JP7806744B2 - power management device - Google Patents

Description

This disclosure relates to a power management device, and in particular to a power management device for a business that supplies power received from an electricity supplier to multiple consumers.

Self-dispatch has been practiced for some time. Self-dispatch is a transmission service provided by general electricity transmission and distribution companies when a company transmits electricity it has self-generated at a factory or other location to its own business premises in a remote location using the company's transmission and distribution network. Self-dispatch applies the "same time and equal amount of planned value" rule, which requires a simultaneous and equal amount of both power generation and demand. The pre-established power generation plan or demand plan must be matched to the actual power generation or demand results in 30-minute increments. If the plan and results do not match, an "imbalance fee" must be paid according to the amount (see, for example, Patent Document 1).

Similarly, for electricity supplied to retail electricity suppliers by power generation companies and general electricity transmission and distribution companies in order for the retail electricity suppliers to supply to consumers, the standard value of the planned amount of electricity supplied to the retail electricity suppliers for each 30-minute period must be matched with the actual value. An imbalance fee must be paid to the general electricity transmission and distribution company according to the amount of imbalance, which is the difference between this standard value and the actual value.

Japanese Patent Application Laid-Open No. 2020-058141

However, if a consumer has DSR (Demand Side Resources), which are energy resources (power generation equipment, power storage equipment, demand equipment) such as electric vehicles, power storage devices, or power generation devices connected below the consumer's receiving point, increases or decreases in the charging and discharging of the electric vehicles or power storage devices, or increases or decreases in power generation by the power generation devices, can prevent the planned amount of electricity supplied to the consumer from being met, and imbalance charges can be incurred.

This disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a power management device that can suppress imbalance charges.

The power management device disclosed herein is a power management device for a utility that supplies power received from a power supplier to multiple consumers. It is capable of controlling a power supply and demand adjustment system and includes a memory that stores a predetermined program and a processor that executes the predetermined program. By executing the predetermined program, the processor identifies a reference value, which is the total planned amount of power to be supplied to multiple consumers for each time slot. To receive the amount of power corresponding to the reference value from the supplier, the processor transmits the reference value to the supplier in advance before the time slot corresponding to the reference value arrives. The processor controls the adjustment system so that, within the range of the allowable increase and decrease amounts, the imbalance amount, which is the difference between the actual value, which is the total amount of power used by the multiple consumers, and the reference value becomes zero, eliminating the imbalance fee that the utility pays to the supplier for the imbalance amount. The allowable increase amount is the amount of power that can be added to the actual value by being used by the adjustment system. The allowable decrease amount is the amount of power that can be subtracted from the actual value by reducing usage by the adjustment system or by supplying power from the adjustment system to multiple consumers. By executing a predetermined program, the processor identifies a reference value that minimizes the imbalance fee for the imbalance amount in at least one frame included in a predetermined period.

With this configuration, when specifying a reference value that is the total planned amount of power to be supplied to multiple consumers for each time slot, the reference value is specified so that the imbalance fee for the imbalance amount in at least one slot included in a specified period is minimized. As a result, it is possible to provide a power management device that can suppress imbalance fees.

1 is a block diagram showing an outline of the configuration of a power management system according to an embodiment of the present invention; 10 is a flowchart showing the flow of a reference value-related process executed by the electricity retailer server in this embodiment. FIG. 10 is a diagram for explaining the specification of a reference value in this embodiment.

Embodiments of the present disclosure will now be described in detail with reference to the drawings. Note that identical or corresponding parts in the drawings will be designated by the same reference numerals, and their description will not be repeated.

Figure 1 is a block diagram showing an outline of the configuration of a power management system 1 according to this embodiment. Referring to Figure 1, thick solid lines with arrows indicate the flow of electricity, and thin solid and dashed lines with arrows indicate the flow of data. In the power management system 1, electricity generated by a power generation company 60 is consigned by an electricity transmission and distribution company 50 to consumers 20 who are retail customers of an electricity retailer 10 (e.g., a regional power company or a new power company) based on an agreement in accordance with the bidding results at a power exchange 40 (e.g., the Japan Electric Power Exchange).

