JP3407015B2 - Lead capacitor and series reactor protection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase advancing capacitor protection device for protecting a power advancing capacitor for power factor correction and a series reactor protection device for protecting a series reactor inserted in series with the phase advancing capacitor.

[0002]

2. Description of the Related Art FIG.
FIG. 5 is a power system diagram to which a conventional harmonic current monitoring device shown in Japanese Patent Publication is connected. In the figure, 1 is an upper system transformer,
Reference numeral 2 is a bus bar, 3 is a power load, 4 is a phase advancing capacitor, and 5 is a series reactor that is connected to suppress a harmonic current flowing through the phase advancing capacitor 4.

In general, this series reactor 5 has an impedance of 6% with respect to the impedance of the phase advancing capacitor 4 when suppressing the fifth harmonic component, and the third harmonic component. In the case of suppressing, the impedance is selected to be 13%. 7 is a current transformer (C
T) and 6 are electromagnetic contactors (VMC) for turning on and off the bus bar 2 and the phase advancing capacitor 4 by an external signal.

Reference numeral 10 denotes a harmonic current monitoring device, which is composed of the following elements. Harmonic current measuring unit 11 that measures the harmonic current of each order from the output of CT7, harmonic current monitoring unit 12 that monitors the harmonic current upper limit of each order, and warning is issued when an upper limit alarm is generated by the harmonic current monitoring unit 12. It is composed of an alarm display unit 13 for displaying. The harmonic current measuring unit 11 is composed of a BPF (band pass filter) and a DET (harmonic component detecting circuit), and the harmonic current monitoring unit 12 is C.
REF that gives a reference voltage to OMP (comparator) and COMP
The alarm display unit 13 is composed of LEDs (reference voltage circuit) and FF (latch circuit). 3 in this example
An upper limit is monitored for each harmonic current of each of the 4th, 5th, and 7th harmonics. If the harmonic current of any of the orders exceeds the upper limit set value, an alarm is displayed.

[0005]

In the conventional harmonic current monitoring device configured as described above, an alarm is displayed if any one of the harmonic currents of each order exceeds the upper limit set value. The degree of influence of the phase capacitor on the thermal overload and overvoltage conditions depends on the harmonic order.

Therefore, when the upper limit set value is set to a value that affects the thermal overload and overvoltage states, assuming that the harmonic currents of each order exist independently, when the harmonics of each order are mixed, Although the harmonic current of any order does not exceed the upper limit set value, the influence of the actual thermal overload and overvoltage states is large, and the phase advance capacitor is deteriorated or burned out. In anticipation of such a situation, if the upper limit setting value is set low, the thermal overload and the overvoltage state of the phase-advancing capacitor have a margin when there are many harmonic components of a specific order. There was a problem of displaying an alarm.

In addition, an alarm must be displayed according to the result of actual measurement of the harmonic current flowing in the phase advancing capacitor.
When the electromagnetic contactor connecting the phase advancing capacitor to the bus bar was open, it was not possible to know the harmonic current flowing through the phase advancing capacitor. For this reason, when the electromagnetic contactor is turned on with a large amount of harmonic components, a large current flows through the phase advancing capacitor, and the phase advancing capacitor is deteriorated more quickly.

As with the phase advancing capacitor, it is necessary to protect the series reactor inserted in series with the phase advancing capacitor from the thermal overload condition and the overvoltage condition.

The present invention has been made in order to solve the above-mentioned problems, and the thermal effect exerted on the phase advancing capacitor of each order even when the harmonics of each order are mixed and the mixing ratio varies. It is possible to judge the safety of the phase advancing capacitor by comprehensively considering the overload and overvoltage conditions.Also, even if the harmonic contact current flowing in the phase advancing capacitor is predicted even when the electromagnetic contactor is open, if the upper limit setting value is exceeded, An object of the present invention is to provide a phase advancing capacitor protection device capable of issuing an alarm and prohibiting the input of a phase advancing capacitor.

It is another object of the present invention to provide a series reactor protection device that protects a series reactor like a phase advancing capacitor.

[0011]

(1) A phase advancing capacitor protection device according to the present invention is a power system in which a phase advancing capacitor is turned on and off, and a harmonic of a predetermined order flowing through the phase advancing capacitor. the current is measured, means for the phase advance capacitor on the basis of the measured value to determine whether a thermal overload or overvoltage condition, and outputs a phase advancing capacitor open signal or alarm signal in response to the determination result , Above
Determine if the phase capacitors are in thermal overload or overvoltage
Thermal overload tolerance (allowable limit)
Boundary value) and overvoltage withstanding value (allowable limit value)
A means for changing either one of the deviations is provided.

