This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2014-208979, filed on Oct. 10, 2014, the entire contents of which are incorporated herein by reference.
The embodiments discussed herein are related to a demand adjustment plan generation apparatus, a method, and a recording medium.
Photovoltaic power generation has attracted attention as a clean energy source. For example, when photovoltaic power generation can be effectively utilized and peak-shaving can be realized, it can be expected to achieve the reduction of contract power, the cutting of the scale of the facilities of an electric power company, etc.
The photovoltaic power generation, however, is susceptible to the influence of weather, so that the output of the photovoltaic power generation is unstable. Therefore, various ideas are necessary to be devised in order to effectively utilize the photovoltaic power generation. For example, in order to effectively realize the peak-shaving by using the photovoltaic power generation, different types of distributed power supplies such as a rechargeable battery and a fuel battery are operated, or power demand is adjusted (see, for example, “High-performance photovoltaic generation system having peak-shaving function of receive power with parallel establishment of storage cell”).
In this regard, references are made to Japanese Laid-open Pant Publication No. 2010-204833, Japanese Laid-open Pant Publication No. 2008-43147, Japanese Laid-open Pant Publication No. 2008-141918, Japanese Laid-open Pant Publication No. 2010-41802, and Japanese Laid-open Pant Publication No. 2001-327080.
Further, reference is made to Noriaki TOKUDA, Makoto RYOJI, and Yoshiaki KOHASHI, “High-performance photovoltaic generation system having peak-shaving function of receive power with parallel establishment of storage cell”, Working plan of Building (697), p 37-41, 2008.
According to an aspect of the present invention, a demand adjustment plan generation apparatus generates an operation plan for a plurality of apparatuses to which power is supplied from a photovoltaic power generator and a rechargeable battery serving as power supply sources of the apparatuses, the rechargeable battery being configured to discharge power in a manner such that a deficiency of power, which is generated by the photovoltaic power generator, relative to a power demand of the apparatuses is maintained to be less than or equal to a previously set target value, the demand adjustment plan generation apparatus including a first memory device configured to, when a power demand adjustment is performed on apparatus groups, each of the apparatus groups including at least one apparatus of the plurality of apparatuses, store expected success probabilities of the power demand adjustment for the apparatus groups; a second memory device configured to store a plurality of combinations of time-series power generation amounts generated by the photovoltaic power generator for a predetermined time span and time-series power demand amounts consumed by the plurality of apparatuses for the predetermined time span; and a processor configured to execute a demand adjustment plan generation process. Further, the demand adjustment plan generation process includes referring to the first memory device and the second memory device, forming a distribution of discharge amounts of power, which is supplied from the rechargeable battery, calculated for each of the combinations, based on the time-series power generation amounts and the time-series power demand amounts included in the combinations and the target value, the distribution being formed for each of time periods generated by dividing the time span, each of the discharge amounts having a ratio in the distribution, selecting, for each of the success probabilities and for each of the time periods, a maximum discharge amount from among a plurality of discharge amounts in the distribution in each of the time periods, each of the plurality of discharge amounts having a value, which is calculated by accumulating the ratios of the discharge amounts greater than or equal to each of the discharge amounts, the value being greater than or equal to each of the success probabilities; and allocating, when a current charge amount of the rechargeable battery is less than a necessary amount in each of the time periods, an insufficient amount of the charge amount relative to the necessary amount to the time periods which are on and after each of the time periods in a manner such that the allocated amount does not exceed the maximum values of each of the time periods calculated for each of the success probabilities, and generating the operation plan which includes the insufficient amount allocated to the time periods as adjustment amounts relative to the power demand. Further, in the generating, time periods in which the insufficient amount is allocated with respect to a relatively low success probability are allocated earlier than time periods in which the insufficient amount is allocated with respect to a relatively high success probability.
The objects and advantages of the embodiments disclosed herein will be realized and attained by means of the elements and combinations particularly pointed out in the claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention as claimed.
In related technologies, for example, in the technique as described in “High-performance photovoltaic generation system having peak-shaving function of receive power with parallel establishment of storage cell”, as soon as the charge amount is insufficient and the output of photovoltaic power generation is lowered, load cut-off is forcibly exercised (instructed). This means that the load cut-off which is inconvenient for a user is likely to occur. For example, the load cut-off is sequentially executed in the increasing order of the priority levels. For example, in a case where only loads having higher priority levels are operated, when both the insufficient charge amount and the output reduction of the photovoltaic power generation occur at the same time by chance, as a result, the power supply to the load having a higher priority is cut off.
To prevent such an inconvenience, if the load cut-off to the loads having lower priorities is done without any careful consideration so as to reduce the possibility of the occurrence of the insufficient charge amount, as a result, it's going to be more likely that unnecessary load cut-off is done. In contrast, if the execution of the load cut-off is controlled, it's going to be more likely that the load having a higher priority is cut-off due to insufficient charge amount.
