JP5872441B2 - State estimation device and state estimation method - Google Patents

Description

  Embodiments described herein relate generally to a load survey technique for estimating a state of a device that consumes power.

  Energy management systems (EMS) are becoming widespread against the background of increasing awareness of energy saving (energy saving) and the need for energy self-sufficiency in the event of a disaster. EMS has functions to create operation schedules for consumer equipment (hereinafter collectively referred to as electrical equipment) possessed by electricity consumers (buildings, factories, homes, stores, offices, etc.) and to respond to demand response. Prepare. According to EMS, not only energy saving but also various advantages such as cost saving, reduction of CO2 emission, introduction of renewable energy, etc. are brought about.

  In order to optimally operate a plurality of electrical devices, it is necessary to know the current state of each electrical device. However, it is not advantageous from the viewpoint of cost or the like to provide an electric device with a function of notifying the state or providing a sensor for detecting the state individually. This is especially true in buildings and factories with many electrical devices. In view of this, a technique has been proposed in which a waveform obtained by a sensor connected to a distribution system in a consumer is subjected to harmonic analysis to estimate an operating electrical device.

Japanese Patent No. 4802129 JP 2006-17456 A Japanese Patent No. 3877269

  All of the proposed technologies are aimed at estimating an electric device in operation, that is, estimating on / off of the electric device. However, some recent electrical devices have not only simple on / off but also a plurality of operation modes. When these devices are mixed, it is difficult to cope with existing methods. In addition, it is impossible to determine the device to be turned off according to the demand response unless the operation mode of the operating electric device is known. In some cases, blindly shutting down electrical equipment in factories can cause enormous damage. There is a demand for a technique that can easily estimate not only the on / off state of electrical equipment but also the operation mode.

  An object is to provide a state estimation device and a state estimation method capable of easily estimating an operation mode of an electric device.

  According to the embodiment, the state estimation device includes a calculation unit, a database, and an estimation unit. The calculation unit performs harmonic analysis on the waveform of the power generated in the power feeding system to which the electrical device is connected, and calculates a harmonic component for each order of the active power harmonic. A database memorize | stores the harmonic content rate for every order of a harmonic for every operation mode of an electric equipment. The estimation unit back-calculates the power consumption for each operation mode based on the harmonic content stored in the database from the calculated harmonic components for each order, and estimates the operation mode of the electric device based on the result. .

FIG. 1 is a diagram illustrating an example of an energy management system to which the state estimation device according to the embodiment can be applied. FIG. 2 is a functional block diagram showing an example of the state estimation apparatus 10 shown in FIG. FIG. 3 is a diagram illustrating an example of a waveform of a measurement amount acquired by the measurement apparatus 20. FIG. 4 is a functional block diagram illustrating an example of the calculation unit 11. FIG. 5 is a graph showing an example of harmonic component calculation results (measured harmonic component results) output from the FFT processing unit 111. FIG. 6 is a diagram showing the distribution of the content ratio of the operation mode harmonic component in the operation mode M1. FIG. 7 is a diagram showing the distribution of the content rate of the operation mode harmonic component in the operation mode M2. FIG. 8 is a diagram showing the distribution of the content rate of the operation mode harmonic component in the operation mode M3. FIG. 9 is a diagram showing the distribution of the content rate of the operation mode harmonic component in the operation mode M4. FIG. 10 is a diagram illustrating an example of the transition of the operation mode of the electric device. FIG. 11 is a diagram schematically illustrating an example of processing in the estimation unit 13. FIG. 12 is a schematic diagram for explaining processing by the estimation unit 13. FIG. 13 is a diagram schematically illustrating another example of processing in the estimation unit 13. FIG. 14 is a diagram schematically illustrating another example of processing in the estimation unit 13. FIG. 15 is a diagram schematically illustrating another example of processing in the estimation unit 13. FIG. 16 is a diagram illustrating another example of the energy management system to which the state estimation device according to the embodiment is applicable. FIG. 17 is a schematic diagram illustrating an example of the transition of the operation mode of one device. FIG. 18 is a schematic diagram illustrating an example of transition of operation modes of a plurality of apparatuses. FIG. 19 is a schematic diagram showing damage when the operation is suddenly stopped for each operation mode. FIG. 20 is a diagram showing the damage Pra, the number n of operations, and the power consumption Pm when all devices are stopped arranged for each mode. FIG. 21 is a functional block diagram illustrating another example of the state estimation device according to the embodiment. FIG. 22 is a diagram illustrating an example of operation mode power consumption displayed on the display device by the result display unit 71. FIG. 23 is a diagram illustrating an example of a graph indicating the duration of each mode for each device.

