JPH11118841A - Average electric variable calculation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calculate electric variable accurately in short time even if it is oscillated and its convergent speed is low. SOLUTION: An abrupt change detecting part 2 outputs a detection calculation start command when an accident occurs, a prior current calculation part 3 calculates a prior current amount immediately before the accident, and a variation current calculation part 4 subtracts a prior current amount from a measurement current amount so as to obtain a variation current amount. A long-term average current calculation part 5 obtains the averaged value of the variation current amount through a relatively long observation window. In addition, a model parameter calculation part 6 obtains the gain of a variation current generating model at the beginning of oscillation before the averaged value of the variation current amount is calculated. Then a calculation result selector part 8 is elected first so that the averaged value of the variation current amount from a model gain calculation part 7 can be used, and also the averaged value of the valuation current amount at the long-term average current calculation part 5 can be used under specified conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an average electric quantity calculating apparatus suitable for obtaining an average value of fluctuations of an electric quantity after an electric quantity of an electric power system or an electric device suddenly changes.

[0002]

2. Description of the Related Art For example, in order to detect an overload in a transmission line of an electric power system, it is necessary to accurately determine the magnitude of a current to be supplied.

[0003] That is, when the average value of the amount of electricity is used as a judgment target for overload detection in a power device or a transmission line, etc., in order to protect the protection target of the electric power system reliably, the electric power can be quickly removed from a system accident. It is necessary to determine the overload by obtaining the average value of the amounts and, if necessary, to shut off the circuit breaker and to issue a control command to an electric device or the like. Further, in order to prevent malfunctions and malfunctions, it is necessary to calculate the average value of the quantity of electricity with high accuracy.

[0004]

However, it is not easy to specify a fluctuating prior electricity quantity, and when a state change such as a system accident occurs, the electricity quantity of the system is higher than the prior electricity quantity. Level, causing vibration or overshoot, and the fluctuation period is not uniform depending on the aspect. Furthermore,
It has been difficult to calculate the average value of the amount of electricity that fluctuates in a short period of time at the beginning of the sway, for example, due to the control during the calculation of the average value of the amount of electricity due to a change in the form of the amount of electricity calculated.

[0005] In particular, when the fluctuation after the second wave is at a low level and the period of the fluctuation is not uniform as compared with the first wave of the fluctuation, the amount of electricity, the amount of electricity that fluctuates in a short time after a sudden change is obtained. It was extremely difficult to calculate the average value of.

Accordingly, the present invention provides a method for calculating the average of electric quantity in a short time with relatively high accuracy even in a situation where it is difficult to calculate the average value of electric quantity, such as when the electric quantity changes and the vibration and the convergence are slow. It is an object of the present invention to provide an average electricity amount calculating device capable of calculating a value.

[0007]

According to a first aspect of the present invention, there is provided an average electric quantity calculating apparatus for calculating an average value of a fluctuating electric quantity due to a sudden change such as an accident in an electric power system or an electric equipment, wherein the electric quantity is calculated. First means for detecting a sudden change in the measured electric quantity converted into the digital quantity and calculating a change electric quantity which is a difference between the average value of the prior electric quantity immediately before the sudden change and the measured electric quantity;
A parameter and a gain of the generation model of the variation current amount are obtained, and an average value of the oscillating variation electric amount shortly after the initial period of the oscillation is obtained as a first average electric amount based on the parameters.
Means and the long observation window to calculate the average value of the
A third means is provided as an average amount of electricity, and a fourth means is provided for switching so as to output the first average amount of electricity as a calculation result while outputting the second average amount of electricity as a calculation result according to a predetermined condition. It is. According to this means,
First, when the amount of electricity of the electric power system or the like is taken in and a sudden change in the measured amount of electricity is detected, a change amount of electricity, which is the difference between the average value of the prior amount of electricity before the sudden change and the actually measured amount of electricity, is obtained. . Second, the parameters and gain of the generation model are obtained for the amount of change, and the average value of the amount of change for a short period of time at the beginning of the sway is calculated based on this, and the output is used as the first average amount of electricity. Is done. Third, an average value is obtained for the amount of change in the observation window that is long in parallel with the second and the average value is output. Fourth,
The first average amount of electricity is output as the average amount of electricity, and then switched under a predetermined condition so that the second average amount of electricity is output as the average amount of electricity. Thus, even after the electric quantity changes, the average electric quantity can be calculated in a short time with high accuracy even in a situation where the vibration is slow, the convergence is slow, and the calculation of the average electric quantity is difficult.

