JP2003168335A - Power switching control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems of the conventional device that only a zero point of power source side voltage is used as a reference, and overvoltage generated when a breaker is thrown in can not be suppressed dependent on the state of a load side voltage. <P>SOLUTION: This power switching device is equipped with a target checking means 10 functionally approximating power source side voltage and load side voltage and deciding a target pole closing time from a waveform obtained by synthesizing interpole voltage on and after the present time with an approximate function; a pole closing time measuring means 16 measuring the pole closing time based on the difference between the output time of a control signal 20 and an operation time of an auxiliary switch 6; a pole closing time prediction means 11 predicting based on the last pole closing time, a present environmental temperature, a control voltage, and an operation pressure; and a pole closing control means 12 outputting a control signal to a breaker at a point of time before by the predicting pole closing time from the target pole closing time so as to close the breaker in the target pole closing time when a pole closing command is inputted. Therefore, the breaker is closed at the optimum timing to suppress overvoltage generation when a power transmission line is closed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power switching control device for controlling the switching timing of a power switching device such as a circuit breaker, and more particularly to a power switching control device for suppressing an overvoltage generated when a power transmission line is turned on. Is.

[0002]

2. Description of the Related Art A conventional power switching control device suppresses an overvoltage when a circuit breaker is turned on by controlling a timing of closing a circuit breaker with reference to a zero point of a power supply side voltage.
Such a power switching control device is disclosed in, for example, Japanese Patent Publication No. 28
No. 92717.

For example, it is known that electric charges remain in a sound phase when an accident occurs in a transmission line. In this case, various voltages are generated not only on the power source side of the circuit breaker but also on the load side of the circuit breaker according to the transmission line conditions. For example, a sine wave voltage having a constant frequency is generated in the load side voltage of the shunt reactor compensation transmission line, and a DC voltage is generated in the shunt reactor non-compensation transmission line. Under such circumstances, in order to suppress the overvoltage when the circuit breaker is turned on, the circuit breaker may be closed so that the circuit is turned on at the timing when the difference between the power supply side voltage and the load side voltage is minimized.

However, in such a power switching control device, since only the zero point of the power supply side voltage is used as a reference,
There is a drawback that the overvoltage when the breaker is turned on cannot be suppressed depending on the state of the load side voltage.

The document “Controlled Closi”
ng on Shunt Reactor Compe
Nested Transmission Line
s ”shows a method of measuring the power supply side voltage and the load side voltage, respectively, and controlling the closing timing of the circuit breaker using the waveform pattern of the voltage between contacts, which is the difference between them. According to this, pattern matching is used to check the zero-point period of the voltage waveform pattern to predict the optimum closing timing.

In this document, the concept of controlling the closing timing of the circuit breaker by measuring the voltage on the power source side and the voltage on the load side and examining the waveform pattern of the voltage between contacts, which is the difference between them, and the zero point period of the voltage waveform pattern. Although the method of obtaining the above is described, a concrete implementation method for determining the optimum closing timing is not shown.

Further, since the pre-arc characteristic of the circuit breaker and the mechanical operation variation characteristic of the circuit breaker are not taken into consideration, there is a drawback that the overvoltage at the time of closing cannot be suppressed depending on the characteristic of the circuit breaker.

[0008]

In the conventional power switching control device as described above, since only the zero point of the power supply side voltage is used as a reference, it is impossible to suppress the overvoltage when the breaker is turned on depending on the state of the load side voltage. There was a problem.

Further, in another conventional power switching control device as described above, the pre-arc characteristic of the circuit breaker and the mechanical operation variation characteristic of the circuit breaker are not taken into consideration. However, there was a problem that the overvoltage of could not be suppressed.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to turn on the circuit breaker at an optimum timing, and thus to suppress the overvoltage generated when the power transmission line is turned on. The purpose is to obtain the device.

[0011]

SUMMARY OF THE INVENTION A power switching control apparatus according to the present invention functionally approximates measured waveforms of a power source side voltage and a load side voltage of a circuit breaker, and uses this approximation function to calculate the inter-electrode voltage after the current time. Based on the difference between the target point detection means for determining the target closing time from the combined waveform, the output time of the control signal for closing the circuit breaker, and the operating time of the auxiliary switch linked with the circuit breaker. , A closing time measuring means for measuring the closing time of the circuit breaker, and the previous closing time measured by the closing time measuring means, based on the current environmental temperature, control voltage, and operating pressure, When a closing pole time predicting unit that predicts a predicted closing time that is a predicted value of the next closing time, and a closing command is input, the circuit breaker is closed at the target closing time. Before the target closing time by the predicted closing time It said control signal at a time is obtained and a closing control means for outputting to the breaker.

