This application relates to and claims the benefit of priority from Japanese Patent Application number 2013-210561, filed on Oct. 7, 2013, the entire disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a power demand adjustment system, a power demand adjustment method, and a power management apparatus.
2. Description of the Related Art
In order to maintain power grid stability, it is necessary to adjust power demand. When there is a power supply surplus or when the power supply is tight, it is possible to manipulate power demand and maintain the balance between the supply and demand of power by controlling the load apparatuses and power-generation apparatuses installed on the consumer side.
Japanese Patent Application Laid-open No. 2005-168258 can be cited as a technique related to adjusting power demand. Japanese Patent Application Laid-open No. 2005-168258 discloses a technique for reducing the supply voltage of a specific region by either 15% or 55% when there is a power supply shortage in order to avoid a large-scale power outage in the distribution lines of an entire area. According to the prior art disclosed in Japanese Patent Application Laid-open No. 2005-168258, it is possible to curb the power consumption of microwave ovens and most other electrical appliances and machinery, while allowing emergency equipment (emergency lighting, elevators) having boost converters to continue functioning. In addition, according to the prior art disclosed in Japanese Patent Application Laid-open No. 2005-168258, it is also possible to increase the power supply by enabling home-use power generators for emergency use (for example, diesel-powered generators or hybrid vehicles) to detect a drop in voltage and start up.
The prior art disclosed in Japanese Patent Application Laid-open No. 2005-168258 is based on the supposition of dealing with a large-scale disaster or other such emergency situation, and does not deal with daily increases and decreases in power demand. Therefore, the prior art disclosed in Japanese Patent Application Laid-open No. 2005-168258 is unable to adjust power demand in accordance with the state of a power supply.
Accordingly, an object of the present invention is to provide a power demand adjustment system and a power demand adjustment method that make it possible to adjust power demand in accordance with the state of a power supply. Another object of the present invention is to provide a power demand adjustment system, a power demand adjustment method, and a power management apparatus for adjusting power demand simply and with high reliability by using an adjustable amount of demand calculated beforehand to create a demand adjustment plan, creating a voltage control plan for realizing the demand adjustment plan, and controlling an output voltage of a voltage control apparatus.
A system for adjusting power demand that accords with one aspect of the present invention for solving the aforementioned problems comprises: voltage control apparatuses for supplying power from a grid to a plurality of consumers; a power management apparatus for controlling an output voltage value of at least one of the voltage control apparatuses; and a demand adjustment plan management apparatus, which is connected to at least one of the power management apparatuses and is for managing a demand adjustment plan for adjusting power demand, wherein the power management apparatus calculates an adjustable amount of demand from the plurality of consumers for enabling power demand to be adjusted, and sends the adjustable amount of demand to the demand adjustment plan management apparatus, the demand adjustment plan management apparatus, on the basis of a request value for an amount of demand adjustment and the adjustable amount of demand received from the power management apparatus, prepares a demand adjustment plan for satisfying the request value for the amount of demand adjustment, and sends the prepared the demand adjustment plan to the power management apparatus, and the power management apparatus, on the basis of the demand adjustment plan received from the demand adjustment plan management apparatus, prepares a voltage control plan for controlling the output voltage value of the voltage control apparatus, and causes the output voltage value of the voltage control apparatus to be controlled in accordance with the prepared voltage control plan.
According to the present invention, it is possible to prepare a demand adjustment plan on the basis of an adjustable amount of demand from a plurality of consumers and a request value for a demand adjustment amount, to prepare a voltage control plan based on the demand adjustment plan, and to control an output voltage value of the voltage control apparatus in accordance with the voltage control plan. By controlling the output voltage value of the voltage control apparatus on the basis of the voltage control plan, it is possible to broadly distribute the required amount of demand adjustment among a plurality of consumers, and to adjust the power demand from the plurality of consumers with relative ease.
An embodiment of the present invention will be explained below on the basis of the drawings. In the following explanation, consumer signifies an entity or facility that consumes power from the grid. Adjusting the power demand of a consumer signifies adjusting the amount of power that is consumed by the consumer's facilities (electrical loads). For convenience of explanation, the consumer and the consumer's facilities may be described without making any distinction therebetween.
In the embodiment, the output voltage value of a voltage control apparatus for supplying power from the grid to a plurality of consumers is controlled in accordance with a voltage control plan. Thus, in the embodiment, the power demand of a plurality of consumers can be adjusted at one time in accordance with single-location voltage control.
For example, reducing the output voltage value of the voltage control apparatus just slightly reduces the amount of power received at each of a plurality of consumers within the area of responsibility of the voltage control apparatus, thereby reducing the total amount of power demand within the area of responsibility. This makes it possible to respond to a request to adjust power demand while operating the facilities at the consumers in a normal state. Power demand may be abridged as demand hereinbelow.
As described above, according to the embodiment, “voltage control under the voltage control apparatus” is used as means for executing demand adjustment. In the embodiment, the demand of each consumer is adjusted at the same time by controlling the supply voltage to a plurality of consumers.