The power generation company 60 has a power generation facility 610 that generates electricity and a power generation company server 600 that manages the power generation business. The power transmission and distribution company 50 has a power transmission and distribution facility 510 that transmits and distributes electricity and a power transmission and distribution company server 500 that manages the power transmission and distribution business. The power generation facility 610 and the power transmission and distribution facility 510 make up a power system (power grid). The power exchange 40 has a power exchange server 400 that manages power trading. The retail electricity company 10 has a retail electricity company server 100 that manages the retail electricity business.

The consumer 20 has a DSR 210, which includes at least one of demand facilities, power storage facilities, and power generation facilities that are energy resources connected below the power receiving point, and a HEMS (Home Energy Management System) 200 that manages the DSR 210. The aggregator 30 has an aggregator server 300. The aggregator server 300 controls and manages DERs (Distributed Energy Resources) 310, which include at least one of power generation facilities and power storage facilities that are energy resources directly connected to the DSR or the power grid.

The electricity retailer server 100 includes a processor 110, a memory 120, an input unit 130, an output unit 140, an auxiliary storage device 160, and a communication unit 190. The memory 120 includes RAM (Random Access Memory), ROM (Read Only Memory), and flash memory, and stores software such as programs executed by the electricity retailer server 100, as well as data to be processed. The auxiliary storage device 160 includes an HDD (Hard Disk Drive), SSD (Solid State Drive), and removable media drive, and supports the memory 120, stores a larger amount of data than the memory 120, and stores software such as programs executed by the electricity retailer server 100, as well as data to be processed. The input unit 130 includes input devices such as a keyboard and a mouse, and transmits information input by a user via the input device to the processor 110. The output unit 140 includes output devices such as a display and a speaker, and outputs information received from the processor 110 to the output device. The communication unit 190 is a device capable of communicating with external devices such as other servers via a communication network 900 such as the Internet, and transmits and receives predetermined information to and from the external devices. The processor 110 processes data from the input unit 130 or the communication unit 190 or data stored in the memory 120 or the auxiliary storage device 160 in accordance with a program stored in the memory 120 or the auxiliary storage device 160, and outputs the data to the output unit 140 or the communication unit 190, or stores the data in the memory 120 or the auxiliary storage device 160.

The aggregator server 300, power exchange server 400, power transmission and distribution company server, and power generation company server 600 have the same configuration as the electricity retailer server 100 described above.

The HEMS 200 can communicate with external devices such as the aggregator server 300 or the power transmission and distribution company server 500 via the communication network 900, controls the supply and demand of power at the DSR 210, and acquires the measured amount of power from a smart meter that measures the amount of power exchanged between the DSR 210 and the power grid.

The HEMS 200 may also have the functionality of a smart meter. The aggregator server 300 may directly or indirectly control or manage the DSR 210. The electricity retailer server 100 may directly or indirectly control or manage the DER 310 or the DSR 210.

In this type of energy management system 1, for the electricity supplied to the retail electricity supplier 10 from the power generation company 60 and the transmission and distribution company 50 in order for the retail electricity supplier 10 to supply to the consumer 20, the reference value of the planned amount of energy to be supplied to the retail electricity supplier 10, which is agreed upon through bidding on the power exchange 40 for each of the 48 30-minute segments into which one day (24 hours) is divided, must match with the actual value actually supplied to the retail electricity supplier 10 by the transmission and distribution company 50. If the difference between this reference value and the actual value falls outside a specified tolerance range, an imbalance fee must be paid to the transmission and distribution company 50 according to the amount of imbalance.

However, if consumer 20 has a DSR 210, which is an energy resource (power generation equipment, power storage equipment, demand equipment) such as an electric vehicle with a traction battery (e.g., a BEV (Battery Electric Vehicle), a PHEV (Plug-in Hybrid Electric Vehicle)), a power storage device (e.g., a stationary power storage system), or a power generation device (e.g., a solar power generation device, a fuel cell power generation device, an engine power generation device) connected below the power receiving point of consumer 20, the planned amount of power supplied to consumer 20 may not be met due to deviations in power demand from household air conditioners, increases or decreases in charging and discharging of the electric vehicle or power storage device, or increases or decreases in power generation by the power generation device, and this may result in the incurrence of an imbalance charge.