Further, in the power switching control device according to the present invention, the target point detection means performs signal conversion based on a pre-arc characteristic of the circuit breaker with respect to a waveform obtained by combining the voltage between contacts, and the circuit breaker. The target closing time is determined after performing signal conversion based on the mechanical operation variation of the above.

Further, the power switching control device according to the present invention detects the interruption time from the load side main circuit current of the circuit breaker when the direct current component of the load side voltage cannot be measured and there is no charge discharge, It further comprises a DC voltage estimating means for estimating the DC component of the load side voltage by using the load side voltage after the interruption time.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. A power switching control device according to Embodiment 1 of the present invention will be described with reference to the drawings. 1 is a diagram showing the configuration of a power switching control device according to a first embodiment of the present invention. In each figure, the same reference numerals indicate the same or corresponding parts.

In FIG. 1, 1 is a main circuit, 2 is a circuit breaker,
3 is a power transmission line, 4 is a power source side voltage measuring means, 5 is a load side voltage measuring means, 6 is an auxiliary switch, 7 is a power source side voltage, and 8 is a load side voltage. As the power supply side voltage measuring means 4, an AC voltage measuring sensor that is generally used in high voltage circuits is used. As the load side voltage measuring means 5, a sensor that can directly measure the AC voltage and the DC voltage component in the high voltage circuit is used.

Further, in the figure, 10 is a target point detecting means, 11 is a closing time predicting means, 12 is a closing control means, 1
3 is environmental temperature measuring means, 14 is control voltage measuring means, 15
Is an operating pressure measuring means, 16 is a closing time measuring means, 17 is a target closing time, 18 is a predicted closing time, 19 is a closing command,
Reference numeral 20 is a control signal.

Further, in the figure, the target point detecting means 10
Outputs the target closing time 17 from the power supply side voltage 7 measured by the power supply side voltage measuring means 4 and the load side voltage 8 measured by the load side voltage measuring means 5.

The closing time measuring means 16 measures the closing time of the circuit breaker 2 from the control signal 20 for closing the circuit breaker 2 and the auxiliary switch 6 linked with the movable contactor of the circuit breaker 2. .

The closing-pole time predicting means 11 includes the closing time at the previous closing time calculated by the closing-time measuring means 16, the environmental temperature measured by the environmental temperature measuring means 13, and the control voltage measuring means 14. From the measured control voltage and the operating pressure measured by the operating pressure measuring means 15, the predicted closing time 18 which is the predicted value of the closing time of the circuit breaker 2 at the next closing time is output.

When the closing command 19 is input, the closing control means 12 causes the circuit breaker 2 to close at the target closing time 17 by the predicted closing time 18 before the target closing time 17. At that time, the control signal 20 is output.

Next, the operation of the power switching control device according to the first embodiment will be described with reference to the drawings.

FIG. 2 is a flowchart showing the operation of the target point detecting means of the power switching control system according to the first embodiment of the present invention.

In step 101, the analog signals of the power supply side voltage 7 and the load side voltage 8 are discretized by the A / D converter at predetermined sampling intervals, and the voltage signals for a fixed time are stored.

Next, in step 102, a plurality of zero point times at which the sign of the obtained voltage signal changes from negative to positive or from positive to negative are detected and stored.

Next, in step 103, it is determined whether the voltage signal is a sine wave signal or a DC signal. For example, all the time intervals between the stored zero point times are calculated. If all the time intervals are within a certain range, it is regarded as a sine wave signal because it oscillates at a certain frequency centered on zero. In other cases, it is regarded as a DC signal. Fast Fourier transform (FFT) of the voltage signal,
The power density for each frequency may be calculated, and if the power within a certain frequency range is a certain value or more, it may be regarded as a sine wave signal, and if not, it may be regarded as a DC signal.

