JP2014171373A - State estimation device, state estimation method, and state estimation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a state estimation device capable of enabling a user to simultaneously estimate a load amount of the user's apparatus and power loss generated in a distribution line, by using a small number of measurement points.SOLUTION: A state estimation device comprises a harmonic component calculation unit, a database, and a state estimation unit. The harmonic component calculation unit acquires measurement information on power and current supplied to an electric system with which a plurality of apparatuses of a user can be connected, and calculates a first harmonic component which is a harmonic component of the power and a second harmonic component which is a harmonic component of the current. The database can store a relative harmonic content of power required by each of the plurality of apparatuses of the user. The state estimation unit estimates effective power of the apparatus of the user and a resistance value in the electric system by expressing the first harmonic component by first power calculated from the effective power and the relative harmonic content of the apparatus of the user and second power calculated from a resistance value in the electric system and the second harmonic component.

Description

  Embodiments described herein relate generally to a state estimation device, a state estimation method, and a state estimation program that estimate a state of a consumer device used by a consumer.

  It is necessary to implement load control such as peak cut and peak shift as supply and demand control in a consumer such as a building having an EMS such as BEMS linked with a commercial system (power company system). In order to carry out peak cuts, peak shifts, etc., it is necessary to monitor the load amount of each consumer device. However, when there are a large number of consumer devices or in a wide area, a large number of measuring devices and measurement transmission systems are required, and monitoring is often difficult. For this reason, the system which can monitor the load amount of a consumer apparatus with few measurement points is desired.

  In addition, when load control such as peak cut or peak shift is performed, it is necessary to estimate the power loss when the power loss caused by the distribution line and the heat generated by the power loss cannot be ignored.

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

  As described above, when load control is performed as demand and supply control in a consumer such as a building, it is necessary to estimate the load amount of the consumer device and the power loss due to the distribution line with a small number of measurement points. No device has been established that can be estimated at the same time.

  Therefore, the object is to provide a state estimation device, a state estimation method, and a state estimation program capable of simultaneously estimating a load amount of a consumer device and a power loss due to a distribution line with a small number of measurement points. It is in.

  According to the embodiment, the state estimation device includes a harmonic component calculation unit, a database, and a state estimation unit. The harmonic component calculation unit obtains measurement information about power and current supplied to an electrical system to which a plurality of consumer devices can be connected, and a first harmonic component that is a harmonic component of the power, A second harmonic component that is a harmonic component of the current is calculated. The database can record the harmonic content of electric power required by each of the plurality of consumer devices. The state estimating unit includes the first harmonic component, the first power obtained from the active power of the consumer device and the harmonic content, the resistance value in the electric system, and the second harmonic component. The effective power of the consumer device and the resistance value in the electrical system are estimated by the second power obtained from the above.

It is a figure which shows the energy management system which can apply the state estimation apparatus which concerns on 1st Embodiment. It is a figure which shows the waveform of the electrophysical quantity acquired with the measuring apparatus shown in FIG. It is a figure which shows the function structure of the state estimation apparatus shown in FIG. It is a figure which shows the function structure of the harmonic component calculation part shown in FIG. It is a figure which shows the calculation result which computed the component for every order of the harmonic content rate about the electrical physical quantity shown in FIG. 2 by the FFT process part shown in FIG. It is a figure which shows the example of the harmonic content rate pattern currently recorded on the database shown in FIG. It is a figure which shows the example of the harmonic content rate pattern currently recorded on the database shown in FIG. It is a figure which shows the example of the harmonic content rate pattern currently recorded on the database shown in FIG. It is a figure which shows the example of the harmonic content rate pattern currently recorded on the database shown in FIG. It is a figure which shows the example of a connection of the consumer apparatus to the local system | strain shown in FIG. It is a figure which shows the other example of a connection of the consumer apparatus to the local system | strain shown in FIG. It is a figure explaining the process of the state estimation part shown in FIG. In the state estimation apparatus 10 shown in FIG. 3, the figure at the time of calculating active electric power and the electrical resistance of a local system | strain is shown. It is a figure explaining the other process of the state estimation part shown in FIG. It is a figure explaining the other process of the state estimation part shown in FIG. It is a figure explaining the other process of the state estimation part shown in FIG. It is a block diagram which shows the function structure of the state estimation apparatus which concerns on 2nd Embodiment. It is a figure which shows the active power displayed on a display apparatus by the result display part shown in FIG. It is a figure which shows the active power displayed on a display apparatus by the result display part shown in FIG. 17, and the power loss by a local system | strain. It is a block diagram which shows the function structure of the state estimation apparatus which concerns on 3rd Embodiment. It is a figure which shows the electric power loss displayed on a display apparatus by the result display part shown in FIG. It is a figure which shows the ratio of the power consumption with respect to a power loss displayed on a display apparatus by the result display part shown in FIG.

  Hereinafter, embodiments will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram illustrating an example of an energy management system to which the state estimation device 10 according to the first embodiment can be applied. In the present embodiment, a building is taken as an example of a consumer. In addition, hospitals, research facilities, schools, factories, and the like can also be consumers. 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 consumer devices 30-1 to 30-5 are connected to the local system 40 through outlets or the like, and function by receiving power supply from the local system 40, respectively. The consumer devices 30-1 to 30-5 are, for example, air conditioners (air conditioners), notebook PCs, desktop PCs, copy / printers, and lighting equipment. In factories and the like, semiconductor manufacturing equipment is also included in consumer equipment.

  A measuring device 20 is connected to a feeder from the bus to the local system 40. The measuring device 20 acquires electrical physical quantities such as current, voltage, and power supplied from the feeder to the local system 40. The measuring device 20 outputs the acquired electrical physical quantity to the building monitoring room.

  In the building monitoring room, the electrical physical quantity for each floor is received, the effective power of the consumer devices 30-1 to 30-5, the resistance value from the measuring device 20 to the consumer devices 30-1 to 30-5, and The state estimation device 10 that estimates power loss from the measuring device 20 to the consumer devices 30-1 to 30-5, and the active power, resistance value, and power loss estimated by the state estimation device 10 An energy management server 50 that manages the energy state is installed.

