JP7355333B2 - Information processing device, information processing method, program - Google Patents

Description

Article 30, Paragraph 2 of the Patent Act applies Publication date: November 5, 2020 Meeting name: 2020 Institute of Electrical Engineers of Japan System/Smart Facility Joint Study Group Publisher: Daichi Higashi, Yoshikazu Fukuyama, Akihiro Oi, Jinzugawa Toru, Hisashi Fujimoto Details of the disclosed invention: Daichi Higashi, Yoshikazu Fukuyama, Akihiro Oi, Toru Jinzugawa, and Hisashi Fujimoto published distribution system state estimation using multiple cross-sections.

The present invention relates to an information processing device, an information processing method, and a program.

A power system generally includes loads such as consumers and a plurality of power facilities that generate power using natural energy. The state value indicating the power of each of these plurality of power facilities is obtained, for example, by optimizing a predetermined objective function using the state value as a variable (for example, Patent Document 1 and Patent Document 2). reference).

Japanese Patent Application Publication No. 2002-51464 Patent Application No. 2015-550285

By the way, in general, when optimizing an objective function, measured values of each of a plurality of nodes in a power system are used, and these measured values are sequentially obtained by a so-called polling method. In such a case, the state value indicating the power of the power equipment will be calculated for each of a plurality of time sections. Therefore, as the number of time sections increases, the number of state values to be calculated also increases, which may cause the problem that state values cannot be calculated with high accuracy when performing optimization of the objective function. .

The present invention has been made in view of the conventional problems as described above, and is capable of calculating the state value of power equipment with high accuracy when measured values indicating the state of the power system are obtained at multiple timings. The purpose of the present invention is to provide an information processing device that can perform the following functions.

The main present invention for solving the above-mentioned problems has a first state value indicating the power of a first power equipment connected to the power grid, and a second state value showing the power of a second power equipment connected to the power grid. The information processing apparatus that calculates , , and at every predetermined period includes an acquisition unit that acquires a measured value indicating the state of the electric power system at each of a plurality of n timings; Optimization of an objective function that includes a system model for estimating the state of the power system, which uses the first state values and the second state values as variables, and a plurality of acquired measured values. and a calculation unit that calculates the n first state values and the second state value.

According to the present invention, when measured values indicating the state of the power system are acquired at a plurality of timings, the state value of the power equipment can be calculated with high accuracy.

1 is a diagram showing the configuration of an information processing device 10. FIG. FIG. 3 is a diagram for explaining a power system 30. FIG. 1 is a diagram for explaining an information processing device 10. FIG. FIG. 3 is a diagram for explaining the timing of acquiring measurement values. 3 is a flowchart illustrating an example of processing executed by the information processing device 10. FIG. 5 is a diagram illustrating an example of an estimated value and a voltage distribution of a power distribution line 41 at timing d=1. FIG.

From the description of this specification and the attached drawings, at least the following matters will become clear.

=====This embodiment =====
<<<Configuration of information processing device 10>>>
FIG. 1 is a diagram showing the configuration of an information processing device 10 that is an embodiment of the present invention. The information processing device 10 is, for example, a device that estimates the state of the power system 30 (described later) shown in FIG. 2, and includes a CPU (Central Processing Unit) 20, a memory 21, a storage device 22, an input device 23, a display device 24, and a communication device 25.

The CPU 20 implements various functions in the information processing device 10 by executing programs stored in the memory 21 and the storage device 22.

The memory 21 is, for example, a RAM (Random-Access Memory), and is used as a temporary storage area for programs, data, and the like.

The storage device 22 is a non-volatile storage unit that stores various data to be executed or processed by the CPU 20.

The input device 23 is a device that receives commands and data input by the user, and includes an input interface such as a keyboard and a touch sensor that detects a touch position on a touch panel display.

The display device 24 is, for example, a device such as a display, and the communication device 25 exchanges various programs and data with other computers via a network (not shown).

<<<An example of the power system 30>>>
FIG. 2 is a diagram illustrating an example of a power system 30 for which the information processing device 10 performs state estimation. The power system 30 is, for example, a 6.6 kV distribution line system, and includes a transformer 40, a distribution line 41, a distributed power source 50, consumers 51 to 54, and sensors S0 to S4. Note that a general power system includes other switches and the like, but for convenience, a simplified power system 30 is shown here as an example.

