JP6240445B2 - Electric power peak cut device - Google Patents

Description

  The present invention relates to a power peak cut device that performs peak cut of received power.

  Conventionally, when a power supplied from a commercial power system becomes a predetermined value or more, a power peak cutting device is used that supplies power from a power storage device such as a storage battery and cuts a power peak (for example, , See Patent Document 1 and Patent Document 2).

  Here, Patent Document 1 discloses a power distribution system (power peak cut device) that can reduce contract power without increasing the capacity of a battery (storage battery). In this power distribution system, the on-site load is a first system load (always power supply load) that is constantly fed, a second system load (peak shift load) that is fed from the storage battery during power peak hours, and power The system is divided into three systems, that is, a third system load (peak cutting load) in which power supply is stopped in the peak time zone. Then, the storage battery connected to the peak shift load is charged in a light load time zone including midnight and discharged in a power peak time zone (for example, around PM 1 to 4 o'clock). That is, in the power peak time zone, power is supplied from the storage battery to the peak shift load. In addition, power supply to the peak cut load is stopped during the peak time period. Thereby, peak power can be cut without increasing the capacity of the storage battery.

  In Patent Document 2, for example, a storage battery or the like is installed in a factory or office where power is supplied from a commercial power system, and the average power becomes a predetermined value or less during a time period when the power usage reaches a peak. A power peak cut device that reduces the contract power charge so that the peak usage (peak power value) of the power supplied from the commercial power system does not exceed the value determined by the contract by supplying power from It is disclosed. This power peak cut device is configured so that the amount of power to be supplied can be continuously varied and the supply time can be controlled, that is, the minimum necessary power can be supplied for the minimum necessary period. .

JP 2000-92717 A JP 2003-189470 A

  As described above, according to the power distribution system (power peak cut device) described in Patent Document 1, power is supplied from the storage battery to the second system load (peak shift load) during the power peak time period. Power feeding is stopped for three loads (peak cut loads). Therefore, contract power can be reduced without increasing the capacity of the storage battery. However, in this power distribution system, since power supply to the load of the third system (peak cutting load) is stopped during the power peak time period, the load connected to the third system during the power peak time period (that is, Electrical equipment) cannot be used. For this reason, when this power distribution system is applied to a factory, an office, or the like, there is a risk that work efficiency may be reduced due to load usage restrictions. On the other hand, it is necessary to increase the capacity of the storage battery so as not to stop the power supply to the load of the third system during the power peak time period in order to prevent a decrease in business efficiency.

  Further, as described above, the peak cut device described in Patent Document 2 is configured to be able to supply the minimum necessary power for the minimum necessary period. By the way, the efficiency of the peak cut device largely depends on the AC / DC conversion efficiency in the charger / inverter. However, the charger / inverter has the highest conversion efficiency at the rated output due to its characteristics, and converts when the output becomes low. Efficiency is reduced. Therefore, in the peak cut device described in Patent Document 2, the energy efficiency of the device may be reduced.

  The present invention has been made in order to solve the above-mentioned problems, and without increasing the size of the storage battery, it is possible to prevent a decrease in business efficiency at the time of peak cut and to improve energy efficiency. An object is to provide a peak cut device.

  A power peak cut device according to the present invention has a measuring means for measuring received power received from a commercial power system, and a bidirectional function connected to a power system that has a grid interconnection function and supplies the received power to a load. Based on the inverter, the storage battery connected to the bidirectional inverter, and the received power measured by the measuring means, the bidirectional inverter is driven so that the average power value for a certain time does not exceed a predetermined power value. Control means for controlling, and when the control means supplies power to the power system from the storage battery, the bidirectional inverter is operated at a rated output.

  According to the power peak cut device according to the present invention, the bidirectional inverter is driven and controlled so that the average power value for a predetermined time does not exceed a predetermined power value. That is, power is supplied from the storage battery to the power system to which the load is connected via the bidirectional inverter. Therefore, by supplying the electric power stored in the storage battery at the time of the maximum demand, it is possible to perform the peak cut of the electric power without providing the load use restriction. At that time, the bidirectional inverter is operated at the rated output (maximum efficiency) with the best power conversion efficiency, and power is supplied to the power system. Here, in the power peak cut device according to the present invention, since the average power value for a predetermined time is controlled so as not to exceed the predetermined power value, even if power more than necessary is temporarily supplied, The stop time of the bidirectional inverter can be extended, and the efficiency can be improved comprehensively. Moreover, it becomes unnecessary to increase the capacity of the storage battery more than necessary. As a result, it is possible to prevent a reduction in business efficiency during peak cut and increase energy efficiency without increasing the size of the storage battery.

  In the power peak cut device according to the present invention, the storage battery is a lithium ion battery, and the control means is set to a state in which the storage battery is fully charged immediately before the preset time when the received power is predicted to reach a peak. Preferably, the storage battery is charged by driving the bidirectional inverter.

  In this case, the overall efficiency can be improved by using a lithium ion battery with high charge / discharge efficiency as the storage battery. By the way, if a lithium ion battery is left in a fully charged state (high potential state) for a long time, the rate at which the electrolytic solution undergoes electrolysis increases, and the deterioration is promoted. However, in the power peak cut device according to the present invention, charging is performed so that the lithium ion pond is fully charged in accordance with the time when the load power consumption (received power) is predicted to reach a peak (immediately before the start of discharge). Is done. Therefore, it is possible to improve the life by suppressing the deterioration of the lithium ion battery.

  In the power peak cut device according to the present invention, the rated output of the bidirectional inverter is preferably 2 to 10 kW.

  If it does in this way, the string containing a bidirectional inverter and a storage battery can be reduced in size. As a result, it is possible to achieve a distributed arrangement of the strings, suppression of excessive investment of expensive storage batteries, and the like.

  In the power peak cut device according to the present invention, it is preferable that a bidirectional inverter and a storage battery can be added according to the amount of power to be cut.

  If it does in this way, according to the electric energy which wants to cut, the number of strings including a bidirectional inverter and a storage battery can be changed. Therefore, the user can have an optimum device configuration in consideration of the cost of the string including the relatively expensive storage battery.