[0008] The invention of claim 2 is an electric power system or
An average-electric-quantity calculating device for calculating an average value of swaying electric quantity due to a sudden change in an electric equipment accident or the like, comprising: an analog / digital conversion unit for converting an electric quantity into a digital quantity and outputting it as a measured electric quantity; / A sudden change detection unit for detecting a sudden change in the measured electricity amount based on the measured electricity amount converted by the digital conversion unit, and, when a sudden change in the measured electricity amount is detected by the sudden change detection unit, the average of the immediately preceding measured electricity amount A pre-electrical quantity calculating unit for obtaining a value as the pre-electrical quantity, and comparing the average value of the pre-electrical quantity obtained by the pre-electrical quantity calculating unit with the measured electric quantity to calculate a difference between the two quantities as a change electric quantity. Parameter calculation unit for calculating a change amount of electricity, and a model parameter calculating unit for calculating a generation model and a parameter of the change amount of electricity based on the change amount of electricity calculated by the change amount of electricity calculation unit And a model for calculating the gain of the parameters of the generation model calculated by the model parameter calculating unit and calculating the average value of the amount of change in a short period of time in the initial period of shaking after a sudden change to calculate a first average amount of electricity. A long-term average electric quantity for which an average value of the change electric quantity is obtained from a relatively long observation window as a second average electric quantity based on the change electric quantity calculated by the gain calculating section and the change electric quantity calculation section. A calculation unit that switches between the first average electricity amount calculated by the model gain calculation unit and the second average electricity level calculated by the long-time average electricity amount calculation unit under any condition, and outputs the calculation result as an operation result A switching section is provided. According to this means, a moving average for a predetermined time is performed on the measured amount of electricity, the prior amount of electricity immediately before the sudden change is obtained, the prior amount of electricity immediately before the sudden change is obtained from the measured amount of electricity, and the changed amount of electricity is obtained. Can be Next, the parameters of the generation model are calculated based on the amount of change in electricity, and the first average amount of electricity that sways in a relatively short time at the beginning of the sway is determined. In parallel with this, the average value of the amount of change in the relatively long observation window is calculated, and the second average amount of electricity is obtained. Then, after the first sudden change in the amount of electricity is detected, first, the first average amount of electricity by the former is used, and then it is switched to the second average amount of electricity by the latter. This makes it possible to calculate the average value of the electric quantity in a short time with relatively high accuracy even in a situation in which it is difficult to calculate the average value of the electric quantity, such as when the electric quantity changes and then vibrates and the convergence is slow. Can be.

According to a third aspect of the present invention, in the average electric quantity calculating apparatus according to the first aspect, the preliminary electric quantity calculating section calculates a value obtained by smoothing a moving average of the measured electric quantity for a predetermined time. It is assumed that. According to this means, the measured amount of electricity is smoothed by a moving average for a predetermined time, so that even if the measured amount of electricity immediately before the sudden change fluctuates, a reasonable prior amount of electricity immediately before the sudden change can be obtained.

According to a fourth aspect of the present invention, in the average electricity amount calculating device according to the first aspect, the long-time average electricity amount calculating section comprises:
After performing a smoothing process on the amount of change by a low-pass filter, if the maximum value and the minimum value of the amount of change within a predetermined time continue, the value is updated. The minimum value is held at the previous value, and the held maximum value and minimum value are added to obtain an average value.
According to this means, when a sudden change in the measured electric quantity is detected, the changed electric quantity is smoothed by the low-pass filter. And
When the maximum value and the minimum value of the electric quantity during the predetermined time after the filtering process continue for a predetermined time, the maximum value and the minimum value of the electric quantity are updated. Since the previous value is held and its average is obtained, the average value of the amount of change can be obtained in a relatively long observation window.

According to a fifth aspect of the present invention, in the average electric quantity calculating apparatus according to the first aspect, the model parameter calculating section calculates an occurrence model based on the change amount of electricity and calculates parameters of the occurrence model. It was made. According to this means, when a sudden change in the measured electric quantity is detected, a generation model of the electric quantity that fluctuates with respect to the changed electric quantity is assumed, and the parameters of the generation model of the changed electric quantity can be calculated. As a result, the parameters of the generation model of the fluctuation electric quantity that fluctuates according to the actual phenomenon are obtained, and the average value of the change electric quantity can be calculated in a relatively short time with high accuracy.

According to a sixth aspect of the present invention, in the average electric quantity calculating apparatus according to the first aspect, the model gain calculating section takes in a parameter of a generation model of the change electric quantity and applies a final value theorem of a discrete time system. Thus, the gain of the generation model is obtained, and the average value of the amount of change in a relatively short time in the initial period of the fluctuation is obtained. According to this means, the gain of the generation model is obtained by using the parameters of the generation model of the amount of change in the amount of fluctuation and applying the theorem of the final value of the discrete time system, and the change of the generation in the initial period of the fluctuation is relatively short. It is possible to calculate the average value of the quantity of electricity.

According to a seventh aspect of the present invention, in the average electric quantity calculating apparatus according to the first aspect, the long-time average electric quantity calculating section comprises:
If the rate of change of the estimated average value of the electric quantity is equal to or more than a predetermined value, the average value of the electric quantity obtained last time is held. According to this means, if the rate of change of the average value of the changed amount of electricity is equal to or greater than the predetermined value, the average value of the changed amount of electricity is held at the previous value. Thereby, when the first wave of the fluctuation of the changed amount of electricity is too large with respect to the second wave and thereafter, the influence of the first wave can be reduced, and the average value of the appropriate changed amount of electricity can be calculated. .

According to an eighth aspect of the present invention, in the average electric quantity calculating apparatus according to the fifth aspect, the model parameter calculating section determines whether or not the change rate of the changed electric quantity is equal to or more than a predetermined value. The parameters of the generation model are calculated on the basis of this. According to this means, if the change rate of the change amount of electricity is equal to or more than the predetermined value during the calculation of the parameter of the generation model of the change amount of electricity, the measured amount of electricity is held at the previous value. As a result, an abnormal value in which the amount of change electric quantity has an adverse effect on the calculation of the parameter of the change amount electric quantity model due to noise or the like is removed. It is possible to calculate the average value of the calculated and changed electric quantities more accurately.

According to a ninth aspect of the present invention, in the average electric quantity calculating apparatus according to the fifth aspect, the model parameter calculating section calculates the change electric quantity based on the calculated generation model and the parameter. If the integrated value of the absolute value of the difference between the quantity of electricity and the actually measured quantity of change is equal to or greater than a predetermined value,
The change amount of electricity used for the calculation is reset. According to this means, an amount of electricity corresponding to the actually measured amount of change is also calculated from the parameters of the calculated generation model of the oscillating change amount of electricity, and the actual value and the calculated value of the amount of change are calculated. If the integrated value of the absolute value of the difference is equal to or greater than a predetermined value during a predetermined period, data used for parameter calculation is reset. As a result, the calculated value of the changed amount of electricity obtained from the parameters of the generation model is compared with the actually measured value, and the parameters of the generation model of the changed amount of electricity are made appropriate according to the actual phenomenon. If it is not suitable, reset the data used for the calculation and calculate the more accurate change generation parameter of the electric quantity even if the response time is slightly sacrificed. The average value of the quantity of electricity can be obtained.