The transformer 40 transforms the voltage supplied from a power transmission line (not shown) and outputs a voltage of 6.6 kV to the power distribution line 41.

The distributed power source 50 is, for example, a solar power generation facility that supplies power generated by sunlight to the power distribution line 41. In this embodiment, the distributed power source 50 is, for example, a solar power generation facility, but it may also be a facility (for example, a wind power generation facility) that supplies power to the power grid 30 based on other natural energy. It's okay.

Further, in this embodiment, the power (that is, active power, reactive power) that the distributed power source 50 supplies to the distribution line 41 is defined as the "state value x _RE " of the distributed power source 50. However, assuming that the power factor of the distributed power source 50 is predetermined, only the active power may be set as the "state value x _RE ".

The consumer 51 is a person who uses the electric power supplied from the power distribution line 41, and the consumer 51 has power equipment (for example, loads of factories, facilities, etc.) that consume electric power.

Like the consumer 51, the consumers 52 to 54 each have a load that consumes the power supplied from the distribution line 41. In this embodiment, the power (that is, active power, reactive power) of the loads of consumers 51 to 54 is defined as "state value x _L1 " to "state value x _L4 ." However, similarly to the distributed power source 50, the consumers 51 to 54 assume that the power factor of the consumers 51 to 54 is predetermined, and only the active power is expressed as "state value x _L1 " to "state value x _L4 ". Also good.

Here, in this embodiment, the distributed power source 50 corresponds to a "first power facility" and each of the consumers 51 to 54 corresponds to a "second power facility". Further, the “state value x _RE ” of the distributed power source 50 corresponds to the “first state value”, and the “state value x _L1 ” to “state value x _L4 ” of the consumers 51 to 54 correspond to the “second state value”. ”.

The sensor S0 is a measuring device that is installed at a “node A” at a sending end to which the transformer 40 and the power distribution line 41 are connected, and measures system information of the power system 30. Specifically, sensor S0 measures voltage V and current I at "node A" of power distribution line 41, and outputs it as "measured value S."

Sensors S1 to S4 are measuring instruments provided at "nodes B1" to "nodes B4" downstream of "node A" at the power transmission end in the power distribution line 41, respectively. Sensors S1 to S4, like sensor S0, measure system information of each node of power system 30 and output it as "measured value M1" to "measured value M4." Note that although the system information in this embodiment is the voltage V and the current I, the following explanation will focus on the voltage V as appropriate for convenience.

Further, in this embodiment, "node A" corresponds to a "first node", and each of "node B1" to "node B4" corresponds to a "second node". Further, the "measured value S" corresponds to a "first measured value," and each of the "measured values M1" to "measured values M4" corresponds to a "second measured value."

<<<Details of information processing device 10>>>
FIG. 3 is a diagram illustrating an example of information stored in the information processing device 10 and functional blocks implemented.

A system model 60 is stored in the storage device 22 of the information processing device 10. In addition, when the CPU 20 executes a predetermined program, the information processing device 10 implements an acquisition section 70, a calculation section 71, and a state estimation section 72.

The system model 60 is, for example, a model that simulates the power system 30 expressed by a state equation. Although the details will be described later, when the power flow calculation is executed with the distributed power source 50 and the consumers 51 to 54 specified, the system model 60 calculates the estimated values of the voltage, current, phase angle, etc. of the distribution line 41. Output.

The acquisition unit 70 accesses the sensors S0 to S4 by, for example, a polling method every predetermined period T1 (for example, 10 minutes), and collects the measured values of the sensors S0 to S4 at every predetermined time interval (for example, 2 minutes). to get to. Specifically, as shown in FIG. 4, the acquisition unit 70 acquires the “measurement value S” at each of four different timings, and at each of the four timings, the acquisition unit 70 acquires the “measurement value M1” to “measurement value S” at each of the four timings. The values M4'' are acquired one by one.