According to an embodiment of the present invention, it becomes possible to alleviate the inconvenience experienced by a user in adjustment of power demand.
In the following, embodiments of the present invention are described with reference to the accompanying drawings.
The power meter 20 is an apparatus which measures the power value of the power externally received via the power network Ne (hereinafter referred to as “received power value”). For example, the power meter 20 measures the received power value from an electric power company.
The load apparatus 40 and the non-target apparatus 50 are apparatuses which have the received power; the rechargeable battery 30 and the photovoltaic power generation system 60 are the supply sources of power. That is, the load apparatus 40 and the non-target apparatus 50 consume the received power, namely the power discharged from the rechargeable battery 30, and the power generated by the photovoltaic power generation system 60. The load apparatus 40 is an apparatus which is to be controlled by the demand adjustment apparatus 10 with respect to the power demand adjustment. For example, the load apparatus 40 is an apparatus to control tuning on/off a lighting device, and an apparatus to control the power of air-conditioning. The non-target apparatus 50 is an apparatus which is not to be controlled with respect to the power demand adjustment by the demand adjustment apparatus 10. The term “power demand adjustment” specifically refers to reducing the power demand or reducing the power supply to the load apparatus 40.
The photovoltaic power generation system 60 is a generation system which generates power using sunlight. The rechargeable battery 30 is a battery which, when the received power value exceeds a peak-shaving target value, realizes peak-shaving by discharging power which corresponds to the excessive value. For example, the charging of the rechargeable battery 30 is performed by using night-time power. Note that the received power value substantially corresponds to the calculation result obtained by subtracting power generated by the photovoltaic power generation system 60 from the power demand (consumption power, energy consumption) by the load apparatus 40 and the non-target apparatus 50.
The demand adjustment apparatus 10 refers to one or more computers which control the rechargeable battery 30, the load apparatus 40, etc., via the network Ni to realize the peak-shaving. For example, when the operations of the demand adjustment system 1 start, the peak-shaving target value is set in the demand adjustment apparatus 10. The “peak-shaving target value” refers to a threshold value relative to the received power value. The demand adjustment apparatus 10 monitors the received power value which is measured by the power meter 20, and performs discharging from the rechargeable battery 30 so that the received power value is maintained to be less than the peak-shaving target value. The demand adjustment apparatus 10 performs demand adjustment when it is expected that the received power value cannot be maintained to be less than the peak-shaving target value due to insufficient charge amount.
A program to realize the process performed by the demand adjustment apparatus 10 is provided by using a recording medium 101. When the recording medium 101 which stores the program therein is set in the drive device 100, the program is installed in the auxiliary memory device 102 from the recording medium 101 via the drive device 100. Note that, however, the installation of the program is not necessarily performed from the recording medium 101. For example, the program may be downloaded from another computer via a network. The auxiliary memory device 102 stores not only the installed program but also necessary files and data.
Upon the instructions to start up the program, the memory device 103 reads the program from the auxiliary memory device 102 and stores the program therein. The CPU 104 executes functions related to the demand adjustment apparatus 10 based on the program stored in the memory device 103. The interface device 105 is used as an interface to connect the demand adjustment apparatus 10 to a network.
For example, the recording medium 101 includes a Compact Disc Read-Only Memory (CD-ROM), a Digital Versatile Disc (DVD), and a Universal Serial Bus (USB) memory. Further, for example, the auxiliary memory device 102 includes a Hard Disk Drive (HDD) and a flash memory. The recording medium 101 and the auxiliary memory device 102 correspond to a computer-readable recording medium.
The rechargeable battery control section 12 controls the rechargeable battery 30. For example, the rechargeable battery control section 12 instructs the rechargeable battery 30 via the network Ni to discharge power which corresponds to the difference: (received power value)−(peak-shaving target value). Further, the rechargeable battery control section 12 acquires a remaining charge amount of the rechargeable battery 30 (hereinafter referred to as “charged power amount”) from the rechargeable battery 30 via the network Ni. The charged power amount is reported to the demand adjustment planning section 11.
The demand adjustment planning section 11 generates an operation plan of the load apparatus 40 to adjust the power demand by the load apparatus 40. For example, the demand adjustment planning section 11 generates the operation plan to perform the demand adjustment when it is expected that the received power value cannot be maintained to be less than the peak-shaving target value. In the generation of the operation plan, the peak-shaving target value, the supply and demand scenario, a demand adjustment policy, etc., are used.
The “supply and demand scenario” refers to the data which include a combination of a demand scenario and a power generation scenario. The “demand scenario” refers to the time series data which indicates the transition of the power demand for a certain period (e.g., one day). The “power generation scenario” refers to the time series data which indicates the transition of the generated power by the photovoltaic power generation system 60 for a certain period (e.g., one day). The supply and demand scenario storage section 14 stores a number of supply and demand scenarios whose “demand scenario” and “power generation scenario” differ from each other.