According to a tenth aspect of the present invention, in the average electric quantity calculating apparatus according to the first aspect, the operation result switching section calculates the first average electric quantity in less than a predetermined time after the sudden change detection by the sudden change detection section. , And after a predetermined period of time, the second average quantity of electricity is output as the calculation result. According to this means,
A predetermined time after the detection of the first sudden change, the first average electric quantity is switched to the second average electric quantity, and the average value of the electric quantity after the change of the measured electric quantity can be obtained and output. This allows
The second average electricity by means suitable for calculating the average value of the relatively long-term change electric quantity from the first average electricity quantity by the means suitable for the calculation of the average value of the change electric quantity in a short time at the beginning of agitation. By switching to the quantity, the average value of the quantity of electricity can be calculated with higher accuracy.

According to an eleventh aspect of the present invention, in the average electricity amount calculating device according to the first aspect, the operation result switching unit calculates the change amount of electricity based on the generation model and the parameter calculated by the model parameter calculation unit. If the integrated value of the absolute value of the difference between the obtained change amount of electricity and the actually measured change amount of electricity is equal to or greater than a predetermined value, the second average amount of electricity is switched and output as the calculation result. is there. According to this means, since the calculated value of the change amount of electricity obtained from the parameters of the generation model of the change amount of electricity is compared with the actually measured value,
It is evaluated whether or not the average value of the calculated change amount of electricity is appropriate according to the actual phenomenon. If it is not suitable, it is switched to output the second average electricity quantity. Thus, even when the mode of fluctuation of the electric quantity changes during the calculation of the average value of the electric quantity, the average value of the electric quantity can be obtained with high accuracy.

According to a twelfth aspect of the present invention, in the average electric quantity calculating apparatus according to the first aspect, the calculation result switching section calculates the change amount of electric quantity based on the parameters of the generation model calculated by the model parameter calculating section. When it is determined that the obtained amount of change has a tendency to diverge, the second average amount of electricity is switched so as to be output as a calculation result. According to this means, when the first average electricity quantity tends to diverge, it is possible to switch to the second average electricity quantity and obtain the average value of the electricity quantity at that time relatively accurately.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a basic configuration diagram in which the average electric quantity calculation device according to the first embodiment of the present invention is applied to overload detection.

An electric quantity is taken in from the electric power system, and the analog electric quantity passed through the input converter A is subjected to the following processing by the first processing means B. First, in the process of (1), after conversion into a digital quantity, and in the process of (2), a sudden change in the quantity of electricity is detected, the quantity of electricity measured by the process of (1) may always fluctuate. In the process of (3), a moving average for a predetermined period of time is performed to obtain the prior electricity amount immediately before the sudden change, and in the process of (4), the sudden change by the process of (3) from the measured electricity amount output from the process of (1). The amount of change is obtained by subtracting the immediately preceding amount of electricity.

The second processing means C assumes a model (transfer function of a discrete time system) in which the input is a unit step function and the output is an actually measured electric quantity in the processing of (5). The parameters of the model are calculated by the multiplication method or the sequential least squares method, and the average value of the amount of change in the amount of fluctuation is calculated in a relatively short time at the beginning of the fluctuation by the theorem of the final value of the discrete time system in the process (6). . In parallel with this, in the third processing means D, the average value of the amount of change in the comparatively long observation window is calculated from the maximum value and the minimum value of the oscillating electric amount (processed by the low-pass filter) in the process (7). Is calculated.

Next, in the fourth processing means E, in the processing of (8), after detecting the first sudden change of the electric quantity by the processing of (2), first, the average value of the electric quantity of the changed quantity by the processing of (6) is obtained. And then switch to the average value of the amount of change in the amount of electricity by the process of (7), and use the prior amount of electricity immediately before the sudden change by the process of (3) to calculate the amount of swaying electricity after the change in the amount of electricity. An average value can be calculated. Using this result, in (9), overload detection can be performed with high accuracy in a short time.

FIG. 2 is a configuration diagram of an average electric quantity calculating device according to a second embodiment of the present invention.

In the second embodiment, the average electric quantity calculating device according to the present invention is particularly applied to a digital transmission line overload detection relay for detecting overload in a transmission line.

The analog / digital converter 1 converts a current input from the transmission line via the input converter 10 into a digital amount to obtain a measured current amount suitable for digital operation.

As shown in FIG. 3, the sudden change detection unit 2 monitors a change in the amount of current measured by the analog / digital conversion unit 1 in a steady state, and the change rate of the amount of measured current is not fixed due to a system failure or the like. If the threshold value is exceeded, it is determined that an accident has occurred, and a detection calculation start command is output.

Since there is a possibility that the measured current amount immediately before the accident also fluctuates, the preliminary current calculation unit 3 calculates the preliminary current amount immediately before the accident by using a moving average for a predetermined time.

The change current calculation unit 4 subtracts the pre-current amount immediately before the sudden change by the pre-current calculation unit 3 immediately before the sudden change from the measured current amount which is the output of the analog / digital conversion unit 1,
Find the amount of change current.

The long-time average current calculation unit 5 processes the amount of change current by the change current calculation unit 4 with a low-pass filter and smoothes the amount, and then sets the maximum value of the change current during a predetermined time after the filter processing. And the minimum value is held until the next maximum value and minimum value continue for a predetermined period of time, and when the next maximum value and minimum value are detected, they are sequentially updated, and the average is obtained. Find the average value of the current.