As a result, the acquisition unit 70 acquires the “measurement value S” and the “measurement value M1” at the timing (d=1), and the “measurement value S” and the “measurement value M2” at the timing (d=2). get. Further, the acquisition unit 70 acquires the “measurement value S” and “measurement value M3” at timing (d=3), and acquires “measurement value S” and “measurement value M4” at timing (d=4). get.

Note that the predetermined period T1 (for example, 10 minutes) is the period until the acquisition unit 70 acquires all the target measurement values, that is, from the timing (d=1) to the timing (d=4). The period is longer than the period (for example, 6 minutes (=2 minutes x 3)).

The calculation unit 71 optimizes a predetermined objective function and calculates the state values of the distributed power source 50 and the customers 51 to 54. Specifically, the calculation unit 71 uses the state values of the distributed power source 50 and the consumers 51 to 54 as decision variables x, and calculates the square of the estimated value of the voltage of the distribution line 41 obtained from the system model 60 and the actual measured value. Optimize the objective function F(x) that minimizes the deviation. Equation (1) is a mathematical expression that indicates the objective function F(x) based on the least squares method, which is calculated in this embodiment,

ここで、“ｄ”は、上述したタイミングであり、“Ｄ”は、時間断面の数（つまり、タイミングの数）であり、“Ｍ”は、センサの数である。また、ｚ_ｄ，ｍは、タイミングｄにおけるセンサｍの計測値であり、ｈ_ｄ，ｍ（ｘ）は、決定変数“ｘ”が与えられた際のタイミングｄにおけるセンサｍのノードの推定値を計算する状態方程式（つまり、系統モデル６０）である。さらに、“ｗ_ｄ，ｍ”は、タイミングｄにおけるセンサｍの計測値と、推定値との偏差の二乗項の重み係数である。

Here, "d" is the above-mentioned timing, "D" is the number of time sections (that is, the number of timings), and "M" is the number of sensors. In addition, z _d,m is the measured value of sensor m at timing d, and h _d,m (x) is the estimated value of the node of sensor m at timing d when the decision variable “x” is given. This is the state equation (that is, the system model 60) to be calculated. Further, “w _d,m ” is a weighting coefficient of the square term of the deviation between the measured value of sensor m at timing d and the estimated value.

In this embodiment, the number of timings is four, so "D"=4, and the number of sensors is five, so "M"=5. Furthermore, the number of timings, 4, corresponds to "n" in the claims.

By the way, as described above, since the distributed power source 50 is a solar power generation facility, the power of the distributed power source 50 changes greatly during the predetermined period T1. Therefore, normally, during the predetermined period T1, changes in the power of the loads of the consumers 51 to 54 are smaller than changes in the power of the distributed power source 50.

Therefore, the calculation unit 71 uses a different "state value x _{RE (d, j)} " as the state value of the output of the distributed power source 50 depending on the timing at which the measured value is acquired. Here, “j” is the j-th distributed power source in the power system 30. In this embodiment, only one distributed power source 50 is provided in the power system 30, so "j"=1. Further, as shown in FIG. 4, for example, the state value of the distributed power source 50 at the timing (d=1) is "state value x _{RE (1, 1)} ".

On the other hand, the calculation unit 71 uses a “state value x _Li ” which is a constant value regardless of the timing at which the measured value is acquired, as the state value of each of the load amounts of the consumers 51 to 54. Here, "i" is the i-th consumer in the power system 30. In this embodiment, the consumers 51 to 54 are the first to fourth consumers, so for example, the state value of the load amount of the consumer 51 is "state value x _L1 ."

In this way, in this embodiment, since the state value "state value x _{RE (d, 1)} " which differs at each timing and the state value "state value x _Li " which is constant regardless of the timing are used, Equation (1) The decision variable "x" in the objective function F(x) is expressed by equation (2).

このため、本実施形態において、例えばタイミング（ｄ＝１）における状態値ｘは、ｘ＝（ｘ_{ＲＥ（ｄ，１）}，ｘ_Ｌ１，ｘ_Ｌ２，ｘ_Ｌ３，ｘ_Ｌ４）の５つとなる。なお、他のタイミング（ｄ＝２～４）における状態値ｘも同様であり、各タイミングにおいて、５つの状態値が含まれることになる。

Therefore, in this embodiment, for example, there are five state values x at the timing (d=1): x=(x _RE(d,1) , x _L1 , x _L2 , x _L3 , x _L4 ). Note that the same applies to the state values x at other timings (d=2 to 4), and five state values are included at each timing.