Next, in step 104, if the signal is a sine wave signal, the frequency, phase, and amplitude of the signal are calculated. For example, the average value of the zero point time intervals is calculated from the plurality of zero point times stored in step 102. Since a zero point is obtained every half cycle in a sine wave signal, a value obtained by taking the reciprocal of the average value of the zero point time interval and doubling it may be used. Regarding the phase, the value of the latest time of the zero point changing from negative to positive is stored as the time of phase 0 degree from the plurality of zero point times stored in step 102. For the amplitude, calculate the effective value by periodically integrating the voltage signal, and
The amplitude may be doubled. Using the above calculated values, the voltage signal is voltage value = amplitude × s at time t = 0 when the phase is 0 degrees.
It can be approximated as in (2π × frequency × t).

On the other hand, in step 105, when the signal is a DC signal, for example, the time average value of the voltage signal is calculated as the DC amplitude.

Next, at step 106, the voltage signal between contacts from the current time to a certain time later is estimated. FIG. 3 shows an example of a time waveform graph. In FIG. 3, the load side voltage is assumed to be a sine wave signal. In FIG. 3, 206 is the current time, the measured power supply side voltage is 201, and the measured load side voltage is 202. 201 in step 104
Since the sine wave signals 202 and 202 are function-approximated, the voltage signals after the current time are extrapolated using the approximation function to obtain the estimated power supply side voltage 203 and the estimated load side voltage 204. Then, the power supply side voltage signal 203 and the load side voltage signal 2
The absolute value 205 of the voltage between contacts, which is a signal obtained by taking the absolute value of the difference of 04, is calculated.

Next, at step 107, the target closing time from the present time to a certain time later is estimated. FIG. 4 shows an example thereof. In FIG. 4, a signal 304 represents the absolute value of the voltage between contacts at each time, and the time when this value becomes small is the optimum closing timing. Therefore, with respect to the absolute value signal 304 of the voltage between contacts, a time region that is equal to or less than the preset threshold value A (301) is sequentially searched from the front. The time regions that are equal to or less than the threshold A are regions A to G. From these, select a time domain that is longer than the preset length. Here, it is assumed that only the area E is selected. Finally, the intermediate point 303 of this area E is selected as the target closing time 17. If there is no time region longer than the length set in advance by the threshold A, the threshold B is changed to a threshold B (302) higher than the threshold A and the same processing is performed. Further, in FIG. 4, only one target closing time 17 is selected as 303 because the time range shown in the figure is short, but in reality, a plurality of target closing times 17 within the fixed time from the current time are set. To be elected. Therefore, all of these are stored as the target closing time 17.

Next, at step 108, the target closing time 17 is updated. Since the target point detection processing is repeatedly performed at regular intervals, it is necessary to update the target closing time 17 calculated in the previous target point detection processing each time the processing is performed. The latest result is regarded as correct, all target closing times calculated in the previous target point detection processing are deleted, and processing is performed to rewrite all the target closing times 17 calculated in this processing.

Next, the closed pole time measuring means 1 shown in FIG.
The operation of No. 6 will be described.

The closing time is calculated by taking the difference between the operating time of the auxiliary switch 6 which operates in conjunction with the movable contactor of the circuit breaker 2 and the time when the control signal 20 is output. In addition,
Although the auxiliary switch 6 is used as the closing-contact time measuring means 16, a rotation angle measuring means such as a rotary encoder is provided on the rotating shaft of the movable contactor drive unit of the circuit breaker 2, and the position signal of the movable contactor is obtained from this. The closing time may be calculated. By providing the rotation angle measuring means, it is possible to easily monitor the operation of the circuit breaker mechanism section.

Next, the operation of the closing time predicting means 11 shown in FIG. 1 will be described.

The change in the closing time of the circuit breaker 2 depends on the environmental conditions such as the environmental temperature, the control voltage, and the operating pressure. The circuit breaker varies depending on the change over time and the state change of each circuit breaker such as a minute individual difference, and the circuit breaker can be individually separated into parts requiring correction. Therefore, regarding the predicted closing time, which is the predicted value of the closing time of the circuit breaker 2 at the next closing time, the correction time ΔT1 based on the environmental conditions of the environmental temperature, the control voltage, and the operating pressure and the past operation history are recorded. The correction is performed based on the correction time ΔT2 based on the correction time.

Specifically, a predetermined environmental temperature is set in advance,
The reference closing time T0, which is the average value of the closing times under control voltage and operating pressure conditions, is measured. Further, the environmental temperature, the control voltage, and the operating pressure condition are changed to close the electrodes, and the average value of the closing times at that time is stored in the table as a difference value with respect to the reference closing time T0.