(2) In a power system in which a phase advancing capacitor is turned on and off, a harmonic voltage of a predetermined order included in the power system is converted into a harmonic current of each order flowing through the phase advancing capacitor. For setting various conditions such as phase advancing capacitor capacity and host system transformer capacity in advance, measure the harmonic voltage of a predetermined order included in the power system, and from the measured value and the above set conditions, The predicted value of the harmonic current of a predetermined order that flows in the phase-advancing capacitor is calculated, and it is determined whether the phase-advancing capacitor is in a thermal overload state or an overvoltage state based on this estimated value. It outputs a phase advancing capacitor closing prohibition signal or an alarm signal.

(3) Further, in a power system in which a phase advancing capacitor is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, the above-mentioned harmonic voltage of a predetermined order included in the power system causes Various conditions such as the capacity of the phase-advancing capacitor and the capacity of the upper system transformer for converting into the harmonic current of each order flowing in the phase-advancing capacitor are set for each bank switching, and the harmonics of the predetermined order included in the power system are set. The wave voltage is measured, and the predicted value of the harmonic current of a predetermined order flowing in the phase advancing capacitor is calculated for each bank switching from the measured value, the phase advancing capacitor capacity, and the conditions set above.
Based on this predicted value, it is determined whether the phase-advancing capacitor bank is in a thermal overload state or an overvoltage state at each bank switching, and a phase-advancing capacitor bank closing prohibition signal or an alarm signal is output according to the determination result. To do.

(4) In a power system in which a phase advancing capacitor is turned on / off, a harmonic voltage of a predetermined order included in the power system is converted into a harmonic current of each order flowing through the phase advancing capacitor. The various conditions such as the capacity of the advanced capacitor and the capacity of the host system transformer are set in advance, and the harmonic voltage of the predetermined order included in the power system is measured with the advanced capacitor open, and this measured value and A predicted value of a harmonic current of a predetermined order that flows in the phase advancing capacitor is calculated from the set condition, and it is determined whether the phase advancing capacitor is in a thermal overload state or an overvoltage based on the calculated value. ,
According to this judgment result, the advance capacitor input prohibition signal or the alarm signal is output, and the harmonic current of a predetermined order flowing in the advance capacitor is measured in the advance capacitor closed state. It judges whether the phase advancing capacitor is in a thermal overload state or an overvoltage state, and outputs a phase advancing capacitor open signal or an alarm signal according to the determination result.

(5) Further, in a power system in which a phase advancing capacitor is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, the above-mentioned harmonic voltage of a predetermined order included in the power system is used. In order to convert the harmonic currents of each order into the phase-advancing capacitor, set various conditions such as the phase-advancing capacitor capacity and the host system transformer capacity for each bank switching, and leave the phase-advancing capacitor open in the power system. Measure the harmonic voltage of a predetermined order included, calculate the predicted value of the harmonic current of a predetermined order flowing in the phase advancing capacitor for each bank switching from this measured value and the conditions set above, and calculate this predicted value. Based on the above, it is determined whether the phase advancing capacitor is in a thermal overload state or an overvoltage state for each bank switching,
Depending on this judgment result, the advance capacitor input prohibition signal or alarm signal is output, the harmonic current of a predetermined order that flows in the input advance capacitor is measured in the advanced capacitor input state, and based on this measurement value Then, it is determined whether the input phase advancing capacitor is in a thermal overload state or an overvoltage state, and a phase advancing capacitor open signal or an alarm signal is output according to the determination result.

(6) Further, in the above item (4) or (5), one harmonic measuring unit is configured to measure both a harmonic current and a harmonic voltage of a predetermined order, and a phase-advancing capacitor. The harmonic current is measured in the closed state, and the harmonic voltage is measured in the phase advance capacitor open state.

(7) Further, in the power system in which the phase advancing capacitor is turned on / off, in the state where the phase advancing capacitor is turned on,
The harmonic current of a predetermined order flowing through the phase advancing capacitor and the harmonic voltage of the same order as the predetermined order included in the power system are measured, and the impedance corresponding to each order is obtained, and the measurement is performed. Based on the harmonic current of each order, it is determined whether the phase advancing capacitor is in a thermal overload state or an overvoltage state, and a phase advancing capacitor open signal or an alarm signal is output according to the determination result, and the phase advancing capacitor is output. In the open state, the high-frequency voltage of the predetermined order contained in the power system is measured, the predicted value of the harmonic current of each order flowing in the phase-advancing capacitor is obtained from this measured value and the impedance obtained above, and this predicted value is obtained. Based on the above, it is determined whether the phase advancing capacitor is in a thermal overload state or an overvoltage state, and a phase advancing capacitor closing prohibition signal or an alarm is output according to the determination result. It is intended.