  FIG. 1 is a diagram illustrating an example of an energy management system to which the state estimation device according to the embodiment can be applied. In the embodiment, a building is taken as an example of a consumer. In addition, hospitals, research facilities, schools, factories, etc. can be customers. In FIG. 1, power drawn from a power grid to a bus in the building is distributed from the bus to a local grid 40 on each floor via a feeder, for example.

  The electric devices 30-1 to 30-5 are connected to the local system 40 through an outlet or the like, and function by receiving power supplied from the local system 40, respectively. The electric devices 30-1 to 30-5 are, for example, an air conditioner (air conditioner), a notebook PC, a desktop PC, a copy / printer, and a lighting fixture. In factories and the like, semiconductor manufacturing equipment is also included in electrical equipment.

  A measuring device 20 is connected to a feeder from the bus to the local system 40. The measuring device 20 acquires values of electrical physical quantities such as current, voltage and power supplied to the local system 40 from the feeder (hereinafter collectively referred to as measured quantities). The acquired measurement amount is given to the state estimation device 10.

  The state estimation device 10 estimates the state of the electrical devices 30-1 to 30-5, the consumed power load, the value of active power, and the like based on the measured amount. In the embodiment, in particular, the state estimation device 10 estimates each operation mode of the electric devices 30-1 to 30-5 and power consumption in the operation mode (hereinafter referred to as operation mode power consumption).

  The result of estimation by the state estimation device 10 is passed to the energy management server 50. Based on the information acquired from the state estimation device 10, the energy management server 50 performs control such as peak cut, peak shift, or demand response of consumer energy consumption.

  In addition, although the example which connects the measuring apparatus 20 to the feeder which reaches the 1st floor of a building is shown in FIG. 1, it is not this limitation. For example, the measuring device 20 may be connected to a branch line or a bus line from the electric power system to obtain a measurement amount in the entire building. Moreover, although the example in which the state estimation apparatus 10 and the energy management server 50 are installed in a building monitoring room is shown, this is also an example. Next, a plurality of embodiments will be described.

[First Embodiment]
FIG. 2 is a functional block diagram showing an example of the state estimation apparatus 10 shown in FIG. The state estimation device 10 is realized by, for example, a computer as hardware including a CPU (Central Processing Unit) and a memory and a program as software including instructions executed by the CPU.

  The state estimation device 10 includes a calculation unit 11, a storage unit 12, an estimation unit 13, and a database 14. Among these, the database 14 memorize | stores the active power harmonic component for every operation mode of an electric equipment. That is, the database 14 stores the harmonic content (described later) for each harmonic order for each operation mode of the electric device. By comparing the harmonic component stored in the database 14 in advance with the harmonic component calculation result calculated by the calculation unit 11, it is possible to estimate the operation mode and the operation mode power consumption of the electric device.

  The calculation unit 11 analyzes the waveform of the measurement amount given from the measurement device 20 and calculates the harmonic component of the active power. That is, the calculation unit 11 performs harmonic analysis on the waveform of power generated in the local system 40 and calculates a harmonic component for each order of the active power harmonic. The calculated harmonic component calculation result (harmonic component calculation result) is stored in the storage unit 12 and passed to the estimation unit 13.