  The power peak cut device according to the present invention is attached to each of a plurality of power systems supplying power to each of a plurality of loads, a plurality of bidirectional inverters and storage batteries connected to each of the plurality of power systems, and each of the plurality of power systems. A plurality of second measuring means for measuring the power supplied by each power system, and the control means receives the received power measured by the measuring means and the plurality of power systems measured by the second measuring means. It is preferable to determine a bidirectional inverter to be driven based on each power value.

  If it does in this way, based on the electric power of each of a plurality of electric power systems, for example, the electric power of a storage battery can be supplied in order from the electric power system with the largest power consumption. Therefore, when performing peak cut, it becomes possible to supply electric power from a storage battery more efficiently.

  A power peak cut device according to the present invention has a grid interconnection function, and includes a power conditioner connected to a power system that supplies generated power to a load, and a private power generation device connected to the power conditioner. It is preferable to further provide.

  If it does in this way, it will become possible to apply the power peak cut device concerning the present invention also to the high voltage power receiving equipment to which a private power generation device (for example, a solar cell etc.) is connected. In this way, it is also possible to perform cooperative control such as supplying electric power generated by the private power generator to the storage battery.

  In the power peak cut device according to the present invention, when the instantaneous power value of the received power exceeds a predetermined power value, the control means drives the bidirectional inverter to supply the power of the storage battery to the power system. During the driving of the bidirectional inverter, it is preferable to stop the driving of the bidirectional inverter when the moving average value of the received power for each predetermined time falls below the predetermined power value.

  In this way, it is possible to perform control (peak cut) so that the average power value for a certain time does not exceed the predetermined power value. In particular, the accuracy of peak cut can be improved even when the load fluctuation period is short.

  Further, in the power peak cut device according to the present invention, when the average value of the received power for each predetermined time exceeds the predetermined power value, the control means drives the bi-directional inverter to supply the power of the storage battery to the power system. During the driving of the bidirectional inverter, it is preferable to stop the driving of the bidirectional inverter when the moving average value of the received power for every predetermined time falls below the predetermined power value.

  Even in this case, it is possible to perform control (peak cut) so that the average power value for a predetermined time does not exceed the predetermined power value. In particular, the control can be simplified and the processing load can be reduced.

  Furthermore, in the power peak cut device according to the present invention, when the instantaneous power value of the received power exceeds a predetermined power value, the control means drives the bidirectional inverter to supply the power of the storage battery to the power system, During the driving of the bidirectional inverter, it is preferable to stop the driving of the bidirectional inverter when the instantaneous power value of the received power falls below a predetermined power value.

  In this way, it is possible to perform control (peak cut) so that the received power does not exceed the maximum power value including predetermined reactive power.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to aim at the improvement of energy efficiency while preventing the fall of the business efficiency at the time of peak cut, without enlarging a storage battery.

It is a block diagram which shows the structure of the electric power peak cut apparatus which concerns on 1st Embodiment. It is a figure which shows an example of the electric power usage condition of a day, and a demand value. It is a flowchart which shows the basic control flow of charging / discharging by the electric power peak cut apparatus which concerns on 1st Embodiment. 6 is a flowchart illustrating a processing procedure of peak cut processing according to the first embodiment. It is a figure which shows the total value of the supplied power from the lithium ion battery in the peak cut process which concerns on Example 1, received power, and supplied power and received power. It is a figure which shows the reduction result of the demand value by the peak cut process which concerns on Example 1. FIG. It is a figure which shows the reduction result of the demand value by the peak cut process which concerns on Example 1. FIG. 12 is a flowchart illustrating a processing procedure of peak cut processing according to the second embodiment. It is a figure which shows the average value for every 5 minutes of the supplied value from a lithium ion battery in the peak cut process which concerns on Example 2, received power, the total value of supplied power and received power, and a total value. It is a figure which shows the reduction result of the demand value by the peak cut process which concerns on Example 2. FIG. It is a figure which shows the reduction result of the demand value by the peak cut process which concerns on Example 2. FIG. 12 is a flowchart illustrating a processing procedure of peak cut processing according to the third embodiment. It is a figure which shows the total value of the supplied electric power from a lithium ion battery in the peak cut process which concerns on Example 3, received electric power, and supplied electric power and received electric power. It is a figure which shows charge operation when the charge process which concerns on Example 4 is performed. It is a figure which shows the charging operation when the charge process which concerns on Example 5 is performed. It is a figure which shows charge operation when the charge process which concerns on Example 6 is performed. It is a figure which shows the charging operation when the charging process which concerns on Example 7 is performed. It is a block diagram which shows the structure of the electric power peak cut apparatus which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the electric power peak cut apparatus which concerns on 3rd Embodiment. It is a block diagram which shows the structure of the electric power peak cut apparatus which concerns on 4th Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Moreover, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

[First Embodiment]
First, the configuration of the power peak cutting device 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a power peak cutting device 1 and a high-voltage power receiving facility 5 to which the power peak cutting device 1 is applied. Here, the case where the power peak cutting device 1 is applied to a high voltage power receiving facility 5 owned by a customer of a high voltage power receiving contract such as an office or a factory will be described as an example.

  The high-voltage power receiving facility 5 is a facility for a customer to receive power from a commercial power system developed by an electric power company. In the high-voltage power receiving facility 5 illustrated in FIG. 1, the drawn commercial power system includes a DS (Disconnecting Switch) 21, a VCT (Voltage Current and Transformer) 22, an OCR (Over). -Current Relay (overcurrent relay) 23 and a VCB (vacuum circuit breaker) 24 are connected to the bus 25. The VCT 22 is connected to a WH (Watt-hour meter) 26 that measures received power and outputs a pulse signal corresponding to the received power.

  The bus 25 is supplied with electric power stepped down by a Tr (Transformer) 28 connected via an LBS (AC Load Break Switch: High Voltage AC Load Switch) 26 to a load (for example, a light, an OA device, etc.). Three systems of single-phase three-wire (1φ3W) power systems (single-phase lamp lines) 32, 33, and 34 to be supplied are connected.

