JP2015037371A - Supply and demand control device - Google Patents

Abstract

In a power system, when calculating an output command value to a generator and a storage battery that are subject to supply and demand control, a conventional method that directly uses a distribution result of economic load distribution using demand prediction is used to predict demand. There was a high possibility that the supply-demand balance would be disrupted if the risk was lost. An output correction amount that needs to correct an output of a generator is calculated from a local requirement amount, and an output distribution ratio to each generator that has an economic load distribution so as to satisfy a power demand prediction value is calculated, A supply and demand control device that adjusts the power generation output of the generator so that the output ratio of each generator approaches the distribution ratio of the economic load distribution after satisfying the output correction amount. [Selection] Figure 1

Description

  The present invention relates to a power supply / demand control apparatus for an electric power system, and more particularly, to a cooperative control method of economic load distribution control (EDC) and load frequency control (LFC).

  In recent years, power generation facilities using renewable energy such as solar power generation and wind power generation have been actively introduced. However, since the amount of power generated using these renewable energy is controlled by the weather, there is a problem that the output is unstable (uncertain). In the power grid, the balance between supply and demand for generated power and load power must be balanced, but if power generation equipment using renewable energy with unstable power output is connected to the power system, the supply and demand for generated power and load power will be The balance is lost, causing frequency fluctuations.

  Conventionally, control of the frequency of the power system is governed by governor-free operation that is performed by a generator alone for demand fluctuations with a short period, and from the central power supply command center for demand fluctuations with a longer period. Is responsible for output control. Output control from the central power supply command center is performed by economic load distribution control (EDC) and load frequency control (LFC). Economic load distribution control (EDC) is performed on demand that fluctuates over a long period of several tens of minutes, and the output of the generator that is the most economical (low cost) after satisfying the forecast result of power demand The distribution is calculated, and the EDC target generator is controlled according to the distribution. Load frequency control (LFC) is applied to demand that fluctuates in a short cycle of several tens of seconds to several minutes. Based on the current supply-demand imbalance (supply-demand difference), LFC targets The generator is controlled (see, for example, Patent Document 1). When there are a large number of generators as in a large-scale system, even if the EDC target and LFC target generators are separated, the LFC capacity (power generation capacity that can be compensated by LFC) can be obtained only with the LFC target generator. Such a conventional control method is also effective if it can be secured sufficiently.

  However, in the case of a small and medium-sized power system such as a microgrid that generates and consumes power in a small area, the number of generators is small. If the control is separately performed, the LFC capacity may be insufficient.

  Therefore, in the case where the number of generators is limited, such as small and medium-sized power systems, the number of generators that can be used for LFC is secured by performing coordinated control that shares the generators with EDC and LFC. It is considered desirable to ensure LFC capacity.

The inventions described in Patent Documents 2 and 3 realize the coordinated control of LFC and EDC by using a long-period component of AR (Area Requirement), which is a difference between supply and demand, to correct the EDC command value. Yes.
Here, a calculation method (known technique) of the regional requirement amount AR will be described. There are three calculation methods for the local requirement AR by the following load frequency control (LFC) method.
1. Constant frequency control (Flat Frequency Control, FFC)
AR [kW] =-system constant [% kW / Hz] × system capacity [kW] × frequency deviation [Hz]
The frequency deviation is defined by the difference between the system frequency and the reference frequency (rated frequency). The reference frequency is 50 Hz or 60 Hz in Japan. The system constant and the system capacity are constants specific to the target power system.
2. Frequency deviation interconnection power control system (Tie Line Load Frequency Control, TBC)
AR [kW] =-system constant [% kW / Hz] × system capacity [kW] × frequency deviation [Hz] + interconnection point power flow deviation [kW]
The linkage point tidal current deviation is defined by the difference between the linkage point tidal current and the linkage point tidal current target value. The tidal current is positive in the direction from the grid to the local grid.
3. Constant line power control system (Flat Tie Line Control, FTC)
AR [kW] = Linkage point tidal current deviation [kW]
The definition of the interconnection point power flow deviation is the same as in the case of the above TBC.