  The estimation unit 13 refers to the database 14 based on the harmonic component calculation result, and estimates each operation mode and operation mode power consumption of the electrical device. That is, the estimation unit 13 back-calculates the power consumption for each operation mode based on the harmonic content stored in the database 14 from the harmonic components for each order calculated by the calculation unit 11. Based on the result, the estimation unit 13 estimates the operation mode of the electric device.

  FIG. 3 is a diagram illustrating an example of a waveform of a measurement amount acquired by the measurement apparatus 20. In the graph of FIG. 3, the horizontal axis is time, and the vertical axis is a measured value. Each waveform of voltage V, current I, and power P is shown.

When the instantaneous value of power is p, the instantaneous value of voltage is v, and the instantaneous value of current is i, the relationship of Equation (1) holds.

  As can be seen from Equation (1), if the instantaneous voltage value v and the instantaneous current value i can be obtained as measured quantities, the instantaneous power value p can be obtained by calculation.

  FIG. 4 is a functional block diagram illustrating an example of the calculation unit 11. The calculation unit 11 includes an FFT processing unit 111 as its processing function. The FFT processing unit 111 performs fast Fourier transformation (FFT) on the measurement amount acquired from the measurement apparatus 20 and calculates a harmonic component included in the waveform of the measurement amount for each order. The calculated harmonic component (harmonic component calculation result) is stored in the storage unit 12. The FFT processing can be performed for any of the instantaneous value p of power, the instantaneous value v of voltage, and the instantaneous value i of current.

In many electric power devices, it can be considered that the phases of voltage and current during operation are almost equal, so that the power factor of each harmonic component can be approximated to power factor = 1. On the other hand, harmonic components are corrected as shown in the following equation (1) ′ in an electric device having a large phase difference between the voltage and current during operation.
Harmonic component of active power P = Harmonic component of power P x Power factor of harmonic component
= Harmonic component of power P × cos (θ) (1) ′
θ: Phase difference between voltage and current of harmonic components
Power factor: cos (θ)
FIG. 5 is a graph showing an example of harmonic component calculation results (measured harmonic component results) output from the FFT processing unit 111. In FIG. 5, the horizontal axis indicates the order of harmonics, and the vertical axis indicates the content of harmonic components (harmonic content) for each order. FIG. 5 shows both the harmonic component of the active power P and the harmonic component of the voltage V. The harmonic content rate can be calculated for each harmonic order, and is defined by the following equation (2).

  Next, the contents stored in the database 14 shown in FIG. 2 will be described. 6 to 9 show examples of contents stored in the database 14. These are graphs showing the content of harmonic components for each order in one operation mode of the electric device, with the horizontal axis showing the order and the vertical axis showing the harmonic content for each order. If the operation modes of a certain electrical device are distinguished from each other by expressing them as M1 to MN, FIGS. 6 to 9 show distributions of harmonic content in the operation modes M1, M2, M3, and M4, respectively. The harmonic content for each operation mode is collectively referred to as a harmonic content pattern.

FIG. 10 is a diagram illustrating an example of the transition of the operation mode of the electric device. It is assumed that an electrical device has five operation modes from a start mode immediately after startup to a transition mode, a steady mode 1, a steady mode 2, and an end mode. In each of the operation modes M1, M2, M3, M4, and M5, the operation mode power consumption expressed as active power is expressed as PL1, PL2, PL3, PL4, and PL5.
Note that the method of harmonic analysis is not limited to FFT. For example, a technique such as wavelet transform can be used. Next, the operation of the above configuration will be described.

FIG. 11 is a diagram schematically illustrating an example of processing in the estimation unit 13. First, let the i-th order harmonic content calculated from Equation (2) be αi, the operation mode power consumption be PL, and the i-th order harmonic magnitude of the operation mode power consumption be PL_i. For example, the relationship of Expression (3) is established.

The operation mode power consumption PL of the operation mode including the harmonics up to the Nth order can be expressed by Expression (4) with reference to Expression (3).

When the operation mode power consumption of the operation mode Mj is PLj and the harmonic content of the i-th order is αij, the relationship of Expression (5) is established.