  Similarly, the bus 25 is loaded with electric power stepped down by a Tr (Transformer) 29 connected through an LBS (AC Load Break Switch) 27 (for example, a compressor, a refrigerator). Three-phase three-wire (3φ3W) power systems (three-phase power lines) 35, 36, and 37 that are supplied to an air conditioner or the like are connected.

  The power peak cut device 1 mainly includes a pulse detector 11, a CT sensor 12, a bidirectional inverter 13, a storage battery 15, a system controller 17, and the like.

  The pulse detector 11 detects a pulse signal (that is, received power) output from the WH (watt-hour meter) 26 described above. That is, the pulse detector 11 functions as a measurement unit described in the claims. The pulse detector 11 is connected to the system controller 17, and the detected pulse signal is output to the system controller 17.

  The CT sensor 12 is attached to the above-described three-phase three-wire power system 37 and detects the value of the current flowing through the power system (that is, the power value supplied to the load). That is, the CT sensor 12 functions as a second measuring unit described in the claims. The CT sensor 12 is connected to the system controller 17, and the detected current value (power value) is output to the system controller 17. For example, a CT / ZCT integrated type may be used as the CT sensor 12.

  The bidirectional inverter 13 converts AC power of 50 Hz / 60 Hz into DC power, converts DC power output from the lithium ion battery 15 into AC power, and is connected to the grid (voltage and frequency conversion or power failure) This is a power conversion device that can be operated under the protection coordination. As described above, the bidirectional inverter 13 has a grid connection function, and is connected to a three-phase three-wire power system 37 that supplies received power to a load. Here, the rated output of the bidirectional inverter 13 is preferably 2 to 10 kW. In the present embodiment, the rated output is 5 kW.

  The inverter controller 14 drives the bidirectional inverter 13 based on a control signal (information) from the system controller 17. The system controller 17 and the inverter controller 14 are connected to each other via a communication line 18 such as a CAN (Controller Area Network) or RS485, for example.

  The storage battery 15 is connected to the bidirectional inverter 13 and is charged with commercial power via the bidirectional inverter 13, while discharging the charged power and supplying power to the load. As the storage battery 15, a lithium ion battery having high energy density and high charge / discharge efficiency is preferably used. The state of the lithium ion battery 15, for example, SOC (State Of Charge), voltage, temperature, and the like are monitored by a BCU (Battery Control Unit) 16.

  The BCU 16 outputs a charge request to the system controller 17 when the amount of charge (SOC) of the lithium ion battery 15 is insufficient. On the other hand, when the charge amount is sufficient, information indicating that discharging is possible is output to the system controller 17. The system controller 17 and the BCU 16 are connected to each other via the communication line 18 described above.

  The system controller 17 includes a CPU that performs calculations, a ROM that stores programs for causing the CPU to execute each process, a RAM that stores various data such as calculation results, a backup RAM that holds stored contents, and an input / output It has an I / F or the like. The system controller 17 controls the timing of discharging (power feeding) and the timing of charging (power receiving) of the lithium ion battery 15. More specifically, the system controller 17 determines the average power value for a predetermined time (30 minutes) based on the received power measured by the pulse detector 11 and the power value of the power system 37 detected by the CT sensor 12. However, the bidirectional inverter 13 is driven and controlled so as not to exceed a predetermined power value determined in advance (details will be described later). At that time (when power is supplied from the lithium ion battery 15 to the power system 37), the system controller 17 operates the bi-directional inverter at the rated output (on / off control). That is, the system controller 17 functions as a control unit described in the claims.

  On the other hand, the system controller 17 sets the lithium ion battery 15 in a fully charged state (maximum capacity) immediately before the preset time (immediately before demand) when the load power consumption (received power) is predicted to reach a peak. Thus, the bidirectional inverter 13 is driven and controlled (charge control) to charge the lithium ion battery 15.

  Here, FIG. 2 shows an example of the daily power usage situation and demand value of the office. More specifically, FIG. 2 shows daily changes in power consumption and demand value (30-minute average value of power consumption) measured in 1 minute units in a certain office. The horizontal axis in FIG. 2 is time, and the vertical axis is power (kW). In FIG. 2, the power consumption per minute is indicated by a thick solid line, and the average value of power consumption for 30 minutes is indicated by a thin solid line. The maximum demand value in the office illustrated in FIG. 2 was 37 (kW).

  By the way, the active power P is obtained by integrating instantaneous power, which is a product of instantaneous values (e (t), i (t)) of voltage and current, and averaging them over one period T. The demand value measured by the electric power company is calculated as an average value of power consumption for 30 minutes, and the maximum demand value for the past 11 months becomes the contract electric power charge (basic charge) with the electric power company for the next year. Therefore, the system controller 17 drives and controls the bidirectional inverter 13 so that the average power value for 30 minutes does not exceed a predetermined power value (for example, 35 kW).

  Next, the operation of the power peak cutting device 1 will be described with reference to FIG. FIG. 3 is a flowchart showing a basic control flow of charge and discharge by the power peak cut device 1. This process is repeatedly executed by the system controller 17 at a predetermined timing.

  First, in step S100, the number of pulses (that is, received power) detected by the pulse detector 11 is read. In the subsequent step S102, it is determined whether or not a request for charging the lithium ion battery 15 is output. If a charge request is output, the process proceeds to step S104. On the other hand, when the charge request is not output, the process proceeds to step S122.

  In step S104, it is determined whether or not the activation condition (reception power value and / or set time, etc.) of the bidirectional inverter 13 is satisfied. Here, if the activation condition is satisfied, the process proceeds to step S106. On the other hand, when the activation condition is not satisfied, the process is temporarily exited.

  In step S106, the current value (power value) of the power system 37 detected by the CT sensor 12 is read, and the load (power consumption) of the power system 37 is acquired. Here, when the CT sensor 12 is attached to a plurality of power systems, it is determined which system has a small load (power consumption). Then, based on the detection value of the CT sensor 12, it is determined from which system power for charging the lithium ion battery 15 is acquired.