  FIG. 2 is a diagram illustrating a waveform example of the electrophysical quantity acquired by the measurement apparatus 20 according to the first embodiment. In FIG. 2, a voltage waveform V, a current waveform I, and a power waveform P are shown as examples of the electrical physical quantity. In FIG. 2, the vertical axis indicates the electrical physical quantity, and the horizontal axis indicates time.

Here, assuming that the instantaneous value of power, the instantaneous value of voltage, and the instantaneous value of current are p, v, and i, respectively, the instantaneous value p of power is

Is required. That is, the instantaneous value p of power can be calculated from the instantaneous value v of voltage and the instantaneous value i of current.

  The state estimation apparatus 10 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) and a RAM (Random Access Memory) including a storage area for programs and data for the CPU to execute processing. . The state estimation device 10 has a function shown in FIG. 3 by causing a CPU to execute a state estimation program. That is, the state estimation device 10 includes a harmonic component calculation unit 11, a storage unit 12, a state estimation unit 13, and a database 14.

  The harmonic component calculator 11 receives the electrical physical quantity supplied from the measuring device 20. The harmonic component calculation unit 11 performs waveform analysis on the electrical physical quantity and calculates a component for each order of the harmonic contained in the electrical physical quantity. The harmonic component calculation unit 11 can calculate a component for each harmonic order among the instantaneous value p of electric power, the instantaneous value v of voltage, and the instantaneous value i of current included in the electrical physical quantity. .

  Harmonics are represented as a collection of sine waves with a constant period and different periods. When the fundamental wave is primary, a wave whose period is 1/2 of the fundamental wave (frequency is twice) is a second harmonic, and a wave whose period is 1/3 of the fundamental wave (frequency is 3 times) is a third harmonic. A wave whose period is 1 / n of the fundamental wave (frequency is n times) is called an nth-order harmonic. When harmonics enter the commercial frequency, the commercial frequency is treated as distorted. The harmonic component can be obtained by Fourier transform or the like. When the observation data is a sampling value, a technique called discrete Fourier transform is used to obtain a harmonic component from the observation data. A method improved so that the discrete Fourier transform can be solved at high speed is called FFT (Fast Fourier Transform), and is the most general method for calculating components for each order of harmonics.

  As shown in FIG. 4, the harmonic component calculation unit 11 includes an FFT processing unit 111 and calculates a component for each harmonic order.

In many consumer devices, it can be considered that the phase of voltage and current during operation is almost equal. Therefore, it is possible to approximate the power factor of each harmonic component as power factor = 1. On the other hand, in a consumer device having a large phase difference between the voltage and current during operation, the harmonic component is corrected as shown in Equation (2).

FIG. 5 is a diagram illustrating an example of a calculation result (hereinafter referred to as a harmonic component calculation result) in which the FFT processing unit 111 calculates a component for each order of the harmonic content rate for the electrical physical quantity illustrated in FIG. . In FIG. 5, the vertical axis represents the harmonic content, and the horizontal axis represents the order of the harmonics. In FIG. 5, the harmonic content rate of the active power P and the voltage V is shown. The harmonic content is calculated for each order of the harmonic and is defined by Equation (3).

The harmonic component calculation unit 11 outputs the calculated harmonic component calculation result and the measurement result of power and current by the measuring device 20 to the storage unit 12. In this embodiment, FFT is used to calculate components for each harmonic order included in the electrical physical quantity. However, components for each harmonic order may be calculated by other methods. .

  The storage unit 12 stores the harmonic component calculation result calculated by the harmonic component calculation unit 11 and the power and current measurement results measured by the measurement device 20.

  The database 14 records the pattern of active power harmonic content for each of the consumer devices 30-1 to 30-5. At this time, the harmonic content pattern may be recorded in the database 14 when the state estimation apparatus 10 is delivered. Further, although the harmonic content pattern is not recorded in the database 14 at the time of delivery, it may be recorded before the state estimation device 10 is used.

  6-9 is a figure which shows the example of the harmonic content rate pattern currently recorded on the database 14. FIG. 6 shows an example of a harmonic content pattern of a copy printer, FIG. 7 shows an example of a harmonic content pattern of a notebook computer, FIG. 8 shows an example of a harmonic content pattern of an air conditioner, and FIG. Shows an example of a harmonic content pattern of general illumination. 6 to 9, the vertical axis represents the harmonic content, and the horizontal axis represents the order of the harmonics.

  Based on the measurement result and the harmonic component calculation result read from the storage unit 12 and the harmonic content pattern read from the database 14, the state estimation unit 13 uses the active power of the consumer devices 30-1 to 30-5, The electric resistance of the local system 40 and the power loss generated by this resistance are calculated.

  Specific processing is shown below. First, it is assumed that five consumer devices 30-1 to 30-5 are connected to the local system 40 in the consumer as shown in FIG. Electric power is supplied to the consumer devices 30-1 to 30-5 from the upper power system via the local system 40. In FIG. 10, the active power supplied to the air conditioner that is the consumer device 30-1 is PL1, and the active power supplied to the notebook computer that is the consumer device 30-2 is PL2, and the consumer device 30-3 The effective power supplied to a certain desktop personal computer is PL3, the effective power supplied to the copy / printer which is the consumer device 30-4 is PL4, and the effective power supplied to the fluorescent lamp which is the consumer device 30-5. Is PL5.

When the harmonic content rate of the i-th order of the active power PL1 of the consumer device 30-1 is α _i1 , the harmonic component PL1 _i of the i-th order of the active power PL1 of the consumer device 30-1 is

Is required. Assuming that the active power of the consumer device 30-1 has an Nth-order harmonic component, the active power PL1 of the consumer device 30-1 is based on equation (4):

Is required.

That is, when the active power of the j-th consumer device 30-j is PLj and the harmonic content of the i-th order of the active power PLj is α _ij , the active power PLj is

Is required.