The “demand adjustment policy” refers to the data indicating the policy of the demand adjustment. For example, the demand adjustment policy includes the upper limit of an adjustment amount of demand. The demand adjustment policy is stored in the demand adjustment policy storage section 15.
The load apparatus control section 13 controls the load apparatus 40 based on the operation plan generated by the demand adjustment planning section 11. For example, the load apparatus control section 13 switches the operation mode of the load apparatus 40 to reduce the consumption power of the load apparatus 40.
Details of the demand adjustment planning section 11 are described.
Based on the peak-shaving target value, the supply and demand scenario, etc., the necessary charge amount calculation section 111 calculates a charge amount which is necessary to attain the peak-shaving target value for each of the time periods which are determined by dividing a certain period such as one day (hereinafter referred to as “necessary change amount”). The term “to attain the peak-shaving target value” refers to controlling the received power value to be less than or equal to the peak-shaving target value.
Based on the peak-shaving target value, the supply and demand scenario, the demand adjustment policy, etc., the demand adjustable amount calculation section 112 calculates the upper-limit evaluation value of the adjustable range of the power demand by the load apparatus 40 (hereinafter referred to as “demand adjustable amount”). The adjustment of the power demand by the load apparatus 40 is performed to reduce the discharge amount of the power from the rechargeable battery 30 for peak-shaving. That is, the demand adjustment of the load apparatus 40 is performed to prevent the occurrence of the insufficient charge amount.
The demand adjustment condition calculation section 113 periodically compares the charge amount which is acquired via the rechargeable battery control section 12 at the moment with the necessary change amount relative to the time period including the moment. When the charge amount is less than the necessary change amount, the demand adjustment condition calculation section 113 calculates a total amount of the power amount which is to be compensated for by the demand adjustment (hereinafter referred to as a “demand adjustment target value”), and further calculates a time period which corresponds to the target of the demand adjustment (hereinafter referred to as a “demand adjustment target period”).
Based on the demand adjustment target value and the demand adjustable amount, the operation plan generation section 114 generates an operation plan to compensate for the insufficient charge amount by performing the demand adjustment on the load apparatus 40 so as to reduce the inconvenience experienced by an operation user of the load apparatus 40 (a user of the load apparatus 40).
In the following, an example procedure of the process performed by the demand adjustment apparatus 10 is described.
For example, when a one-day operation of the demand adjustment system 1 starts, the demand adjustment planning section 11 initializes an operation plan of the load apparatus 40 (step S11). As a result of the initialization of the operation plan, for example, the operation plan is generated in which, for example, zero is set to the data indicating the operation state in a normal state of the apparatus for each of the time periods (planned value) and zero is also set to the data indicating the adjustment amount of the demand adjustment.
Next, when it is time to review the operation plan (every thirty minutes in this embodiment) (YES in step S12), the demand adjustment planning section 11 executes an operation plan generation process (step S13). In the operation plan generation process, when the charge amount at the moment is less than the necessary charge amount, the operation plan is generated to execute the demand adjustment.
Next, when it is time to control the load apparatus 40 (control timing) (every thirty minutes in this embodiment) (YES in step S14), the load apparatus control section 13 performs a control process on the load apparatus 40 based on the operation plan (step S15). The process after the step S12 is periodically executed until the time to terminate the operation (step S16).
Next, details of the process in step S13 are described.
In step S101, the necessary charge amount calculation section 111 calculates a peak-shaving discharge amount and a necessary charge amount for each of the supply and demand scenarios stored in the supply and demand scenario storage section 14. The “peak-shaving discharge amount” is the discharge amount from the rechargeable battery 30 for the peak-shaving.
The supply and demand scenarios include respective demand scenarios and power generation scenarios of 24 hours. The demand scenarios are indicated by dotted lines and the power generation scenarios are indicated by dashed-dotted lines.
The necessary charge amount calculation section 111 first calculates the difference between the demand scenario and the corresponding power generation scenario, that is, (values of the demand scenario)−(values of the power generation scenario), to obtain a supply and demand. The supply and demand is indicated by a solid line. Here, the difference between the supply and demand and the peak-shaving target value, that is, (values of the supply and demand)−(peak-shaving target values) refers to the peak-shaving discharge amount. The peak-shaving target values are indicated by a dashed-two dotted line.
For example, with respect to the scenario “A”, the parts surrounded by respective circles are calculated as the peak-shaving discharge amounts. The peak-shaving discharge amounts are depicted as the bar graphs for respective time periods under the respective supply and demand scenarios.