  In subsequent step S108, various relays are turned on (connected), and the bidirectional inverter 13 is activated.

  Next, in step S110, a determination is made as to whether or not the received power value is less than or equal to a charging (power receiving) start threshold value. If the received power value is less than or equal to the charging start threshold value, the process proceeds to step S112. On the other hand, when the charging power value is larger than the charging start threshold, the process is temporarily exited.

  In step S112, the bidirectional inverter 13 is driven, power is received from the power system 37, and the lithium ion battery 15 is charged.

  Subsequently, in step S114, a determination is made as to whether or not the received power value is less than or equal to the charge stop threshold value. If the received power value is larger than the charge stop threshold value, the process proceeds to step S118. On the other hand, when the received power value is less than or equal to the charge stop threshold value, the process proceeds to step S116.

  In step S116, a determination is made as to whether charging of the lithium ion battery 15 has been completed (whether the SOC has reached a target value). Here, when the charging of the lithium ion battery 15 is completed, the process proceeds to step S118. On the other hand, when the charging of the lithium ion battery 15 is not completed, the process proceeds to step S114 described above, and the charging of the lithium ion battery 15 is continuously performed.

  In step S118, the power reception by the bidirectional inverter 13 is terminated, and the charging of the lithium ion battery 15 is terminated. In step S120, the bidirectional inverter 13 is stopped.

  Next, in step S122, it is determined whether or not the lithium ion battery 13 can be discharged. If the discharge is possible, the process proceeds to step S124. On the other hand, when the discharge cannot be performed, the process is temporarily exited.

  In step S124, a determination is made as to whether or not a start condition (conditions such as received power and / or set time) of the bidirectional inverter 13 is satisfied. Here, if the activation condition is satisfied, the process proceeds to step S126. On the other hand, when the activation condition is not satisfied, the process is temporarily exited.

  In step S126, the current value (power value) of the power system 37 detected by the CT sensor 12 is read, and the load (power consumption) of the power system 37 is acquired. Here, when the CT sensor 12 is attached to a plurality of power systems, it is determined which system has a large load (power consumption). Based on the detection value of the CT sensor 12, it is determined which system the power of the lithium ion battery 15 is supplied to.

  In subsequent step S128, various relays are turned on (connected), and the bidirectional inverter 13 is activated.

  Next, in step S130, a determination is made as to whether the received power value is greater than or equal to a power supply (discharge) start threshold value. If the received power value is greater than or equal to the power supply start threshold value, the process proceeds to step S132. On the other hand, when the received power value is smaller than the power supply start threshold value, the process is temporarily exited.

  In step S132, the bidirectional inverter 13 is driven, and the power of the lithium ion battery 15 is supplied (powered) to the power system 37.

  Subsequently, in step S134, a determination is made as to whether or not the received power value is greater than or equal to the power supply (discharge) stop threshold value. If the received power value is smaller than the power supply stop threshold, the process proceeds to step S138. On the other hand, when the received power value is greater than or equal to the power supply stop threshold, the process proceeds to step S136.

  In step S136, a determination is made as to whether or not the SOC (charge amount) of the lithium ion battery 15 has decreased below a predetermined value. Here, when the SOC of the lithium ion battery 15 has decreased to a predetermined value or less, the process proceeds to step S138. On the other hand, when the SOC of the lithium ion battery 15 has not yet decreased, the process proceeds to step S134 described above, and the power supply from the lithium ion battery 15 is continuously executed.

  In step S138, the power supply by the bidirectional inverter 13 is finished, and the discharge (power supply) of the lithium ion battery 15 is finished. In step S140, the bidirectional inverter 13 is stopped.

  Next, three (Examples 1 to 3) peak cutting methods will be described with reference to FIGS. 4, 8, and 12. Here, FIG. 4 is a flowchart illustrating the processing procedure of the peak cut processing according to the first embodiment (example of demand value reduction by instantaneous power value). FIG. 8 is a flowchart illustrating the processing procedure of the peak cut processing according to the second embodiment (an example of reducing the demand value based on the integrated power value). FIG. 12 is a flowchart illustrating the processing procedure of the peak cut processing according to the third embodiment (an example of reduction of the instantaneous maximum power value). The flowcharts shown in FIGS. 4, 8, and 12 correspond to the discharge process (peak cut process) in the basic charge / discharge control flow (shown in FIG. 3) described above, that is, steps S130 to S134. .

Example 1
First, the peak cut processing according to the first embodiment will be described with reference to FIG. Here, the threshold value is set on the assumption that a pulse signal of 50,000 (pulse / kWh) is output from the WH 26 (detected by the pulse detector 11). For example, when the target power value is 35 (kW), since 1 (kW) = 50,000 / 3,600 = 13.88 pulses, a threshold of 35 × 13.88 = 486 (pulse) is set. Value.

  In step S200, the number of pulses detected by the pulse detector 11 is counted. Next, in step S202, whether or not the number of pulses counted in step S200 is greater than or equal to a predetermined value (for example, 486 pulses: equivalent to 35 kW), that is, the instantaneous power value of received power is greater than or equal to a predetermined value (35 kW). A determination is made whether or not. If the number of pulses is equal to or greater than the predetermined value, the process proceeds to step S204. On the other hand, when the number of pulses is less than the predetermined value, the process proceeds to step S206.

  In step S204, the bidirectional inverter 13 is driven, and the power of the lithium ion battery 15 is supplied (powered) to the power system 37. Thereafter, the process proceeds to step S208. On the other hand, in step S206, the power supply by the bidirectional inverter 13 is finished, and the discharge (power supply) of the lithium ion battery 15 is finished. Then, the bidirectional inverter 13 is stopped. Thereafter, the process is temporarily exited.

  In step S208, for example, whether the moving average value of the number of pulses every 5 minutes is equal to or greater than a predetermined value (for example, 486 pulses: equivalent to 35 kW), that is, the moving average value of the received power every 5 minutes is a predetermined value (35 kW). ) A determination is made as to whether or not this is the case. If the moving average value of the number of pulses every 5 minutes is greater than or equal to the predetermined value, the process proceeds to step S200, and the processes after step S200 described above are repeatedly executed.

