via a network, a dedicated line, or the like. The power generators 4 and 5 include power generators using renewable energy obtained by using solar panels, wind power generation facilities, etc., and power generators using other energy. The electric power company 2 supplies electric power to power consumers such as factories and homes through transmission and distribution lines (not shown).

The virtual power plant 1 includes an aggregator 6 connected to a power company 3 via a network, a dedicated line, or the like, and a plurality of power consumers 7 and 8 connected to the aggregator 6 via a network, a dedicated line, or the like. Electric power consumers 7 and 8 basically receive electric power from the electric power company 2 through transmission and distribution lines (not shown), but use small-scale electric power generation/holding facilities such as in-house power generation facilities, storage batteries, and heat storage facilities as electric power resources. It is equipped as From this, the virtual power plant 1 is conceptualized as one virtual power plant that bundles the power generated and held by each of the power consumers 7 and 8 .

As a result, when looking at the overall power supply source in FIG. 1, the electric power company 2 becomes a centralized power supply located on the upstream side, and the power generated and held by the power consumers 7 and 8 is located on the downstream side. Energy resource department.

The aggregator 6 bundles the power demand of the power consumers 7 and 8, and bundles the energy resources generated or owned by the power consumers 7 and 8 to build a single virtual power plant. Energy management is performed so that the power to be supplied is matched with the power generated and stored in the downstream side (energy resource section) so that the power distribution to each consumer is efficient.

Although there are various forms of energy management of the aggregator 6, this embodiment shows energy management by setting a power command value and a power receiving point power curve.

The power command value is a value for commanding power at the receiving point of power consumers 7 and 8 . This power command value is set every 30 minutes in this embodiment, and the power consumers 7 and 8 are requested that the actual measured value of the power at the receiving point after 30 minutes has passed is the set power command value. be.

For example, the aggregator 6 increases the power command value set for the power consumers 7 and 8 when the power generation by the renewable energy (solar energy, etc.) power generation company increases and there is surplus electricity on the upstream side. set. Also, when the power demand is tight, the aggregator 6 sets the power command value set for the power consumers 7 and 8 to a smaller value.

A power receiving point power curve is a curve that indicates past power reception results at power receiving points of the power consumers 7 and 8 . Receiving point power curves that show past power reception results include, for example, a receiving point power curve for the same time period one day ago, a receiving point power curve for the same time period on the same day one year ago, and a statistically processed power reception for the same time period on the same day. point power curve and the like.

When the power consumers 7 and 8 of the present embodiment receive the power command value and the power curve at the receiving point from the aggregator 6, they refer to them, and after 30 minutes, the measured value of the power at the receiving point becomes the power command value. so as to adjust energy resources. That is, when the power command value is greater than or equal to the power receiving point power curve, the difference is regarded as surplus power and stored in the power holding means. Also, when the power command value is less than the receiving point power curve, the difference is regarded as insufficient power and released from the power holding means so that the actual measured value of the receiving point power becomes the power command value after 30 minutes. to control.

In the present embodiment, in the aggregator 6, a chargeable/dischargeable storage battery is used as the power holding means, which is an energy resource for each of the power consumers 7 and 8. FIG.

Therefore, for example, when the aggregator 6 sets the power command value set for the power consumers 7 and 8 to a larger value, the power consumers 7 and 8 set the power command value and the receiving point power The storage battery is charged based on the difference (surplus power) from the curve. In addition, when the aggregator 6 sets the power command value set for the power consumers 7 and 8 to a smaller value, the power consumers 7 and 8 compare the set power command value and the power receiving point power curve. The storage battery is discharged based on the difference (insufficient power).

A power command value is created every 30 minutes, which is a predetermined period, and transmitted to each of the power consumers 7 and 8 . Each of the power consumers 7 and 8 performs charging/discharging control of the storage battery so that the actually measured value of the power at the power receiving point becomes the power command value after 30 minutes.

As described above, in each of the power consumers 7 and 8, when the power at the receiving point predicted by the power curve at the receiving point is smaller than the power command value set at that time, the storage battery is charged with the surplus power, and the negative power is received. If the power at the power receiving point predicted by the point power curve is greater than the power command value, the difference power is covered by the discharge from the storage battery.