The model parameter calculation unit 6 executes the calculation in parallel with the long-time average current calculation unit 5, and inputs the input as a unit step function and outputs the measured change current and the change current measured by the change current calculation unit 4, respectively. Each generation model (transfer function of a discrete time system) of the variation current is assumed, and then the parameters of the variation current generation model are calculated using the least square method or the like. The model gain calculator 7 obtains the gain of the change current generation model by the theorem of the final value of the discrete time system and calculates the average value of the change current amount.

The operation result switching unit 8 is a first average current amount which is an average value of the amount of change current from the model gain calculation unit 7 and an average value of a change amount current of the long time average current calculation unit 5. (2) The average current amount is input, first, switching is performed so as to use the first average current amount from the model gain calculation unit 7, and then, under a predetermined condition after a predetermined time, the long-time average current calculation unit 5 Is switched to use the second average current amount.

The overload judging section 9 comprises a model gain calculating section 7
When the average value of the variation current amount from and the addition value of the preliminary current amount or the addition value of the average value of the variation current amount from the long-term average current calculation unit 5 and the preliminary current amount is larger than a predetermined value, Outputs overload judgment.

As described above, according to the second embodiment, a moving average for a predetermined time is performed on the measured current amount, the pre-current amount immediately before the sudden change is obtained, and the pre-current amount immediately before the sudden change is obtained from the measured current amount. Then, the change current amount is obtained. Next, the parameters of the model in which the variation current amount is generated are calculated, and the first average current amount that fluctuates in a relatively short time at the beginning of the fluctuation is obtained. By averaging this, the average value of the change current amount in the relatively long observation window is calculated, and the second average current amount is obtained. After the first sudden change in the amount of current is detected, first, the first average current amount by the former is used, and then the second
Switch to current. This makes it possible to calculate the average value of the current amount in a short time with relatively high accuracy even in a situation where it is difficult to calculate the average value of the current amount, such as when the current amount changes and the vibration oscillates slowly. Can be.

FIG. 4 is a configuration diagram of a pre-current calculation unit provided in an average electric quantity calculation device according to a third embodiment of the present invention.

When the sudden change detecting section 2 detects a sudden change in the measured current, the preliminary current calculating section 3 starts the calculation, smoothes the measured current amount by a moving average for a predetermined time, and outputs the preliminary current amount.

As described above, according to the third embodiment, the measured electric quantity is smoothed by the moving average for a predetermined time, so that even if the measured electric quantity just before the sudden change is fluctuating, it is necessary to make a suitable Electricity is obtained.

FIG. 5 is a configuration diagram of a long-time average current calculation unit 5 provided in an average electricity calculation device according to a fourth embodiment of the present invention.

The long-time average current calculation section 5 smoothes the change current amount by the change current amount calculation section 4 with a low-pass filter (5a) having a time constant T, and then smoothes the change amount during a predetermined time after the filter processing. When the maximum value and the minimum value (5b, 5c) of the current continue for a predetermined time, the maximum value and the minimum value of the current are updated, and when the current does not continue for a predetermined time, the previous values of the maximum value and the minimum value of the current are held (5d, 5d). 5e) Then, the average (5f) of the held maximum value and minimum value is obtained from the following equation (1), and the average value of the variation current amount is obtained in a relatively long observation window.

[0040]

(Equation 1)

As described above, according to the fourth embodiment, when a sudden change in the measured current amount is detected, the change amount is smoothed by the low-pass filter, and then the maximum amount of the current amount during the predetermined time after the filtering process is performed. When the value and the minimum value continue for a predetermined time, the maximum value and the minimum value of the amount of electricity are updated.
Since the previous values of the maximum value and the minimum value of the current amount are held and the average is obtained, the average value of the current amount of the change can be obtained in a relatively long observation window.

FIGS. 6 and 7 are block diagrams of a model parameter calculating section 6 provided in an average electric quantity calculating apparatus according to a fifth embodiment of the present invention.

FIG. 6 shows the relationship between the input / output and the transfer function of the discrete time system in the model parameter calculation unit 6. FIG. In the calculation, a case where a least square method of batch processing in which batch processing is performed after data necessary for calculation is completed is applied.

First, the current amount Δ of the change after the sudden change of the measured current
I (k) is represented by the following equation (2).

ΔI (k) = I (k) −Io (2) where I (k): measured current amount Io: preliminary current amount

(1) Modeling Next, the generation model of the variation current ΔI (k) according to the above equation (2) is expressed by the pulse transfer function equation (3).

[0047]

(Equation 2)

The model here corresponds to a second-order transfer function of a continuous time system. The order of the model is not limited to the second order and needs to be determined according to the fluctuation phenomenon.

Next, the following equation (4) holds for the pulse transfer function and the change current ΔI (k) expressed by the above equation (3).

[0050]

(Equation 3)

However, the input value u (k) is a unit step function represented by the following equation (5).

[0052]

(Equation 4)

(2) Calculation of Parameters First, the parameters of the transfer function represented by the above equation (3) are calculated from the measured data. That is, the following equation (6) and (7) are obtained by substituting the equation (3) into the equation (5).

[0054]

(Equation 5)

Next, the above equation (7) is expressed by the following equation (10).

[0056]

(Equation 6)

Further, the above equation (10) is obtained by the following equation (11).
To (13).

[0058]

(Equation 7)

Next, in order to apply the least squares method, the following equation (15) and (16) are obtained by multiplying the equation (11) by the following matrix equation (14).

[0060]

(Equation 8)

Next, when the above equation (16) is represented by a vector, the following equation (17) is obtained, and the parameter vector of the equation (9) is obtained from the equation (16) or (17).