Further, in this embodiment, the upper and lower limits of the power output by the distributed power source 50 and the upper and lower limits of the power of the loads of the consumers 51 to 54 are determined as shown in equations (3) and (4). .

ここで、式（３）における、ｘ_{ＲＥ（ｄ，ｊ），ｍｉｎ}は、状態値の最小値、つまり設備容量（供給可能電力）の下限値であり、ｘ_{ＲＥ（ｄ，ｊ），ｍａｘ}は、状態値の最大値、設備容量（供給可能電力）の上限値である。また、式（４）における、ｘ_{Ｌｉ，ｍｉｎ}は、状態値の最小値、つまり負荷容量（負荷電力）の下限値であり、ｘ_{Ｌｉ，ｍａｘ}は、状態値の最大値、つまり負荷容量（負荷電力）の上限値である。

Here, in equation (3), x _{RE (d, j), min} is the minimum value of the state value, that is, the lower limit value of the installed capacity (supplied power), and x _{RE (d, j), max} is , the maximum value of the state value, and the upper limit value of the equipment capacity (power that can be supplied). In addition, in equation (4), x _Li,min is the minimum value of the state value, that is, the lower limit value of load capacity (load power), and x _Li,max is the maximum value of the state value, that is, the load capacity (load power). power).

The calculation unit 71 of this embodiment uses the objective function F(x ) is calculated at each of four timings.

なお、図４に示すよう、タイミング（ｄ＝１）の場合、計測値Ｓ，Ｍ１（センサｍ＝１，２の計測値）のみが取得されるため、ｍ＝１，２以外の重み係数“ｗ_ｄ，ｍ”は、例えば“０（ゼロ）”と設定されている。なお、タイミングｄ＝２～４のそれぞれについても、取得される計測値以外の重み係数“ｗ_ｄ，ｍ”は、“０”となる。

As shown in FIG. 4, in the case of timing (d=1), only the measured values S and M1 (measured values of sensors m=1 and 2) are acquired, so the weighting coefficients other than m=1 and 2 are w _d,m ” is set to, for example, “0 (zero)”. Note that for each of the timings d=2 to 4, the weighting coefficient "w _d,m " other than the acquired measurement value is "0".

By executing such a calculation, the calculation unit 71 calculates, for example, the decision variable x for each of the four timings, that is, the "state value x _{RE (d, j)} " of the distributed power source 50 for each of the four timings, and the demand The "state value x _L1 " of each of the houses 51 to 54 can be calculated.

The state estimation unit 72 calculates the “state value x _{RE (d, j)} ” of the distributed power source 50 at each of four timings calculated by the calculation unit 71 and the “state value x _L1 ” of each of the consumers 51 to 54. The state of the power system 30 is estimated using the system model 60 and the system model 60. Specifically, the state estimation unit 72 calculates the voltage distribution of the power distribution line 41 at each of four different timings.

==Example of state estimation processing executed by the information processing device 10==
FIG. 5 is a flowchart illustrating an example of a state estimation process of the power system 30, which is executed by the information processing device 10.

First, the acquisition unit 70 uses a polling method to obtain, for example, four different timings (d=1 to
d=4), the measured values S, M1 to M4 are acquired (S20: acquisition process). Note that, as described above, the acquisition unit 70 acquires the measured value S1 of the upstream power transmission end to which the transformer 40 and the distribution line 41 are connected at every timing (d=1 to 4). Furthermore, the acquisition unit 70 sequentially acquires the measured values M1 to M4 at each timing (d=1 to 4).

Next, the calculation unit 71 uses the state values of the distributed power source 50 and the consumers 51 to 54 as decision variables x, and calculates the square deviation between the estimated value of the voltage of the distribution line 41 obtained from the system model 60 and the actual value. The objective function F(x) to be minimized (see equation (1)) is optimized (S21: calculation process).