Further, a necessary discharge amount (necessary charge amount) for each of the time periods can be calculated by accumulating the peak-shaving discharge amounts on and after the time period. For example, the necessary charge amount at 11:00 can be calculated by accumulating the discharge amounts on and after 11:00. The necessary discharge amounts (necessary charge amount) are depicted in the line charts under the respective supply and demand scenarios.
Note that the supply and demand scenario may be generated based on, for example, the forecast using the past record data. Further, for example, one-month average values of the demand in a month corresponding to the execution time periods of the process in
Further, the power generation scenarios may be generated by estimating a solar radiation amount and then estimating the photovoltaic power generation amount based on the solar radiation amount. The estimation of the solar radiation amount may be based on the past record data or weather forecast. For example, when the past record data are used, the past weather record data are used to select the record data depending on weather, so that the change of the average solar radiation amount depending on weather is used as the power generation scenario. Otherwise, for example, a possible power generation scenario may be determined by modeling the past record data or modeling the change of the solar radiation amount.
Further, in this embodiment, for explanatory purposes, a case is described where only three supply and demand scenarios are used. Note that, however, for example tens, hundreds, or thousands of supply and demand scenarios may be used.
Next, the necessary charge amount calculation section 111 acquires the necessary charge amount in consideration of the all the supply and demand scenarios (step S102). Specifically, the necessary charge amount calculation section 111 acquires the necessary charge amount in consideration of all the supply and demand scenarios by selecting the maximum value from among the necessary charge amounts calculated based on the respective supply and demand scenarios for each of the time periods.
Next, based on the peak-shaving discharge amounts calculated based on the respective supply and demand scenarios and the demand adjustment policy, the demand adjustable amount calculation section 112 performs a process of calculating the demand adjustable amount (step S103).
Details of the process in step S103 are described.
In step S111, the demand adjustable amount calculation section 112 generates a histogram for each of the time periods with respect to the peak-shaving discharge amounts (
Next, based on the histograms of the respective time periods, the demand adjustable amount calculation section 112 calculates the demand adjustable amount for each of the time periods on a load apparatus group basis (step S112). Here, the term “load apparatus group” refers to a set of one or more load apparatuses 40 which is a target of the same (similar) demand adjustment at the same time. The demand adjustable amount corresponding to each of the load apparatuses 40 is calculated based on a guarantee level set based on the demand adjustment policy.
The restriction ID refers to the identification information of the data which indicates the restriction in the demand adjustment with respect to the load apparatus group (hereinafter referred to as “restriction data”). For example, the adjustable range and the time period with respect to the power demand may differ depending on the load apparatus groups. The restriction data includes such restrictions. Further, the entity of the restriction data is stored in, for example, the demand adjustment policy storage section 15.
In step S112, the demand adjustment policy stored in the demand adjustment policy storage section 15 is referred to, and with respect for each of the load apparatus groups corresponding to the apparatus group IDs included in the demand adjustment policy, the demand adjustable amounts of the time periods are calculated for each of the guarantee levels corresponding to the load apparatus groups.
In this embodiment, for each of the guarantee levels, the demand adjustable amount to secure the guarantee level is calculated. The securing the guarantee level is estimated based on the supply and demand scenarios. That is, from among all the supply and demand scenarios, the demand adjustable amount by which the demand adjustment can succeed with respect to the 50% supply and demand scenario is calculated as the demand adjustable amount which can secure the 50% guarantee level. In the same manner, from among all the supply and demand scenarios, the demand adjustable amount by which the demand adjustment can succeed with respect to the 95% supply and demand scenario is calculated as the demand adjustable amount which can secure the 95% guarantee level.
In
An object of the demand adjustment is to reduce the peak-shaving discharge amount. Thus, in order for the demand adjustment to succeed, it is desired that the peak-shaving discharge amount is greater than or equal to a demand adjustment amount by the demand adjustment. In other words, with respect to the time period from 13:30 to 14:00, when the demand adjustment amount is 1.3 kWh, the demand adjustment can succeed with the 50% scenario. That is, with respect to the time period from 13:30 to 14:00, the demand adjustable amount which can secure the 50% guarantee level is 1.3 kWh. Here, the “demand adjustment amount” refers to a power amount to be reduced by the demand adjustment to be supplied to (or to be consumed by) the load apparatus 40.
Similarly, the range “a2” refers to a range whose lower limit corresponds to the maximum value of the peak-shaving discharge amount from among the peak-shaving discharge amounts, a ratio of each of the peak-shaving discharge amounts being determined as a sum of the ratios of all the peak-shaving discharge amounts greater than or equal to each of the peak-shaving discharge amounts being greater than or equal to 95%. Here, the lower limit of the range “a2” is 0 kWh. Therefore, in the time period from 13:30 to 14:00, the demand adjustable amount corresponding to the 95% guarantee level is 0 kWh. In other words, in the time period from 13:30 to 14:00, there is no demand adjustable amount so that the demand adjustment can succeed in the 95% supply and demand scenario. This is because, in the time period from 13:30 to 14:00, the ratio of the supply and demand scenario where the peak-shaving discharge amount is zero exceeds 5% of all the supply and demand scenarios.