  On the other hand, when the moving average value of the number of pulses every 5 minutes is less than the predetermined value, the power supply by the bidirectional inverter 13 is terminated in step S206, and the discharge (power supply) of the lithium ion battery 15 is terminated. Then, the bidirectional inverter 13 is stopped. Thereafter, the process is temporarily exited.

  Here, the peak cut result (demand value reduction result) by the peak cut processing according to the first embodiment is shown in FIGS. FIG. 5 shows the supplied power from the lithium ion battery 15, the received power, and the total value of the supplied power and the received power from the lithium ion battery 15 (that is, the received power when there is no power supply from the lithium ion battery 15. ) Respectively. In addition, the horizontal axis of FIG. 5 is time, and a vertical axis | shaft is electric power (kW). In FIG. 5, the received power is indicated by a thin solid line, the total value is indicated by a thick solid line, and the supplied power is indicated by an intermediate solid line. As shown in FIG. 5, when the instantaneous power value calculated from the pulse signal is 35 kW or more, 5 kW constant power is supplied (discharged) from the bidirectional inverter 13 (lithium ion battery 15), and 5 minutes. FIG. 6 shows a change in demand value (reduction result) in the case where control is performed so that power supply is stopped when the moving average value for each time falls below 35 kW.

  FIG. 6 is a diagram illustrating a demand value reduction result by the peak cut processing (instantaneous power value control) according to the first embodiment. In FIG. 6, the 30-minute average value (demand value) of the received power is indicated by a thin solid line, and the 30-minute average value (demand value) of the total value is indicated by a thick solid line. FIG. 7 collectively shows the graph of FIG. 5 and the graph of FIG. In FIG. 7, the received power is a thin solid line, the 30-minute average value (demand value) of the received power is a thin broken line, the total value is a thick solid line, and the 30-minute average value (demand value) of the total value is a thick broken line. The power supply is shown by the solid line in the middle.

  As shown in FIGS. 6 and 7, according to this embodiment, when the threshold value is 35.000 (kW) and the battery power at the time of peak cut is 5.000 (kW), 3.000 It was confirmed that the demand peak value can be reduced by 5.4% with a battery capacity of (kWh), that is, the peak power value can be suppressed to 34.655 (kW). The time taken for the above moving average is not limited to 5 minutes. As the time is shortened, the followability to the control target value is improved.

(Example 2)
Next, a peak cut process according to the second embodiment will be described with reference to FIG. Since the threshold value (number of pulses) setting method is as described above, detailed description thereof is omitted here.

  In step S300, the number of pulses detected by the pulse detector 11 is counted. Next, in step S302, whether or not the 5-minute average value of the number of pulses counted in step S300 is equal to or greater than a predetermined value (for example, 486 pulses: equivalent to 35 kW), that is, the received power average value for 5 minutes is A determination is made as to whether or not it is equal to or greater than a predetermined value (35 kW). Here, if the average value of the number of pulses is equal to or greater than the predetermined value, the process proceeds to step S304. On the other hand, when the average value of the number of pulses is less than the predetermined value, the process proceeds to step S306.

  In step S304, the bidirectional inverter 13 is driven, and the power of the lithium ion battery 15 is supplied (powered) to the power system 37. Thereafter, the process proceeds to step S300, and the processes after step S300 described above are repeatedly executed.

  On the other hand, in step S306, the power supply by the bidirectional inverter 13 is finished, and the discharge (power supply) of the lithium ion battery 15 is finished. Then, the bidirectional inverter 13 is stopped. Thereafter, the process is temporarily exited.

  Here, the peak cut results (demand value reduction results) by the peak cut processing according to the second embodiment are shown in FIGS. FIG. 9 shows the power supplied from the lithium ion battery 15, the received power, the total value of the power supplied from the lithium ion battery 15 and the power received (that is, the power received when power is not supplied from the lithium ion battery 15), and It is a figure which shows the average value for every 5 minutes of a total value, respectively. In addition, the horizontal axis | shaft of FIG. 9 is time, and a vertical axis | shaft is electric power (kW). In FIG. 9, the received power is indicated by a thin solid line, the total value is indicated by a thick solid line, the average value of the total value every 5 minutes is indicated by a thick broken line, and the supplied power is indicated by an intermediate solid line. As shown in FIG. 9, when the average value every 5 minutes calculated from the pulse signal becomes 35 kW or more, the bi-directional inverter 13 (lithium ion battery 15) supplies (discharges) a constant power of 5 kW. FIG. 10 shows a change in demand value (reduction result) when control is performed so that power supply is stopped when the moving average value every 5 minutes falls below 35 kW.

  FIG. 10 is a diagram illustrating a demand value reduction result by peak cut processing (average power value control every 5 minutes) according to the second embodiment. In FIG. 10, the 30-minute average value (demand value) of the received power is indicated by a thin solid line, the total value is indicated by a thick solid line, and the average value of the total value every 5 minutes is indicated by a thick broken line. FIG. 11 collectively shows the graph of FIG. 9 and the graph of FIG. In FIG. 11, the received power is a thin solid line, the 30-minute average value (demand value) of the received power is a thin broken line, the total value is a thick solid line, and the 30-minute average value (demand value) of the total value is a thick broken line. The power supply is shown by the solid line in the middle.

  As shown in FIGS. 10 and 11, according to this embodiment, when the threshold value is 35.000 (kW) and the battery power at the time of peak cut is 5.000 (kW), 3.083 kWh It was confirmed that the demand peak value can be reduced by 5.4% with the battery capacity of, that is, the peak power value can be suppressed to 34.655 (kW).

(Example 3)
Next, a peak cut process according to the third embodiment will be described with reference to FIG. Since the threshold value (number of pulses) setting method is as described above, detailed description thereof is omitted here.