(8) In addition, in a power system in which a phase advancing capacitor is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, the above-mentioned phase advancing for each bank switching is performed with the phase advancing capacitor being turned on. A harmonic current of a predetermined order flowing through the capacitor and a harmonic voltage of the same order as the predetermined order included in the power system are measured, and the impedance corresponding to each order is obtained for each bank switching. Measure the harmonic current of a predetermined order that flows through the injected phase advancing capacitor, and determine whether the phase advancing capacitor is in a thermal overload state or an overvoltage state based on this measurement value and the input phase advancing capacitor capacity. It is determined whether or not the phase advancing capacitor open signal or alarm signal is output according to the result of the determination, and in the phase advancing capacitor open state, the high frequency of the above-mentioned predetermined order included in the power system. Measuring a voltage, it obtains a predicted value of each order harmonic current flowing from the impedance obtained for each the measured value and the bank switching in the phase advancing capacitor,
Based on this predicted value, it is determined whether the phase-advancing capacitor is in a thermal overload state or an overvoltage state for each bank switching, and a phase-advancing capacitor closing prohibition signal or an alarm signal is output according to the determination result. is there.

(9) Further, in any one of the above items (3), (5) and (8), when the capacitor capacity is set, the current is measured for each capacitor bank switching, and the capacitor is measured based on this measured value. A means for determining and setting the capacity is provided.

(10) Further, in any one of the above items (2) to (9), when the phase advancing capacitor is opened and the judgment result is that the phase advancing capacitor is not in a thermal overload state or an overvoltage state. A means for canceling the advance capacitor input prohibiting signal or the alarm signal is provided.

(11) Further, in any one of the above items (2) to (10), when the determination result is that the phase advancing capacitor is in a thermal overload state or an overvoltage state, it is transmitted from another device or another device. It is provided with a means for blocking the signal for inputting the phase advancing capacitor by the operation.

(12) Further, in any one of the above items (2) to (11), after measuring the harmonic voltage of a predetermined order included in the power system, the measured harmonic voltage of each order. Is provided, and a predicted value of the harmonic current of each order flowing through the phase advancing capacitor is calculated from the harmonic voltage of each order after the averaging process.

(13) Further, the above (1), (3)-
In any one of (8), after measuring a harmonic current of a predetermined order that flows in the phase advancing capacitor, means for performing a weighted moving average processing on each measured harmonic current of each order is provided, and this averaging processing is performed. It is configured to determine whether the phase advancing capacitor is in a thermal overload state or an overvoltage state based on the subsequent harmonic current of each order.

(14) Further, in any one of the above items (2) to (12), when it is determined that the phase advancing capacitor is not in a thermal overload state or an overvoltage state while the phase advancing capacitor is open, a predetermined value is set. Delay means is provided for canceling the signal for prohibiting the introduction of the phase advancing capacitor or the alarm signal after a lapse of time.

(15) Further, in any one of the above items (1) to (14), it is determined that the phase advancing capacitor is in a thermal overload state or an overvoltage state, and if this state continues for a predetermined time, the phase advancing A delay means for outputting a capacitor open signal or an alarm signal is provided.

(16) In any one of the above items (2) to (15), the thermal overload withstanding value which is a reference value for determining whether the phase advancing capacitor is in a thermal overload state or overvoltage. A means for changing at least one of the (allowable limit value) and the overvoltage withstanding value (allowable limit value) is provided.

(17) A series reactor protection device according to the present invention is a power system in which a phase advancing capacitor connected to a series reactor is turned on and off, and a harmonic current of a predetermined order flowing through the phase advancing capacitor. Means for determining whether the series reactor is in a thermal overload state or an overvoltage state based on the measured value, and outputting a phase advancing capacitor open signal or an alarm signal according to the determination result.
And the above series reactor is overheated or overvoltage
Thermal overload resistance, which is the criterion value for determining whether or not
Amount (permissible limit value) and overvoltage withstand capability (permissible limit value)
Even if there is a means to change either one,
Of.

(18) Further, in a power system in which a phase advancing capacitor connected with a series reactor is turned on and off, each order flowing from the harmonic voltage of a predetermined order included in the power system to the phase advancing capacitor. The various conditions such as the capacity of the phase-advancing capacitor and the capacity of the transformer of the upper system to be converted into the harmonic current of are set, and the harmonic voltage of the predetermined order included in the power system is measured. Calculate a predicted value of a harmonic current of a predetermined order flowing in the phase advance capacitor from the set condition, and determine whether the thermal overload state or the overvoltage state of the series reactor based on this predicted value, Depending on the result of this determination, the advance capacitor input prohibition signal or the alarm signal is output.