In the above description, the calculation of the demand adjustable amount with respect to one time period is described. Note that the process described with reference to
Further, in the calculation of the demand adjustable amount, for example, statistical processing such as a bootstrap technique may be used.
In this embodiment, the guarantee level is set to each of the load apparatus groups. This is because, for example, it becomes possible to alleviate the inconvenience experienced by a user due to the demand adjustment. In this regard, it is desired that a relatively lower guarantee level (e.g., 50% guarantee level in this embodiment) is set to a load apparatus group which can relatively easily be targeted to be demand adjusted. The “load apparatus group which can relatively easily be targeted to be demand adjusted” refers to, for example, the load apparatus group whose degree of the inconvenience experienced by a user is relatively low even when the load apparatus group is set to be targeted to be demand adjusted. With respect to the load apparatus group to which the 50% guarantee level is set, insufficient charge amount may be expected. This is because such load apparatus group is likely to be targeted to be demand adjusted even when it is not an imminent danger situation. In this situation, however, it is not requested to ensure that the demand adjustment can succeed. Therefore, 50% success probability is enough.
On the other hand, it is preferable that a relatively higher guarantee level (e.g., 95% guarantee level in this embodiment) is set to a load apparatus group which can be targeted to be demand adjusted only if it is unavoidable and the inconvenience experienced by a user is large if the load apparatus group is demand adjusted. This is because, for example, the load apparatus group, to which the 95% guarantee level is set, is targeted to be demand adjusted in a case where it is desired to resolve the insufficient charge amount with higher probability.
Note that the number of the guarantee levels may be three or more.
Next, the demand adjustable amount calculation section 112 applies the restriction, which is indicated by the restriction data related to the load apparatus group corresponding to the guarantee level, to the demand adjustable amounts of the time periods for each of the guarantee levels (step S113).
Each of the restriction data includes an adjustment upper limit, an inconvenience level, etc., for each start time of the time periods. The “adjustment upper limit” refers to the upper limit value of the demand adjustment amount corresponding to the time period. The “inconvenience level” refers to the degree of the inconvenience experienced by a user when the demand adjustment is performed on the load apparatus group.
As illustrated in graph “g1”, the adjustment upper limit of the restriction data “d1” is constant at 1.0 kWh. On the other hand, as illustrated in graph “g2”, the adjustment upper limit of the restriction data “d2” varies depending on the time periods. Further, in step S113, the restriction, which is applied to the demand adjustable amount, refers to the adjustment upper limit.
In the case of
In the following, the term “demand adjustable amount” refers to the demand adjustable amount which is formed by applying the adjustment upper limit.
Next, in the operation plan generation process, the procedure is described which is executed by the demand adjustment condition calculation section 113 based on the necessary charge amount which is calculated by the necessary charge amount calculation section 111 (
In step S201, the demand adjustment condition calculation section 113 inputs current time “t” and current charge amount “SOC”. The current time “t” refers to the current time at the timing when the process in step S12 of
Next, the demand adjustment condition calculation section 113 compares the “SOC” with the necessary charge amount (t) at the current time “t” (step S202). The “necessary charge amount (t)” refers to the value of the necessary charge amount in
Demand adjustment target value “D”=(necessary charge amount(t))−(SOC) Formula (1)
The demand adjustment target value “D” can be illustrated in a figure as illustrated in
Next, the demand adjustment condition calculation section 113 calculates the time limit by when the demand adjustment is to be completed, and assigns the calculation result (“time limit”) to a variable “t_end” (step S204). The demand adjustment is performed to reduce the peak-shaving discharge amount. Thus, the demand adjustment can be performed while the charge amount remains. Therefore, the time when the necessary charge amount becomes zero is assigned to the variable “t_end”. In
Next, the demand adjustment condition calculation section 113 assigns “1” to a variable “i” (step S205). The variable “1” is used to identify the guarantee level to be processed. Next, the demand adjustment condition calculation section 113 selects the “i”th highest guarantee level (hereinafter “guarantee level (i)”) as the target to be processed (step S206). The “i”th highest guarantee level is identified by, for example, referring to the demand adjustment policy (
Next, with respect to the “i”th highest guarantee level, the demand adjustment condition calculation section 113 calculates the demand adjustment target period (step S207). The demand adjustment target period can be acquired by accumulating the demand adjustable amounts of the time periods from the “t_end” in the time reverse direction until the accumulated value exceeds the demand adjustment target value “D”. In this case, note that an adjustment margin, which is set to the demand adjustment policy, is used for the load apparatus group corresponding to the guarantee level (i). Therefore, strictly, the demand adjustable amounts in the time period are accumulated until the following Formula (2) is satisfied.