Now, for example, assuming that the loss can be ignored between each operation mode power consumption PL1, PL2, PL3, PL4, PL5 in FIG. 10 and the active power P passing through the measuring device 20, the following equation (6) is satisfied. There is a relationship.

Equation (6) is an equation that considers the presence of a plurality of electric devices. However, if one electric device is provided, equation (6) can also be expressed as equation (7).

Assuming that P includes an Nth-order harmonic and assuming that the i-th harmonic component is Pi, the relationship of Expression (8) is established.

From Expression (8), Expression (4), and Expression (5), the relationship of Expression (9) is established between the i-order harmonic of P and the i-order harmonic of the operation mode power consumption.

When Expression (9) is summarized for each harmonic order and the harmonic orders are considered up to the fifth order, the determinant shown in Expression (10) is obtained.

When Expression (10) is rewritten for operation mode power consumption PL1, PL2, PL3, PL4, and PL5, Expression (11) is obtained.

  In equation (11), αij is an amount stored in the database 14, that is, a known amount. Since P1,..., P5 are harmonic components included in the active power P measured by the measuring device 20 (Equation (8)), the operation mode power consumption PL1, PL2, PL3, PL4, and PL5 can be obtained.

  That is, in FIG. 11, the estimation unit 13 acquires the harmonic components P <b> 1 to P <b> 5 from the storage unit 12, and acquires the harmonic content rate αij from the database 14. And the estimation part 13 carries out back calculation of operation mode power consumption PL1, PL2, PL3, PL4, PL5 based on harmonic content rate alphaij using a harmonic component P1-P5 using Formula (11).

  Since the operation mode power consumption PL1, PL2, PL3, PL4, and PL5 correspond to the operation mode on a one-to-one basis, it becomes possible to estimate the operation mode of the electric device individually. The obtained operation mode power consumption PL1 to PL5 and the operation mode are passed to the energy management server 50 as an estimation result.

FIG. 12 is a schematic diagram for explaining processing by the estimation unit 13. Each of the operation modes M1 to MN has a unique harmonic pattern and active powers PL1 to PLN. The harmonic patterns of the operation modes M1 to MN are indicated by column vectors in the matrix [αij] of the equation (10) and are stored in advance in the database 14. On the other hand, when the measurement amount obtained by the measurement device 20 is FFT processed, Harmonic components (P1 to PN) of active power at the measurement point are obtained. Since P1 to PN are obtained by multiplying PL1 to PLN by the matrix [αij] of Expression (10), PL1 to PLN can be calculated backward by multiplying P1 to PN by the inverse matrix of the matrix [αij]. is there. If PL1 to PLN can be obtained, that is, the operation modes M1 to MN can be specified.

  As described above, in the first embodiment, the measured active power waveform is subjected to harmonic analysis by FFT processing, and the harmonic components P1 to PN for each order are calculated. Further, a harmonic pattern for each operation mode is obtained in advance, and the harmonic content is stored in the database 14. And based on the harmonic content rate, the operation mode of the electric equipment is estimated by calculating back the active powers PL1 to PLN for each operation mode from the harmonic components P1 to PN for each order. Accordingly, the operation mode can be obtained by calculating the operation mode of the electric device from the measurement result at one measurement point (measurement device 20), and the operation mode of the electric device can be easily estimated. Become.

  That is, according to the first embodiment, even if the electrical equipment connected to the local system 40 is installed in a wide area on one floor of the building or the entire building, it is based on the measurement data obtained at one measurement point. Thus, it becomes possible to estimate the operation mode of each electric device. Therefore, it is not necessary to provide a large number of measuring devices, communication facilities, and the like, so that the equipment cost can be reduced. In addition, by specifying the operation mode, it is possible to smartly implement supply and demand control such as peak cut and peak shift in the consumer.