  Next, it is assumed that five consumer devices 30-1 to 30-5 are connected to the local system 40 in the consumer shown in FIG. In FIG. 11, the local system 40 is a local system 40-1 that is an electrical system for an air conditioner that is connected to an air conditioner or the like, a local system 40-2 that is an underfloor electrical system that is connected to a notebook computer, a desktop personal computer, a copy / printer, It is classified into a local system 40-3 which is a ceiling system connected to a lighting device such as a fluorescent lamp. The local system 40-1 is connected to an air conditioner that is a consumer device 30-1, and the local system 40-2 is a notebook personal computer that is a consumer device 30-2 and a desktop personal computer that is a consumer device 30-3. The copy / printer that is the consumer device 30-4 is connected, and the fluorescent lamp that is the consumer device 30-5 is connected to the local system 40-3.

  As shown in FIG. 11, electric power PL1 is supplied to the air conditioner that is the consumer device 30-1 via the measuring device 20-1 and the local system 40-1. Here, the electric power and the electric current which pass the measuring apparatus 20-1 are set to Pa and Ia, respectively.

  Moreover, electric power PL2 is supplied to the notebook personal computer which is the consumer device 30-2 via the measuring device 20-2 and the local system 40-2. Electric power PL3 is supplied to the desktop personal computer, which is the consumer device 30-3, via the measuring device 20-2 and the local system 40-2. The power / PL4 is supplied to the copy / printer which is the consumer device 30-4 via the measuring device 20-2 and the local system 40-2. Here, the electric power and the current passing through the measuring device 20-2 are Pb and Ib, respectively.

  Moreover, electric power PL5 is supplied to the fluorescent lamp which is the consumer apparatus 30-5 via the measuring device 20-3 and the local system 40-3. Here, it is assumed that the electric power and the current passing through the measuring device 20-3 are Pc and Ic, respectively.

Here, the relationship between the power PL1 supplied to the consumer device 30-1 and the power Pa measured by the measuring device 20-1 is the power loss that occurs when the power PL1 passes through the local system 40-1. Let Ploss1 be

It is expressed.

Similarly, the power PL2 supplied to the consumer device 30-2, the power PL3 supplied to the consumer device 30-3, the power PL4 supplied to the consumer device 30-4, and the measuring device 20-2. The relationship between the power Pb and the power Pb measured by the power PL2, the power PL3, and the power PL4 passing through the local system 40-2 is Plos2, Plos3, and Plos4, respectively.

It is expressed.

Furthermore, the relationship between the electric power PL5 supplied to the consumer device 30-5 and the electric power Pc measured by the measuring device 20-3 is that the electric power loss generated by the electric power PL5 passing through the local system 40-3 is represented by Plos5. If

It is expressed.

Next, Formula (7), Formula (8), and Formula (9) are developed for each harmonic order. Assuming that the i-order harmonic component of the power Pa is Pa _i , the i-order harmonic component of the power PL1 is PL1 _i , and the one resulting from the i-order harmonic of Plos1 is Plos1 _i , the power Pa _i is

It is expressed.

Similarly, the powers Pb _i and Pc _i are

It is expressed.

Furthermore, through the local line 40-1 from the measuring device 20-1, the electrical resistance leading to consumer devices 30-1 and Ra, when the i-order harmonic component of the current Ia and Ia _i, equation (10) ,

Next, assuming that the electrical resistance from the measuring device 20-2 through the local system 40-2 to the consumer devices 30-2 to 30-4 is Rb and the i-order harmonic component of the current Ib is Ib _i , Equation (11) is

It is expressed.

In addition, as a local system 40-3 from the measuring device 20-3, the electrical resistance leading to consumer devices 30-5 and Rc, if the i-order harmonic component of the current Ic and Ic _i, equation (12) ,

It is expressed.

Here, if the relationship of Formula (6) is used for Formulas (13) to (15), the electric power Pa _i , Pb _i , and Pc _i are

It is expressed. Here, in Equation (16), the harmonic content α _i1 is known because it is recorded in the database 14 in advance, and the harmonic component Pa _i of the power and the harmonic component Ia _i of the current are the harmonic component calculation unit. 11 is a known harmonic component result obtained at 11. That is, in the equation (16), the values to be obtained are two values of the power PL1 and the electric resistance Ra. In order to obtain two values of the power PL1 and the electric resistance Ra using the equation (16), two or more independent equations are required.

In the equation (17), the harmonic content ratios α _i2 , α _i3 , and α _i4 are known because they are recorded in the database 14 in advance, and the harmonic component Pb _{i of} power and the harmonic component Ib _i of current are Since it is a harmonic component result acquired by the harmonic component calculation unit 11, it is known. That is, the values to be obtained in Expression (17) are the four values of electric power PL2, PL3, PL4 and electric resistance Rb. In order to obtain the four values of the electric powers PL2, PL3, PL4 and the electric resistance Rb using the equation (17), four or more independent equations are required.

In the equation (18), the harmonic content α _i5 is known because it is recorded in the database 14 in advance, and the harmonic component Pc _i of the power and the harmonic component Ic _i of the current are the harmonic component calculator 11. It is known because it is a harmonic component result obtained in (1). That is, the values to be obtained in Expression (18) are the two values of power PL5 and electric resistance Rc. In order to obtain two values of the power PL5 and the electric resistance Rc using the equation (18), two or more independent equations are required.

When Expression (16) is expressed by k-order harmonics, Expression (16) is

It is expressed. In the equations (16) and (19), the variables are two simultaneous equations and there are two independent equations. That is, the power PL1 and the electric resistance Ra are obtained from these equations.

Further, when Expression (16) and Expression (19) are represented by a matrix,

It is expressed. Since Expression (16) and Expression (19) are independent expressions, the matrix represented by Expression (20) is a regular matrix in which an inverse matrix exists. Therefore, in the equation (20), it is possible to summarize the equations for the power PL1 and the electric resistance Ra,

It becomes. By solving the equation (21), the power PL1 and the electric resistance Ra are obtained.