ΣDR(T)>D×(1+α) Formula (2)
Where DR(T): demand adjustable amount in time period “T”;
α: adjustment margin
That is, the demand adjustable amounts of the time periods are accumulated until the accumulated amount exceeds the (demand adjustment target value “D”)×(1+α).
Further, in this embodiment, the demand adjustable amounts are accumulated from the “t_end” in the time reverse direction. A reason for this is to delay the time period when the demand adjustment is performed as much as possible. That is, the demand adjustment will cause inconvenience to a user. Therefore, it is preferable that the demand adjustment is not performed as much as possible. Further, in this embodiment, it is determined that the demand adjustment is desired when the SOC is less than the necessary charge amount (t). The necessary charge amount, however, is acquired by selecting the maximum value of all the supply and demand scenarios for each of the time periods as illustrated in
Next, the demand adjustment condition calculation section 113 adds “1” to the variable “i” (step S208). Then, the demand adjustment condition calculation section 113 determines whether there exists the guarantee level (i) based on the demand adjustment policy (
When it is determined that there exists no guarantee level (i) (NO in step S209), the process of the demand adjustment condition calculation section 113 is terminated. On the other hand, when determining that there exists the guarantee level (i) (YES in step S209), the demand adjustment condition calculation section 113 assigns the start time of the demand adjustment target period, which is calculated with respect to the “i−1”th guarantee level, to the variable “t_end” (step S210). Further, it should be noted that any time other than the start time may be assigned to the “t_end” as long as the assigned time is earlier than the start time.
Next, with respect to the guarantee level (i), the process in step S206 is performed, so that the demand adjustment target period relative to the guarantee level (i) is calculated.
In a case where the “i” is “2”, in this embodiment, the process in step S206 with respect to the 50% guarantee level is performed. As a result, the demand adjustment target period as illustrated in part (2) of
As described above, in this embodiment, the demand adjustment is planned (scheduled) so that the demand adjustment corresponding to relatively lower guarantee level is performed earlier. As a result, it becomes possible to alleviate the inconvenience experienced by a user. That is, when the demand adjustment corresponding to relatively lower guarantee level is performed earlier and the demand adjustment succeeds, it becomes possible to increase the likelihood that it is no longer necessary to perform the demand adjustment corresponding to a relatively higher guarantee level.
Next, an example procedure is described which is executed by the operation plan generation section 114 based on the demand adjustment target periods of the respective guarantee levels (load apparatus groups) calculated by the demand adjustment condition calculation section 113.
The operation plan generation section 114 generates the operation plan of the load apparatus 40 based on the demand adjustment target value “D” and the demand adjustable amounts so as to alleviate the inconvenience experienced by a user. The “operation plan of the load apparatus 40” refers to the plan which describes, for example, which level (amount) of the demand adjustment is performed on which load apparatus 40 in which time periods.
In step S301, the operation plan generation section 114 determines whether the demand adjustment target period is calculated by the demand adjustment condition calculation section 113. This determination may be made by determining whether the demand adjustment target period is stored in the memory device 103. Further, this determination corresponds to the determination whether the demand adjustment is desired. That is, when it is determined as YES in step S202 of
When the demand adjustment target period is calculated (YES in step S301), the operation plan generation section 114 distributes the demand adjustment target value “D” in the time periods in the demand adjustment target period for each of the guarantee levels corresponding to the calculated demand adjustment target periods. The distributed results are allocated to the respective time periods as the demand adjustment amounts. For example, the operation plan generation section 114 determines (calculates) optimal demand adjustment amounts for the time periods for each of the demand adjustment target periods “T1” and “T2” acquired for the respective guarantee levels.
That is, when the demand adjustment target period is acquired, the adjustment margin is set. Due to this, the demand adjustment amounts included in each of the demand adjustment target periods are greater than the demand adjustment target value “D”. Therefore, there exists a degree of freedom corresponding to the adjustment margin in the allocation of the demand adjustment amount, which is to be actually applied to the load apparatus 40, to the time periods. Therefore, the operation plan generation section 114 allocates the demand adjustment target value “D” to the time periods so as to alleviate the inconvenience experienced by a user by the demand adjustment.
In distributing the demand adjustment target value “D”, the restriction condition is given by the following Formula (3).
ΣΔD(t)≧D Formula (3)
Here, “D” denotes the demand adjustment target value “D”, and “ΣΔD(t)” denotes the sum of the demand adjustment amounts allocated to the time periods in the demand adjustment target period. That is the “ΔD(t)” denotes the demand adjustment amount allocated to the time period “t” (or time “t”). Further, the “ΔD(t)” is less than or equal to the demand adjustable amount in the time period “t”. Note that, however, it is allowed that the demand adjustment amount is greater than or equal to the demand adjustable amount by the restriction based on, for example, the specification of the load apparatus 40. Such restriction includes, for example, a case where the demand adjustment amount cannot be set to be equal to the demand adjustable amount due to the restriction of the minimum unit of the adjustable consumption power.