JP 2007-143375 A JP 2001-238355 A JP 2013-62953 A

  However, in the inventions described in Patent Document 2 and Patent Document 3, load distribution by economic load distribution control (EDC) satisfies the supply-demand balance with respect to the demand prediction value, and thus when the demand prediction is out of order. Is likely to be overpowered or deficient in generated power, and there is a high possibility that the supply-demand balance cannot be maintained. Therefore, the present invention has been made to solve the above-described problem, and when the demand prediction is lost by using the distribution result to the generator obtained by EDC using the demand prediction value as a distribution ratio for control. However, the present invention is to provide a supply and demand control device that makes it difficult for excess and deficiency of power generation to occur and can maintain a balance between supply and demand.

  A supply and demand control device according to the present invention that solves the above-described problems is a supply and demand control device for a power system having a plurality of generators, and calculates a regional requirement amount using a system frequency, a system capacity, and a reference frequency. Using an amount calculation unit, an output correction amount conversion unit that calculates an output correction amount that needs to correct the output of the generator from the regional requirement amount, fuel cost characteristics and upper and lower limits of the output of each generator An economic load distribution so as to satisfy a preset power demand, an economic load distribution calculation unit for calculating a distribution ratio of the output to each of the generators, and after satisfying the output correction amount, And a power command value distribution calculation unit that adjusts the power generation output of the generator so that the output ratio of the machine approaches the distribution ratio.

  According to the supply and demand control apparatus of the present invention, the demand forecast is lost by indirectly using the distribution result to each generator calculated by the economic load distribution (EDC) as the distribution ratio in the load frequency control (LFC). Even in such a case, a highly reliable power system that can maintain a balance between supply and demand can be realized.

It is a figure showing the structure of the supply-and-demand control apparatus of Example 1 and Example 2. FIG. 6 is a flowchart illustrating an operation procedure of load frequency control according to the first and second embodiments. It is a flowchart which shows the operation | movement procedure of the generator allocation amount calculation part of Example 1. FIG. It is a flowchart which shows the operation | movement procedure of the generator allocation amount calculation part of Example 2. It is a figure showing the structure of the supply-and-demand control apparatus of Example 3. 12 is a flowchart illustrating an operation procedure of a distribution amount calculation unit according to the third embodiment.

<Example 1>
Hereinafter, with reference to FIG. 1, the outline | summary and structure of the supply-and-demand control apparatus in one Embodiment of this invention are demonstrated. FIG. 1 shows the configuration of the supply and demand control device 100, the generator 200 to be controlled, and the storage battery 300.

The supply and demand control device 100 receives the frequency and connection point flow of the power system, the power generated by the generator, the charge / discharge power of the storage battery, the remaining capacity of the storage battery, and the predicted power demand, and the generated power and storage battery for the generator 200. Calculation / command of charge / discharge power to 300 is given. The supply and demand control device 100 is a computer such as a personal computer or a PLC (Programmable Logic Controller), and is mounted with a memory, a transmission device (not shown) such as a CPU and a LAN. In the memory of the supply and demand control apparatus 100, an economic load distribution calculation unit 110, a memory 120 for storing the calculation result of the economic load distribution, a regional requirement amount calculation unit 130, an output correction amount conversion unit 140, a power command value distribution amount A calculation unit 150 is implemented. The power supply / demand control apparatus 100 of the present invention configured as described above is characterized in that the electric power command value distribution is made so that the output ratio of the generator and the storage battery is close to the distribution ratio that is the output of the economic load distribution calculation unit 110. The quantity calculator 150 distributes the output to the generator and the storage battery. Each component of the supply-and-demand control apparatus of this invention provided with such a characteristic is demonstrated below.
Input information to the supply and demand control apparatus 100 will be described below. The following various information that is measurement information is measured at each measurement point and then transmitted to the supply and demand control apparatus 100.

The frequency is measured from one point of the power system.
The connection point tidal current is a measurement of the tidal current at the connection point with the connected power system.
The generated power is obtained by measuring the generated power (unit: [kW]) that is the output of the controlled generator, and is measured individually when there are a plurality of generators.