Moreover, when Expression (17) is expressed by harmonics of k-order, l-order, and m-order,

It is expressed. Equations (17) and (22) to (24) are four simultaneous equations with four variables and four independent equations. That is, from these equations, electric powers PL2, PL3, PL4 and electric resistance Rb are obtained.

Further, when Expression (17) and Expression (22) to Expression (24) are represented by a matrix,

It is expressed. Since the equations (17) and (22) to (24) are independent equations, the matrix represented by the equation (25) is a regular matrix. Therefore, in the equation (25), it is possible to summarize the equations for the powers PL2, PL3, PL4 and the electric resistance Rb.

It becomes. By solving the equation (26), the electric powers PL2, PL3, PL4 and the electric resistance Rb are obtained.

Further, when Expression (18) is expressed by k-th order harmonics,

It is expressed. In the equations (18) and (27), the variables are two simultaneous equations and there are two independent equations. That is, the power PL5 and the electric resistance Rc are obtained from these equations.

Further, when Expression (18) and Expression (27) are represented by a matrix,

It is expressed. Since Expression (18) and Expression (27) are independent expressions, the matrix represented by Expression (28) is a regular matrix in which an inverse matrix exists. Therefore, in the equation (28), it is possible to summarize the equations for the power PL5 and the electric resistance Rc,

It becomes. By solving the equation (29), the power PL5 and the electric resistance Rc are obtained.

Moreover, the electric power loss Plos_a until the electric current Ia which passes the measuring apparatus 20-1 passes along the local system 40-1 from the measuring apparatus 20-1 to the consumer apparatus 30-1 is as follows.

Is required. The current Ia is known because it is measured by the measuring device 20-1.

Further, the power loss Plos_b from the current Ib passing through the measuring device 20-2 to the consumer devices 30-2 to 30-4 through the local device 40-2 from the measuring device 20-2 is

Is required. The current Ib is known because it is measured by the measuring device 20-2.

Furthermore, the power loss Plos_c from the current Ic passing through the measuring device 20-3 to the consumer device 30-5 from the measuring device 20-3 through the local system 40-3 is:

Is required. The current Ic is known because it is measured by the measuring device 20-3.

FIG. 12 is a diagram illustrating the processing of the state estimation unit 13 according to the first embodiment. State estimating unit 13, the harmonic component _Pa i the active power Pa, which is stored in the storage unit 12, Pa _k, and the harmonic component _Ia i of the current Ia, and Ia _k, harmonic content to be recorded in the database 14 By substituting the rates α _i1 and α _k1 into the equation (21), the active power PL1 of the consumer device 30-1 and the electric resistance Ra of the local system 40-1 are calculated. Further, the state estimation unit 13 substitutes the current Ia stored in the storage unit 12 and the calculated electrical resistance Ra into the equation (30), thereby generating electric power generated by the electrical resistance Ra of the local system 40-1. Loss Plos_a is calculated.

The state estimation unit 13 also includes harmonic components Pb _i , Pb _k , Pb _l , Pb _{m of} the active power Pb stored in the storage unit 12 and harmonic components Ib _i , Ib _k , Ib _{l of the} current Ib. , Ib _m and harmonic content α _i2 , α _i3 , α _i4 , α _k2 , α _k3 , α _k4 , α _l2 , α _l3 , α _l4 , α _m2 , α _m3 , α _m4 recorded in the database 14. Is substituted into the equation (26), the active power PL2 of the consumer device 30-2, the active power PL3 of the consumer device 30-3, the active power PL4 of the consumer device 30-4, and the local system 40 -2 electrical resistance Rb. In addition, the state estimation unit 13 substitutes the current Ia stored in the storage unit 12 and the calculated electrical resistance Rb into the equation (31), thereby generating electric power generated by the electrical resistance Rb of the local system 40-2. Loss Plos_b is calculated.

The state estimation unit 13 also includes harmonic components Pc _i and Pc _{k of} the active power Pc stored in the storage unit 12 and harmonic components Ic _i and Ic _{k of the} current Ic and harmonics recorded in the database 14. By substituting the wave contents α _i5 and α _k5 into the equation (29), the active power PL5 of the consumer device 30-5 and the electric resistance Rc of the local system 40-3 are calculated. Further, the state estimation unit 13 substitutes the current Ic stored in the storage unit 12 and the calculated electrical resistance Rc into the equation (32), thereby generating electric power generated by the electrical resistance Rc of the local system 40-3. Loss Plos_c is calculated.

FIG. 13 is a schematic diagram for calculating, for example, the active powers PL2 to PL4 and the electric resistance Rb of the local system 40-2 in the state estimation device 10 according to the first embodiment. The state estimation unit 13 multiplies the harmonic content pattern for each device recorded in the database 14 by the active powers PL2 to PL4 of the consumer devices 30-2 to 30-4 and the current at the measurement point. Consumer equipment 30-2 to 30- so that the sum of the square of the higher harmonics multiplied by the resistance Rb of the local system 40-2 becomes the harmonics Pb _{i to} Pb _m of the active power at the measurement point. 4 active powers PL2 to PL4 and the resistance Rb of the local system 40-2 are obtained.

  As described above, in the first embodiment, the harmonic component calculation unit 11 calculates the harmonic component of the active power and the harmonic component of the current measured by the measuring device 20. The database 14 records the harmonic content rate patterns for the plurality of consumer devices 30-1 to 30-5 in advance. The state estimation unit 13 determines the harmonic component of the active power from the power obtained from the active power and the harmonic content of the consumer devices 30-1 to 30-5, and the harmonic component of the resistance value and current by the local system 40. It is expressed by the electric power obtained from The state estimation unit 13 estimates the active power and the resistance value of the local system 40 for each of the consumer devices 30-1 to 30-5 by using power in a plurality of orders. Thereby, the state estimation apparatus 10 only receives the measured value of the electric power and electric current supplied to the electric power grid | system 40 from the measuring apparatus 20, and the active electric power in the consumer apparatus 30-1 to 30-5, the local electric grid 40 It is possible to estimate the electrical resistance of the.