(19) Further, in a power system in which a phase advancing capacitor is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, the above-mentioned harmonic voltage of a predetermined order included in the power system is used to obtain the above. Various conditions such as the capacity of the phase-advancing capacitor and the capacity of the upper system transformer for converting into the harmonic current of each order flowing in the phase-advancing capacitor are set for each bank switching, and the harmonics of the predetermined order included in the power system are set. The wave voltage is measured, and the predicted value of the harmonic current of a predetermined order that flows in the phase advancing capacitor is calculated for each bank switching from this measured value, the phase advancing capacitor capacity, and the conditions set above. On the basis of the thermal overload state or overvoltage state of the phase advancing capacitor bank based on each switching, the phase advancing capacitor bank closing prohibition signal is determined according to the determination result. Other and outputs an alarm signal.

(20) Further, in a power system in which a phase advancing capacitor connected with a series reactor is turned on and off, each order flowing from the harmonic voltage of a predetermined order included in the power system to the phase advancing capacitor. The harmonic voltage of a predetermined order included in the power system is measured with the advanced capacitor open and the various conditions such as the advanced capacitor capacity and host system transformer capacity to be converted into the harmonic current of the power system set. Then, the predicted value of the harmonic current of a predetermined order flowing in the phase advance capacitor is calculated from this measured value and the set condition, and the thermal overload state or overvoltage state of the series reactor is calculated based on this calculated value. It is determined whether or not the phase advancing capacitor input prohibition signal or alarm signal is output according to the result of the determination, and the phase advancing capacitor is in the state of advancing the phase advancing capacitor. Measures the harmonic current, determines whether the series reactor is in a thermal overload state or an overvoltage state based on this measurement value, and outputs a phase-advancing capacitor open signal or an alarm signal according to the determination result. Is.

(21) Further, in a power system in which a phase advancing capacitor to which a series reactor is connected is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, a predetermined order included in the power system. The phase-advancing capacitor is opened by setting various conditions such as the phase-advancing capacitor capacity and the host system transformer capacity for each bank switching in order to convert the harmonic voltage of the above into the harmonic current of each order that flows in the phase-advancing capacitor. In this state, measure the harmonic voltage of a predetermined order contained in the power system, and from this measured value and the condition set above, the predicted value of the harmonic current of a predetermined order flowing through the phase advance capacitor is calculated for each bank switching. It is calculated, and based on this predicted value, it is determined whether the series reactor is in a thermal overload state or an overvoltage state at each bank switching, and the phase advancing capacitor is turned on according to this determination result. Outputs a stop signal or an alarm signal, measures the harmonic current of a predetermined order that flows in the advanced capacitor that has been injected with the advanced capacitor turned on, and based on this measurement value, the thermal effect of the series reactor that has been injected above. It is determined whether or not it is in an overload state or an overvoltage state, and outputs a phase advancing capacitor open signal or an alarm signal according to the determination result.

(22) Further, in a power system in which a phase advancing capacitor connected with a series reactor is turned on and off, in a state where the phase advancing capacitor is turned on, a harmonic current of a predetermined order flowing through the phase advancing capacitor and , The harmonic voltage of the same order as the predetermined order included in the power system is measured, and the impedance corresponding to each order is obtained, and the heat of the series reactor is calculated based on the measured harmonic current of each order. It is determined whether the overload condition or the overvoltage condition, the phase advancing capacitor open signal or the alarm signal is output according to the judgment result, and the high frequency of the above-mentioned predetermined order included in the power system in the phase advancing capacitor open state. Measure the voltage,
Obtaining the predicted value of the harmonic current of each order flowing in the phase advancing capacitor from this measured value and the impedance obtained above,
Based on this predicted value, it is determined whether the series reactor is in a thermal overload state or an overvoltage state, and a phase advancing capacitor closing prohibition signal or an alarm is output according to the determination result.

(23) Further, in a power system in which a phase advancing capacitor to which a series reactor is connected is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, the bank with the phase advancing capacitor turned on is used. A harmonic current of a predetermined order flowing through the phase advance capacitor for each switching and a harmonic voltage of the same order as the predetermined order included in the power system are measured, and the impedance corresponding to each order is switched to a bank. The harmonic overcurrent of a predetermined order that flows in the input phase advancing capacitor is measured, and the thermal overload state of the series reactor is determined based on this measured value and the input phase advancing capacitor capacity. Or, it judges whether it is an overvoltage condition or not, and outputs a phase advancing capacitor open signal or an alarm signal according to the judgment result, and when the phase advancing capacitor is open, The high-frequency voltage of the predetermined order is measured, and the predicted value of the harmonic current of each order flowing in the phase-advancing capacitor is obtained from this measured value and the impedance obtained at each bank switching, and based on this predicted value. Whether or not the series reactor is in a thermal overload state or an overvoltage state is determined for each bank switching, and a phase advancing capacitor closing prohibition signal or an alarm signal is output according to the determination result.