The optimal distribution of the demand adjustment target value “D” may be determined by resolving the optimization problem by using the following Formula (4) as the evaluation function under the restriction condition of Formula (3). That is, in this embodiment, the “optimal” refers to the optimal based on the evaluation function
Minimize(Σ(wit×Δdit)) Formula (4)
Where “Minimize(x)” denotes the function to minimize the value of “x”; “wit” denotes a degree of inconvenience relative to the load apparatus group “i” in the time period “t”; and “Δdit” denotes the demand adjustment amount relative to the load apparatus group “i” in the time period “t”. Further, the load apparatus group “i” corresponds to the guarantee level focused in the distribution of the demand adjustment amounts. The “wit” can be acquired from the restriction data (
That is, Formula (4) acquires the distribution (i.e., the value of each Δdit) of the demand adjustment target value “D” in a manner such that the inconvenience experienced by a user can be minimized by obtaining a weighted sum of the demand adjustment amounts in the time periods as the inconvenience, the weighted sum being acquired by using the degree of the inconvenience of the load apparatus group “i” in the time periods as the weighting. Further, the optimization problem related to the distribution of the demand adjustment target value “D” may be resolved by using an evaluation function other than Formula (4).
When such optimization is performed on each of the guarantee levels, for example, as illustrated in
In the demand adjustment plan “p1”, the sum of the demand adjustment amount in the demand adjustment target period “T1” is less than the sum of the demand adjustable amount in the demand adjustment target period “T1”. Similarly, in the demand adjustment plan “p2”, the sum of the demand adjustment amount in the demand adjustment target period “T2” is less than or equal to the sum of the demand adjustable amount in the demand adjustment target period “T2”. This is because the demand adjustment amounts are allocated in a manner such that the restriction condition of Formula (3) is satisfied.
Next, the operation plan generation section 114 generates the operation plan of the load apparatus group corresponding to each of the guarantee levels based on the demand adjustment plan (step S303).
Those operation plans are data including respective demand adjustment amounts allocated to the time periods in the starting time of the time periods. The demand adjustment amounts with respect to the time periods which are not included in the respective demand adjustment target periods are zero.
Further, by generating the demand adjustment plan in which the allocation of the demand adjustment amount is optimized with respect to the guarantee levels, it becomes possible to realize both secure peak-shaving and reduction of the execution of the demand adjustment which makes the inconvenience experienced by a user relatively larger.
Further, in this embodiment, a case is described where the demand adjustment plan is generated so that the demand adjustment target value “D” can be achieved for each of the guarantee levels. Note that, however, the demand adjustment plan for a relatively higher guarantee level is generated so that the peak-shaving can be realized with higher probability. Therefore, the demand adjustment plan for a relatively lower guarantee level may be generated so that, for example, the values less than the demand adjustment target value “D” are distributed in the time periods of the demand adjustment target period by assuming that demand adjustment plan for the relatively higher guarantee level is executed.
On the other hand, in step S301, when the demand adjustment target period is not calculated (NO in step S301), the operation plan generation section 114 generates the operation plan where the demand adjustment amount is zero across the entire time periods for each of the load apparatus groups (step S304). By executing the process of step S304, even when a demand adjustment plan is generated in the previous generation timing of the operation plan so that, based on the demand adjustment plan, an operation plan is generated where a demand adjustment amount greater than zero is set in any of the time periods, it becomes possible to cancel the operation plan.
After step S303 or S304, the operation plan generation section 114 inputs the generated operation plans in the load apparatus control section 13 (step S305).
Next, details of the process in step S15 of
In step S401, the load apparatus control section 13 receives the input of the current time “t” and the operation plan. Then, the load apparatus control section 13 determines whether the demand adjustment amount at the current time “t” is greater than zero in the operation plan relative to the target apparatus group (step S402). When determining that the demand adjustment amount is greater than zero (YES in step S402), the load apparatus control section 13 generates control instructions relative to each of the load apparatuses 40 belonging to the target apparatus group so that the consumption power amount corresponding to the demand adjustment amount by the target apparatus group is reduced, and transmits the control instructions to the load apparatuses 40 (step S403). For example, in a case where the number of the load apparatuses 40 belonging to the target apparatus group is one, the instructions to reduce the consumption amount corresponding to the demand adjustment amount may be transmitted to the one load apparatus 40. Further, for example, in a case where the load apparatuses 40 are the air conditioners whose consumption power varies depending on the selected operation modes (High, Middle, Low, Stop, etc.), the control instructions may be transmitted to change the selected operation mode by selecting the operation mode to lower the consumption power so that the consumption power corresponding to the demand adjustment amounts can be reduced. Further, in a case where the number of the load apparatuses 40 belonging to the target apparatus group is more than one, the load apparatus control section 13 divides and allocates the demand adjustment amount into and to the load apparatuses 40. Any allocation method may be used. It is not always necessary that the demand adjustment amount is equally allocated. For example, in a case where the load apparatuses 40 are lighting devices which can perform only ON/OFF control, the lighting devices to be switched from ON to OFF may be selected so that the consumption power corresponding to the demand adjustment amount can be reduced, and the control instructions to switch from ON to OFF may be transmitted to the selected lighting devices only.