During operation, the table closest to the table is based on the environmental temperature measured by the environmental temperature measuring means 13, the control voltage measured by the control voltage measuring means 14, and the operating pressure measured by the operating pressure measuring means 15. By interpolating from the value, the correction time ΔT1 based on the environmental condition is calculated.

Further, regarding the actual closing time obtained by the closing time measuring means 16 and the predicted closing time during the operation, the error for the past n times (for example, the past 10 times) is calculated, and the error is calculated. Weighting is performed to calculate the correction time ΔT2 based on the past operation history. That is, the error in the i-th operation in the past is multiplied by the weighting coefficient w (i) and added over the past n times to calculate the correction time ΔT2. ΔT2 = Σ {w (i) × (actual closing time (i) -predicted closing time (i))} (i = 1 to n) The weighting coefficient w (i) has a sum of 1. . Regarding the weighting coefficient, it is desirable to increase the coefficient for the latest data in order to improve the response to the fluctuation of the closing time.

The predicted closing time 18 is calculated using the above values.

Predicted closing time = T0 + ΔT1 + ΔT2

Next, the operation of the closing control means 12 shown in FIG. 1 will be described.

When the closing command 19 is input, the control signal 20 is output so as to close the circuit breaker 2 at the target closing time 17 obtained by the target point detecting means 10. The predicted closing time 18 obtained by the closing time prediction means 11 is
Since it is a predicted value of the time from when the control signal 20 is output until the circuit breaker 2 is closed, in order to close the target closing time 17, the predicted closing time 1 from the target closing time 17
It suffices to output the control signal 20 at a time point 8 before.

Since the target closing time 17 is stored in plural points, the respective values are read out and the difference from the predicted closing time 18 is taken to calculate the candidate of the control signal output time. Among the candidates for the control signal output time, one time after the current time and closest to the current time is selected and set as the control signal output time. Then, the control signal 20 is output at the control signal output time.

In this operation, there is no limitation on the control delay time from the input of the closing command 19 to the output of the control signal 20. For example, in an obligation such as fast reclosing, the maximum value of the control delay time may be specified. When the load side voltage 8 is a sine wave signal and the frequency thereof is close to the frequency of the power source side voltage 7, the appearance time interval of the target closing time 17 becomes large, so in some cases the control is performed within the maximum value of the control delay time. It is also assumed that there is no candidate for signal output time.

Therefore, the maximum value of the control delay time is set in advance, and if there is no candidate for the control signal output time within this maximum value, the control signal 20 is forcibly forced.
May be output. Alternatively, the control signal 2 is set as the target closing time 17 with the zero point of the voltage 7 on the power supply side that is the closest to the current closing time and is after the predicted closing time 18.
It may operate so as to output 0. In this case, the target is not the optimum target, but since the applied voltage has the peak value of the load side voltage 8 even in the worst case, it is possible to avoid the worst case condition of the assumed overvoltage.

That is, the power switching control apparatus according to the first embodiment approximates the measured waveforms of the power source side voltage and the load side voltage of the circuit breaker 2 by a function, and uses this approximation function to calculate the inter-electrode voltage after the current time. Target point detecting means 10 for determining the target closing time 17 from the combined waveform, the output time of the control signal 20 for closing the circuit breaker 2, and the operation of the auxiliary switch 6 linked with the circuit breaker 2. A closing time measuring means 16 for measuring the closing time of the circuit breaker 2 based on the time difference;
Predicted closing time 1 which is a predicted value of the next closing time based on the previous closing time measured by the closing time measuring means 16 and the current environmental temperature, control voltage and operating pressure.
When the closing pole time predicting means 11 that predicts 8 and the closing pole command 19 are input, the predicted closing time is calculated from the target closing time 17 so that the circuit breaker 2 is closed at the target closing time 17. It is composed of a closing control means 12 for outputting the control signal 20 to the circuit breaker 2 and the like at a time point before the pole time 18.

According to this structure, the target closing time 17 can be determined after accurately predicting the inter-electrode voltage, so that the circuit breaker can be closed at the optimum timing. Therefore, it is possible to provide an apparatus that can suppress an overvoltage that occurs when the power transmission line is turned on, and that can prevent a phenomenon that is harmful to the grid and equipment.

Although the above-described first embodiment is premised on that the circuit breaker 2 has a single phase, it can be applied to a three-phase individual operation circuit breaker by providing the above-described configuration for each phase. Needless to say.