  In the first embodiment, the state estimation unit 13 uses the calculated electrical resistance to calculate a power loss due to the electrical resistance. As a result, the state estimation device 10 can estimate the power loss due to the electrical resistance of the local system 40 only by receiving the measurement values of the power and current supplied to the power system 40 from the measurement device 20.

  Therefore, according to the state estimation apparatus 10 which concerns on 1st Embodiment, in a consumer, the load amount of a consumer apparatus, the resistance of a distribution line, and the power loss by a distribution line can be estimated simultaneously with few measurement points. it can. That is, in a customer such as a building having an EMS such as BEMS, which is often difficult to monitor when there are a large number of customer devices or in a wide area, the load amount for each customer device and each customer device occur. It becomes possible to monitor the power loss, and it becomes easy to implement peak cut and peak shift as supply and demand control.

  In the first embodiment, when the active power PL1 and the electrical resistance Ra are obtained, the i-th order and k-order harmonics are used, and when the active powers PL2, PL3, PL4 and the electrical resistance Rb are obtained. In the above description, the i-th and k-order harmonics are used as an example when the active power PL5 and the electrical resistance Rc are obtained using the i-th, k-th, l-th and m-th harmonics. However, it is not limited to this. For example, the state estimation unit 13 may select a characteristic harmonic based on the harmonic characteristic of each consumer device.

  For example, the harmonic content of the copy / printer shown in FIG. 6 is characterized by orders 5, 7, 11, and 13. The harmonic content of the notebook computer shown in FIG. 7 is characterized by orders 3, 5, 7, 9, 11, 13, 15, 17, and 19. The harmonic content of the air conditioner shown in FIG. 8 is characterized by orders 3, 5, 7, 9, 11, 13, 15, 17, and 19. Further, the harmonic content of the general illumination shown in FIG. 9 is characterized by orders 3, 5, 7, 9, and 11.

  The state estimation unit 13 selects an order characterized by the harmonic content rate, and calculates using the selected harmonic content rate. Thereby, the state estimation part 13 becomes easy to obtain | require the active power of the consumer apparatus 30. FIG. For example, the harmonic content of the copy / printer is particularly characteristic of the 11th and 13th orders, the harmonic content of the air conditioner is particularly characteristic of the 3rd and 15th orders, and the harmonic content of general lighting is the 3rd order. There are special features in the fifth and seventh orders. That is, for example, when the third, fifth, seventh, eleventh, and thirteenth harmonics are selected in the formula (21), the formula (26), and the formula (29), the state estimation unit 13 selects the active power and Easy to calculate electrical resistance.

  More specifically, the state estimation unit 13 sets i = 3 and k = 5 assuming that the third order and the fifth order are selected in the equation (21). It is also effective to select the fundamental wave component (first order), i = 1, k = 3.

  In addition, the state estimation unit 13 sets i = 3, k = 5, l = 7, and m = 13 by selecting the third, fifth, seventh, and thirteenth orders in the equation (26). It is also effective to select the fundamental wave component (first order), i = 1, k = 3, l = 5, and m = 7.

  Moreover, the state estimation part 13 sets i = 3 and k = 5, selecting the 3rd order and the 5th order in Formula (29). It is also effective to select the fundamental wave component (first order), i = 1, k = 3.

FIG. 14 is a diagram for explaining the above-described processing of the state estimation unit 13 according to the first embodiment. The state estimation unit 13 includes the harmonic components Pa ₃ and Pa _{5 of} the active power Pa stored in the storage unit 12 and the harmonic components Ia ₃ and Ia _{5 of the} current Ia and the harmonic content recorded in the database 14. By substituting the rates α ₃₁ and α ₅₁ into the equation (21), the active power PL1 of the consumer device 30-1 and the electric resistance Ra of the local system 40-1 are calculated. Further, the state estimation unit 13 substitutes the current Ia stored in the storage unit 12 and the calculated electrical resistance Ra into the equation (30), thereby generating electric power generated by the electrical resistance Ra of the local system 40-1. Loss Plos_a is calculated. The harmonics may be i = 1 and k = 3.

The state estimation unit 13 also includes harmonic components Pb ₃ , Pb ₅ , Pb ₇ , Pb _{13 of} the active power Pb stored in the storage unit 12 and harmonic components Ib ₃ , Ib ₅ , Ib _{7 of the} current Ib. , Ib ₁₃ and harmonic content α ₃₂ , α ₃₃ , α ₃₄ , α ₅₂ , α ₅₃ , α ₅₄ , α ₇₂ , α ₇₃ , α ₇₄ , α ₁₃₂ , α ₁₃₃ , α ₁₃₄ recorded in the database 14. Is substituted into the equation (26), the active power PL2 of the consumer device 30-2, the active power PL3 of the consumer device 30-3, the active power PL4 of the consumer device 30-4, and the local system 40 -2 electrical resistance Rb. In addition, the state estimation unit 13 substitutes the current Ia stored in the storage unit 12 and the calculated electrical resistance Rb into the equation (31), thereby generating electric power generated by the electrical resistance Rb of the local system 40-2. Loss Plos_b is calculated. The harmonics may be i = 1, k = 3, l = 5, and m = 7.

The state estimation unit 13 also includes harmonic components Pc ₃ and Pc _{5 of} the active power Pc stored in the storage unit 12 and harmonic components Ic ₃ and Ic _{5 of the} current Ic and harmonics recorded in the database 14. By substituting the wave contents α _i5 and α _k5 into the equation (29), the active power PL5 of the consumer device 30-5 and the electric resistance Rc of the local system 40-3 are calculated. Further, the state estimation unit 13 substitutes the current Ic stored in the storage unit 12 and the calculated electrical resistance Rc into the equation (32), thereby generating electric power generated by the electrical resistance Rc of the local system 40-3. Loss Plos_c is calculated. The harmonics may be i = 1 and k = 3.