Therefore, according to the embodiment, demand can be adjusted easily without the need to monitor, make predictions about, and control numerous and varied consumer facilities one by one, and initial installation costs are also relatively inexpensive. In addition, according to the embodiment, demand adjustment can be realized with relatively high execution reliability using a power management apparatus managed by a distributor, regional aggregator, or the like. In addition, in the embodiment, it is possible to execute fine-tuned voltage control for a wide range of consumers, thereby enabling a large adjustable amount of demand to be assured and demand adjustment to be performed without reducing the amenities of the consumer. In addition, in the embodiment, as will be described below, it is possible to create a voltage control plan that takes into account demand adjustment start time and/or reset time, thereby enabling demand to be adjusted in a highly stable manner for both the consumer and the grid.
The electricity market 1501 uses an electricity market management apparatus 1502, the grid operator 1601 uses a supply-demand adjustment management apparatus 1602, the retailer 1701 uses a power retail sales management apparatus 1702, the demand adjustment provider 1201 uses a demand adjustment plan management apparatus 1202, and the distributor 1101 uses a power management apparatus 1102. These computer systems 1502, 1602, 1702, 1202, and 1102 are connected so as to be able to communicate in a two-way manner via a communication network 1001 that uses either public or leased lines.
The attributes of the business entities will differ in accordance with the business environment. For example, they may be the grid operator 1601, the retailer 1701, the demand adjustment provider 1201 and the distributor or aggregator 1101. One computer system may combine a plurality of the aforementioned computer systems 1502, 1602, 1702, 1202, and 1102. In addition, one computer system may be configured by interlinking a plurality of computers. In addition, the power management apparatus 1102, for example, may be disposed in the same enclosure as the voltage control apparatus 1302, or may be disposed in the same computer system as that of the demand adjustment plan management apparatus 1202.
In this arrangement, one demand adjustment plan management apparatus 1202 can manage a plurality of power management apparatuses 1102. One power management apparatus 1102 can manage a plurality of voltage control apparatuses 1302. The voltage control effects of one voltage control apparatus 1302 cover a plurality of consumers.
In this example, it is supposed that a demand adjustment provider 1201 and a distributor 1101 have concluded a demand adjustment contract beforehand. In a supply-demand adjustment contract, for example, a calculation interval and a calculation period for an adjustable amount of demand, a calculation method for an adjustable amount of demand, a reservation fee, a utilization fee, and a penalty are agreed upon between the demand adjustment provider 1201 and the distributor 1101.
On the basis of the demand adjustment contract, each distributor 1101 calculates an adjustable amount of demand using the power management apparatus 1102 and declares this amount to the demand adjustment provider 1201.
The demand adjustment provider 1201, on the basis of the declared adjustable amount of demand, either tenders a bid for a product related to power demand reduction from the electricity market 1501, or receives a request for a power demand adjustment from either the grid operator 1601 or the retailer 1701. The demand adjustment provider 1201 uses the demand adjustment plan management apparatus 1202 to register a demand adjustment task based on the product or the adjustment request. The demand adjustment provider 1201 prepares a demand adjustment plan and sends the plan to the power management apparatus 1102 of each distributor 1101 from the demand adjustment plan management apparatus 1202.
The distributor 1101, on the basis of the received demand adjustment plan, uses the power management apparatus 1102 to create a voltage control plan. The power management apparatus 1102 of the distributor 1101 controls the output voltage value of the voltage control apparatus 1302 by sending a control signal that conforms to the voltage control plan to the voltage control apparatus 1302. In addition, the power management apparatus 1102 adjusts the power demand by controlling the output voltage value of the voltage control apparatus 1302 while collecting a variety of power-related information from the grid using the power information collection apparatus 1402. The power information collection apparatus 1402, for example, measures the voltage value, a current value, and a frequency of the grid, and sends this information to the power management apparatus 1102.
A plurality of feeders emanates from the distribution substation and a plurality of pole-mounted transformers is connected to each feeder. A plurality of consumers is connected to each pole-mounted transformer. Therefore, controlling the output voltage value of the distribution substation makes it possible to perform voltage control at the source of the so-called transmission system and to simultaneously adjust demand for a large number of consumers over a wide area.
Alternatively, when controlling the output voltage value of a pole-mounted transformer, the demand of the plurality of consumers connected to the pole-mounted transformer is adjusted. Thus, the range capable of being covered by demand adjustment in accordance with controlling the output voltage value of the pole-mounted transformed is narrower than when controlling the output voltage value of the distribution substation, and the adjustable amount of demand is also small. However, demand can be more finely adjusted by controlling the output voltage value of the pole-mounted transformer.
For example, it is assumed that one group of consumers connected to one pole-mounted transformer that is linked to a certain distribution substation is made up of ordinary private homes, and another group of consumers connected to another pole-mounted transformer that is linked to the same distribution substation is made up of public facilities such as hospitals. In this case, when the output voltage value of the distribution substation is reduced, the amount of power received by not only the private homes but also the public facilities is reduced, and as such, when these facilities are not equipped with boosting and/or electric storage equipment, the provision of services at these facilities is likely to be impacted. Alternatively, when the configuration is such that the output voltage value of the one pole-mounted transformer and the output voltage value of the other pole-mounted transformer is each able to be controlled individually, the demand of the group of private homes can be reduced more than the demand of the public facilities. Thus, when the voltage control apparatus 1302 is disposed in the pole-mounted transformer, it is possible to adjust demand in accordance with the characteristic feature of the consumer.