Embodiment 2. A power switching control device according to Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 5 is a flowchart showing the operation of the target point detecting means of the power switching control device according to the second embodiment of the present invention. The configuration is similar to that of the first embodiment.

As shown in FIG. 5, as compared with FIG. 2, a pre-arc correction (step 401) and a motion variation correction (step 402) are newly added, and the target closing time estimation in step 107 is partially modified. Then, the target closing time is estimated (step 403).

The operation of the target point detecting means 10 will be described. The processing of steps 101 to 106 and 108 is similar to that of the first embodiment.

The characteristics of the circuit breaker 2 will be described with reference to FIG. It is known that when the circuit breaker 2 is turned on, the main circuit current starts to flow due to the preceding discharge before the mechanical contact (closing) of the contact. This preceding discharge is called "pre-arc" and the moment when the main circuit current begins to flow is read as turning on. The closing time depends on the absolute value of the voltage between contacts, which is the voltage applied between the contacts of the circuit breaker 2, and the same type of circuit breaker has the same characteristics.

The withstand voltage line 501 shown in FIG. 6 shows the withstand voltage value between the contacts at a certain time in the circuit breaker closed at the target closing time A (502). If the absolute value of the voltage between contacts is lower than the withstand voltage value at a certain time,
It is not turned on because the withstand voltage between contacts is higher, but
At 503 in the figure, which is the intersection of the withstand voltage straight line and the voltage between contacts,
Since the withstand voltage between the contacts becomes equal to the inter-electrode voltage, a pre-arc is generated and injection is performed. Since the optimum closing timing is the moment when the closing voltage becomes the lowest, it is necessary to determine the target closing time 17 in consideration of such pre-arc characteristics.

Further, it is known that the circuit breaker 2 has a mechanical operation variation, and even when the environmental temperature, the control voltage, and the operating pressure are constant, the closing time is normally distributed with a certain spread. Become a state. For example, the target closing time B (5
When the contact is closed at 04), the actual closing time may change from the minimum value shown at 505 to the maximum value shown at 506. For example, if the closing time is 505,
The turn-on time B is 507, which is a high turn-on voltage. Since the optimum closing timing is the moment when the closing voltage becomes the lowest, it is necessary to determine the target closing time 17 in consideration of such operation variation characteristics.

Considering the above characteristics, step 40
In the pre-arc correction processing of No. 1, a signal obtained by correcting the absolute value signal of the inter-electrode voltage is obtained in consideration of the pre-arc characteristic of the circuit breaker 2. As a specific correction method, conversion into a signal projected in the direction of the withstand voltage straight line is performed.

An example of conversion will be described with reference to FIG. Figure 7
In, the slope of the withstand voltage line 606 is k. Starting from the point 601 where the voltage value is zero, 1 on the withstand voltage line 606
It moves to the previous position sampling by sampling, and the point 602 where the absolute value signal of the voltage between contacts exceeds the value and the point 603 one point behind.
The value of the intersection 604 is obtained by interpolating the values of and. The voltage value at the intersection 604 is the result of the pre-arc correction at the time 601, so it is equal to the voltage value at the intersection 604, and the point 605 at the time 601 becomes the pre-arc correction signal. This is repeated at all sampling points, and
The pre-arc correction signal 702 for the absolute value 701 of the voltage between contacts is obtained.

Next, in the operation variation correction processing of step 402, a signal obtained by further correcting the prearc correction signal 702 obtained by the prearc correction processing by the operation variation of the circuit breaker 2 is obtained. The maximum operation variation time ± Emsec shall be measured in advance for each circuit breaker model applied.

FIG. 8 shows an example. When the maximum operation variation time is ± Emsec, a maximum value filter with a width of 2 Emsec may be applied to the pre-arc correction signal 702. The maximum value filter is a filter that outputs the maximum value of the signal within the filter width. An operation variation correction signal subjected to this processing is shown at 703. This signal 7
03 is the result when E = 1 msec. The operation variation correction signal 703 indicates the maximum voltage value that may occur due to the operation variation of the circuit breaker 2 when the electrodes are closed by aiming at a certain target closing time.

Next, the process of estimating the target closing time at step 403 will be described. An example is shown in FIG. The operation variation correction signal 703 is a signal in which the pre-arc characteristic and the operation variation characteristic are taken into consideration in the absolute value of the voltage between contacts, and the time when this value becomes small is the optimum closing timing. Therefore, for the operation variation correction signal 703,
A time region having a preset threshold value 705 or less is searched in order from the front. The time region in which the threshold value is 705 or less is region A to region C in FIG. The midpoint is selected as the target closing time in each region. For example, the target closing time in region B is 706.