Note that in the present embodiment, charging and discharging are not performed successively in the 30-minute period T1 from time t1 to t3, as shown in FIG. 1, but either charging or discharging is performed only once within the period T1. Then, at time t3 after the period T1 has elapsed, control is performed so that the actual measurement value of the power at the receiving point matches the power command value instructed by the aggregator 6. FIG.

FIG. 3 is a schematic configuration diagram of power consumers 7 and 8. As shown in FIG.

The power equipment 11 of the power consumers 7 and 8 includes a power receiving point 12 connected to an external power system (system) 10 , a transformer equipment 13 , a load 14 , a storage battery 15 and a power control device 16 .

The power control device 16 includes a power detector 161 that detects the power at the power receiving point 12 (power at the power receiving point), a power controller 162 called EMS (Energy Management System), a PLC (sequencer) 163, a PCS (Power Conditional Subsystem). ) 164. The power receiving point 12 receives power from the grid 10 . Power detector 161 detects power at the receiving point. The power controller 162 has a communication terminal 162 a that is network-connected to the host server 100 provided in the aggregator 6 . When the power controller 162 receives the power command value C and the power receiving point power curve D from the host server 100, the power controller 162 sets them, and performs charge control or discharge control of the storage battery 15 according to the procedure described later.

A PLC (sequencer) 163 is connected to the power controller 162 and controls the PCS 164 through a communication line according to the control contents of the power controller 162 . The PCS 164 controls charging to the storage battery 15 and discharging control from the storage battery 15 to the load 14, and includes a converter circuit including switching elements. A PLC (sequencer) 163 grasps the state of charge (voltage, etc.) of the storage battery 15 from the SOV signal and sends it to the power controller 162 .

Next, specific operations of the power controller 162 will be described.

In this embodiment, charging and discharging are not performed during the 30 minutes of the period T1, and charging or discharging is performed only once during the 30 minutes of the period T1.

FIG. 4 is a diagram for explaining the operation when only discharging to the storage battery is performed.

The figure shows a power command value C, a power receiving point power curve D, and details of discharge control for the storage battery 15 . The vertical axis indicates the power at the power receiving point, and the horizontal axis indicates the elapsed time since the power command value C was set. The power command value C is a command value for the power supplied from the power system to the power receiving point 12, and the power receiving point power curve D is predicted based on the past power performance of the power receiving point. For example, there is a receiving point power curve in the same time zone one day ago, a receiving point power curve in the same time zone on the same day one year ago, a statistically processed receiving point power curve in the same time zone on the same day, and the like.

The power command value C and the power receiving point power curve D are both received from the host server 100 every 30 minutes and set in the power controller 162 .

At time t1 at 10:30 in the morning, the power command value C and the power receiving point power curve D are sent from the host server 100 in the aggregator 6 via the network. The charging/discharging control of the storage battery 15 is performed as follows so that the measured value of the power at the power receiving point becomes the power command value C when .

At time t1, a power receiving point power curve D for a period T1 of 30 minutes is set, and the slope of the power receiving point power curve D is calculated. P1 is the receiving point power P1 at time t1 when the receiving point power curve D is set.

When the power receiving point power curve D is set at time t1, the amount of charge required by time t3 at 11:00 a.m., which is 30 minutes later, in order to match the actual measurement value of the power receiving point with the power command value C And the total integrated value K(all) of the amount of discharge is calculated. The total integrated value K (all) is a value obtained by integrating the difference between the power receiving point power curve D and the power command value C every period T2 (one minute), which is the charge/discharge control cycle, from time t1 to time t3, It is obtained as follows. In FIG. 4, time t2 is the time when the power receiving point power curve D and the power command value C intersect, that is, the time when the calculated charging period changes to the calculated discharging period.

From time t1 to time t2, (receiving point power curve D-power command value C) is integrated every period T2 (one minute), which is a charge/discharge control cycle. This charge/discharge control cycle is a measurement cycle for measuring the power at the power receiving point and performing charge/discharge control. This integrated value is defined as a first integrated value K1. From time t2 to time t3, (receiving point power curve D-power command value C) is integrated every period T2 (one minute). This integrated value is defined as a second integrated value K2.

Then, total integrated value K(all)=integrated value K1 (negative value)+integrated value K2 (positive value). FIG. 4 shows a case where the total integrated value K(all) is positive.