The power management apparatus 1102, on the basis of the demand adjustment contract, calculates the adjustable amount of demand at the voltage control apparatus 1302 based on information such as meteorological information, calendar information, demand results and the like, and sends this adjustable amount of demand to the demand adjustment plan management apparatus 1202. The power management apparatus 1102, on the basis of a demand adjustment plan received from the demand adjustment plan management apparatus 1202, creates and sends a voltage control plan to each voltage control apparatus 1302. The power management apparatus 1102 updates the parameters required to create the voltage control plan based on the difference between the demand adjustment results resulting from voltage control and the voltage control plan.
The power management apparatus 1102, for example, is configured as a computer system comprising a microprocessor (hereinafter central processing unit (CPU)) 2101, an input device 2102, an output device 2103, a communication device 2104, and a storage device 2105. The power management apparatus 1102, for example, can be configured as an information processing apparatus such as a personal computer, a server computer, a handheld computer, or a wearable computer.
The CPU 2101 realizes the functions of the power management apparatus 1102 by executing prescribed computer programs stored in the storage device 2105. The input device 2102 is for a service provider (distributor) operator to input instructions and information into the power management apparatus 1102. The input device 2102, for example, may be a keyboard, a mouse or other such pointing devices, a touch panel, a voice-input device, and/or a device that detects and inputs a line of sight, brain waves or motion. The output device 2103 is for an operator to obtain information from the power management apparatus 1102. The output device 2103, for example, may be a display, a voice synthesis device, and/or a printer. The communication device 2104 is for communicating with another computer system 1202, 1302, and 1402 via the communication network 1001 and/or the communication channels 1002 and 1003. Communications may be either wireless or wired communications. The storage device 2105 is a memory for storing computer programs and data, and, for example, comprises a random access memory (RAM), a hard disk drive, and so forth.
The demand adjustment plan management apparatus 1202, on the basis of the adjustable amount of demand received from each of the power management apparatuses 1102, bids on an electricity market product and/or registers a demand adjustment task. In addition, the demand adjustment plan management apparatus 1202 creates and sends a demand adjustment plan to each of the power management apparatuses 1102 on the basis of the demand adjustment task.
The demand adjustment plan management apparatus 1202, for example, is configured as a computer system comprising a CPU 2201, an input device 2202, an output device 2203, a communication device 2204, and a storage device 2205. The CPU 2201 realizes the functions of the demand adjustment plan management apparatus 1202 by executing prescribed computer programs stored in the storage device 2205. The input device, output device, communications device, and storage device are substantially the same as those described for the power management apparatus 1102, and as such, explanations will be omitted.
The voltage control apparatus 1302 controls the output voltage value on the basis of the voltage control plan received from the power management apparatus 1102. The voltage control apparatus 1302, for example, is configured as a computer system comprising a CPU 2301, an input device 2302, an output device 2303, a communication device 2304, and a storage device 2305. The CPU 2301 realizes a prescribed function by executing a prescribed computer program stored in the storage device 2305, and controls the output voltage value in accordance with the voltage control plan. The input device, output device, communications device, and storage device are substantially the same as those described for the power management apparatus 1102, and as such, explanations will be omitted.
The power information collection apparatus 1402 collects power information regarding power lines under the control of the voltage control apparatus 1302. The collected power information is sent from the power information collection apparatus 1402 to the power management apparatus 1102. The configuration may be such that the collected power information is sent from the power information collection apparatus 1402 to the voltage control apparatus 1302. The power information collection apparatus 1402, for example, is configured as a computer system comprising a CPU 2401, an input device 2402, an output device 2403, a communication device 2404, and a storage device 2405. Prescribed functions are realized, and the collection and sending of power information are performed in accordance with the CPU 2401 executing prescribed programs stored in the storage device 2405. The input device, output device, communications device, and storage device are substantially the same as those described for the power management apparatus 1102, and as such, explanations will be omitted.
Furthermore, the voltage control apparatus 1302 and the power information collection apparatus 1402 do not necessarily have to be configured as apparatuses that are capable of executing computer programs, and may be configured from hardware circuits. Also, the input devices, output devices, communication devices, and storage devices are incorporated in accordance with the purpose of the computer system, and as such may differ from the configurations described for the power management apparatus 1102.
The storage device 2105 of the power management apparatus 1102, for example, stores computer programs for realizing an adjustable-amount-of-demand estimation part 2106, an adjustable-amount-of-demand management part 2107, a demand adjustment plan management part 2108, a voltage control plan creation part 2109, a voltage control plan management part 2110, and a percentage-of-voltage-correlation-apparatuses management part 2111.
The adjustable-amount-of-demand estimation part 2106 calculates the adjustable amount of demand at a future time on the basis of the demand adjustment contract. The adjustable-amount-of-demand estimation part 2106, for example, calculates the adjustable amount of demand for each voltage control apparatus 1302 based on information such as the demand adjustment contract, meteorological information, calendar information, and demand results.