[0034]

[0035]

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a configuration block diagram of a phase advancing capacitor protection device according to a first embodiment of the present invention. In the figure, 1 to 7 are the same as those described in the conventional example. Reference numeral 8 denotes a capacitor closing control device for opening and closing the electromagnetic contactor 6 by an electric signal from the outside. Reference numeral 20 is a main body of the phase-advancing capacitor protection device, and 21 is a harmonic component measuring unit, which is a harmonic current component (first, third, fifth, seventh, and ninth in this embodiment) included in the secondary output of CT7. Next, 11th, 13th) is measured.

The harmonic component measuring section 21 is the A / D converter 2
2. A high-speed Fourier transform circuit (FFT) 23 extracts a harmonic current component for each order and measures it. A harmonic current display unit 24 displays the harmonic component current value for each order. As for the display, the respective harmonic component current values from the 3rd to 13th order may be individually displayed, or the order and the harmonic component current values may be combined and sequentially displayed.

Reference numeral 25 is a monitoring alarm section, and 26 is an alarm display section, which displays an alarm by a signal from the monitoring alarm section 25.
Reference numeral 27 is a signal inversion circuit, which inverts the output of the monitoring / alarm unit 25 and outputs it to the capacitor closing control device 8. That is, the capacitor closing control device 8 is for matching the signal form of another control device that closes the electromagnetic contactor 6 when the input signal is "H" and opens when the input signal is "L".

In the monitoring / warning unit 25, the harmonic component measuring unit 21
The thermal overload state or overvoltage state of the phase-advancing capacitor 4 is obtained by the following calculation from the harmonic current Icn for each order measured in (4). The calculation of this thermal overload state or overvoltage state uses the following formula quoted from “Electrical Joint Research Vol. 37, No. 3, page 78, Table 2-1”.

Assuming that the fundamental frequency current of the harmonic current Icn is I1, the condition for generating the thermal overload alarm of the phase-advancing capacitor is expressed by the equation (1).
Like

[0041]

[Equation 1]

The condition for generating the overvoltage alarm of the phase advancing capacitor is expressed by the equation (2).

[0043]

[Equation 2]

That is, the relationship obtained from the fundamental frequency current I1 and the harmonic current Icn of each order including the fundamental frequency current I1 is the alarm output as a dangerous region of thermal and overvoltage withstanding of the phase advancing capacitor under the conditions of the above equation. , Or outputs a signal for opening the phase advancing capacitor 4.

The above-mentioned conditional expression is an expression which gives a standard of allowable limit as in "Electrical Joint Research Vol. 37, No. 3, page 78, Table 2-1-1," which cites this expression, The values of "1.35" and "0.256" may be changed.

As described above, even when the harmonics of each order are mixed and the mixing ratio varies, the thermal overload and the overvoltage state exerted on the phase advancing capacitor of each order are comprehensively integrated. You can judge the safety and protect it.

Embodiment 2. 2 is a configuration block diagram of a phase advancing capacitor protection device according to a second embodiment of the present invention. In the figure, 1 to 6,
8, 20, 23, 25 to 27 are the same as those described in the first embodiment. Reference numeral 9 is a transformer (PT), 30 is a condition setting unit, and a transformation ratio setting unit 31, a phase advancing capacitor capacity setting unit 32, a series reactor reactance ratio setting unit 33, an upper system transformer capacity setting unit 34, a higher order of the PT9. It is composed of a system transformer percent reactance value setting unit 35.

The shift ratio S of PT9 is sent to the shift ratio setting section 31.
(No unit) is set to the phase-advancing capacitor capacity setting unit 32 by the capacity Q (Var) of the phase-advancing capacitor connected to the power system.
In the series reactor reactance ratio setting unit 33, the ratio b (%) of the series reactor 5 to the reactance value of the phase advance capacitor 4 is set. The rated capacity P (VA) of the host system transformer 1 is input to the host system transformer capacity setting unit 34, and the percent reactance value a (%) of the host system transformer 1 is input to the host system transformer percent reactance value setting unit 35. , You can input each value.