The charge / discharge power of the storage battery is obtained by measuring the charge / discharge power (unit: [kW]) of the storage battery to be controlled, and is individually measured when there are a plurality of storage batteries.
The remaining capacity of the storage battery is obtained by measuring the remaining capacity of the storage battery to be controlled, and is individually measured when there are a plurality of storage batteries. The remaining capacity of the storage battery may be measured by measuring the remaining capacity as 0 to 100 [%] with respect to the full charge capacity, or in units such as [kWh].

  The predicted power demand value is input information used by the economic load distribution calculation unit 110 (EDC), and when the EDC processes, for example, at a cycle of one minute, a value predicted from the power demand after one minute is used. In the present invention, the power demand predicted value is handled as a set value for setting the predicted value.

In addition, the fuel cost characteristics representing the efficiency of the generator, the upper and lower limits of the output of the generator and the storage battery, and the constraint condition of the output change rate are also set.
The economic load distribution calculation unit 110 receives the power demand prediction value as input, and distributes the load to each generator using the known incremental fuel cost method (equal λ method) or the like so as to be most economical. calculate. The load distribution is stored in the memory 120. For example, when there are three generators A to C (not shown), distribution results of 50 [kW] for the generator A, 30 [kW] for the generator B, and 40 [kW] for the generator C were obtained. At that time, the distribution result is stored in the memory 120 as an output distribution value. In this embodiment, the economic load distribution calculation unit 110 performs the above calculation at a cycle of 1 minute, and updates the information stored in the memory 120.

  The output distribution value stored in the memory 120 calculated by the economic load distribution calculation unit 110 is used for load frequency control (LFC) in a 1-second cycle described below. The flow of LFC control will be described below with reference to FIGS.

The regional requirement amount calculation unit 130 calculates the regional requirement amount AR (supply / demand imbalance) from the system frequency, the reference frequency (rated frequency), the interconnection point flow, and the like (step S11 in FIG. 2).
The output correction amount conversion unit 140 multiplies the regional requirement amount AR obtained by the regional requirement amount calculation unit 130 by a control coefficient, and converts it into an output correction amount P that requires correction to the output of the generator and storage battery to be controlled. (Step S12 in FIG. 2). For example, when the load frequency control is performed by PID control, the output correction amount P (necessary generated power) is calculated as in the following equation.

Output correction amount P = control coefficient (proportional gain Kp, integral gain Ki, differential gain Kd) × region required amount AR
Here, it can be said that the output correction amount P is a total value of electric power that needs to be corrected for the outputs of the generator and the storage battery.

  The power command value distribution amount calculation unit 150 calculates the output distribution of how the output correction amount P calculated by the output correction amount conversion unit 140 is distributed to the generator and storage battery to be controlled. The generated power command value (or charge / discharge power command value) is an output command value given to the generator (or storage battery), and its unit is [kW].

The electric power command value distribution amount calculation unit 150 includes a correction amount division unit 151, a generator distribution calculation unit 152, and a storage battery distribution calculation unit 153, which will be described below.
The correction amount dividing unit 151 corrects the output correction amount P calculated by the output correction amount conversion unit 140 by a generator according to some standard or a predetermined logic (Pg_total: N generators). 2) and a correction amount to be compensated by the storage battery (Pl_total: total value of M storage batteries) (step S13 in FIG. 2). For example, in order to control the remaining capacity (State of Charge, SOC) so as to bring the remaining capacity of the storage battery close to the target value, allocate as much load as possible to the generator, and allocate to the storage battery the amount that cannot be allocated due to the output constraints of the generator A method is conceivable. For example, when the output correction amount P is 100 [kW], the upper limit of 80 [kW] that can be covered by the generator is set as Pg_total, and the remaining 20 [kW] is set as Pl_total. It is possible to allocate to storage batteries.

  The generator distribution calculation unit 152 distributes the correction amount (Pg_total) to be compensated by the generator calculated by the correction amount dividing unit 151 to N generators (1) to (N) (not shown) (see FIG. 2). Step S14).