When the total integrated value K(all) is positive, discharging should be performed before time t3 in order for the actual measurement value of the power at the power receiving point to match the power command value C at time t3. Therefore, from time t2 to time t3, the time t4 of the integrated value K2' where the integrated value K1 (negative value) + integrated value K2' (positive value) = 0 is obtained. is not controlled, and discharge control is performed every period T2 (one minute) from time t5, which is time (t4+T2), to time t3. Therefore, the section indicated by oblique lines in the figure is the discharge control section. According to the above control, in the period T1 (30 minutes), only discharging is performed for a certain period before the time t3. It should be noted that it is also possible to correct the amount of discharge with the actually measured value of the power at the receiving point while such control is being performed. For example, if there is a sudden change in the load, the amount of discharge in the discharge control section is corrected with the actually measured value of the power at the power receiving point. That is, the power at the power receiving point (power at the power receiving point 12) is measured every period T2 (one minute), and the amount of discharge calculated from the power curve D at the power receiving point and the power command value C is sequentially calculated using the actual measured power at the power receiving point. Perform correction control. By performing such control, it is possible to satisfy the request of the aggregator 6 to make the power receiving point power equal to the power command value C at time t3 after the period T1 has elapsed from the time t1 when the power command value C was instructed. can. In addition, by actually measuring the power at the receiving point every period T2 (one minute) and correcting the calculated charge/discharge amount every period T2, the accuracy of matching the power at the receiving point to the power command value C at time t3 is enhanced. can also

On the other hand, the control performed only for charging is as follows.

FIG. 5 is a diagram for explaining the operation when only charging the storage battery.

In FIG. 5, the slope of the set power receiving point power curve D is gentler than in FIG.

In this case, total integrated value K(all)=integrated value K1 (negative value)+integrated value K2 (positive value) is negative.

Therefore, between time t1 and time t2, time t6 of the integrated value K1′ where integrated value K1′ (negative value)+integrated value K2 (positive value)=0 is obtained, and time t1 to time t6 and time t2 From time t3 to time t3, charging/discharging control of the storage battery 15 is not performed, and charging control is performed every period T2 (one minute) from time t7, which is time (t6+T2), to time t2. Therefore, the sections indicated by dots in the drawing are charging control sections. Note that in FIG. 5 as well, the power at the receiving point is actually measured every period T2 (one minute), and the calculated charge/discharge amount is corrected for each period T2. It is also possible to increase the accuracy of matching.

According to the above control, in the period T1 (30 minutes), only charging is performed for a certain period before the time t2.

In this way, if the slope of the power receiving point power curve D is large, only one discharge (FIG. 4) is performed in the period T1 (30 minutes), and if the slope of the power receiving point power curve D is small, the period T1 (30 minutes ), only one charge (FIG. 5) is performed. In either case, power reception and discharge are not performed once each as shown in FIG. Therefore, the number of charging/discharging cycles of the storage battery is reduced, resulting in a longer life.

Also, the converter operation in the PCS 164 is not performed in the section where the charge control or the discharge control is not performed. Therefore, the switching loss can be reduced, and the power consumption of the entire device can be reduced.

It should be noted that there is a time zone in which the power curve D at the receiving point does not intersect with the power command value C and a time zone in which the slope calculated from the power curve D at the receiving point is small, that is, during the daytime and at night when the power demand does not change significantly. In the band, when the power curve D at the power receiving point is less than the power command value C, only charging is performed, and when the power curve D at the power receiving point is greater than or equal to the power command value C, only discharging is performed.

FIG. 6 is a flowchart illustrating the above operations performed by power controller 162 .

In ST1, when the power command value C and the power curve D at the power receiving point are received from the host server 100 at time t1, the slope of the power curve D at the power receiving point is calculated and set inside. Also, the power command value C is set internally. The power command value C and the power receiving point power curve D are set in the host server 100 . The power command value C is set, for example, according to an increase or decrease in the amount of power generated on the upstream side or an increase or decrease in energy resources on the downstream side. The power receiving point power curve D is set based on the past performance of the power receiving point, and predicts the current power receiving point curve.