The adjustable-amount-of-demand management part 2107 registers the adjustable amount of demand calculated by the adjustable-amount-of-demand estimation part 2106 in an adjustable-amount-of-demand storage part 2122, and, in addition, sends the adjustable amount of demand to the demand adjustment plan management apparatus 1202.
The demand adjustment plan management part 2108 registers the demand adjustment plan received from the demand adjustment plan management apparatus 1202 in a demand adjustment plan storage part 2123.
The voltage control plan creation part 2109 creates a voltage control plan for each voltage control apparatus 1302 on the basis of the demand adjustment plan registered by the demand adjustment plan management part 2108.
The voltage control plan management part 2110 registers the voltage control plan created by the voltage control plan creation part 2109 in a voltage control plan storage part 2117, and sends this voltage control plan to the voltage control apparatus 1302.
The percentage-of-voltage-correlation-apparatuses management part 2111 updates the demand adjustment results received from the power information collection apparatus 1402 and the percentage-of-voltage-correlation-apparatuses storage part 2120 based on differences between voltage control plans.
The storage device 2105 of the power management apparatus 1102, in order to perform demand adjustment by controlling the voltage, stores a demand adjustment contract storage part 2112, a voltage control apparatus storage part 2113, a meteorological forecast storage part 2114, a meteorological results storage part 2115, a calendar information storage part 2116, a voltage control plan storage part 2117, a demand adjustment results storage part 2118, a demand results storage part 2119, a percentage-of-voltage-correlation-apparatuses storage part 2120, a power grid information storage part 2121, an adjustable-amount-of-demand storage part 2122, and a demand adjustment plan storage part 2123. The table configurations for storing these respective storage parts 2112 through 2123 will be described below.
The storage content of the demand adjustment plan management apparatus 1202, the voltage control apparatus 1302, and the power information collection apparatus 1402 will be explained using
The demand adjustment task management part 2206 registers a demand adjustment task in the demand adjustment task storage part 2210 on the basis of a bid-tendered product from the electricity market. Also, the demand adjustment task management part 2206, for example, can register a demand adjustment task in the demand adjustment task storage part 2210 on the basis of a demand adjustment request from the supply-demand adjustment management apparatus 1602 of the grid operator.
The demand adjustment plan creation part 2207 creates a demand adjustment plan for each power management apparatus 1102 relative to the demand adjustment task registered by the demand adjustment task management part 2206. That is, either one or a plurality of power management apparatuses 1102 is used to solve for a single demand adjustment task. Therefore, either one or a plurality of demand adjustment plans is associated with a single demand adjustment task.
The demand adjustment plan management part 2208 sends the demand adjustment plan created by the demand adjustment plan creation past 2207 to the power management apparatus 1102.
The power management apparatus storage part 2209 and the demand adjustment task storage part 2210 will be explained below. The demand adjustment plan storage part 2211 is the same as the demand adjustment plan storage part 2123 retained by the power management apparatus 1102. The difference is that whereas the demand adjustment plan storage part 2211 of the demand adjustment plan management apparatus 1202 stores a demand adjustment plan for each target power management apparatus 1102, each power management apparatus 1102 only stores a demand adjustment plan for its own apparatus.
The demand adjustment results storage part 2407 is the same as the demand adjustment results storage part 2118 of the power management apparatus 1102. However, since the power management apparatus 1102 acquires and manages power information indicating the power demand results from the power information collection apparatus 1402 corresponding to each voltage control apparatus 1302, the demand adjustment results storage part 2118 stores the demand results from each power information collection apparatus 1402. Alternatively, the power information collection apparatus 1402 only stores the demand results that have been acquired by its own apparatus.
In Step S101, the power management apparatus 1102, on the basis of the contents of the demand adjustment contract, extracts a time in the future at which the adjustable amount of demand should be calculated. In addition, the power management apparatus 1102 estimates and calculates for each extracted prediction-target time an adjustable amount of demand based on information such as meteorological information, calendar information, past demand results, and a percentage of voltage correlation apparatuses. The power management apparatus 1102 sends the calculated adjustable amount of demand to the demand adjustment plan management apparatus 1202.
In Step S102, the demand adjustment plan management apparatus 1202, on the basis of the adjustable amount of demand received from the power management apparatus 1102, bids on a product from the electricity market and registers a demand adjustment task. In addition, the demand adjustment plan management apparatus 1202 creates a demand adjustment plan for each power management apparatus 1102 that satisfies the registered demand adjustment task.
In Step S103, the demand adjustment plan management apparatus 1202 determines whether demand adjustment plans that satisfy the demand adjustment task were prepared. When it has been determined that demand adjustment plans that satisfy the demand adjustment task have been prepared, the demand adjustment plan management apparatus 1202 sends the respective demand adjustment plans to the corresponding power management apparatuses 1102. Alternatively, when it has been determined demand adjustment plans satisfying the demand adjustment task could not be prepared (S103: NO), the demand adjustment plan management apparatus 1202 ends the processing.
Steps S105 through S109 described below are implemented for all the voltage control plans (S104).