The distribution method of the generator distribution calculation unit 152 in the first embodiment is one of the realizing methods for bringing the output ratio of the generator close to the distribution ratio of economic load distribution.
First, the generator distribution calculation unit 152 acquires the output distribution value to each generator from the memory 120 storing the result calculated by the economic load distribution calculation unit 110. Based on the output distribution value, the generator distribution calculation unit 152 calculates the distribution coefficient (K (1) to K (n)) of each generator using Equation 1 (step S21 in FIG. 3). The distribution coefficient is obtained by normalizing the output distribution value so that the total output value of all the generators is 1.

K (1) = Ga_edc (1) / (Ga_edc (1) + Ga_edc (2) +… + Ga_edc (n)) Equation 1
K (2) = Ga_edc (2) / (Ga_edc (1) + Ga_edc (2) +… + Ga_edc (n))
...
K (n) = Ga_edc (n) / (Ga_edc (1) + Ga_edc (2) +… + Ga_edc (n))
However, Ga_edc (1), Ga_edc (2),... Ga_edc (n) are output distribution values to the generators (1) to (N) calculated by the economic load distribution calculation unit 110.

  Next, the generator distribution calculation unit 152 calculates the output ratio coefficient (L (1) to L (n)) of each of the N generators based on the actual output value of each generator using Equation 2 (step S22). ). The output ratio coefficient is a coefficient normalized so that the total value of the actual output values of all the generators is 1.

L (1) = Ga_past (1) / (Ga_past (1) + Ga_past (2) +… + Ga_past (n)) Equation 2
L (2) = Ga_past (2) / (Ga_past (1) + Ga_past (2) +… + Ga_past (n))
...
L (n) = Ga_past (n) / (Ga_past (1) + Ga_past (2) +… + Ga_past (n))

However, Ga_past (1), Ga_past (2),... Ga_past (n) are actual output power values (generated power) at the present time of each generator.

  Next, the generator distribution calculation unit 152 compares the distribution coefficient calculated in step S21 with the output ratio coefficient calculated in step S22, and allocates a correction amount (Pg_total) to be compensated by the generator. Is set (step S23).

An example of the priority setting method is given below.
When Pg_total is positive, for each generator, calculate the difference between K (i) and L (i) (K (i) -L (i) (i = 1, 2, ..., n)) The order of priority of generators is set higher in descending order. When Pg_total is negative, the difference between K (i) and L (i) is calculated for each generator, and the priority order of the generators is set lower in descending order of the difference. The difference between K (i) and L (i) is the difference between the distribution ratio, which is the ideal ratio obtained by economic load distribution, and the output ratio, which is the ratio of the current output. It is used as an evaluation index representing generally (distance). In the first embodiment, the output ratio is brought closer to the distribution ratio by allocating the correction amount so that the distance between the two ratios approaches zero.

  Next, the generator distribution calculation unit 152 allocates all the correction amounts (Pg_total) to be compensated by the generator to the generator with the highest priority (the generator with priority 1) (step S24). Here, the generator to be allocated is called an allocated generator, and the correction amount (corrected power correction amount) allocated to the allocated generator is called an allocated power generation amount. In the first embodiment, in step S24, the generator having the highest priority is set for the allocated generator, and the correction amount (Pg_total) to be compensated by the generator is set for the allocated power generation amount.