Specifically, the calculation unit 71 calculates the decision variable x that minimizes the objective function F(x) at each of four different timings. As a result, the decision variable x, that is, five state values (x _RE(d,1) , x _L1 , x _L2 , x _L3 , x _L4 ) are calculated at each of four different timings (d = 1 to 4). will be done.

Note that FIG. 6 is a diagram for explaining the processing of the calculation unit 71 at the timing d=1 among the four different timings. In FIG. 6, "black circles" indicate actual measured values, and "white circles" indicate estimated values. Based on equation (1), the calculation unit 71 of the present embodiment calculates the distributed power source 50, The state values x of the consumers 51 to 54 are determined.

The state estimation unit 72 calculates the “state value x _{RE (d, j)} ” of the distributed power source 50 at each of four timings calculated by the calculation unit 71 and the “state value x _L1 ” of each of the consumers 51 to 54. The state of the power system 30 is estimated using the system model 60 and the system model 60. As a result, for example, the voltage distribution of the power distribution line 41 shown in FIG. 6 is obtained. Note that FIG. 6 is a diagram showing an example of the voltage distribution at the timing of d=1 among the four different timings.

Note that the information processing apparatus 10 of the present embodiment repeatedly executes the process S10 in FIG. 5 every predetermined period T1 (for example, 10 minutes) that is longer than the period during which all measured values are acquired by the polling method. Therefore, the information processing device 10 can estimate the latest state of the power system 30 every time a measurement value is acquired.

=====Summary=====
The information processing device 10 of this embodiment has been described above. In this embodiment, since measured values are acquired in four time sections by the polling method every predetermined period T1, it is necessary to obtain state values of the power equipment of the power system 30 for each of the four time sections. In the present embodiment, in the predetermined period T1, different state values are set for each of four time sections for the distributed power source 50 with a large change in power, and for consumers 51 to 54 with a small change in power, four state values are set. A state value that is constant over time is set. This allows the calculation unit 71 to reduce the number of state values to be calculated when minimizing the objective function F(x), so in this embodiment, the state values of the power equipment are calculated with high accuracy. can do.

Further, the acquisition unit 70 of the present embodiment acquires the measured value S of the upstream power transmission end (first node) of the power system 30 for every four time sections. The calculation unit 71 calculates the state value of the power equipment of the power system 30 by minimizing the objective function F(x) that includes the square term of the deviation between at least the measured value S on the upstream side of the power system 30 and the estimated value. can be calculated.

Further, the acquisition unit 70 of this embodiment sequentially acquires the measured values M1 to M4 in each of the four time sections. At each timing, the calculation unit 71 calculates an objective function F( By minimizing x), the state value of the power equipment of the power system 30 is calculated. As a result, the state value x can be calculated with higher accuracy. Note that, for example, when minimizing the objective function F(x), for example, a predicted value of the measured value M1 not obtained at timing d2 may be used based on the measured value obtained at timing d1. is also possible. However, if the predicted value is used, the accuracy of the state value x may deteriorate depending on the prediction accuracy. In this embodiment, when minimizing the objective function F(x), a predicted value is not used, so a highly accurate state value x can be obtained.

Further, the calculation unit 71 of the present embodiment calculates that the change in the power of the consumers 51 to 54 is smaller than the change in the power of the distributed power source 50 during the predetermined period T1, and the “state value x _Li ” is constant during the predetermined period T1. Under certain conditions, the state value x that minimizes the objective function F(x) is calculated. Since the objective function F(x) is calculated in consideration of such conditions, in this embodiment, the state value x can be determined with higher accuracy.

Further, the acquisition unit 70 acquires the measured values S, M1 to M4 every predetermined period T1, which is longer than the period until the measured values are acquired, for example, by a polling method. Furthermore, the calculation unit 71 also calculates the state value x every predetermined period T1. Therefore, the information processing device 10 can estimate the state of the power grid 30 each time a measured value of the power grid 30 is acquired using, for example, a polling method.