The processor 110 of the electricity retailer server 100 therefore identifies a reference value, which is the total amount of electricity planned to be supplied to multiple consumers 20, for each frame of each time period, and transmits the reference value to the electricity transmission and distribution company 50 in advance before the time period of the frame corresponding to the reference value arrives in order to receive the amount of electricity of the identified reference value from the electricity transmission and distribution company 50.The processor 110 controls the DER 310 or DSR 210 with the goal that, within the range of the amount that can be increased or decreased in each frame, the imbalance amount, which is the difference between the actual value, which is the total amount of electricity used by multiple consumers 20, and the reference value, will become zero, so that no imbalance fee will be paid by the electricity retailer 10 to the electricity transmission and distribution company 50 for the imbalance amount. The increaseable amount is the amount of power that can be added to the actual value by being used by the DER 310 or DSR 210, and the decreaseable amount is the amount of power that can be subtracted from the actual value by reducing use by the DER 310 or DSR 210 or by supplying power from the DER 310 or DSR 210 to multiple consumers 20. In specifying the reference value, the processor 110 specifies the reference value so that the imbalance charge for the imbalance amount in at least one frame included in the specified period is minimized.

As a result, when specifying a reference value that is the total planned amount of electricity to be supplied to multiple consumers 20 for each time slot, the reference value is specified so that the imbalance fee for the imbalance amount in at least one slot included in the specified period is minimized. As a result, the imbalance fee can be reduced.

Figure 2 is a flowchart showing the flow of reference value-related processing executed by the electricity retailer server 100 in this embodiment. Referring to Figure 2, the processor 110 of the electricity retailer server 100 determines whether the current time is the timing for setting the reference value (step S111). The setting timing is, for example, a specific time, such as a predetermined time before the bidding close time. In the case of a day-ahead market, it is 9:00, one hour before 10:00 on the day before the bidding close time of the relevant slot, and in the case of an intraday market (hour-ahead market), it is one hour before the start time of each slot, which is the bidding close time.

If it is determined that the current time has reached the set timing (YES in step S111), the processor 110 identifies a reference value, which is the total amount of electricity planned to be supplied to the consumer 20 in the target frame, so that the imbalance charge for the imbalance amount is minimized for at least one frame included in the specified period (step S112).

Figure 3 is a diagram for explaining the determination of the reference value in this embodiment. Referring to Figure 3, as shown in Figure 3(A), the distribution of the predicted probability p of the DSR power demand (kJ) for each frame is thought to exhibit, for example, a Gaussian distribution, as indicated by line L0. Typically, the power amount corresponding to the highest probability p in the probability distribution is set as the planned reference value (the value indicated by the bar graph).

In each frame, the electricity retailer server 100 compares the total power at the receiving end of the consumers 20 with a reference value, and controls the electric vehicles or power storage equipment included in the DER 310 or DSR 210 to increase or decrease the amount of power used within the range of the allowable increase or decrease. The allowable increase amount is the amount of power that can be added to the amount of power actually used (actual value) by being charged by the electric vehicles or power storage equipment included in the DER 310 or DSR 210. The allowable decrease amount is the amount of power that can be subtracted from the actual value by supplying power to the demand equipment of multiple consumers 20 by reducing charging to the electric vehicles or power storage equipment included in the DER 310 or DSR 210 or increasing discharging from the electric vehicles or power storage equipment.

If demand at consumer 20's demand facilities and power storage facilities falls below this allowable increase amount, an imbalance fee b will be incurred according to the amount of imbalance that deviates from the reference value, as shown by line L2. Similarly, if demand at consumer facilities and power storage facilities increases above the allowable decrease amount, an imbalance fee b will be incurred according to the amount of imbalance that deviates from the reference value, as shown by line L3. The imbalance fee is paid by electricity retailer 10 to electricity transmission and distribution company 50. The value obtained by multiplying imbalance fee b by probability p is the expected value b×p of imbalance fee b. The expected values b×p corresponding to lines L2 and L3 are indicated by areas A2 and A3, respectively.