When the generator (1) is a generator of priority 1, the correction amounts Pg (1), Pg (2),... Pg (n) assigned to each generator are expressed by Equation 3.
Pg (1) = Pg_total Equation 3
Pg (2) = 0
...
Pg (n) = 0
Next, the generator distribution calculation unit 152 assumes that the correction amount calculated in Equation 5 is added to the current output, and calculates the output ratio coefficient (N (1) to N (n)) of each generator. Calculation is performed using Equation 4 and Equation 5 (step S25).
Ga_out (1) = Pg (1) + Ga_past (1) Equation 4
Ga_out (2) = Pg (2) + Ga_past (2)
...
Ga_out (n) = Pg (n) + Ga_past (n)
However, Ga_past (1), Ga_past (2),... Ga_past (n) are actual output power values (generated power) at the present time of each generator. Ga_out (1), Ga_out (2),... Ga_out (n) are generated power command values of the respective generators.
N (1) = Ga_out (1) / (Ga_out (1) + Ga_out (2) +… + Ga_out (n)) Equation 5
N (2) = Ga_out (2) / (Ga_out (1) + Ga_out (2) +… + Ga_out (n))
...
N (n) = Ga_out (n) / (Ga_out (1) + Ga_out (2) +… + Ga_out (n))
Next, the generator allocation calculation unit 152 for the allocated generators, the allocation coefficient (K (1) to K (n)) calculated in step S21 and the output ratio coefficient (N (1)) calculated in step S25. ... (N (n)) are compared to determine whether or not the correction amount (allocated power generation amount) allocated to the allocated generator is appropriate (step S26). Here, although details will be described later, it is determined that it is appropriate if the correction amount is not too large, and the entire allocated power generation amount is allocated to the allocated generator, and the process proceeds to step S27. If the allocated power generation amount is too large, it is not appropriate and the process proceeds to step S28.

The criteria for determining whether the correction amount is appropriate will be described below.
If Pg_total is positive, the output ratio coefficient N is subtracted from the allocation coefficient K for the allocated generator. If the result (K−N) is positive, the allocation ratio is still added even if the allocated power generation amount is added. Since there is still room for approach, it is determined that the allocation is not excessive. On the other hand, if the result of subtracting the output ratio coefficient N from the distribution coefficient K (K−N) is negative, it will be over-allocated if all Pg_total is allocated to the generator with the highest priority. .

When Pg_total is negative, if the allocation coefficient K is subtracted from the output ratio coefficient N for the assigned generator, and the result (N−K) is positive, it is determined to be valid in the same manner as above and becomes negative. Judge that it is not appropriate in some cases.
Next, the generator distribution calculation unit 152 calculates a correction amount (Pg_hosei) for K and N that is calculated in steps S21 and S25 for the assigned generator. The correction amount (Pg_hosei) is calculated by Expression 6 when the assigned generator is the generator (1) (step S28).

Pg_hosei = K (1) × (Ga_past (1) + Ga_past (2) +… + Ga_past (n) + Pg_total) −Ga_past (1) Equation 6
Next, the generator distribution calculation unit 152 allocates the correction amount (Pg_hosei) calculated in step S28 to the assigned generator (step S29).

  In step S30, the generator distribution calculation unit 152 sets the next highest priority generator to the assigned generator, and sets the remaining correction amount (Pg_total−Pg_hosei) assigned to the assigned power generation amount, and then proceeds to step S25. Returning, the flow of FIG. 3 is repeated until all the correction amounts to be compensated by the generator have been allocated.

When the correction amount allocated to each generator is Pg (1), Pg (2), ... Pg (n), the assigned generator is the generator (1), and the next highest priority generator is the generator (2). In this case, Equation 7 is obtained.
Pg (1) = Pg_hosei Equation 7
Pg (2) = Pg_total −Pg_hosei
Pg (3) = 0
...
Pg (n) = 0
Finally, after all the correction amounts to be compensated by the generators have been allocated, the correction amount allocated to each generator is added to the current output power actual value of each generator, which is the output to each generator. A generated power command value is calculated (step S27). The generated power command value (Ga_out (1) to Ga_out (n)) of each generator is calculated by Expression 8.

Ga_out (1) = Pg (1) + Ga_past (1) Equation 8
Ga_out (2) = Pg (2) + Ga_past (2)
...
Ga_out (n) = Pg (n) + Ga_past (n)
However, Ga_past (1), Ga_past (2),... Ga_past (n) are actual output power values (generated power) at the present time of each generator.

  The output correction amount can also be calculated by using the difference between the generator output ratio and the distribution ratio as an evaluation index, setting the minimization problem using the sum of squares of the difference as an objective function, and solving it using an optimization method. Can be distributed. In that case, since the difference between the output ratio of the generator and the distribution ratio is allocated so as to be the smallest, the output ratio of the generator can be brought closer to the distribution ratio more quickly.