In Step S105, the power management apparatus 1102, on the basis of the demand adjustment plan received from the demand adjustment plan management apparatus 1202, creates a voltage control plan based on information such as meteorological information, calendar information, past demand results, and a percentage of voltage correlation apparatuses.
In Step S106, the power management apparatus 1102 determines whether the created voltage control plan is an appropriate plan that falls within an acceptable voltage range. A voltage control plan that either exceeds the acceptable voltage upper limit value or falls below the acceptable voltage lower limit value is determined to be inappropriate. When it has been determined that an appropriate voltage control plan could not be prepared (S106: NO), the power management apparatus 1102 returns to Step S102, and notifies the demand adjustment plan management apparatus 1202. Upon receiving the notification, the demand adjustment plan management apparatus 1202 is able to reconsider and revise the demand adjustment plan. When revision is not possible, a demand adjustment plan that satisfies the demand adjustment task cannot be prepared (S103: NO), and as such, the demand adjustment plan management apparatus 1202 notifies either the electricity market or the source of the demand adjustment request to this effect and ends the processing.
For example, the demand adjustment plan management apparatus 1202 once again creates a demand adjustment plan for each of the other power management apparatuses 1102 except the power management apparatus 1102 from which there was a notification to the effect that an appropriate voltage control plan could not be prepared, and sends the demand adjustment plan to each of these power management apparatuses 1102 (S102). When a notification is issued by any of the other power management apparatuses 1102 to the effect that an appropriate voltage control plan could not be prepared, the demand adjustment plan management apparatus 1202 sends a notification to the effect that demand adjustment is not possible to either the electricity market or the source of the demand adjustment request (Step S103: NO), and ends the processing.
When it is possible to prepare an appropriate voltage control plan via which the output voltage value can be controlled within the acceptable voltage range (S106: YES), the voltage control apparatus 1302 controls the output voltage on the basis of the received voltage control plan (S107). The phrase “control the output voltage value” may be abridged to either output voltage control or voltage control.
In Step S108, the power information collection apparatus 1402 collects power information results regarding voltage fluctuations resulting from output voltage control, and sends these results to the power management apparatus 1102.
In Step S109, the power management apparatus 1102 updates the percentage of voltage correlation apparatuses using the voltage control plan and the demand adjustment results.
This processing ends when the execution of all the voltage control plans has ended. When unprocessed voltage control plans exist, the processing returns to Step S105.
The adjustable-amount-of-demand estimation part 2106 estimates for each voltage control apparatus 1302 how much demand adjustment can be assured at a time in the future, and sends this estimate to the demand adjustment plan management apparatus 1202 (S201 through S206).
The adjustable-amount-of-demand estimation part 2106, on the basis of an adjustable-amount-of-demand calculation interval and an adjustable-amount-of-demand calculation period stored in the demand adjustment contract storage part 2112, extracts a time at which an adjustable amount of demand should be calculated. For example, in the demand adjustment contract table of
The adjustable-amount-of-demand estimation part 2106 calculates the adjustable amount of demand at each extracted time. For example, the adjustable amount of demand calculation of S201 at time “2012/08/16 18:00” for voltage control apparatus ID “VCM01” will be explained as one example. Using the voltage control apparatus ID “VCM01” as a key, “T201” is selected from a voltage control apparatus table in the voltage control apparatus storage part 2113 of
The adjustable-amount-of-demand estimation part 2106 uses the map mesh ID “M001” and the time “2012/08/16 18:00” in T201 as keys, and selects “T301” from a meteorological forecast table in the meteorological forecast storage part 2114 of the
The adjustable-amount-of-demand estimation part 2106 uses the time “2012/08/16 18:00” as a key, and selects “T501” from a calendar information table in the calendar information storage part 2116 of the
The adjustable-amount-of-demand estimation part 2106, on the basis of the selected meteorological forecast “T301” and the calendar information “T501”, selects from a demand results table in the demand results storage part 2119 of
The variables and calculation formulas used in the explanations given below are defined here using Table 1 below.
{circumflex over (P)}: Power value targeted by demand adjustment
{tilde over (P)}: Power value at normal times when demand adjustment not implemented
ΔP: Adjusted power value resulting from demand adjustment
(ΔP={tilde over (P)}−{circumflex over (P)} Expression A)
{circumflex over (V)}: Voltage value targeted by demand adjustment
{tilde over (V)}: Voltage value at normal times when demand adjustment not implemented (Feed voltage setting value configured in accordance with summer season, winter season, and in-between periods)
ΔV: Adjusted voltage value resulting from demand adjustment
(ΔP={tilde over (V)}−{circumflex over (V)} Expression B)
kn: Percentage of voltage correlation apparatuses
Now then, an inverter, an automatic booster, and a direct current-alternating current switching apparatus (PCS) are electrical apparatuses that operate so as to detect a fluctuation in received voltage, and automatically absorb this voltage fluctuation. These electrical apparatuses cannot simply be represented as Ohm's Law (P[w]=I[A]·V[V]) for a power line to which the electrical appliances and machinery thereof is most likely connected.