  Furthermore, intelligent response to demand response becomes possible. In other words, there is an operation mode in which electric devices cause damage when stopped. Therefore, it is possible to minimize the cost impact by estimating the operation mode using the method of the embodiment and stopping from the electrical equipment in the operation mode with less damage when demand response is requested. become.

[Second Embodiment]
FIG. 13 is a diagram schematically illustrating another example of processing in the estimation unit 13. 6 to 9 again, it can be seen that there is a characteristic in the content rate (harmonic pattern) of the harmonic component for each operation mode. For example, the operation mode M1 in FIG. 6 is characterized by orders 5, 7, 11, 13, 17, and 19. The operation mode M3 in FIG. 8 is characterized by orders 3, 5, 7, 9, 11, 13, 15, 17, and 19. The operation mode M4 in FIG. 9 is characterized by orders 3, 5, 7, 9, and 11.

Therefore, it is possible to estimate the operation mode with higher accuracy by selecting a characteristic order and substituting it into the equation (11). For example, the operation mode M1 is significant in the 17th order, the 19th order, the operation mode M3 is the third order, the 15th order, and the operation mode M4 is significant in the orders 3, 5, and 7. , 15, and 17 are applied to the expression (11), the expression (11) is expressed as the expression (12).

  In FIG. 13, the estimation unit 13 acquires P3, P5, P7, P15, and P17 among the harmonic components of the active power at the measurement point from the storage unit 12, and obtains the third, fifth, seventh, and 15 from the database 14. It is shown that the next and 17th harmonic content is acquired and the operation mode power consumptions PL1, PL2, PL3, PL4, and PL5 are obtained using Expression (12).

  FIG. 14 is a diagram schematically illustrating another example of processing in the estimation unit 13. Here, a method for correcting the error due to the power loss by estimating the power loss for each harmonic component with the power loss taken into consideration will be disclosed.

In Expression (9), when the power loss due to the i-th harmonic of the j-th operation mode power consumption is expressed as Plosij, the relations of Expression (13) and Expression (14) are established.

  In Equation (13), r represents the resistance applied to the jth operation mode. In Expression (14), QLij represents the i-th harmonic component of the reactive power in the j-th operation mode. Vij represents the i-th harmonic component of the voltage in the j-th operation mode. aij and bij represent constants relating to the approximate expression of the i-th order active power harmonic component of the j-th operation mode power consumption.

When the relationship between Expression (13) and Expression (14) is applied to Expression (10), Expression (10) can be rewritten as Expression (15).

When Expression (15) is rewritten with respect to operation mode power consumption PL1, PL2, PL3, PL4, and PL5, Expression (16) is obtained.

  In Expression (16), γij can be regarded as a known amount, and is stored in the database 14 in advance. Since P1,..., P5 are harmonic components included in the active power P measured by the measuring device 20 (Equation (8)), the operation mode power consumption PL1, PL2 is based on Equation (16). , PL3, PL4, PL5 can be obtained.

  That is, in FIG. 14, the estimation unit 13 acquires the harmonic components P1 to P5 from the storage unit 12, and acquires the coefficient γij obtained by correcting the harmonic content rate αij with the error component from the database 14. And the estimation part 13 back-calculates operation mode power consumption PL1, PL2, PL3, PL4, PL5 based on the corrected harmonic content rate (gamma) ij using harmonic expression P1-P5 (16). Thereby, it becomes possible to estimate the operation mode of an electric equipment separately.

  As described above, in the second embodiment, it is possible to estimate the power loss for each harmonic component, correct the error due to the power loss, and estimate the operation mode, thereby realizing more realistic processing. Is possible.

[Third Embodiment]
FIG. 15 is a diagram schematically illustrating another example of processing in the estimation unit 13. In the first embodiment, it is shown that there is a relationship of Expression (9) and Expression (10) between the harmonic component of the active power P and the harmonic component of the operation mode power consumption. Although the matrix shown in Expression (10) is a square matrix, the number of rows and columns may actually be different. In the third embodiment, a method for dealing with such a situation will be described.