  In addition, as a method of assigning correction amounts, a method of assigning the correction amounts in order from the highest priority, a method of assigning a larger correction amount to a generator with a longer distance according to the above distance, and the like can be considered.

  In the first embodiment, by distributing the output so as to reduce the difference between the distribution ratio of the economic load distribution and the output ratio, it is possible to realize supply and demand control with less influence even when the demand forecast used in the economic load distribution is off. .

In the first embodiment, the output ratio can be reliably brought close to the distribution ratio by assigning the correction amount from the generator having the largest difference between the output ratio and the distribution ratio of each generator.
Also, by distributing all the allocated amounts in order from the generator with the highest priority, the number of generators whose output is changed can be reduced.

  Next, the storage battery distribution calculation unit 153 distributes the correction amount (Pl_total) to be compensated by the storage battery calculated by the correction amount dividing unit 151 to the M storage batteries (step S15 in FIG. 2). The storage battery allocation calculation unit 153 can perform processing in the same manner as in the case of the above-described generator by changing the allocation amount from Pg_total to Pl_total and the allocation number from N to M, and thus the description thereof is omitted. The charge / discharge electric power command value which is an output to each storage battery is output, and the control for one cycle of supply and demand control is completed.

  Note that when the output correction amount P is distributed to the generator and storage battery to be controlled, it is necessary to consider the upper and lower limit constraints and the output change rate constraint of the generator and storage battery, but the invention will be briefly described. For this reason, in this embodiment, the restriction on the output change rate is omitted. The output change rate is the upper and lower limits of the output that can change within a unit time.

The present invention can be applied to any of the three methods of load frequency control (LFC) described above.
The control cycle of the LFC is not limited to 1 second, but may be 3 seconds, for example. The EDC control cycle is not limited to 1 minute, and may be, for example, 5 minutes.

The information stored in the memory 120 may not be the output distribution value itself but only its ratio (referred to as distribution ratio).
The processes of the generator distribution calculation unit 152 and the storage battery distribution calculation unit 153 may be performed first in order to obtain the same result even if the order is changed.

  The distribution ratio of the generators obtained by economic load distribution (EDC) is highly economical, and supply and demand control that takes into account the economic efficiency is performed by performing coordinated control with the LFC using the distribution ratio. Can do.

Further, the correction amount dividing unit 151 divides the correction amount into the generator and the storage battery so that the remaining capacity of the storage battery approaches the target value, thereby reducing the remaining capacity of the storage battery in order to absorb a sudden fluctuation in the supply and demand balance. Because it can be secured, more reliable supply and demand control can be realized.
<Example 2>
The second embodiment is different from the first embodiment in that output information (output ratio) of the generator is not used when the generator distribution calculation unit 152 distributes the output to the generator. Since other components are the same as those in the first embodiment, the description thereof is omitted. Below, the operation | movement procedure of the generator allocation calculation part 152 is demonstrated using FIG.

  First, the generator distribution calculation unit 152 calculates the distribution coefficient (K (1) to K (n)) of each generator from Equation 1 from the output distribution value to each generator calculated by EDC (step 1). S41). The calculation method of the distribution coefficient is the same as that in the first embodiment.

Next, the generator distribution calculation unit 152 calculates the correction amount (Pg (1) to Pg (n)) to each generator based on the distribution coefficient (K (1) to K (n)) using Equation 9. Calculation is performed (step S42 in FIG. 4).
Pg (1) = K (1) x Pg_total Equation 9
Pg (2) = K (2) × Pg_total
...
Pg (n) = K (n) × Pg_total
Finally, the generator distribution calculation unit 152 calculates and outputs the generated power command value (Ga_out (1) to Ga_out (n)), which is an output to each generator, using Equation 10 (step S43 in FIG. 4). .