Figures 3(B) to 3(D) show the probability p of forecasting demand (kW) for the demand facilities and energy storage facilities included in DER310, the imbalance charge b, and the expected value b x p of the imbalance charge for each second of a specified period (here, 48 hours) from time t. By accumulating these expected values b x p for the specified period from time, the expected value b x p for the reference value is calculated. Changing the reference value changes the amount that can be increased or decreased, and therefore the expected value b x p changes.

While varying the reference value, the amount by which it can be increased or decreased is identified, the expected value for this amount is calculated, and the two are summed to calculate the expected value corresponding to the reference value. In step S112, the reference value that minimizes this expected value is identified.

Returning to Figure 2, the processor 110 of the electricity retailer server 100 submits a bid to the power exchange server 400 for the reference value and unit price identified in step S112 (step S113).

If it is determined that it is not time to set the reference value (NO in step S111), or after step S113, the processor 110 determines whether the contract result has been notified from the power exchange server 400 (step S121). If it is determined that the contract result has been notified (YES in step S121), the processor 110 stores the contract result in the memory 120 or the auxiliary storage device 160 (step S122).

If it is determined that the timing has not yet arrived when the contract result has been notified (NO in step S121), or after step S122, the processor 110 determines whether the contracted power delivery time has arrived (step S131). If it is determined that the delivery time has arrived (YES in step S131), the processor 110 starts supplying the power supplied from the power transmission and distribution company 50 to the target block to the consumer 20 based on the contract result (step S132). In this supply, the processor 110 uses the DER 310 or the DSR 210 to control the amount of power that can be increased or decreased within the range of the amount that can be increased or decreased, and controls the demand for power with the goal of matching the actual value with the contracted reference value. The control of the DSR 210 is performed directly by the processor 110 of the electricity retailer server 100 or indirectly via the HEMS 200. The DER 310 is controlled directly by the processor 110 of the electricity retailer server 100, or indirectly via the aggregator server 300.

The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present disclosure is indicated by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims.

1 Power management system, 10 Electricity retailer, 20 Consumer, 30 Aggregator, 40 Power exchange, 50 Electricity transmission and distribution company, 60 Power generation company, 100 Electricity retailer server, 110 Processor, 120 Memory, 130 Input unit, 140 Output unit, 160 Auxiliary storage device, 190 Communication unit, 200 HEMS, 210 DSR, 300 Aggregator server, 310 DER, 400 Power exchange server, 500 Electricity transmission and distribution company server, 510 Electricity transmission and distribution equipment, 600 Power generation company server, 610 Power generation equipment, 900 Communication network.

Claims (1)

A power management device of a business operator that supplies power received from a power supplier to a plurality of consumers,
The power management device
It is possible to control the electricity supply and demand adjustment system,
a memory for storing a predetermined program;
a processor that executes the predetermined program,
The processor executes the predetermined program,
Identifying a reference value that is a total amount of power planned to be supplied to the plurality of consumers for each time slot;
In order to receive the amount of power of the specified reference value from the supplier, the reference value is transmitted to the supplier in advance before a time slot corresponding to the reference value is reached;
In each frame, the adjustment system is controlled so that the imbalance amount, which is the difference between the actual value that is the total amount of electricity used by the plurality of consumers and the reference value, becomes zero within the range of the amount that can be increased and decreased, so that no imbalance fee is paid by the business operator to the supplier for the imbalance amount;
the possible increase is an amount of power that can be added to the actual value by being used by the adjustment system,
the possible reduction amount is an amount of power that can be subtracted from the actual value by reducing usage by the adjustment system or supplying power to the plurality of consumers from the adjustment system;
The processor executes the specified program to specify the reference value so that the imbalance fee for the imbalance amount in at least one frame included in a specified period is minimized.