Reference numeral 40 denotes P for measuring the voltage of the electric power system.
An A / D converter that converts the secondary output of T9, 41 is a harmonic voltage measurement unit, and measures the harmonic voltage components included in the secondary output of PT9 through the A / D converter 40 and FFT23, respectively. To do. Reference numeral 42 denotes a harmonic current calculation unit, which is predicted to flow from the harmonic voltage vn of each order measured by the harmonic voltage measurement unit 41 (n indicates the harmonic order) to the phase advance capacitor 4. The order harmonic current Icn is calculated by the following procedure.

[0050]   Harmonic voltage of primary voltage Vn = S * vn   Leading capacitor reactance value Xc = V1 2 / Q   Series reactor reactance value XL = Xc * (b / 100)   Upper system transformer reactance value Xo = (a / 100) * (V1 2 / P)

Then, based on these values, the harmonic current Icn of each order is calculated from the harmonic voltage of the primary voltage by the following formula quoted from “Electrical Joint Research Vol. 37, No. 3, p. 69”. Icn = Vn / (nXo + nXL- (Xc / n)) (3)

In the open condition of the phase advancing capacitor 4, the monitoring alarm unit 25 explains the thermal overload alarm generating condition and the overvoltage alarm generating condition by the harmonic current obtained from the equation (3) in the first embodiment. The state of the phase-advancing capacitor 4 is monitored by calculating with the arithmetic expressions (1) and (2).

In the phase-advancing capacitor protection device configured as described above, in the power system without the means (CT7) for measuring the harmonic current of the phase-advancing capacitor 4, the harmonic voltage contained in the power system is dealt with. Then, the harmonic current that will flow through the phase-advancing capacitor 4 is calculated, and thermal overload,
It is possible to constantly monitor whether there is an overvoltage condition.
Even when the phase advancing capacitor is open, the harmonic current flowing in the phase advancing capacitor can be predicted, and if the upper limit setting value is exceeded, an alarm can be issued or the phase advancing capacitor can be prohibited from being turned on. The safety of phase capacitors can be judged and protected.

Embodiment 3. In the second embodiment, the upper transformer reactance value X
In order to calculate o by the following formula Xo = (a / 100) * (V1 2 / P), the percent reactance value a (%) of the upper transformer was required, but in the third embodiment, , A (%) is not set, and Xo is derived.

From the equivalent circuit of FIG. 3, I = E / (Xo + (XL + Xc)), and from this equation, Xo is: Xo = (E / I)-(XL + Xc) = (P / I2)-
(XL + Xc). Therefore, P is the rated capacity (VA) of the high-order transformer 1 described in the second embodiment, and XL and Xc are also obtained by the above-mentioned equation of the second embodiment, so that if the current I is obtained, Xo
Is required, and the setting of a (%) is unnecessary.

Fourth Embodiment 4 is a block diagram showing the configuration of a phase advancing capacitor protection device according to a fourth embodiment of the present invention. In the figure, 1-9, 2
0 to 27, 30 to 35, 40 to 42 are the same as those in the first embodiment.
It is the same as that of the description of 2 and 2. Reference numeral 43 denotes a changeover switch, which outputs the output of the harmonic current measuring unit 21 in synchronization with turning on and off of the phase advancing capacitor 4, which will be described later.
Switch to 2 output.

That is, in the closed state of the phase advancing capacitor 4, C
Thermal overload and overvoltage conditions are directly monitored by the monitoring alarm unit 25 from the harmonic current of T7, and the harmonic current calculating unit is operated from the voltage from PT9 and the above-mentioned various condition values when the advance capacitor 4 is opened. The thermal overload and overvoltage states are monitored by the harmonic current calculated in 42. Therefore, the phase advancing capacitor 4
Since the thermal overload and the overvoltage state at the time of turning on are used the actual measured harmonic current, the determination of the alarm output in the turned-on state of the phase advance capacitor 4 is more accurate than in the case of the second embodiment. .

Embodiment 5. 5 is a configuration block diagram of a phase advancing capacitor protection device according to a fifth embodiment of the present invention. In the figure, 1-9, 2
0 to 27, 30 to 35, 40 to 43 are the same as those in the fourth embodiment.
Is the same as the one described above. Reference numeral 44 is a second changeover switch, which is interlocked with the opening and closing of the phase advancing capacitor 4 and the FF.
Input to T23 from A / D converter 22 (current) to A / D
Switch to converter 40 (voltage).

In the fifth embodiment, the changeover switch 44 is linked to the opening / closing of the phase advancing capacitor 4 and the A / D converter 2
The harmonic voltage measuring unit 4 according to the second embodiment is configured by switching from 2 (current) to the A / D converter 40 (voltage).
By performing the operation 1 in the harmonic component measuring unit 21 and sharing the harmonic current and voltage measuring unit, the apparatus can be simply and inexpensively manufactured.