If the left side of Equation (10) is the measured harmonic vector, the column vector in the matrix of Equation (10) is the operation mode harmonic vector, the number of harmonics is m, and the number of electrical devices 5 is n, then Equation (10) 10) can be expressed by an approximate expression as shown in Expression (17).

A vector obtained from the right side of Expression (17) is expressed as measured harmonic approximate value vectors P1 ′, P2 ′,..., Pm ′, and Expression (17) is expressed as Expression (18).

  In the third embodiment, vectors (PL1, PL2,..., PLN) that minimize the difference (error) between the left side of Expression (17) and the left side of Expression (18) are obtained, and this is calculated as the operation mode power consumption PL1. , PL2,..., PLN. Specifically, the error is minimized using the least square method.

The error can be minimized by minimizing the square of each element (denoted as S) of the difference vector between the vector on the left side of equation (17) and the vector on the left side of equation (18). When this is mathematically expressed, Equation (19) is obtained.

  Hereinafter, in order to avoid complications, the sum from i = 1 to i = n is simply displayed as Σ.

A vector (PL1, PL2,..., PLN) that partially differentiates Equation (19) by each of the operation mode power consumption and sets these to 0 (zero) represents the operation mode power consumption. Equation (20) represents a term obtained by partial differentiation of Equation (19) with respect to the j-th operation mode power consumption.

When formula (20) is expanded, formula (21) is obtained.

Determining equation (21) as 0 and obtaining the determinant (22).

The matrix on the right side of Expression (22) is a symmetric matrix, and each element thereof is Σαki × αji (k columns j rows or j columns k rows) and Σαji × αji (diagonal components of j columns j rows). If the condition [number of harmonic orders ≧ number of operation modes] is satisfied, this symmetric matrix becomes a regular matrix (Non-Singular Matrix), and the inverse matrix can be calculated. That is, the vector (PL1, PL2,..., PLN) can be obtained based on the equation (23), and therefore the operation mode and the operation mode power consumption can be calculated.

  That is, in FIG. 15, the estimation part 13 acquires the harmonic components P1-Pm from the preservation | save part 12, and calculates operation mode power consumption PL1, PL2, ..., PLn based on Formula (23). Thereby, it becomes possible to estimate the operation mode of an electric equipment separately.

[Fourth Embodiment]
FIG. 16 is a diagram illustrating another example of the energy management system to which the state estimation device according to the embodiment is applicable. In FIG. 16, it is clearly shown that there is a device type in the electrical equipment. In FIG. 1, the electrical devices 30-1 and 30-2 are referred to as a device A, the electrical devices 30-3 and 30-4 are referred to as a device B, and the electrical device 30-5 is referred to as a device C. In addition, the code | symbol 100 is attached | subjected and shown to a state estimation apparatus.

In the following, for ease of explanation, it is assumed that apparatus A and apparatus B have two operation modes, and apparatus C has one operation mode. The operation mode power consumption in the two operation modes of the apparatus A is referred to as PLA_1 and PLA_2, respectively. The operation mode power consumption in the two operation modes of the apparatus B is assumed to be PLB_1 and PLBA_2, respectively. The operation mode power consumption of the apparatus C is set to PLC_1. Using these variables, Expression (6) can be expressed as Expression (24).

Through the same discussion as in the first embodiment, PLA_1, PLA_2, PLB_1, PLB_2, and PLC_1 can be obtained as in Expression (24) to Expression (25).

Considering the power loss, Expression (16) can be expressed as Expression (26).

  As described above, according to the fourth embodiment, it is possible to specify the power consumption and the operation mode in each device even when there are a plurality of types of electrical equipment.

[Fifth Embodiment]
FIG. 17 is a schematic diagram illustrating an example of the transition of the operation mode of one device. In FIG. 17, the horizontal axis indicates time, and the vertical axis indicates power consumption P in each operation mode. For simplicity, three operation modes are assumed, mode M1 is a transient mode, mode M2 is a steady mode, and mode M3 is an end mode. P1, P2, and P3 respectively indicate power consumption per device in mode M1, power consumption per device in mode M2, and power consumption per device in mode M3.