Ga_out (1) = Pg (1) + Ga_past (1) Equation 10
Ga_out (2) = Pg (2) + Ga_past (2)
...
Ga_out (n) = Pg (n) + Ga_past (n)
However, Ga_past (1), Ga_past (2),... Ga_past (n) are actual output power actual values (generated power) of each generator.

In the second embodiment, the output correction amount P is distributed to each generator based on the distribution ratio for each control cycle. Therefore, when the output ratio of the generator is already close to the distribution ratio, the ratio is set as follows. The output correction amount P can be distributed while keeping it. Therefore, in the second embodiment, when the output ratio of the generator is close to the distribution ratio, the output prediction amount P is distributed to each generator according to the distribution ratio of the economic load distribution, so that the demand forecast used in the economic load distribution Even if the power goes off, supply and demand control can be realized with less influence.
<Example 3>
Example 3 differs from the above example in that a storage battery is added to the target of economic load distribution (EDC), and not only the economics of a certain time section but also the economic load that evaluates economics over a certain time series. It is a point to distribute. The economic load distribution calculation unit 110 has, for example, a demand forecast value for one day. After satisfying the demand that changes every moment, how to distribute the load to the generator and the storage battery, the most economical operation throughout the day. Calculate what will be.

  The components of the third embodiment that are different from the above-described embodiment are an economic load distribution calculation unit 110, a power demand prediction value that is input information thereof, and a distribution calculation unit 160 shown in FIG. Other configurations are the same as those in the first embodiment, and thus the description thereof is omitted.

The power demand prediction value is time series data of the power demand prediction value in a certain time zone. In the present invention, the power demand prediction value is handled as set value information.
The economic load distribution calculation unit 110 according to the third embodiment receives the power demand prediction value as input, and calculates the load distribution to each generator and storage battery so that the entire time schedule is most economical. The calculation method sets the cost of the generator and storage battery in the objective function, sets the upper and lower limit constraints of the generator, the output change rate constraint, the constraint due to the capacity of the storage battery, etc., and applies the optimization method as an optimization problem. Can be solved.

  In the third embodiment, since the output distribution is determined without distinguishing between the generator and the storage battery, the distribution calculation unit 160 performs processing equivalent to the algorithm of the generator distribution calculation unit 152 of the first and second embodiments. The distribution amount for all the control target devices is calculated, and the output command value is output.

  The operation procedure in the distribution calculation unit 160 will be described with reference to FIG. The distribution calculation unit 160 starts the following flow from the point of time when step S12 (calculating the output correction amount P), which is the flow of load frequency control, is completed.

  First, the distribution calculation unit 160, for example, one minute ahead from the output distribution value schedule (for example, the output distribution value for one day) to the control target devices (each generator and each storage battery) obtained by the economic load distribution calculation unit 110. Only the output distribution value is used as an input. The distribution calculation unit 160 calculates the distribution coefficient (K (1) to K (all)) of the control target device using Equation 11 using the output distribution value one minute ahead (step S51). If the number of generators is N and the number of storage batteries is M, the number of devices to be controlled is the total number of N and M units (denoted as all in Equation 11).

K (1) = Ga_edc (1) / (Ga_edc (1) + Ga_edc (2) +… + Ga_edc (all)) Equation 11
K (2) = Ga_edc (2) / (Ga_edc (1) + Ga_edc (2) +… + Ga_edc (all))
...
K (all) = Ga_edc (n) / (Ga_edc (1) + Ga_edc (2) +… + Ga_edc (all))
However, Ga_edc (1), Ga_edc (2),... Ga_edc (all) are output distribution values to the control target device one minute ahead calculated by the economic load distribution calculation unit 110.

  The distribution calculation unit 160 applies the distribution method to the generator as described in the first embodiment and the second embodiment by treating each generator and each storage battery as a control target device without distinguishing each generator and each storage battery. (Pg (1) to Pg (all)) is calculated (step S52).

  Finally, the distribution amount to the control target device calculated in step S52 and the current output power actual value of each generator and each storage battery are added together, and the output command value of the control target device (the generated power command value and the charge / discharge power) The sum of the command values is calculated (step S53). Output command values (Ga_out (1) to Ga_out (all)) of the control target device are calculated by Expression 12.