Reference numeral 36 denotes a tolerance coefficient setting unit, which is a condition of the thermal overload alarm generation condition in the monitoring alarm unit 25, the coefficient "1.35" of the arithmetic expression (1) shown in the first embodiment, and The coefficient "0.256" of the arithmetic expression (2) shown in the first embodiment, which is the overvoltage alarm generation condition, is variably set to another value.

From the tolerance factor setting unit 36 to the phase advance capacitor 4
Of the alarm output of over voltage, or the judgment level of the signal output for opening the phase advancing capacitor 4 is variably set, so as to meet the characteristics of the phase advancing capacitor 4 to be protected,
The danger zone of overvoltage can be set.

Then, the coefficient setting from the withstanding capacity coefficient setting unit 36 is set to a value for outputting an alarm of thermal overload and overvoltage, and the phase advancing capacitor 4 can be reclosed after leaving the thermal and overvoltage danger zone. The value to be set can be different. Frequent on / off of the alarm output can be eliminated by making the value for outputting the alarm different from the value for enabling re-input. In the variable setting of the coefficient, for example, in the case of the formula (1), the capacitor is opened with the coefficient of 1.35, and the capacitor is turned on again with 1.05.

Sixth Embodiment In Embodiments 2 and 3 above, the current value predicted to flow when the phase advancing capacitor 4 is opened is calculated as the harmonic voltage Vn of each order.
And the capacitance b (Var) of the phase advancing capacitor set and input from the condition setting unit 30 and the ratio b to the reactance value.
(%), Percent reactance value a of the upper transformer
(%) Etc. are used to obtain from the arithmetic processing.

These set input values are rated values of these devices, and there are differences with actual values and variations due to the installation state of the devices in the power system. Therefore, a difference from the actual state occurs in the determination of the thermal overload and the overvoltage state of the phase advance capacitor 4. The fifth embodiment eliminates this difference and more accurately determines the thermal overload and overvoltage states of the phase advancing capacitor 4 when the phase advancing capacitor 4 is open.

FIG. 6 is a configuration block diagram of a phase advancing capacitor protection device according to a sixth embodiment of the present invention. In the figure, 1 to 9, 20 to 27 and 40 to 42 are the same as those described in the first and second embodiments. Reference numeral 45 is a comparative impedance calculator, and 46 is a storage memory.

The operation of the sixth embodiment will be described with reference to the flowchart of FIG. (1) Phase-advancing capacitor 4 with phase-advancing capacitor 4 turned on
Is measured as a harmonic current of each order by the harmonic component measuring unit 21 via the CT7 → A / D converter 22 → FFT23 (step 401). (2) On the other hand, the voltage of the power system to which the phase-advancing capacitor 4 is connected is measured as the harmonic voltage Vn of each order by the harmonic voltage measuring unit 41 via the PT9 → A / D converter 40 → FFT23 ( Step 402).

(3) From the measured higher harmonic voltage Vn and higher harmonic current Icn, the impedance Zn corresponding to each order of the phase advancing capacitor 4 and the power system is Zn = Vn / Icn.
Can be learned from (step 403). Note that Zn
Is (nXo + nXL- (Xc) of the formula (3) of the second embodiment.
/ N). (4) Next, the actually measured harmonic current Icn is calculated by the equations (1) and (2) described in the first embodiment (step 404),

(5) A thermal overload or overvoltage state of the phase advancing capacitor 4 is judged (step 405), an alarm is output when a dangerous area is reached, or an opening signal (prohibition signal of closing) of the phase advancing capacitor 4. Is output (step 406). (6) Then, the impedance Zn corresponding to each order when the phase advancing capacitor 4 is opened is recorded in the storage memory 46 (step 407). (7) Since the phase-advancing capacitor 4 is opened thereafter, the actually measured harmonic current Icn cannot be obtained. Therefore, the measured harmonic voltage Vn of each order is read (step 4).
08),

(8) The current value in of each order that will flow from the impedance Zn corresponding to each order recorded in the storage memory 46 to the phase advance capacitor 4 is obtained from in = Vn / Zn (step 409). (9) The current value in of each order is expressed by the above equation (1),
If the thermal overload or overvoltage condition of the phase advancing capacitor 4 is monitored in (2) and the danger zone is exited, an alarm output or an open signal (prohibition signal for closing) of the phase advancing capacitor 4 is released to proceed. It enables reclosing of the phase capacitor 4 (steps 410, 411, 412, 413).