Further, in FIG. 8, only one target closing time 706 is selected because the time range shown in the figure is short, but in reality, a plurality of target closing times are set within a fixed time from the current time. Is selected. Therefore, all of these are stored as the target closing time.

According to such a configuration, the target closing time 17 is determined in consideration of the circuit breaker characteristic, so that there is an effect that the circuit breaker can be closed at the optimum timing.
Therefore, it is possible to provide an apparatus that can suppress an overvoltage that occurs when the power transmission line is turned on, and that can prevent a phenomenon that is harmful to the grid and equipment.

Embodiment 3. A power switching control device according to Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 9 is a diagram showing a configuration of a power switching control device according to Embodiment 3 of the present invention.

In the power switching control apparatus according to the first embodiment, the load side PT5 used has a direct current component that can be directly measured. However, in the third embodiment, for example, a transformer for a capacitor partial pressure type instrument is used. Even if the load side voltage measuring means 801 which does not have the electric charge discharge and the DC component cannot be measured, the same effect as that of the first embodiment can be obtained.

In FIG. 9, as compared with the first embodiment shown in FIG. 1, there is no charge discharge and the DC component cannot be measured, and the load side voltage measuring means 801 and the main circuit current 803 measured by the current transformer 802. Is added to the DC voltage estimating means 805 for estimating the DC voltage.

FIG. 10 shows an example of the operation. The signal measured by the load side voltage measuring unit 801 is the load side voltage 90.
1. The signal 803 measured by the current transformer 802 is the main circuit current 902. The transmission line 3 is not subjected to shunt reactor compensation, and an example in which electric charges remain on the load side after interruption and the true value of the load side voltage is a DC voltage is shown. Since the load side voltage measuring means 801 cannot measure the DC voltage, the load side voltage 901 is observed as an attenuation signal having a constant time constant immediately after the interruption.

Load side voltage 901 and main circuit current 902
As for, the data from the current time to a certain time before is always stored. Then, when it is detected that the auxiliary switch 6 changes from closed to open, the storage of the data is stopped when a certain time has elapsed. As a result, it is possible to store the signals before and after the cutoff time 903 as shown in FIG.
This stored data is used in the following processing.

First, the cutoff time 903, which is the point where the main circuit current 902 becomes zero, is found. Next, the load side voltage 901 is function-approximated using a plurality of sampling points of voltage values for a fixed time from the cutoff time 903. When there is a direct current component, it is observed that the voltage value decays with a constant time constant immediately after the cutoff.
For K × exp (−α × time), the plurality of sampling points are least-squares approximated to obtain K and α, and an approximate function 905 is obtained.
To create. From the obtained approximate function 905, the cutoff time 9
The voltage value at 03 is obtained and used as a DC voltage estimated value 904.

Then, the target point detecting means 10 may use this DC voltage estimated value 904 instead of the process of calculating the DC amplitude in step 105 on the load side voltage side in FIG.

In the above description, the transmission line 3 is not shunt reactor compensated, and the load side voltage is a DC voltage. However, in the case where the transmission line 3 is shunt reactor compensated, The load side voltage is zero DC voltage and becomes a sine wave signal. In this case, since the approximate function 905 is estimated to be K = 0, that is, the voltage value = 0, it can be handled by the same processing.

Regarding the power supply side voltage measuring means 4,
Since the DC component is usually a zero value when the circuit breaker 2 is opened / closed, it is not necessary to perform the above process regardless of the type of voltage measuring means.

According to this structure, the value of the DC component of the load-side voltage remaining after the interruption can be found even if the voltage measuring means that does not discharge electric charges and cannot measure the DC component is used. The advantage is that it is possible to easily configure a device that turns on the circuit breaker at the optimum timing.