Accordingly, in this example, the percentage of the electrical appliances and machinery connected to a power line under the control of the voltage control apparatus 1302 accounted for by voltage correlation apparatuses, which change the amount of received power using voltage control, is stored in the percentage-of-voltage-correlation-apparatuses storage part 2120 as a percentage of voltage correlation apparatuses kn.
This satisfies the relational expression P=I·V·kn. The percentage of voltage correlation apparatuses kn is a percentage of electrical appliances and machinery accounted for by voltage correlation apparatuses that change the amount of received power in accordance with controlling voltage, and as such, is influenced by meteorological information, calendar information, and other such items that affect consumer living patterns.
As illustrated in
A target voltage value using demand adjustment can be determined from Expression A and Expression B in Table 1, and the aforementioned Expression C as Formula 1 below.
The adjustable-amount-of-demand estimation part 2106, on the basis of the selected meteorological forecast “T301” and the calendar information “T501”, selects from a percentage-of-voltage-correlation-apparatuses table in the percentage-of-voltage-correlation-apparatuses storage part 2120 of
In addition, a voltage drop phenomenon must be taken into account when current is flowing through a power line. A voltage drop value Vd is expressed using the following expression.
Vd(In,Ln)=Ku·In·Ln·Z·10−3 (Expression D)
In Expression D, Vd represents a voltage drop value, In represents an electrical current, Ln represents a distance (m), Z represents an impedance (Ω/km), and Ku represents a distribution system-based coefficient. “1” is configured in the Ku coefficient in the case of a “single-phase two-wire or single-phase three-wire system with loads connected between voltage lines”, “2” is configured in the case of a “single-phase three-wire or three-phase four-wire system with loads connected between voltage line and neutral line”, and “3” is configured in the case of a “three-phase three-wire or three-phase four-wire system with loads connected between voltage lines”.
The aforementioned Expression D, as illustrated in
Appropriate voltage upper limit and lower limit values are established beforehand as the standard voltage at each substation. As an example, under Japan's current Electricity Business Act, the standard voltage for a low-voltage consumer is established as being within 101+6 [V] in a 100 [V] circuit, and within 202+20 [V] in a 200 [V] circuit. For a distribution grid, the articles of agreement of electric power companies stipulate a standard voltage of within 6600+300 [V] for metropolitan areas, and within 6600+600 [V] for other areas. A deviation from the upper limit value and lower limit value of an appropriate voltage calculated based on these standard voltages is a violation of the terms of service, and as such, power must be distributed to consumers within the aforementioned ranges.
The adjustable-amount-of-demand estimation part 2106 selects “T1001” from a power grid information table (
Next, the adjustable-amount-of-demand estimation part 2106, so as to satisfy the standard voltages described hereinabove and illustrated in
P=({tilde over (V)}−{circumflex over (V)})·In [Formula 2]
For example, an adjustable amount of demand of “+100 [kW]” is calculated when a voltage of “+100 [V]” can be adjusted, and the current In is “1000 [A]”.
The adjustable-amount-of-demand estimation part 2106 uses the calculated adjustable amount of demand to calculate a reservation fee and a utilization fee. The calculation method, for example, uses a value obtained by multiplying a reservation fee unit price by the amount of a demand adjustment for the reservation fee, and for the utilization fee, uses a value obtained by multiplying a utilization fee unit price by an amount of demand adjustment calculated using a baseline determined in accordance with the demand adjustment contract and an amount of demand adjustment calculation formula.
For example, based on demand adjustment plan “T101”, a reservation fee of “10,000×100=¥1,000,000”, and a maximum utilization fee of “20,000×100=¥2,000,000” are calculated.
Actually, it is assumed here that a variety of plans resulting from the demand adjustment contract exist for the reservation fee and the utilization fee, and it is conceivable that a unit price is set so as to increase when a flat-rate system or a certain fixed reference amount is exceeded, or that the respective unit prices are set in accordance with whether the adjustable amount of demand is a plus value or a minus value.
Lastly, the adjustable-amount-of-demand estimation part 2106 sends the adjustable amount of demand to the demand adjustment plan management apparatus 1202 (S206).
The configurations of the tables stored in the storage parts will be explained by referring to
The voltage control plan ID is information for identifying a voltage control plan. The voltage control apparatus ID is information for identifying a voltage control apparatus 1302 that is taking part in the voltage control plan. The voltage target value is a value that serves as the target for the output voltage control by the voltage control apparatus 1302. The control start time is the time at which the control for demand adjustment (output voltage control) starts. The target-voltage-reached time is the time at which the output voltage value reaches the voltage value being targeted. The reset control start time is the time at which the control for demand adjustment ends. The standard-voltage-reached time is the time at which the voltage value of the power line (the output voltage value of the voltage control apparatus 1302) resets to the pre-demand adjustment standard voltage.
The demand adjustment results ID is information for identifying demand adjustment results information. The pre-adjustment amount of demand is the amount of power demand prior to demand adjustment being performed. The post-adjustment amount of demand is the amount of demand subsequent to demand adjustment being performed. The voltage result is the voltage value when the output voltage has been controlled. The voltage control plan ID is information for identifying a voltage control plan that has been implemented in accordance with the demand adjustment plan. The demand adjustment start time is the time at which demand adjustment started. The demand adjustment end time is the time at which the demand adjustment ended.