  In the first embodiment, the case where the electrical resistance is the same regardless of the order of the harmonics has been described as an example. However, it is not limited to this. The state estimation unit 13 may estimate the active power of the consumer device and the resistance value for each order when the distribution line resistance value varies depending on the harmonic order.

  When different types of distribution line cables are used for the local systems 40-1 to 40-3 and some parallel circuits are included in the electric circuit, the distribution line resistance may differ depending on the order of the harmonics. . This is because a distribution line cable has an inductance component and a capacitance component, and therefore, when different types of distribution line cables and parallel circuits are mixed, a frequency component appears in the resistance component of the electrical system. Since the frequency varies depending on the order of the harmonics, in such a case, the resistance of the electric system also varies depending on the harmonics.

The local system 40-1 will be described as an example. It is assumed that the harmonic component of the electrical resistance of the local system 40-1 differs between the i-th order, the k-th order, and the l-order. Here, the harmonic components of the electrical resistance of the i-th, k-th, and l-order local systems 40-1 are _denoted as Ra _i , Ra _k , and Ra _l , respectively.

Expressions (16) and (19) are cases where the electrical resistance of the local system 40-1 does not vary depending on the order. Therefore, when Expression (16) and Expression (19) are expanded so that the harmonic components of the electrical resistance of the local system 40-1 are different between the i-th order, the k-th order, and the l-order, the electric power Pa _i , Pa _k , Pa _l. Is

It is expressed.

In Expression (33), Expression (34), and Expression (35), the variables are power PL1, electric resistances Ra _i , Ra _k , and Ra _l , and the number of expressions is three equations. Therefore, one formula is not enough to find an independent solution. Therefore, the following approximation is performed. That is, when the average value of the Ra _i and Ra _k and _{Ra ik,}

It is expressed. Using the relationship of Equation (36), Equation (33) and Equation (34) are

It is expressed. Since the expressions (37) and (38) are independent expressions, the state estimation unit 13 can obtain the powers PL1 and Ra _ik from the expressions (37) and (38). State estimating unit 13, using the PL1 determined, determine the Ra _k from equation (34) obtains the Ra _l from Equation (35). Furthermore, the state estimation unit 13 obtains Ra _i from Expression (36).

Further, power loss due to i-th order harmonics and Plos_a _i, the power loss due to the k-th order harmonics and Plos_a _k, the power loss due l harmonics and _{Plos_a l, Plos_a i, Plos_a k} , Plos_a l Respectively

It is expressed.

FIG. 15 is a diagram for explaining the above-described processing of the state estimation unit 13 according to the first embodiment. In FIG. 15, the local system 40-1 will be described as an example. State estimating unit 13, the harmonic component _Pa i the active power Pa, which is stored in the storage unit _12, Pa k, Pa _l, and the harmonic component _Ia i of the current _Ia, Ia k, and Ia _l, the database 14 By substituting the recorded harmonic content α _i1 , α _k1 , α _l1 into the equations (33) to (38), the active power PL1 of the consumer device 30-1 and the electricity of the local system 40-1 resistance _{Ra i, Ra k,} calculates a Ra _l. The state estimating unit 13, the current _Ia i which is stored in the storage unit _12, Ia k, Ia _l and electrical resistance _Ra i to be _calculated, Ra k, and Ra _l Equation (39), formula (40) , by substituting each into equation (41), to calculate the electrical resistance _Ra i local lines _40-1, Ra k, the power generated by Ra _l loss Plos_a _i, Plos_a _k, the Plos_a _l.

  Here, the processing for the local system 40-1 has been described, but the same processing can also be performed for the local systems 40-2 and 40-3.

  Moreover, in 1st Embodiment, the case where a distribution line resistance value is the same irrespective of a consumer apparatus is demonstrated to the example. However, it is not limited to this. When the distribution line resistance value differs depending on the consumer device, the state estimating unit 13 may estimate the active power of the consumer device and the resistance value for each consumer device.

  Here, as an example, the electrical resistance from the measuring device 20-2 through the local system 40-2 to the consumer device 30-2 is Rb2, and the electrical resistance to the consumer device 30-3 is Rb3. The case where the electrical resistance to the device 30-4 is Rb4 and the electrical resistances Rb2 to Rb4 are obtained will be described.

  In the first embodiment, from the formula (17), the formula (22), the formula (23), and the formula (24), the active powers PL2, PL3, and PL4 of the consumer devices 30-2 to 30-4, and the local The case of obtaining the electrical resistance Rb of the system 40-2 has been described.

The current flowing from the measuring device 20-2 through the local system 40-2 to the consumer device 30-2 is Ib_2, the current flowing to the consumer device 30-3 is Ib_3, and the current flowing to the consumer device 30-4 is and Ib_4, current Ib_2, Ib_3, Ib_2 each i-th order harmonic of Ib_4 _i, Ib_3 _i, when the Ib_4 _i, equation (17), equation (22), using the relationship of equation (23),

Is guided. The k-th and l-order harmonic components can be obtained in the same manner.

Moreover, the current i following a harmonic component Ib_2 _i, Ib_3 _i, Ib_4 _i, if the voltage of the consumer devices 30-2～30-4 is V,

It is expressed. V is the voltage of the consumer devices 30-2 to 30-4, but can be approximated by the rated voltage. When Expression (42) to Expression (44) are expressed in matrix form,

It is expressed. Summarizing equation (48) for electrical resistances Rb2, Rb3, Rb4,

It is expressed. By solving the equation (49), the electric resistances Rb2, Rb3, Rb4 can be obtained.