Ga_out (1) = Pg (1) + Ga_past (1) Equation 12
Ga_out (2) = Pg (2) + Ga_past (2)
...
Ga_out (all) = Pg (all) + Ga_past (all)
However, Ga_past (1), Ga_past (2),... Ga_past (all) are actual output power actual values (generated power and storage battery charge / discharge power) of the control target device.

  In addition, regarding how to approximate the output ratio and the distribution ratio with respect to the control target device including the storage battery, the difference between the output ratio and the distribution ratio as described in Example 1 is used as an evaluation index, and the square of the difference is calculated. Needless to say, a method for solving the minimization problem with the sum as an objective function can be applied. In addition, as a method of assigning the correction amount to all the control target devices, a method of assigning the correction amount in order from the highest priority, or assigning a larger correction amount to a control target device with a longer distance according to the above distance Possible methods.

  In Example 3, when the demand forecast used for economic load distribution is off by distributing the output to the control target device so as to reduce the difference between the distribution ratio of the economic load distribution and the output ratio of the generator and each storage battery. However, supply and demand control with less influence can be realized.

  In the third embodiment, the optimal allocation ratio is obtained by the economic load distribution for all the control target devices, and the output correction amount P is distributed so that the output ratio is close to the distribution ratio. Supply and demand control can be performed.

DESCRIPTION OF SYMBOLS 100 Supply-demand control apparatus 110 Economic load distribution calculation part 120 Memory 130 Area requirement amount calculation part 140 Output correction amount conversion part 150 Power command value distribution amount calculation part 151 Correction amount division part 152 Generator distribution calculation part 153 Storage battery distribution calculation part 160 Distribution Quantity calculation unit 200 Generator 300 Storage battery

Claims (6)

A power supply and demand control apparatus for a power system having a plurality of generators, wherein a regional requirement amount calculation unit that calculates a regional requirement amount using a system frequency, a system capacity, and a reference frequency, and the output of the generator from the regional requirement amount Using an output correction amount conversion unit that calculates an output correction amount that needs to be corrected, and fuel cost characteristics and output upper and lower limit values of each of the generators so as to satisfy a predetermined power demand. And an economic load distribution calculation unit for calculating a distribution ratio of output to each of the generators,
After satisfying the output correction amount, a power command value distribution calculation unit that adjusts the power generation output of the generator so that the output ratio of each generator approaches the distribution ratio;
A supply and demand control device comprising:   The supply / demand control apparatus according to claim 1, wherein the power command value distribution calculation unit adjusts the power generation output of the generator so that a difference between the output ratio and the distribution ratio is small.   The supply / demand control according to claim 2, wherein the power command value distribution calculation unit distributes a part or all of the output correction amount to a generator having the largest difference between the output ratio and the distribution ratio. apparatus.   The supply / demand control apparatus according to claim 2, wherein the power command value distribution calculation unit distributes the output correction amount using a difference ratio between the output ratio and the distribution ratio.   2. The supply and demand according to claim 1, wherein the power command value distribution calculation unit distributes the output correction amount using the distribution ratio when the output ratio of each of the generators is the distribution ratio. Control device.   A demand and supply control device for a power system having a plurality of generators and at least one storage battery, wherein a regional requirement amount calculation unit that calculates a regional requirement amount using a system frequency, a system capacity, and a reference frequency, and the regional request Output correction amount conversion unit for calculating an output correction amount that needs to correct the output of the generator and the storage battery from the amount, fuel cost characteristics and output upper and lower limit values of each generator, and the output of the storage battery Using the lower limit value, an economic load distribution is performed so as to satisfy a preset power demand, and an output ratio of the output to each generator and storage battery is calculated, and the output correction amount is satisfied. And an electric power command value distribution calculation unit for adjusting the power generation output of the generator and the charge / discharge output of the storage battery so that the output ratio of each of the generators and the storage battery approaches the distribution ratio. Supply and demand control apparatus according to claim Rukoto.