Furthermore, in the present embodiment, a solar power generation facility, for example, is used as the distributed power source 50 whose power changes during the predetermined period T1 is larger than that of the consumers 51 to 54. Then, the state values of such equipment are changed for each time section, and the state values of the customers 51 to 54 are kept constant over a plurality of time sections. Note that although solar power generation equipment has been described as an example of equipment in which power changes are large (or severe) during the predetermined period T1, other equipment (for example, an electric furnace) may be used. Furthermore, although a consumer has been described here as an example of equipment whose power changes are small (or gradual) during the predetermined period T1, other equipment (for example, a fuel cell) may be used.

Further, the state estimating unit 72 of this embodiment estimates the state of the power system 30 using the calculated state value x and the system model 60. As a result, the voltage distribution and the like of the power system 30 in each of a plurality of time sections can be obtained.

The above-described embodiments are provided to facilitate understanding of the present invention, and are not intended to be interpreted as limiting the present invention. Further, the present invention can be modified and improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof.

10 Information processing device 20 CPU
21 Memory 22 Storage device 23 Input device 24 Display device 25 Communication device 30 Power system 40 Transformer 41 Distribution line 50 Distributed power sources 51 to 54 Consumers 60 System model 70 Acquisition unit 71 Calculation unit 72 State estimation unit S0 to S4 Sensor

Claims (9)

Information processing that calculates, at predetermined intervals, a first state value indicating the power of a first power facility connected to the power system and a second state value indicating the power of a second power facility connected to the power system. A device,
an acquisition unit that acquires a measured value indicating the state of the power system at each of a plurality of n timings;
A system model for estimating the state of the power system, which uses the n first state values and the second state value at each of the n timings as variables, and a plurality of acquired measurements. a calculation unit that calculates the n first state values and the second state value by performing optimization of an objective function including the n values;
An information processing device comprising: The information processing device according to claim 1,
The plurality of measured values are
A first measurement value of a first node provided upstream of a node to which the first power equipment is connected in the power system and a node to which the second power equipment is connected,
The acquisition unit includes:
obtaining the first measurement value at each of the n timings;
An information processing device characterized by: The information processing device according to claim 2,
The plurality of measured values are
including a plurality of second measurement values of each of a plurality of second nodes downstream of the first node in the power system,
The acquisition unit includes:
Sequentially acquiring at least one measurement value of the plurality of second measurement values at each of the n timings;
An information processing device characterized by: The information processing device according to any one of claims 1 to 3,
The calculation unit includes:
The optimization of the objective function is performed on the condition that the power that changes in the second power equipment is smaller than the first power equipment in the predetermined period, and the n first state values and the calculating a second state value;
An information processing device characterized by: The information processing device according to any one of claims 1 to 4,
The predetermined period is a period longer than a period during which the acquisition unit acquires the plurality of measured values,
The acquisition unit acquires the plurality of measured values within the predetermined period,
The calculation unit calculates the n first state values and the second state value for each predetermined period;
An information processing device characterized by: The information processing device according to any one of claims 1 to 5,
The first power facility is a facility that supplies power to the power system based on natural energy,
the second power equipment is a load that consumes power from the power system;
An information processing device characterized by: The information processing device according to any one of claims 1 to 6,
a state estimation unit that estimates the state of the power system at each of the n timings based on the calculated n first state values and second state values and the system model;
An information processing device further comprising: A computer calculates, at predetermined intervals, a first state value indicating the power of a first power facility connected to the power system and a second state value indicating the power of a second power facility connected to the power system. An information processing method, comprising:
an acquisition process of acquiring a measured value indicating the state of the power system at each of a plurality of n timings;
A system model for estimating the state of the power system, which uses the n first state values and the second state value at each of the n timings as variables, and a plurality of acquired measurements. a calculation process of calculating the n first state values and the second state value by performing optimization of an objective function including the n values;
An information processing method characterized by comprising: A computer that calculates, at predetermined intervals, a first state value indicating the power of a first power facility connected to the power system and a second state value indicating the power of a second power facility connected to the power system. ,
an acquisition process of acquiring a measured value indicating the state of the power system at each of a plurality of n timings;
A system model for estimating the state of the power system, which uses the n first state values and the second state value at each of the n timings as variables, and a plurality of acquired measurements. a calculation process of calculating the n first state values and the second state value by performing optimization of an objective function including the n values;
A program to run.

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