FIG. 16 is a diagram for explaining the above-described processing of the state estimation unit 13 according to the first embodiment. In FIG. 16, the local system 40-2 will be described as an example. The state estimation unit 13 includes harmonic components Pb _i , Pb _k , Pb _l , Pb _{m of} the active power Pb stored in the storage unit 12 and harmonic components Ib _i , Ib _k , Ib _l , Ib of the current Ib. _By substituting _m and the harmonic content α _ij recorded in the database 14 into the equation (26), the active powers PL2 to PL4 of the consumer devices 30-2 to 30-4 and the local system 40-2 The electric resistance Rb is calculated. In addition, the state estimation unit 13 substitutes the harmonic content α _ij recorded in the database 14 and the calculated active powers PL2 to PL4 into the equations (45) to (47), so that the current i Next harmonic components Ib_2 _i , Ib_3 _i , and Ib_4 _i are calculated. Further, the state estimation unit 13 expresses the harmonic components Ib _i , Ib _k , Ib _{l of} the current Ib stored in the storage unit 12, the calculated electric resistance Rb, and the calculated harmonic component of the current. By substituting into (49), the electrical resistances Rb2, Rb3, Rb4 of the path from the measuring device 20-2 to the consumer devices 30-2 to 30-4 are calculated.

  In the first embodiment, as shown in the equations (20), (21), (25), (26), (28), and (29), the matrix shown in the matrix equation is square. The case of a matrix has been described as an example. However, the present invention is not limited to this. In practice, the number of rows and columns is often different.

For example, the number of harmonics is m, the number of consumer devices is n−1, the left side of Equation (20) is the measured harmonic vector, and the column vectors in the matrix of Equation (20) are the first through nth. , The measured harmonic vector is

It is expressed by the approximate expression.

Since Expression (50) is an approximate expression, an approximate value vector is obtained from the right side of Expression (50) as follows.

The active powers PL1 to PLn-1 and the electrical resistance R of the consumer devices 30-1 to 30-n are when the error between the measured harmonic vector and the approximate value vector represented by the equation (51) is minimized. It is calculated | required as effective electric power PL1-PLn-1 and the electrical resistance R. FIG.

  Here, the sum of the squares of the differences between the measured harmonic vector elements and the approximate value vector elements is minimized so that the error between the measured harmonic vector and the approximate value vector is minimized. This method is called a least square method, and is a general method for obtaining an approximate expression with the smallest error.

Assuming that the sum of the squares of the differences between the measured harmonic vector elements and the approximate value vector elements is S, S

It is expressed.

In order to minimize the error between the actually measured harmonic vector and the approximate value vector by the least square method, Equation (52) is partially differentiated by the active power of each consumer device, and the active power at which these become zero is obtained. Necessary. For example, when the equation (52) is partially differentiated with the active power of the j-th consumer device 30-j,

And expanding equation (53),

It becomes. When formula (54) is set to zero and formula (54) is calculated for customer devices 30-1 to 30- (n-1) and expressed in matrix form, the following formula is obtained. However, for simplification, Ii ² = α _in ; i = 1, m.

Here, each element in the matrix on the right side of Equation (55) is Σα _ik × α _ij of k columns and j rows or j columns and k rows, and in the diagonal component of j columns and j rows, Σα _ij × α _ij It is a symmetric matrix.

The right-hand side matrix of Equation (55) is a regular matrix if the number of harmonic orders ≧ the number of consumer devices, and the inverse matrix can be calculated. That is, it is expressed as Expression (56), and it becomes possible to calculate the effective powers PL1 to PLn-1 and the electrical resistance R of the consumer devices 30-1 to 30- (n-1).

  Thereby, the state estimation apparatus 10 can estimate the active power and the electrical resistance of the consumer device even when the number of harmonic orders is different from the number of consumer devices. .

(Second Embodiment)
FIG. 17 is a block diagram illustrating a functional configuration of the state estimation device 60 according to the second embodiment. The state estimation device 60 includes a harmonic component calculation unit 11, a storage unit 12, a state estimation unit 13, a database 14, and a result display unit 61.

  The result display unit 61 displays the active power of the consumer device 30 calculated by the state estimation unit 13, the electrical resistance of the local system 40, and the power loss caused by this electrical resistance (display device installed in the building monitoring room). Display). At this time, the result display unit 61 may display these on the display device every time the active power, electrical resistance, and power loss are calculated by the state estimation unit 13, or at every elapse of a preset time. The calculated active power, electrical resistance, and power loss may be displayed on the display device.

  FIG. 18 is a diagram illustrating a display example of the active power of the consumer devices 30-1 to 30-5 displayed on the display device by the result display unit 61. In FIG. 18, the active power is displayed in a trend graph, the vertical axis indicates the power value, and the horizontal axis indicates time. In FIG. 18, the effective power estimation result for 24 hours a day of an air conditioner, a notebook computer, a desktop computer, and general lighting is shown.

  FIG. 19 is a diagram illustrating a display example of the active power of the consumer device 30-1 displayed on the display device by the result display unit 61, the power loss by the local system 40, and the total value thereof. In FIG. 19, the vertical axis indicates the power value, and the horizontal axis indicates time. In FIG. 19, the effective power of the air conditioner, the power loss in the route from the measuring device 20-1 to the air conditioner via the local system 40-1, and the total value of the active power and the power loss for 24 hours a day. The estimation result is shown.

  As described above, in the second embodiment, the state estimation device 60 causes the result display unit 61 to display the estimation result on the display device. As a result, the manager of the consumer can visually acquire the power demand within the consumer, and can perform supply and demand control such as peak cut and peak shift of the power demand within the consumer.

(Third embodiment)
FIG. 20 is a block diagram illustrating a functional configuration of the state estimation device 70 according to the third embodiment. The state estimation device 70 includes a harmonic component calculation unit 11, a storage unit 12, a state estimation unit 13, a database 14, a selection unit 71, and a result display unit 72.

  The selection unit 71 refers to the power loss calculated by the state estimation unit 13 and selects a consumer device having the largest power loss as a candidate for load control. The selection unit 71 displays the selected load control candidates on a display device (not shown).

  The result display unit 72 displays the power loss calculated by the state estimation unit 13 on a display device installed in the building monitoring room.