  FIG. 18 is a schematic diagram illustrating an example of transition of operation modes of a plurality of apparatuses. That is, FIG. 18 is a graph showing the sum of the power consumption shown in FIG. 17 over all the devices, and shows the power consumption in the modes M1, M2, and M3 measured at the measurement points. Of course, the vertical scale of FIG. 18 is longer than the vertical scale of FIG. P1m, P2m, and P3m in FIG. 18 indicate the total power consumption of the mode M1 device, the total power consumption of the mode M2 device, and the total power consumption of the mode M3 device, respectively.

The power consumption of one device in each mode is known as the rated value of the device and is stored in the database 14. Therefore, when the number of operating devices in the operation mode M1 is n1, the number of operating devices in the operation mode M2 is n2, and the number of operating devices in the operation mode M3 is n3, the equation (27) is established.

  As described above, in the fifth embodiment, the number of operating units for each operation mode is calculated by dividing the power consumption for each operation mode obtained by the harmonic analysis by the power consumption per device. Is possible.

[Sixth Embodiment]
FIG. 19 is a schematic diagram showing damage when the operation is stopped for each operation mode. The vertical axis of the graph in FIG. 19 indicates an index Pr representing the magnitude of damage. In the figure, Pr1 indicates damage when one device in mode M1 stops operation. Pr2 indicates damage when one device in mode M2 stops operation. Pr3 indicates damage when one device in mode M3 stops operation. The database 14 stores in advance information that associates an index Pr that means damage (risk) associated with the operation stop for each operation mode.

  FIG. 20 is a diagram showing the damage Pra, the number n of operations, and the power consumption Pm when all devices are stopped arranged for each mode. Subscripts 1, 2, and 3 of Pra, n, and Pm correspond to modes M1, M2, and M3. Since the operating numbers n1, n2, and n3 for each mode can be obtained from the equation (27), the total damage Pr1a, Pr2a, and Pr3a can be obtained by multiplying the operating numbers n1, n2, and n3 by Pr1, Pr2, and Pr3. it can. Since the method for obtaining P1m, P2m, and P3m has already been described, it is omitted here.

  According to FIG. 20, it can be seen that the damage at the time of stoppage is the smallest in mode M2 and increases in the order of mode M1 and mode M3. On the contrary, the load reduction effect due to the operation stop is shown to be higher in the order of mode M3, mode M1, and mode M2. The estimation unit 13 also outputs to the energy management server 50 a risk when the electrical device in the estimated operation mode is stopped. With reference to this result, the energy management server 50 can make a more advantageous operation plan for a demand response, for example. That is, the energy management server 50 can determine the priority of whether or not the operation can be stopped based on the estimated operation mode of the electric device and the risk when the electric device is stopped.

  For example, if the air conditioner is stopped in midsummer, the work efficiency of workers may be reduced, causing damage. Alternatively, when the manufacturing equipment in operation in the factory stops, there is a case where the yield of the product is extremely deteriorated to cause great damage. According to the sixth embodiment, it is possible to prepare for such a situation.

[Seventh Embodiment]
FIG. 21 is a functional block diagram illustrating another example of the state estimation device. In FIG. 21, parts that are the same as those in FIG. 2 are given the same reference numerals, and only different parts will be described here. Note that the state estimation device is denoted by reference numeral 70 to distinguish it from the configuration of FIG.
The state estimation device 70 passes the operation mode power consumption estimated by the estimation unit 13 to the result display unit 71. The result display unit 71 graphically displays the operation mode power consumption in a form such as a trend graph on a display device (not shown) installed in a building monitoring room or the like. The result display unit 71 updates the display content, for example, regularly or every time the operation mode power consumption is calculated.

  FIG. 22 is a diagram illustrating an example of operation mode power consumption displayed on the display device by the result display unit 71. The vertical axis of the graph represents the operation mode power consumption, and the horizontal axis represents time (time). In FIG. 22, the result over 24 hours a day is shown. FIG. 22 shows a graph in which each power consumption in the operation mode M1, the operation mode M2, the operation mode M3, and the operation mode M4 is plotted for 24 hours a day.