[0062]

(Equation 9)

As described above, according to the fifth embodiment, when a sudden change in the measured current amount is detected, a generation model of the current amount fluctuating with respect to the changed current amount is assumed, and the change amount current amount The parameters of the occurrence model can be calculated. Thus, the parameters of the generation model of the fluctuation current that fluctuates in accordance with the actual phenomenon can be obtained, and the average value of the fluctuation current can be calculated in a relatively short time and with high accuracy.

FIG. 8 is a configuration diagram of a model parameter calculator 6 provided in an average electric quantity calculator according to another embodiment of the fifth embodiment of the present invention.

In the present embodiment, in the calculation of the parameters of the generation model of the oscillating change current amount by the model parameter calculation unit 6, if data necessary for the calculation is acquired at a certain point in time, the data used for the parameter calculation is obtained. Is sequentially applied, and the successive least squares method is applied. The recursive least squares method for obtaining the recursive optimal parameters is represented by the following equation (1)
8) to (20), the inverse matrix of the correlation matrix of equation (17) is obtained.

[0066]

(Equation 10)

With this configuration, data is updated sequentially, and 1
Since the parameters of the generation model of the variation current amount before the time point are fed back, it is not necessary to find the inverse matrix of the correlation matrix in the least squares calculation operation, and a more stable calculation result of the parameters of the generation model of the variation current amount is obtained. Can be

FIG. 9 is a block diagram of a model gain calculator 7 provided in an average electricity calculator according to a sixth embodiment of the present invention.

The model gain calculation unit 7 generates the fluctuation current amount which fluctuates using the parameters of the generation model of the change current amount calculated by the model parameter calculation unit 6 and the final value theorem of the discrete time system. The gain of the model is obtained, and the average value of the amount of change current is calculated in a relatively short time at the beginning of the oscillation.

The average variation current amount ΔIo (k) is calculated by the following equation (21) using the final value theorem relating to the pulse transfer function of equation (3), which is a generation model of the oscillating variation current amount.
Required by

[0071]

[Equation 11]

As described above, according to the sixth embodiment, since the parameters of the generation model of the fluctuation amount of the current amount which fluctuates in accordance with the actual phenomenon are obtained, the average value of the current can be calculated in a relatively short time with high accuracy. Can be calculated.

FIG. 10 is a configuration diagram of a long-time average current calculation unit provided in an average electric quantity calculation device according to a seventh embodiment of the present invention.

The long-time average current calculation section 5 is provided with a sudden change detection function 5g and a previous value holding function 5h in FIG. 5 of the fourth embodiment, so that the change rate of the average value of the change current amount is equal to or more than a predetermined value. If so, the calculated value (the average value of the amount of change current) is held at the previous value.

As described above, according to the seventh embodiment, when the long-term average current calculation unit 5 calculates the average value of the amount of change current,
When the first wave of the fluctuation of the variation current amount is extremely large with respect to the second and subsequent waves, the influence of the first wave can be reduced, and the average value of the variation current amount can be calculated accurately.

FIG. 11 is a block diagram of a model parameter calculating section 6 provided in an average electric quantity calculating device according to an eighth embodiment of the present invention.

The model parameter calculation section 6 has a configuration in which a function of holding the current value of the change before the change amount is added if the change rate of the current amount of the change is a predetermined value or more.

As described above, according to the eighth embodiment, the variation current amount becomes an abnormal value that adversely affects the parameter calculation of the variation current amount generation model due to system control, noise, and the like. Even remove outliers. The model parameter calculation unit 6 can calculate the parameters of the generation model of the appropriate change current amount at that time, and calculate the average value of the accurate change current amount.

FIG. 12 shows a model parameter calculator 6 provided in an average electricity calculator according to a ninth embodiment of the present invention.
FIG.

The model parameter calculation unit 6 also calculates a change current amount corresponding to the change current amount by the oscillating change current amount calculation unit 4 from the parameters of the change current amount generation model. If the integrated value of the absolute value of the difference between the measured value and the calculated value of the variation current is equal to or more than a predetermined value, the model parameter calculator 6 resets the data used for calculating the parameters of the generation model of the variation current. It is.

As described above, according to the ninth embodiment, the calculated value of the amount of change current obtained from the parameters of the generation model of the amount of change current is compared with the actually measured value. Is evaluated to see if the parameters of the generation model of the amount of change current correspond to the actual phenomena, and if the parameters are inappropriate, the data is reset. Thereby, even if the response time is somewhat simulated, the parameters of the generation model of the variation current amount can be calculated more accurately, and the average value of the variation current amount can be obtained by the model gain calculator 7.

FIG. 13 is a configuration diagram of the calculation result switching unit 8 provided in the average electric quantity calculation device according to the tenth embodiment of the present invention.

The calculation result switching unit 8 calculates the change current amount by the long-time average current calculation unit 5 from the average value of the change current amount by the model gain calculation unit 7 a predetermined time after the first sudden change detection of the current. Switch to the average value.

As described above, according to the tenth embodiment, the first average current amount is switched from the first average current amount to the second average current amount a predetermined time after the first sudden change detection, and the current amount is changed using the pre-current amount immediately before the sudden change. Can be calculated and output. Thereby, the first average current amount by the means suitable for calculating the average value of the variation current amount in a short time at the beginning of the oscillation is the second average value by the means suitable for calculating the average value of the variation current amount for a relatively long time. (2) By switching to the average current amount, it is possible to calculate the average value of the current amount for the change with higher accuracy.

FIG. 14 is a configuration diagram of a calculation result switching unit provided in the average electricity quantity calculation device according to the eleventh embodiment of the present invention.