In ST2, from the power command value C and the power receiving point power curve D, the total integrated value K (all) of the charge/discharge amount required for the period T1 (30 minutes) from time t1 to time t3 is calculated. do. In ST3, if the total integrated value K (all) is positive (“0” or more), discharge control is performed in ST4 or less (Fig. 4), and if negative (less than “0”), charge control is performed in ST10 or less (Fig. 5). transition to

In the discharge control, in ST4, the time t4 of the integrated value K2' where the integrated value K1 (negative value)+integrated value K2' (positive value)=0 is obtained in the section from time ST2 to time ST4. Proceeding to ST5, discharge control is performed every period T2 (one minute) from time t5 of time (t4+T2) to time t3. Until time t4, charging/discharging control of the storage battery 15 is not performed, and discharging control is performed every period T2 (one minute) from time t5 to time t3.

In the charging control, in ST10, the time t6 of the integrated value K1' where the integrated value K1' (negative value)+integrated value K2 (positive value)=0 is obtained in the section from time t1 to time t2. In ST5, charging control is performed every period T2 (one minute) from time t7 of time (t6+T2) to time t2. From time t1 to time t6 and from time t2 to time t3, charging/discharging control of the storage battery 15 is not performed, and charging control is performed every period T2 (one minute) from time t7 (t6+T2) to time t2.

FIG. 6 shows the control in the time period when the receiving point power curve D and the power command value C intersect as shown in FIGS. Only charging takes place. For example, in the period T1 (30 minutes), when the power curve D of the receiving point is less than the power command value C, only charging is performed continuously, and when the power curve D of the receiving point is greater than or equal to the power command value C, Only discharge is performed continuously.

Further, in FIG. 4, the discharge is controlled in the section from time t5 to time t3, but the discharge may be controlled in any range in the section from time t2 to time t3. For example, discharge control in a section as shown in FIG. 7 is also possible. Similarly, in the charging control shown in FIG. 5, charging control can be performed in sections such as those shown in FIG.

Further, when the power receiving point power curve D and the power command value C cross each other twice or more in the period T1 (30 minutes), as in FIG. 4 or 5, after integrating the total integrated value K (all), When the integrated value is positive, the discharge is controlled by finding a section in which the positive amount is discharged. Also, if the integrated value is negative, the charging control is performed by finding a section in which the battery is charged by the negative amount.

In this embodiment, the host server 100 sets the power receiving point power curve D, but it is also possible for the power controller 162 itself to set it. In this case, the power controller 162 stores the record of power reception in the past at the power receiving point, and predicts and sets the power curve D at the power receiving point based on this value.

In addition, since the PLC 163 monitors the state of charge of the storage battery 15 based on the SOV signal from the storage battery 15, the charge/discharge control is limited so as not to overcharge or overdischarge.

12-power receiving point 15-storage battery 16-power control device 162-power controller

Claims (5)

a power receiving point to which power is input from an external power system;
a communication terminal that receives a power command value of power at the power receiving point to be input to the power receiving point from a host server every period T1;
A power controller that includes means for setting a predicted power receiving point power curve for each period T1 , and performs charging and discharging control of a storage battery so that the power at the receiving point reaches the power command value when the period T1 elapses,
The power controller performs charging control when the power command value of the power receiving point is greater than the value of the power receiving point power curve, and discharge control when the power command value of the power receiving point is smaller than the value of the power receiving point power curve. is performed in units of a period T2 shorter than the period T1,
obtaining an integrated value of a difference between the power receiving point power curve and the power command value in the period T1 when the power command value is received at the communication terminal;
Only one of discharge control and charge control is set based on the integrated value so that the power receiving point power reaches the power command value when the period T1 elapses, and in the case of charge control, the storage battery is charged. The charging control is performed every period T2 within the period T1 by setting the amount, the charging start time, and the charging period. and performing discharge control every period T2 within the period T1 . 2. The power control apparatus according to claim 1 , wherein said power controller actually measures said receiving point power every said period T2, and corrects said discharge amount or said charge amount every said period T2. 3. The power control device according to claim 1, wherein said power receiving point power curve is set based on past power demand. 4. The power control device according to claim 1, wherein said power receiving point power curve is input from said host server to said communication terminal. 5. The power control device according to claim 1, wherein said power receiving point power curve is set by said power controller.

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