  As described above, in the seventh embodiment, the estimation result of the operation mode and the power consumption thereof are visually displayed. This allows users (such as building managers) to visually understand the operation mode and power consumption of electrical equipment in the building, which can be used for supply and demand control such as peak cut and peak shift of power demand. become.

[Eighth Embodiment]
FIG. 23 is a diagram illustrating an example of a graph indicating the duration of each mode for each device. Since the duration of the operation mode is known in advance for each apparatus, this is, for example, tabulated and stored in the database 14. The estimation unit 13 acquires the duration of the operation mode shown in FIG. 23 from the database 14 in addition to the relationship between the damage caused by the operation stop of the apparatus and the load reduction (FIG. 6: sixth embodiment). And the estimation part 13 optimizes the timing of the load control of the electric equipment in the estimated operation mode based on such information.

  That is, the estimation unit 13 calculates the operation stop timing of the apparatus that can obtain the maximum effect in consideration of the duration of the operation mode. As a result, it is possible to perform control that balances both damage due to operation stop and cost reduction by load control.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  30-1 to 30-5 ... electric equipment, 40 ... local system, 20 ... measuring device, 10, 70,100 ... state estimation device, 50 ... energy management server, 11 ... calculation unit, 12 ... storage unit, 13 ... estimation Part, 14 ... database, 71 ... result display part

Claims (10)

A calculation unit that calculates a harmonic component for each order of active power harmonics by performing harmonic analysis on a power waveform generated in a power feeding system to which electrical equipment is connected;
A database for storing the harmonic content for each order of the harmonics for each operation mode of the electrical device;
From the calculated harmonic components for each order, the power consumption for each operation mode is calculated based on the harmonic content rate stored in the database, and the operation mode of the electrical device is estimated based on the result. A state estimation device comprising an estimation unit. The database stores the power consumption for each operation mode as the rated value of the electrical equipment,
The state estimation apparatus according to claim 1, wherein the estimation unit estimates the number of the electrical devices in the estimated operation mode based on the back-calculated power consumption and the rated value. The database previously stores information associating risks associated with operation suspensions for each operation mode,
The state estimation device according to claim 1, wherein the estimation unit outputs a risk when the electrical device in the estimated operation mode is stopped.   The state estimation apparatus according to claim 1, further comprising a display control unit that visually displays the estimated operation mode. The database stores a duration for each operation mode,
The state estimation device according to claim 1, wherein the estimation unit optimizes the timing of load control of an electric device in the operation mode based on the duration of the estimated operation mode. A state estimation method for estimating the state of an electrical device by a computer,
The computer performs harmonic analysis of the waveform of power generated in a power feeding system to which electrical equipment is connected,
The computer calculates a harmonic component for each order of active power harmonics,
The computer stores the harmonic content for each harmonic order in a database for each operation mode of the electrical equipment,
The computer reversely calculates the power consumption for each operation mode based on the harmonic content stored in the database from the calculated harmonic components for each order.
A state estimation method in which the computer estimates an operation mode of the electric device based on the power consumption calculated in reverse. The computer stores power consumption for each operation mode in the database as a rated value of the electrical equipment,
The state estimation method according to claim 6, wherein the estimating includes estimating the number of the electric devices in the estimated operation mode based on the back-calculated power consumption and the rated value. The computer stores in advance in the database information that associates risks associated with the suspension of operation for each operation mode,
The state estimation method according to claim 6, wherein the estimating outputs a risk when the electrical device in the estimated operation mode is stopped.   The state estimation method according to claim 6, wherein the computer further visually displays the estimated operation mode. The computer stores the duration for each operation mode in the database,
The state estimation method according to claim 6, wherein the estimating includes optimizing a load control timing of an electric device in the operation mode based on the duration of the estimated operation mode.

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