The calculation result switching unit 8 also calculates a change amount of current corresponding to the actually measured change amount of fluctuation from the parameters calculated by the model parameter calculation unit 6, and measures the change amount of current during a predetermined time. If the integrated value of the absolute value of the difference between the calculated value and the calculated value is equal to or greater than a predetermined value, the average value of the amount of change current by the long-term average current calculation unit 5 is calculated from the average value of the amount of change current by the model gain calculation unit 7. It switches to a value.

According to the twelfth embodiment, the estimated value of the amount of change current obtained from the parameters is compared with the actually measured value, and the average value of the amount of change current calculated by the model gain calculator 7 is used as the actual phenomenon. Is appropriate along the line. In this case, if the current value is inappropriate, the current value is switched to the average value of the amount of change calculated by the long-time average current calculation unit 5.

FIG. 15 is a diagram showing the configuration of a calculation result switching unit provided in the average electric quantity calculation device according to the eleventh embodiment of the present invention.

The calculation result switching unit 8 determines the convergence and divergence of the change current amount by the change current amount calculation unit 4 from the parameters of the generation model of the change current amount calculated by the model parameter calculation unit 6 and diverges. When it is determined that there is a tendency, the value calculated by the model gain calculator 7 (the average value of the amount of change current) is switched to the value calculated by the long-time average current calculator 5 (the average value of the amount of change current). is there.

For example, the tendency of convergence and divergence of the amount of change current can be detected as follows. That is, when the transfer function of the discrete time system of Expression (3), which is the change amount current generation model of the model parameter calculation unit 6, is transformed, the following Expression (22) is obtained.

[0091]

(Equation 12) Here, the transfer function of the discrete time system is not limited to the order 2.

The convergence and divergence of the variation current amount are determined by the following equation (23) using α and β which are the poles of the transfer function of the equation (22).

[0093]

(Equation 13)

As described above, among the poles of the transfer function, 1
If any one has a larger absolute value, the change amount of current diverges.

As shown in the above example, two means having different characteristics are used to calculate the fluctuation amount of the fluctuation current in the observation window that is relatively long or to calculate the current amount in a short time at the beginning of the fluctuation, and to compensate for the disadvantages of each other. Since it is used together in the form, and calculates and selects the average value of the amount of change current associated with the phenomenon of the system, it is possible to calculate the average amount of electricity after the elimination of the accident in a short time and with high accuracy.

According to the twelfth embodiment, when the variation current amount obtained by the variation current amount calculation unit 4 has a tendency to diverge, the average value of the variation current amount by the model gain calculation unit 7 is: An appropriate calculated value cannot be obtained as the average value of the current amount of the change at that time. For this reason, the tendency of dispersion of the amount of change current is detected early, and the average value of the amount of change current is switched to the average value of the amount of change current by the long-term average current calculation unit 5, and the average value of the amount of change current at that time is relatively determined. Can be obtained with high accuracy.

Next, examples of response waveforms according to the first to twelfth embodiments will be described with reference to FIGS.

First, in FIG. 16, the measured value (input waveform) of (a), which is the measured current value, suddenly changes to t1 after about 2 seconds and becomes the value of (b) in the PU value, and the ninth embodiment is performed. The waveform according to the form rises to the vicinity of (c). This state is detected by the sudden change detection unit 2, and the sudden change detection unit 2 calculates the amount of change current. Further, it is notified to the long-time average current calculation unit 5 and the model parameter calculation unit 6. The model parameter calculation unit 6 and the model gain calculation unit 7 calculate the average value of the amount of change current based on the amount of change current. In the state (d), the data is reset to the state (e) by resetting the data according to the ninth embodiment. On the other hand, the measured value (input waveform) is represented by (he).

As a result, the output from the model gain calculator 7 gradually converges, and is smaller than the measured value in the figure after 6 seconds. On the other hand, the calculation result of the model parameter calculation unit 6 according to the fourth embodiment is (6)
After 2 seconds, it gradually decreases from a peak at a PU value of about 2.8.

Also, the case of FIG. 17 is the same as that of FIG. 16, and it is assumed that the measured value (input waveform) (a) suddenly changes at time t1 two seconds later. In this state, the calculation result of the model gain calculator 7 according to the sixth or ninth embodiment has substantially the same waveform in (b).

However, in (c), there is a difference between the waveforms of the sixth and ninth embodiments, and as shown in (d), the case of the sixth embodiment does not match the actual situation. In (e), the ninth
In the case of the implementation, the reset is performed, and the calculation result of the model gain calculation unit 7 is smaller than the measured value (g) and converges as shown in (f). On the other hand, in the waveform according to the fourth embodiment, the result is output as shown in (h), and the waveform gradually changes with a peak of about PV 2.5.

FIGS. 18A and 18B show waveforms in which the model parameter calculating section 6 according to the eighth embodiment holds the previous values when the measured value changes suddenly excessively, as shown in FIGS. Applies the eighth to ninth embodiments. Others are almost the same as those in FIG. 16 and FIG. That is, (c) shows the measured values, (d) shows the ninth embodiment, and (e) shows the respective waveforms of the fourth embodiment.

[0103]

As described above, according to the first aspect of the present invention, a change electric quantity, which is a difference between the average value of the prior electric quantity immediately before the sudden change and the actually measured electric quantity, is obtained, The gain is obtained to obtain the first average electric quantity in a short period of time at the beginning of the oscillation, and in parallel with this, the second average electric quantity is obtained in a long observation window by the change electric quantity, and the first average electric quantity is used as the average electric quantity. Output, and then switch under a predetermined condition so that the second average electric quantity is output as the average electric quantity.
Even after the measured amount of electricity has changed, the average amount of electricity can be calculated in a short time with high accuracy even in a situation in which the measured amount of electricity oscillates, converges slowly, and it is difficult to calculate the average amount of electricity.