  In step S400, the number of pulses detected by the pulse detector 11 is counted. Next, in step S402, whether or not the number of pulses counted in step S400 is greater than or equal to a predetermined value (for example, 486 pulses: equivalent to 35 kW), that is, whether the instantaneous value of received power is greater than or equal to a predetermined value (35 kW). A determination is made as to whether or not. Here, when the number of pulses (instantaneous value of received power) is equal to or greater than a predetermined value, the process proceeds to step S404. On the other hand, when the number of pulses is less than the predetermined value, the process proceeds to step S406.

  In step S404, the bidirectional inverter 13 is driven, and the power of the lithium ion battery 15 is supplied (powered) to the power system 37. Thereafter, the process proceeds to step S400, and the processes after step S400 described above are repeatedly executed.

  On the other hand, in step S406, the power supply by the bidirectional inverter 13 is finished, and the discharge (power supply) of the lithium ion battery 15 is finished. Then, the bidirectional inverter 13 is stopped. Thereafter, the process is temporarily exited.

  Here, the peak cut result by the peak cut processing according to Example 3 is shown in FIG. FIG. 13 shows the supplied power from the lithium ion battery 15, the received power, and the total value of the supplied power and the received power from the lithium ion battery 15 (that is, the received power when no power is supplied from the lithium ion battery 15). FIG. In FIG. 13, the horizontal axis represents time, and the vertical axis represents power (kW). In FIG. 13, the received power is indicated by a thin solid line, the supplied power is indicated by an intermediate solid line, and the total value is indicated by a thick solid line. As shown in FIG. 13, when the instantaneous power value calculated from the pulse signal becomes 35 kW or more, a constant power of 5 kW is supplied (discharged) from the bidirectional inverter 13 (lithium ion battery 15) for 1 minute. It was confirmed that the power value of the maximum 38.3 kW can be reduced by 13%, that is, 33.321 kW, when the power supply is controlled to stop when the subsequent power value falls below 35 kW.

  Next, four charging methods (Examples 4 to 7) will be described with reference to FIGS. 14, 15, 16, and 17.

Example 4
The first method is to receive power (charge) when the received power becomes 30 (kW) or less, and to stop charging when the moving average value every 5 minutes exceeds 30 (kW), for example. It is. Here, FIG. 14 shows a charging operation when the charging process (charging control method) according to the fourth embodiment is executed. The horizontal axis in FIG. 14 is time, and the vertical axis is power (kW). In FIG. 14, the 30-minute average value (demand value) of received power is indicated by a thin solid line, the power supplied from the lithium ion battery 15 is indicated by an intermediate solid line, and the 30-minute average value (demand value) of the total value is indicated by a thick solid line. Respectively. In the example (charge pattern) shown in FIG. 14, after the maximum demand value decreases (18: 10-18: 30), the lithium ion battery 15 is charged until the SOC reaches 50%, and the next day power supply (discharge) ) Fully charged immediately before (8: 00-8: 15). In this way, the life of the lithium ion battery 15 can be improved.

(Example 5)
The second method is a control method in which, in addition to the charging pattern described above, power is received (charged) even during a time zone where the power rate is low, that is, charging is performed using midnight power. Here, FIG. 15 shows a charging operation when the charging process (charging control method) according to the fifth embodiment is executed. The horizontal axis in FIG. 15 is time, and the vertical axis is power (kW). In FIG. 15, the 30-minute average value (demand value) of the received power is indicated by a thin solid line, the power supplied from the lithium ion battery 15 is indicated by an intermediate solid line, and the 30-minute average value (demand value) of the total value is indicated by a thick solid line. Respectively. In the example (charge pattern) shown in FIG. 15, the nighttime power (5: 30-5: 40) is used to charge the lithium ion battery 15 to a predetermined SOC (for example, 80%), and then power supply (discharge) is performed. The battery was fully charged immediately before (8: 00-8: 05). In this way, the life of the lithium ion battery 15 can be improved.

(Example 6)
The third method is a control method in which the lithium ion battery 15 is charged to SOC 80% after feeding, and is fully charged immediately before feeding (discharging) the next day. Here, FIG. 16 shows a charging operation when the charging process (charging control method) according to the sixth embodiment is executed. The horizontal axis in FIG. 16 is time, and the vertical axis is power (kW). In FIG. 16, the 30-minute average value (demand value) of received power is indicated by a thin solid line, the power supplied from the lithium ion battery 15 is indicated by an intermediate solid line, and the 30-minute average value (demand value) of the total value is indicated by a thick solid line. Respectively. In the example (charge pattern) shown in FIG. 16, after power feeding (18: 10-18: 40), the lithium ion battery 15 is charged to about 80% SOC, the emergency power is stored, and power feeding on the next day ( The battery was fully charged immediately before (discharged) (8: 00-8: 05). If it does in this way, the lifetime improvement of the lithium ion battery 15 and the electric power storage provided at the time of emergency can be made compatible.

(Example 7)
The fourth method is a control method that compensates for power supplied (discharged) in the morning by receiving power (charging) even during a time period when power during lunch breaks decreases. Here, FIG. 17 shows a charging operation when the charging process (charging control method) according to the seventh embodiment is executed. The horizontal axis in FIG. 17 is time, and the vertical axis is power (kW). In FIG. 17, the 30-minute average value (demand value) of the received power is indicated by a thin solid line, the power supplied from the lithium ion battery 15 is indicated by an intermediate solid line, and the 30-minute average value (demand value) of the total value is indicated by a thick solid line. Respectively. In the example (charge pattern) shown in FIG. 17, charging was also performed at low power consumption (12: 00-12: 10) during the lunch break. In this example, the electric energy consumed in the morning (0.83 kWh) could be charged during the lunch break. In this way, the equipment capacity of the lithium ion battery 15 can be reduced.