The percentage of voltage correlation apparatuses ID is information for identifying percentage of voltage correlation apparatuses information. The voltage control apparatus ID is information for identifying a voltage control apparatus 1302. The percentage of voltage correlation apparatuses, as described hereinabove, is the percentage of electrical appliances and machinery of each consumer connected to the voltage control apparatus 1302 accounted for by voltage correlation apparatuses via which demand (amount of power consumed) changes in accordance with changing received voltage.
The voltage control apparatus ID is information identifying a voltage control apparatus 1302. The electric current is a current value outputted from the voltage control apparatus 1302. The distance is the length of the power line emanating from the voltage control apparatus 1302. The impedance is percent impedance (% Z). The distribution system is a system for supplying power to a consumer from the voltage control apparatus 1302. The acceptable grid voltage fluctuation is an acceptable value for a voltage fluctuation in a power line.
The demand adjustment plan ID is information for identifying a record (demand adjustment information) of the demand adjustment plan table. The demand adjustment task ID is information for identifying a demand adjustment task. The power management apparatus ID is information for identifying a power management apparatus 1102. The demand-adjustment-request amount is the amount of demand adjustment that should be reached by the group of consumers for which the power management apparatus 1102 is in charge. The demand adjustment start time is the time at which a demand adjustment starts. The demand adjustment end time is the time at which the demand adjustment ends. The pre-instruction start time and the post-instruction end time will be explained below.
The processing for creating a demand adjustment plan will be explained by using
The demand adjustment plan management apparatus 1202 receives an adjustable amount of demand, a reservation fee and a utilization fee sent from each power management apparatus 1102 (S301). The demand adjustment plan management apparatus 1202, on the basis of the information received from the power management apparatus 1102, either tenders a bid for a product from the electricity market 1501 or receives a demand adjustment request from a demand-adjustment-request source such as a grid operator, and registers a demand adjustment task in the demand adjustment task storage part 2210 (S302).
The demand adjustment plan management apparatus 1202, for each power management apparatus (S303), creates a demand adjustment plan using the demand adjustment task and the adjustable amount of demand (S304).
This processing will be explained in more detail. The demand adjustment plan management apparatus 1202, on the basis of the demand adjustment contract, receives an adjustable amount of demand from each power management apparatus 1102 (S301). For example, the demand adjustment plan management apparatus 1202 receives the adjustable amount of demand for the period from time “2012/08/16 18:00” to time “2012/08/18 18:00”. Based on these adjustable amounts of demand, and the reservation fees and utilization fees, the demand adjustment plan management apparatus 1202 determines whether or not to tender a bid for a product from the electricity market 1501, or to receive a demand adjustment request from the demand-adjustment-request source. For example, in a case where it has been determined that, during the period from time “2012/08/16 18:00” to time “2012/08/16 20:00”, an amount of demand adjustment of “+10000 kw” can be assured and a profit can be made, and a bid has been tendered for a product with an amount of demand adjustment of “+10000 kw”, a pre-instruction start time of “2012/08/16 16:30”, and a post-instruction end time of “2012/08/16 21:30”, the demand adjustment task is registered as “T1201” in the demand adjustment task table in the demand adjustment task storage part (S302).
Next, the demand adjustment plan management apparatus 1202 partitions an amount of demand adjustment for each power management apparatus 1102 from the registered demand adjustment task and determines a demand-adjustment-request amount. For example, the demand adjustment plan management apparatus 1202 finds a solution to the knapsack problem that is targeted at satisfying the amount of demand adjustment in the demand adjustment task, and, in addition, holding the reservation fees and utilization fees to the minimum. This enables the creation of a demand adjustment plan that makes it possible to maximize the profits of the service provider (demand adjustment provider) 1201.
In addition to minimizing the reservation fees and utilization fees, for example, the target set at this point can also include minimizing carbon dioxide emissions, and/or maximizing the reliability of demand adjustment implementation. The method for calculating a demand-adjustment-request amount for each power management apparatus 1102 may make use of a solution other than that for the knapsack problem.
By solving for the knapsack problem, the demand adjustment plan management apparatus 1202, for example, configures a demand-adjustment-request amount that achieves a demand adjustment of “−1000 [kw]” for the power management apparatus 1102 during the period from time “2012/08/16 18:00” to time “2012/08/16 20:00”.
The demand adjustment plan management apparatus 1202 creates a demand adjustment plan based on the demand-adjustment-request amount for each power management apparatus 1102 (S304). In addition to the demand adjustment start time and the demand adjustment end time, the pre-instruction start time and the post-instruction end time can be included as restrictive conditions when creating the demand adjustment plan.
A pre-instruction period is an acceptable period of time from the start of a demand adjustment until the amount of demand adjustment reaches the demand-adjustment-request amount. In this example, this start time is called the pre-instruction start time (Refer to
Similarly, a post-instruction period is an acceptable period of time from the end of the demand adjustment period until the amount of demand can be reset to normal, and in this example, the end time therefor is called the post-instruction time (Refer to
In other words, the period of time during which the change is made from the standard voltage value to the target voltage value at the start of the demand adjustment is the pre-instruction period, and the period of time during which the target voltage value is reset to the standard voltage value subsequent to the end of the demand adjustment is the post-instruction period.