[0071]

As described above, the power switching control device according to the present invention functionally approximates the measured waveforms of the power source side voltage and the load side voltage of the circuit breaker, and uses this approximation function to calculate the gap between Based on the difference between the target point detecting means for determining the target closing time from the waveform obtained by combining the voltages, the output time of the control signal for closing the circuit breaker, and the operating time of the auxiliary switch linked with the circuit breaker. Based on the closing time measuring means for measuring the closing time of the circuit breaker, the previous closing time measured by the closing time measuring means, the current environmental temperature, the control voltage, and the operating pressure. A closing pole time predicting unit that predicts a predicted closing time that is a predicted value of the next closing time, and a closing command is input, so that the circuit breaker is closed at the target closing time. The predicted closing time from the target closing time Since it has the closing control means for outputting the control signal to the circuit breaker at the time before the circuit breaker, the circuit breaker can be closed at the optimum timing, and the overvoltage generated when the power transmission line is closed can be suppressed. Therefore, it is possible to prevent the occurrence of a phenomenon that is harmful to the system or equipment.

Further, in the power switching control device according to the present invention, as described above, the target point detection means converts the waveform obtained by combining the inter-electrode voltage based on the pre-arc characteristic of the circuit breaker. , And the target closing time is determined after performing signal conversion based on the mechanical operation variation of the circuit breaker, so that the circuit breaker can be closed at the optimum timing, and the overvoltage generated when the power transmission line is closed can be reduced. The effect is that it can be suppressed and the occurrence of a phenomenon that is harmful to the system and equipment can be prevented.

Further, as described above, the power switching control apparatus according to the present invention, when there is no charge discharge and the DC component of the load side voltage cannot be measured, the cutoff time from the main circuit current on the load side of the circuit breaker is cut off. Since it further comprises a DC voltage estimating means for estimating the DC component of the load side voltage by using the load side voltage after the interruption time, the circuit breaker can be turned on at the optimum timing, and when the transmission line is turned on. It is possible to suppress an overvoltage that occurs and prevent an occurrence of a phenomenon that is harmful to the system or equipment.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a power switching control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of target point detection means of the power switching control device according to the first embodiment of the present invention.

FIG. 3 is a timing chart showing an operation of the power switching control device according to the first embodiment of the present invention.

FIG. 4 is a timing chart showing an operation of the power switching control device according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing an operation of target point detecting means of the power switching control apparatus according to the second embodiment of the present invention.

FIG. 6 is a timing chart showing an operation of the power switching control device according to the second embodiment of the present invention.

FIG. 7 is a timing chart showing an operation of the power switching control device according to the second embodiment of the present invention.

FIG. 8 is a timing chart showing an operation of the power switching control device according to the second embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of a power switching control device according to a third embodiment of the present invention.

FIG. 10 is a timing chart showing an operation of the power switching control device according to the third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 main circuit, 2 circuit breaker, 3 power transmission line, 4 power supply side voltage measuring means, 5 load side voltage measuring means, 6 auxiliary switch, 10 target point detecting means, 11 closing time predicting means,
12 closing poles, 13 environmental temperature measuring means, 14 control voltage measuring means, 15 operating pressure measuring means, 16 closing time measuring means, 805 DC voltage estimating means.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroki Ito             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Haruhiko Kayama             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F-term (reference) 5G034 AA06 AC09 AC20 AD01

Claims (3)

[Claims] 1. A target inspection for approximating a measured waveform of a power source side voltage and a load side voltage of a circuit breaker by a function approximation and determining a target closing pole time from a waveform obtained by synthesizing an inter-electrode voltage after the present time using this approximation function. A closing time for measuring the closing time of the circuit breaker, based on the difference between the output means and the output time of the control signal for closing the circuit breaker, and the operating time of the auxiliary switch interlocking with the circuit breaker. Based on the measuring means and the previous closing time measured by the closing time measuring means, the current environmental temperature, the control voltage, and the operating pressure, the predicted closing time is the predicted value of the next closing time. When a closing command is input, a closing pole time predicting unit that predicts the closing pole time predicting means for closing the circuit breaker at the target closing time, so that the predicted closing time is before the target closing time. Closed control for outputting the control signal to the circuit breaker An electric power switching control device comprising: a control means. 2. The target point detection means converts a signal based on a pre-arc characteristic of the circuit breaker and a signal conversion based on a variation in mechanical operation of the circuit breaker with respect to a waveform obtained by combining the voltage between contacts. The power switching control device according to claim 1, wherein the target closing time is determined after performing the above. 3. When there is no charge discharge and the DC component of the load side voltage cannot be measured, the break time is detected from the load side main circuit current of the circuit breaker, and the load side voltage after the break time is used. The power switching control device according to claim 1, further comprising a DC voltage estimating means for estimating a DC component of the load side voltage.