  As described above in detail, according to the present embodiment, the bidirectional inverter 13 is drive-controlled so that the average power value for a predetermined time does not exceed a predetermined power value (for example, 35 kW). That is, power is supplied from the lithium ion battery 15 to the power system 37 to which the load is connected via the bidirectional inverter 13. Therefore, by supplying the electric power stored in the lithium ion battery 15 at the time of maximum demand, the peak of electric power can be cut without providing a load use restriction. At that time, the bidirectional inverter 13 is operated at the rated output (maximum efficiency) with the highest power conversion efficiency, and power is supplied to the power system 37. Here, in the present embodiment, since the average power value for a certain time (30 minutes) is controlled (peak cut) so as not to exceed a predetermined power value (for example, 35 kW), power more than necessary is temporarily supplied. Even if it is done, the subsequent stop time of the bidirectional inverter 13 can be lengthened, and the efficiency can be improved comprehensively when converged to the target peak cut power value. Further, it is not necessary to increase the capacity of the lithium ion battery 15 more than necessary. As a result, according to the present embodiment, it is possible to prevent a reduction in business efficiency at the time of peak cut and improve energy efficiency without increasing the size of the lithium ion battery 15.

  In addition, according to the present embodiment, the bidirectional inverter 13 is connected to the three-phase power line system, and it is possible to cut the peak of a load that has a large power consumption such as air conditioning and is likely to have a peak. Can be further enhanced. Further, according to the present embodiment, the bidirectional inverter 13 is connected after being stepped down by the Tr 29, and the power of the lithium ion battery 13 is supplied. That is, since electric power is injected closer to the actual load, transmission loss of electric power can be suppressed and energy efficiency can be further increased.

  According to this embodiment, the overall efficiency can be improved by using the lithium ion battery 15 having a high charge / discharge efficiency (about 95%) as the storage battery. In addition, according to the present embodiment, the lithium ion battery 15 is charged so as to be in a fully charged state at the time when the power consumption (received power) of the load is predicted to reach a peak (immediately before the start of discharge). Therefore, the life of the lithium ion battery 15 can be improved.

  According to this embodiment (Example 1), when the instantaneous power value of the received power exceeds a predetermined power value, the bidirectional inverter 13 is driven and the power of the lithium ion battery 15 is supplied to the power system 37. When the moving average value of the received power for each predetermined time falls below the predetermined power value, the driving of the bidirectional inverter 13 is stopped, so that the average power value for a predetermined time (30 minutes) is the predetermined power value. It is possible to control (peak cut) so as not to exceed.

  Further, according to the present embodiment (Example 2), when the average value of the received power for each predetermined time exceeds the predetermined power value, the bidirectional inverter 13 is driven, and the power of the lithium ion battery 15 is the power. Since the driving of the bidirectional inverter 13 is stopped when the moving average value of the received power that is supplied to the system 37 and falls every predetermined time is lower than the predetermined power value, the average power value for a certain time (30 minutes) is reduced. It is possible to control (peak cut) so as not to exceed a predetermined power value. Further, according to the present embodiment (Example 2), in particular, the control can be further simplified and the processing load can be reduced.

  Furthermore, according to the present embodiment (Example 3), when the instantaneous power value of the received power exceeds a predetermined power value, the bidirectional inverter 13 is driven and the power of the lithium ion battery 15 is changed to the power system 37. When the instantaneous power value of the received power falls below a predetermined power value, the bi-directional inverter 13 is stopped from driving so that the received power does not exceed the predetermined power value (peak cut). It becomes possible to do.

[Second Embodiment]
In the first embodiment described above, one bidirectional inverter 13 and lithium ion battery 15 (hereinafter also referred to as “string”) are used. However, two or more strings, that is, bidirectional inverters, are used depending on the amount of power to be peak cut. 13 and the lithium ion battery 15 may be provided. Then, next, the structure of the electric power peak cut apparatus 2 which concerns on 2nd Embodiment is demonstrated using FIG. FIG. 18 is a block diagram illustrating a configuration of the power peak cut device 2. In FIG. 18, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals.

  In addition to the configuration of the power peak cut device 1 described above, the power peak cut device 2 further includes two strings, that is, two bidirectional inverters 13 and 13 and two lithium ion batteries 15 and 15. It differs from the electric power peak cut device 1 mentioned above. All the bidirectional inverters 13 and the lithium ion batteries 15 are connected to the same power system 37. The other configuration is the same as or similar to that of the power peak cutting device 1 described above, and thus detailed description thereof is omitted here. The number of strings (two-way inverter 13 and lithium ion battery 15) to be added is not limited to two, and the number of extension can be set according to the maximum demand value of the consumer.

  According to this embodiment, the number of strings including the bidirectional inverter 13 and the lithium ion battery 15 can be changed according to the amount of power to be cut. Therefore, the user can make an optimum device configuration in consideration of the cost of the string including the relatively expensive lithium ion battery 15 and the like. In addition, since each string (bidirectional inverter 13 and lithium ion battery 15) can be reduced in size in this way, it is possible to reduce the excessive investment of the expensive lithium ion battery 15 and the like. It is also possible to plan. In addition, maintenance and inspection can be performed without stopping the entire system.

[Third Embodiment]
In the second embodiment described above, three strings (bidirectional inverter 13 and lithium ion battery 15) are connected to one power system 37, but may be configured to be connected to separate power systems. . Then, next, the structure of the power peak cut device 3 which concerns on 3rd Embodiment is demonstrated using FIG. FIG. 19 is a block diagram illustrating a configuration of the power peak cutting device 3. In FIG. 19, the same or equivalent components as those in the second embodiment are denoted by the same reference numerals.

  The power peak cut device 3 differs from the power peak cut device 2 described above in that three strings (bidirectional inverter 13 and lithium ion battery 15) are connected to separate power systems 35, 36, and 37, respectively. Is different. Further, the above-described power peak is configured such that the CT sensor 12 is attached to each of the power systems 35, 36, and 37, and the power of each of the power systems 35, 36, and 37 can be measured. Different from the cutting device 2.

  The system controller 17 of the present embodiment is configured to drive strings based on the received power measured by the pulse detector 11 and the powers of the plurality of power systems 35, 36, and 37 measured by the CT sensor 12 (both The direction inverter 13 and the lithium ion battery 15) are determined. More specifically, the system controller 17 determines which system has a large load (power consumption) based on the detection value of the CT sensor 12 and determines a system for supplying the power of the lithium ion battery 15. Further, the system controller 17 determines which system load (power consumption) is small based on the detection value of the CT sensor 12, and determines a system for acquiring power for charging the lithium ion battery 15. Other configurations are the same as or similar to those of the power peak cut device 2 described above, and thus detailed description thereof is omitted here.