When an adjustment to power demand is provided to the electricity market 1501 as a power-related product, in addition to achieving the demand-adjustment-request amount, it is also necessary to achieve a demand-adjustment-request amount with the highest possible reliability. Accordingly, in this example, a pre-instruction start time and a post-instruction end time are configured when it is necessary to enhance merchantability to create a demand adjustment plan that satisfies these requirements.
The demand adjustment plan management apparatus 1202, for example, includes the pre-instruction start time and the post-instruction end time described hereinabove, and registers the demand adjustment plan as “T1401” in the demand adjustment plan table of the demand adjustment plan storage part 2123 (Refer to
The processing of the voltage control plan creation part 2109 will be explained in detail using
First, the power management apparatus 1102 uses the received demand adjustment plan to allocate a demand-adjustment-request amount to each voltage control apparatus 1302 so as to satisfy the demand-adjustment-request amount.
The power management apparatus 1102 applies the latest percentage of voltage correlation apparatuses, the power value at normal times, and the voltage value at normal times (the voltage value at normal times when prior to the execution of the voltage control plan, and the current voltage when execution is in progress) to Formula 1, and calculates a voltage target value in each voltage control apparatus 1302.
The voltage target value here must satisfy appropriate voltage restrictions taking into account the voltage drop phenomenon as described in the adjustable-amount-of-demand estimation process illustrated in
The power management apparatus 1102 creates a voltage control plan that satisfies the voltage target value for each voltage control apparatus 1302 (S403). The voltage control plan can be prepared at this time so as to satisfy the restrictions of the pre-instruction period and the post-instruction period. In addition, it is preferable that the plan be one that satisfies an acceptable grid voltage fluctuation (an acceptable range for voltage fluctuations per unit of time that makes it possible to assure grid safety) to prevent the deterioration of the power grid, and to prevent the occurrence of reverse power flows and power outages.
Depending on the type of voltage control apparatus 1302, there are apparatuses that can change the voltage using a continuous value, and there are apparatuses that can only change the voltage using a discrete value. Accordingly, the power management apparatus 1102 selects a voltage control method from the voltage control apparatus table illustrated in
When any of the aforementioned restrictive conditions is not satisfied (S404: NO), the power management apparatus 1102 sends a signal to the demand adjustment plan management apparatus 1202 to the effect that a demand adjustment cannot be executed, creates enough demand adjustment plans to make demand adjustment possible, and moves the processing to Step S303 on
When the power management apparatus 1102 was able to prepare a voltage control plan that satisfies all of the prescribed restrictive conditions (S404: YES), this apparatus 1102 sends the voltage control plan to each of the voltage control apparatuses 1302 (S405) and ends the processing.
The processing for managing the percentage of voltage correlation apparatuses will be explained using
Upon receiving demand adjustment results information from the power information collection apparatus 1402 (S501), the power management apparatus 1102 stores the demand adjustment results information in the demand adjustment results storage part 2118, and, in addition, reads the voltage control plan from the voltage control plan storage part 2117, and compares the demand adjustment results information to the voltage control plan (S502).
When the rate of agreement between the results and the plan is equal to or less than a prescribed value, the power management apparatus 1102 recalculates and updates the percentage of voltage correlation apparatuses based on the demand adjustment results information and the voltage control plan (S502). For example, when the demand adjustment results obtained using a voltage control plan created having a percentage of voltage correlation apparatuses of 60% is around 90 percent of the demand-adjustment-request amount, the power management apparatus 1102 updates the percentage of voltage correlation apparatuses that was used to 60%×0.9=54%.
According to the example, which is configured in this manner, controlling the output voltage value of the voltage control apparatus 1302 that supplies power to a plurality of consumers makes it possible to adjust the power demand for this plurality of consumers atone time. Therefore, according to the example, power demand can be adjusted effectively using a relatively simple control configuration without the need to monitor and control the state of the facilities of each consumer individually.
In the example, it is possible to adjust demand by distributing the adjustment among a plurality of consumers in a relatively widespread manner without forcing a demand adjustment on a specific consumer. Therefore, each consumer's facilities (electrical appliances and machinery) can operate substantially as usual, and power demand can be adjusted without loss of amenities.
In the example, an adjustable amount of demand is estimated and a voltage control plan is prepared by changing the output voltage value of the voltage control apparatus 1302 by taking into account the percentage of electrical appliances and machinery accounted for by voltage correlation apparatuses that change the amount of power received. Therefore, power demand can be adjusted relatively accurately even when consumers have electrical appliances and machinery that include booster circuits and the like.
In the example, the output voltage value is made to change in stages (also includes cases in which the output voltage value is made to change continuously) before the demand adjustment period and after the demand adjustment period. Therefore, demand can be adjusted by smoothly controlling the output voltage.
The present invention is not limited to the example described hereinabove. A person with ordinary skill in the art will be able to make various additions and changes without departing from the scope of the present invention.
Number | Date | Country | Kind |
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2013-210561 | Oct 2013 | JP | national |