On the other hand, when the demand adjustment amount of the current time “t” is zero (NO in step S402), the load apparatus control section 13 transmits the control instructions which indicates that the demand adjustment amount is set to zero to each of the load apparatuses 40 belonging to the target apparatus group (step S404).
Further, the association information between the load apparatus groups and the load apparatuses 40 is stored in, for example, the auxiliary memory device 102.
Further, in the above description, a case is described where each of the sections included in the demand adjustment planning section 11 performs real-time processing. Note that, however, the input information such as the peak-shaving target value, the supply and demand scenario, and the demand adjustment policy to be input in the necessary charge amount calculation section 111 and the demand adjustable amount calculation section 112 is given in advance. Therefore, it is not always necessary to periodically execute the processes which are performed by the necessary charge amount calculation section 111 and the demand adjustable amount calculation section 112. For example, those processes may be executed at the timing of step S11 of
Further, when the demand adjustment apparatus 10 is specialized for the real-time processing, the necessary charge amount calculation section 111 and the demand adjustable amount calculation section 112 may be included in an external apparatus which is connected to the demand adjustment apparatus 10 via a network.
In
The demand scenario generation section 81 generates the demand scenario which constitutes the supply and demand scenario. The power generation scenario generation section 82 generates the power generation scenario which constitutes the supply and demand scenario.
The necessary charge amount calculation section 111 and the demand adjustable amount calculation section 112 execute the processes of
As described above, according to this embodiment, it becomes possible for the demand adjustment apparatus 10 to detect the likelihood of the insufficient charge amount based on the necessary charge amount calculated based on the supply and demand scenario and perform the demand adjustment in a planned manner to reduce the peak-shaving discharge amount before it becomes impossible to perform the peak-shaving discharge due to insufficient charge amount. As a result, it becomes possible to perform the demand adjustment so as to alleviate the inconvenience experienced by a user of the load apparatus 40 when compared with the case where power which is supplied to the load apparatus 40 is forcibly cut off in a case of insufficient charge amount.
Further, different guarantee levels can be set to each of the load apparatus groups, and the demand adjustment amounts in the time periods are calculated for each of the guarantee levels. Further, for each of the guarantee levels, the insufficient charge amount (demand adjustment target value “D”) is divided into the time periods within a range of the demand adjustable amounts calculated with respect to the guarantee level. In this case, the time periods when the insufficient amount with respect to a lower guarantee level having relatively lower success probability is divided comes earlier than the time periods when the insufficient amount with respect to a higher guarantee level having relatively higher success probability is divided.
As a result, it becomes possible to lower the likelihood that the demand adjustment which cause larger inconvenience is performed.
Further, the plan is generated so that the demand adjustment corresponding to the guarantee levels is performed in a later period as much as possible.
As a result, it becomes possible to realize both secure peak-shaving and reduction of the execution of the demand adjustment which makes the inconvenience experienced by a user relatively larger. That is, not only by reducing the execution of the demand adjustment which is performed on the load apparatus group having a higher guarantee level but whose inconvenience caused by the demand adjustment is relatively large but also by delaying the timing when the demand adjustment having a lower guarantee level but whose inconvenience caused by the demand adjustment is relatively small, it becomes possible to prevent the easy execution of the demand adjustment when a larger necessary charge amount is estimated due to uncertainty of photovoltaic power generation.
Further, the detection of the possibility of the occurrence of the insufficient charge amount is performed based on the necessary charge amount which is largely estimated in consideration of uncertainty of photovoltaic power generation. As a result, it becomes possible to realize a highly secured peak-shaving.
Further, in this embodiment, the demand adjustment apparatus 10 is an example of a demand adjustment plan generation apparatus. The demand adjustment policy storage section 15 is an example of a first memory device. The supply and demand scenario storage section 14 is an example of a second memory device. The demand adjustable amount calculation section 112 is an example of a first calculator. The operation plan generation section 114 is an example of a generator. The necessary charge amount calculation section 111 is an example of a second calculator. The demand adjustment condition calculation section 113 is an example of a third calculator.
All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventors to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of superiority or inferiority of the invention. Although an embodiment of the present invention has been described in detail, it is to be understood that various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.
Number | Date | Country | Kind |
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2014-208979 | Oct 2014 | JP | national |