  Also according to this embodiment, the number of strings including the bidirectional inverter 13 and the lithium ion battery 15 can be changed according to the amount of power to be cut. Therefore, the user can make an optimum device configuration in consideration of the cost of the string including the relatively expensive lithium ion battery 15 and the like. In addition, since each string (bidirectional inverter 13 and lithium ion battery 15) can be reduced in size in this way, it is possible to reduce the excessive investment of the expensive lithium ion battery 15 and the like. It is also possible to plan.

  Moreover, according to this embodiment, based on the electric power of each of the plurality of electric power systems 35, 36, 37, for example, the electric power of the lithium ion battery 15 can be supplied in order from the electric power system with the largest power consumption. Therefore, when performing peak cut, it becomes possible to supply electric power from the lithium ion battery 15 more efficiently.

[Fourth Embodiment]
In the third embodiment described above, the three bidirectional inverters 13 and the lithium ion battery 15 (string) are provided, but instead of the lithium ion battery 15, a private power generation device such as a solar power generation device is connected to the system. It can also be set as the structure to do. Then, next, the structure of the power peak cut device 4 which concerns on 4th Embodiment is demonstrated using FIG. FIG. 20 is a block diagram showing the configuration of the power peak cut device 4. In FIG. 20, the same or equivalent components as those in the third embodiment are denoted by the same reference numerals.

  The power peak cut device 4 further includes a power conditioner 40 and a solar cell 42 (in-house power generation device) connected to the power conditioner 40. The solar cell 42 generates electric power according to the amount of light (irradiation amount). The power conditioner 40 has a grid connection function, converts DC power from the solar battery 42 into AC power, and outputs the AC power to the power system 35. Other configurations are the same as or similar to those of the power peak cut device 3 described above, and thus detailed description thereof is omitted here.

  According to the present embodiment, the power peak cutting device 4 can be applied to the high-voltage power receiving equipment to which the solar cell 42 is connected. In addition, according to the present embodiment, it is possible to perform cooperative control such as supplying the power generated by the solar battery 42 to the lithium ion battery 15. Note that the private power generation device is not limited to the solar battery 42, and for example, a wind power generation device or a generator may be used.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above embodiment, the case where the power peak cut device 1 is applied to a high voltage power receiving facility (cubicle) owned by a customer of a high voltage power receiving contract such as a factory or an office has been described as an example. The apparatus 1 can also be applied to peak cut in a general household by making the bidirectional inverter 13 a single phase.

  Moreover, in the said embodiment, although the lithium ion battery was used as a storage battery, it can replace with a lithium ion battery and can also use a lead storage battery, a nickel hydrogen storage battery, a NaS (sodium sulfur) storage battery etc., for example.

  In the above embodiment, the bidirectional inverter 13 is connected after the voltage is dropped by the Tr 29. However, the bidirectional inverter 13 may be connected before the voltage is lowered by the Tr 29 (upstream side).

1, 2, 3, 4 Power peak cut device 5 High-voltage power receiving equipment 11 Pulse detector 12 CT sensor 13 Bidirectional inverter 14 Inverter controller 15 Lithium ion battery 16 BCU
17 System controller 32, 33, 34 Single-phase three-wire power system 35, 36, 37 Three-phase three-wire power system 40 Power conditioner 42 Solar cell

Claims (8)

Measuring means for measuring the received power received from the commercial power system;
The electric power receiving-and multiple power system for supplying a plurality of loads,
A plurality of bidirectional inverters each having a grid interconnection function and connected to each of the plurality of power systems ;
A plurality of storage batteries connected to each of the plurality of bidirectional inverters;
A plurality of second measuring means attached to each of the plurality of power systems and measuring the power supplied by each power system;
Control means for driving and controlling the bidirectional inverter so that an average power value for a predetermined time does not exceed a predetermined power value based on the received power measured by the measuring means;
The control means, when supplying power from the storage battery to the power system, the received power measured by the measurement means and the power values of the plurality of power systems measured by the second measurement means. based on, to determine the bi-directional inverter for driving the power peak shaving apparatus, characterized in that the OPERATION the bi-directional inverter. The storage battery is a lithium ion battery,
The control means drives and controls the bidirectional inverter so that the storage battery is fully charged immediately before a preset time when the received power is predicted to reach a peak, and charges the storage battery. The power peak cut device according to claim 1.   The power peak cut device according to claim 1, wherein the bidirectional inverter has a rated output of 2 to 10 kW.   The power peak cut device according to claim 3, wherein the bidirectional inverter and the storage battery can be added according to the amount of power to be cut. A power conditioner having a grid connection function and connected to a power system for supplying generated power to a load;
Power peak shaving apparatus according to any one of claims 1 to 4, further comprising a, a private power generation device connected to the power conditioner. The control means drives the bidirectional inverter when the instantaneous power value of the received power exceeds the predetermined power value, supplies the electric power of the storage battery to the power system, and drives the bidirectional inverter. during, when the moving average of each predetermined time of the received power is below said predetermined power value, to any one of claims 1 to 5, characterized in that stops driving of the bidirectional inverter The power peak cut device described. The control means drives the bidirectional inverter when the average value of the received power every predetermined time exceeds the predetermined power value, and supplies the electric power of the storage battery to the power system, the bidirectional power during inverter drive, when the moving average of each predetermined time of the received power is below said predetermined power value, claim 1-5, characterized in that stops driving of the bidirectional inverter The power peak cut device according to Item 1. The control means drives the bidirectional inverter when the instantaneous power value of the received power exceeds the predetermined power value, supplies the electric power of the storage battery to the power system, and drives the bidirectional inverter. The power peak according to any one of claims 1 to 5 , wherein when the instantaneous power value of the received power falls below the predetermined power value, the driving of the bidirectional inverter is stopped. Cutting equipment.

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