According to the second aspect of the present invention, the parameters of the generation model are calculated for the amount of change in electric quantity, and the first average electric quantity to be swayed is determined in a relatively short time at the beginning of the sway, and the relatively long average electric quantity is calculated in parallel. Obtain the second average electric quantity which is the average value of the change electric quantity in the observation window, and after detecting the sudden change of the first electric quantity, first use the first average electric quantity by the former, and then,
The second electric quantity is switched to the latter. This makes it possible to calculate the average value of the electric quantity in a short time with relatively high accuracy even in a situation in which it is difficult to calculate the average value of the electric quantity, such as when the electric quantity changes and then vibrates and the convergence is slow. Can be.

According to the third aspect of the present invention, since the measured electric quantity is smoothed by the moving average for a predetermined time, even if the measured electric quantity immediately before the sudden change fluctuates, the appropriate prior electric quantity just before the sudden change is obtained. can get.

According to the fourth aspect of the invention, after the change amount of electricity is smoothed by the low-pass filter, when the maximum value and the minimum value of the amount of electricity for a predetermined time after the filter processing continue for a predetermined time, the amount of change If the maximum and minimum values are updated for a predetermined period of time, the previous values of the maximum and minimum values of the electric quantity are held and their averages are calculated. The value can be determined.

According to the fifth aspect of the present invention, since the parameters of the generation model of the fluctuation electric quantity which fluctuates with respect to the fluctuation electric quantity are calculated, the parameters of the generation model of the fluctuation electric quantity which fluctuate according to the actual phenomenon are changed. It is possible to calculate the average value of the variation current in a relatively short time and with high accuracy.

According to the sixth aspect of the present invention, by using the calculated parameters of the generation model of the amount of change in the amount of fluctuation,
The gain of the generation model is obtained by applying the final value theorem of the discrete-time system, and the average value of the amount of change in a relatively short period of time at the beginning of the oscillation can be calculated.

According to the seventh aspect of the present invention, if the rate of change of the average value of the amount of change is equal to or more than a predetermined value, the average value of the amount of change is held at the previous value. When the first wave of the fluctuation of the amount is too large with respect to the second and subsequent waves, the influence of the first wave can be reduced, and the average value of the amount of change in the amount of change can be calculated.

According to the eighth aspect of the present invention, if the change rate of the change amount of electricity is equal to or more than the predetermined value during the calculation of the generation model parameters, the measured electricity amount is held at the previous value. Abnormal values that cause adverse effects on the parameter calculation of the generation model of the variation component due to noise or the like are removed, and the parameters of the generation model are calculated based on the removed variation component, resulting in a more accurate change. It is possible to calculate the average value of the quantity of electricity.

According to the ninth aspect of the present invention, the amount of electricity corresponding to the actually measured change amount of electricity is also calculated from the parameters of the generation model, and the absolute value of the difference between the measured value and the calculated value of the change amount of electricity is calculated. If the integrated value is equal to or more than a predetermined value during a predetermined period, the data used for calculating the parameter is reset, so that the parameter of the generation model of the amount of change in electric quantity can be calculated more accurately according to the actual phenomenon, and the change with higher accuracy The average value of the quantity of electricity can be obtained.

According to the tenth aspect of the present invention, since the first average electric quantity is switched to the second average electric quantity a predetermined time after the detection of the sudden change, the average value of the change electric quantity in a short time at the beginning of the oscillation is calculated. Is switched from the first average amount of electricity by means suitable for the second period to the second average amount of electricity by means suitable for calculation of the average value of the amount of change for a relatively long time, and the average value of the amount of change is calculated with high accuracy Can be.

According to the eleventh aspect of the present invention, the calculated value of the amount of change obtained from the parameters of the generation model is compared with the actually measured value. Even when the mode is switched so as to output the average electric quantity, and the manner of fluctuation of the electric quantity changes during the calculation of the average value of the electric quantity, the average value of the electric quantity can be obtained with high accuracy.

According to the twelfth aspect, when the first average electricity quantity tends to diverge, it is possible to switch to the second average electricity quantity and obtain the average value of the electricity quantity at that time relatively accurately. it can.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of an average electricity amount calculating device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an average electric quantity calculation device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a sudden change detection unit included in the average electricity amount calculation device of FIG. 2;

FIG. 4 is a configuration diagram of a pre-current calculation unit included in an average electric quantity calculation device according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of a long-time average current calculation unit provided in an average electricity amount calculation device according to a fourth embodiment of the present invention.

FIG. 6 is a diagram illustrating a generation model of a model parameter calculation unit included in an average electric quantity calculation device according to a fifth embodiment of the present invention.

FIG. 7 is a configuration diagram of a model parameter calculation unit provided in an average electric quantity calculation device according to a fifth embodiment of the present invention.

FIG. 8 is a diagram showing another embodiment of the fifth embodiment of the present invention.

FIG. 9 is a configuration diagram of a model gain calculation unit provided in an average electric quantity calculation device according to a sixth embodiment of the present invention.

FIG. 10 is a configuration diagram of a long-time average current calculation unit provided in an average electricity amount calculation device according to a seventh embodiment of the present invention.

FIG. 11 is a configuration diagram of a model parameter calculation unit included in an average electric quantity calculation device according to an eighth embodiment of the present invention.

FIG. 12 is a configuration diagram of a model parameter calculation unit provided in an average electric quantity calculation device according to a ninth embodiment of the present invention.

FIG. 13 is a configuration diagram of an average electricity amount calculating device according to a tenth embodiment of the present invention.

FIG. 14 is a configuration diagram of a calculation result switching unit provided in an average electric quantity calculation device according to an eleventh embodiment of the present invention.

FIG. 15 is a configuration diagram of a calculation result switching unit provided in an average electric quantity calculation device according to a twelfth embodiment of the present invention.