  FIG. 21 is a diagram illustrating a display example of the power loss displayed on the display device by the result display unit 72. In FIG. 21, the vertical axis indicates the power value, and the horizontal axis indicates time. In FIG. 21, the power loss in the path from the measuring device 20-1 to the air conditioner via the local system 40-1, and the power loss in the path from the measuring device 20-2 to the notebook computer via the local system 40-2. , Power loss in the path from the measuring device 20-2 to the desktop personal computer via the local system 40-2, and power loss in the path from the measuring device 20-2 to the copy / printer via the local system 40-2, The estimation result for 24 hours a day with the power loss in the path from the measuring device 20-3 to the general illumination via the local system 40-3 is shown. In this case, the air conditioner with the largest power loss is the target of load control when a necessity such as peak cut occurs.

  As described above, in the third embodiment, the selection unit 71 selects a consumer device with the largest power loss as a candidate for load control. As a result, the manager of the consumer can automatically acquire load control candidates, and the power demand in the consumer can be suppressed.

  In the third embodiment, the selection unit 71 has been described by taking as an example the case where the consumer device with the largest power loss is selected as a candidate for load control. However, it is not limited to this. The selection unit 71 may make a consumer device having a large ratio of power consumption to power loss a candidate for load control. At this time, the result display unit 72 displays the ratio of the power consumption to the power loss on the display device.

  FIG. 22 is a diagram illustrating a display example of the ratio of the power consumption to the power loss, which is displayed on the display device by the result display unit 72. In FIG. 22, the vertical axis represents the ratio, and the horizontal axis represents time. FIG. 22 shows the estimation results for 24 hours a day of the ratio of the air conditioner, the ratio of the notebook personal computer, the ratio of the desktop personal computer, the ratio of the copy / printer, and the ratio of the general lighting. In this case, the air conditioner having the largest ratio is the target of load control when necessity of peak cut or the like occurs.

(Other embodiments)
In the first to third embodiments, the case where the state estimation device is installed in a consumer has been described as an example. However, the present invention is not limited to this. The state estimation device according to the first to third embodiments may be portable. In this case, the state estimation device includes a connector connected to the measurement device 20 that measures the power and current supplied to the local system 40, or a communication unit that communicates with the measurement device 20, and is acquired by the measurement device 20. Get electrophysical quantities.

  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 embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... State estimation apparatus, 11 ... Harmonic component calculation part, 111 ... FFT processing part, 12 ... Storage part, 13 ... State estimation part, 14 ... Database, 20, 20-1 to 20-3 ... Measurement apparatus, 30, 30-1 to 30-5 ... consumer device, 40, 40-1 to 40-3 ... local system, 50 ... energy management server, 60 ... state estimation device, 61 ... result display unit, 70 ... state estimation device, 71 ... Selection part, 72 ... Result display part

Claims (14)

Measurement information about power and current supplied to an electrical system to which a plurality of consumer devices can be connected is acquired, and a first harmonic component that is a harmonic component of the power and a harmonic component of the current A harmonic component calculation unit for calculating a second harmonic component;
A database capable of recording the harmonic content of power required by each of the plurality of consumer devices;
The first harmonic component is obtained from the first power obtained from the active power of the consumer device and the harmonic content, and the second value obtained from the resistance value and the second harmonic component in the electrical system. A state estimation device comprising: a state estimation unit that estimates effective power of the consumer device and a resistance value in the electrical system.   The state estimation apparatus according to claim 1, wherein the state estimation unit estimates a power loss in the electric system from measurement information about the current and the estimated resistance value. The harmonic content recorded in the database has a characteristic order indicating a characteristic value for each of the plurality of consumer devices,
The state estimation unit according to claim 1, wherein the state estimation unit estimates the active power and the resistance value based on a first harmonic component for the feature order and a second harmonic component for the feature order. apparatus. The resistance value in the electrical system is different for each harmonic order,
The state estimation device according to claim 1, wherein the state estimation unit estimates a resistance value for each harmonic order in the electrical system. The resistance value in the electrical system is different for each consumer device connected to the electrical system,
The state estimation device according to claim 1, wherein the state estimation unit estimates a resistance value for each of the consumer devices connected to the electrical system.   The state estimation device according to claim 5, wherein the state estimation unit estimates a power loss for each of the consumer devices from the measurement information about the current and the estimated resistance value for each of the consumer devices.   The state estimation device according to claim 1, further comprising a result display unit that causes the display device to display the active power and / or the resistance value estimated by the state estimation unit.   The state estimation device according to claim 2, further comprising a result display unit that causes the display device to display at least one of active power, resistance value, and power loss estimated by the state estimation unit.   The state estimation apparatus according to claim 6, further comprising a selection unit that selects a consumer device having a large power loss as a candidate for load control.   The state estimation apparatus according to claim 6, further comprising a selection unit that selects a consumer device having a large ratio of power consumption to the power loss as a candidate for load control. Record the harmonic content of power required by multiple consumer devices in the database in advance,
Obtaining measurement information about power and current supplied to an electrical system to which the plurality of consumer devices can be connected;
Calculating a first harmonic component that is a harmonic component of the power and a second harmonic component that is a harmonic component of the current;
The first harmonic component is obtained from the first power obtained from the active power of the consumer device and the harmonic content, and the second value obtained from the resistance value and the second harmonic component in the electrical system. The state estimation method which estimates the effective power of the said consumer apparatus, and the resistance value in the said electric system by expressing with the electric power of.   The state estimation method according to claim 11, wherein a power loss in the electrical system is estimated from measurement information about the current and the estimated resistance value. In a state estimation program used in a state estimation device having a database capable of recording the harmonic content of power required by each of a plurality of consumer devices,
Measurement information about power and current supplied to an electrical system to which the plurality of consumer devices can be connected is acquired, and the first harmonic component that is a harmonic component of the power and the harmonic component of the current A process of calculating a second harmonic component;
The first harmonic component is obtained from the first power obtained from the active power of the consumer device and the harmonic content, and the second value obtained from the resistance value and the second harmonic component in the electrical system. A state estimation program that causes the computer of the state estimation device to execute processing for estimating the effective power of the consumer device and the resistance value in the electrical system.   The state estimation program according to claim 13, which causes the computer to execute a process of estimating a power loss in the electrical system from the measurement information about the current and the estimated resistance value.

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