FIG. 16 is a first waveform example according to the embodiment of the present invention;

FIG. 17 is a second waveform example according to the embodiment of the present invention.

FIG. 18 is a third waveform example according to the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 analog / digital conversion unit 2 sudden change detection unit 3 pre-current calculation unit 4 change current calculation unit 5 long-term average current calculation unit 6 model parameter calculation unit 7 model gain calculation unit 8 calculation result switching unit 9 overload determination unit 10 Input converter

Claims (12)

[Claims] 1. An average electricity amount calculating device for calculating an average value of a fluctuating electricity amount due to a sudden change such as an accident of an electric power system or an electric equipment, etc., wherein a sudden change of a measured electricity amount obtained by converting the electricity amount into a digital amount. The first means for calculating a change amount of electricity which is a difference between the average value of the prior electricity amount immediately before the sudden change and the measured amount of electricity, and a parameter and a gain of the generation model of the change amount of current are obtained. Means for obtaining an average value of the amount of change in the amount of fluctuation after a short period of time as the first average amount of electricity based on the following formula: and calculating the average value of the amount of change in the amount of change using a long observation window. And a fourth means for outputting the first average amount of electricity as a calculation result and switching the second average amount of electricity to output as a calculation result in accordance with a predetermined condition. The average electric quantity calculating apparatus according to symptoms. 2. An average electricity amount calculating device for calculating an average value of an electric amount that fluctuates due to a sudden change such as an accident of an electric power system or an electric equipment, wherein the electric amount is converted into a digital amount and converted into a measured electric amount. An analog / digital converter for outputting, a sudden change detecting unit for detecting a sudden change in the measured electric quantity based on the measured electric quantity converted by the analog / digital converting unit, and a sudden change in the measured electric quantity detected by the sudden change detecting unit When it is performed, a preliminary electric amount calculation unit that determines the average value of the immediately preceding measured electric amount as the preliminary electric amount, and compares the average value of the preliminary electric amount obtained by the preliminary electric amount calculation unit with the measured electric amount. A change amount of electricity calculation unit that calculates a difference between the two amounts as a change amount of electricity, and a generation module of the change amount of electricity based on the change amount of electricity calculated by the change amount of electricity calculation unit. Model parameter calculation unit for calculating the parameters and parameters, and calculating the gain of the parameters of the generation model calculated by the model parameter calculation unit, and averaging the amount of change in a short period of time in the initial period of shaking after a sudden change. A model gain calculating section for calculating a first average electric quantity as a value, and comparing an average value of the changed electric quantity as a second average electric quantity based on the changed electric quantity calculated by the changed electric quantity calculating section. A long-term average electric quantity calculation unit obtained from a long observation window, a first average electric quantity calculated by the model gain calculation unit, and the second average electric level calculated by the long-time average electric quantity calculation unit And a calculation result switching unit that switches under any one of the conditions and outputs the calculated result as a calculation result. 3. The average electricity amount according to claim 1, wherein the preliminary electricity amount calculation unit sets a value obtained by smoothing a moving average of the measured electricity amount for a predetermined time as an advance electricity amount. Quantity calculation device. 4. The long-time average electricity amount calculation unit, after performing a smoothing process on the variation electricity amount with a low-pass filter, continues the maximum value and the minimum value of the variation electricity amount within a predetermined time. If the current value is not interrupted for a predetermined time, the maximum value and the minimum value of the amount of change are held at the previous value, and the held maximum value and minimum value are added to obtain an average value. 2. The average electricity amount calculation device according to 1. 5. The average electricity amount calculation device according to claim 1, wherein the model parameter calculation unit calculates an occurrence model based on the change amount of electricity and calculates a parameter of the occurrence model. 6. The model gain calculating unit obtains a gain of the generation model by applying a parameter of the generation model of the change amount of electricity and applying a final value theorem of a discrete time system to obtain a change of the generation model in a relatively short period of time at the beginning of perturbation. 2. The average electricity amount calculation device according to claim 1, wherein an average value of the electricity amount is obtained. 7. The long-term average electricity amount calculation unit holds the average value of the electricity amount obtained last time if the rate of change of the estimated average value of the electricity amount is equal to or more than a predetermined value. The average electricity amount calculation device according to claim 1. 8. The model parameter calculation section calculates a parameter of a generation model based on a previous change amount of electricity when a change rate of the change amount of electricity is equal to or more than a predetermined value. Item 6. The average electricity amount calculating device according to Item 5. 9. The model parameter calculation unit calculates an absolute value of a change amount based on the calculated generation model and the parameter, and calculates an absolute value of a difference between the change amount and the actually measured change amount. If the integral of the value is equal to or greater than the predetermined value,
The average electricity amount calculation device according to claim 5, wherein the change electricity amount used for the calculation is reset. 10. The operation result switching unit switches to output the first average amount of electricity as an operation result for less than a predetermined time after the sudden change is detected by the sudden change detection unit,
2. The average electric quantity calculating device according to claim 1, wherein the switching is performed so that the second average electric quantity is output as a calculation result after the predetermined time. 11. The calculation result switching unit calculates a change amount of electricity based on the generation model and the parameter calculated by the model parameter calculation unit and a change amount of change actually measured. 2. The average electric quantity calculation device according to claim 1, wherein if the integrated value of the absolute value of the difference between the second average electric quantity and the absolute value is equal to or more than a predetermined value, the second average electric quantity is switched and output as a calculation result. 12. The calculation result switching unit calculates a change amount of electricity based on the parameters of the generation model calculated by the model parameter calculation unit, and determines that the change amount of change obtained has a tendency to diverge. 2. The average electric quantity calculation device according to claim 1, wherein the switching is performed so as to output the second average electric quantity as a calculation result when the operation is performed.