With the above-mentioned configuration, the phase advancing capacitor 4 is actually used under the condition of the harmonic voltage Vn by using the impedance Zn calculated based on the harmonic current Icn flowing in the phase advancing capacitor 4. When the capacitor opens, the phase advance capacitor 4
Since the current to the phase-advancing capacitor 4 is calculated, it is possible to monitor the thermal overload and overvoltage states of the phase-advancing capacitor 4 according to the actual conditions. Further, it becomes unnecessary to set and input various condition values for knowing the impedance Zn described in the second embodiment.

Embodiment 7. 8 is a block diagram showing the configuration of a capacitor protection device according to a seventh embodiment of the present invention. In the figure, 1-9, 2
0 to 27, 36, 40 to 42, 45 and 46 are the same as those described in the fifth embodiment. Reference numeral 47 denotes an AND circuit, which is an inversion signal of the output of the monitoring / alarm unit 25 and a capacitor closing signal 48 from an unillustrated power factor automatic adjusting device or the like.
And the combined output is input to the capacitor closing controller 8.

In the capacitor protection device having the above-described configuration, the signal inversion circuit 27 receives the capacitor closing signal 48 sent from another device such as the automatic power factor adjusting device or by an operation from the outside, and the signal from the monitoring alarm unit 25. And a signal inverted by the capacitor input control device 8 via the AND circuit 27.
Since the phase-advancing capacitor 4 is controlled to a thermal overload state or an overvoltage state, the capacitor input signal output from the automatic power factor adjusting device or the like is prohibited in a state where there are many high harmonic order voltages. It is possible to prevent a burnout accident of the phase-advancing capacitor 4.

Eighth Embodiment 9 is a block diagram showing the configuration of a capacitor protection device according to a seventh embodiment of the present invention. In the figure, 1-9, 2
0 to 27, 36, 40 to 42, 45 and 46 are the same as those described in the fifth embodiment. 49 is a monitoring alarm unit 2
5 is a time limit timer provided between the signal inversion circuit 27 and the signal inverting circuit 27, and can set two kinds of time limits of a first predetermined time and a second predetermined time. Of these, the output of the monitoring alarm unit 25 is monitored for a first predetermined time, and the output state of the monitoring alarm unit 25 (a thermal overload condition or an overvoltage condition of the phase-advancing capacitor) continues for a first predetermined time or longer. Then, the output is sent to the signal inverting circuit 27 for the first time.

When the output from the monitoring alarm unit 25 is not present for the second predetermined time or longer during the output of the time limit timer 49, the output to the signal inverting circuit 27 is released and stopped. As described above, the timed timer 49 delays the continuation of the presence or absence of the output of the monitoring / warning unit 25, whereby the frequent ON / OFF of the alarm output can be eliminated.

In the above description, a time limit timer that can set two types of time limits, that is, the first predetermined time period and the second predetermined time period, is provided. However, this is provided with a time period timer that can set any one type of time period. May be.

Ninth Embodiment Embodiment 9 FIG. 10 is a configuration block diagram of a capacitor protection device showing Embodiment 9 of the present invention. In the figure, 1-9,
20 to 27, 30 to 35, 40 to 43 are the same as those described in the fourth embodiment. Reference numeral 50 denotes a harmonic voltage tendency calculation unit, which inputs to the harmonic current calculation unit 42 a value calculated by the “weighted moving average method (exponential smoothing method)” for each transition of the harmonic voltage of each order.

Since the harmonic voltage measuring section 41 samples the voltage measurement and performs digital processing, the time series of the sampling is taken as (t) and the tendency of the harmonic voltage value is obtained by the following formula.

[0078]             En (t + 1) = α · Vn (t) + (1-α) En (t) ····· (4) Where α: smoothing index (0 <α <1) En: Harmonic voltage after moving average processing of nth order Vn: nth-order instantaneous harmonic voltage

Then, the harmonic current calculator 42 obtains the harmonic current Icn from the harmonic voltage after the moving average processing. Icn = En / (nXo + nXL- (Xc / n)) Based on this harmonic current Icn, the thermal overload alarm generating condition and the overvoltage alarm generating condition of the phase advancing capacitor are expressed by the formula (1) (of the first embodiment) ( Calculated according to 2).

As described above, by performing the moving average processing of the instantaneous harmonic voltage Vn, it is possible to eliminate the frequent ON / OFF of the alarm output due to the fluctuation of the instantaneous harmonic voltage Vn, and at the same time, the exponential smoothing method is used. Since a near future value can be obtained by appropriately selecting the smoothing index α used for demand forecasting, a rapid change is fast and a gradual change is an alarm output at a timing that matches the tendency of slow change. Done.

As shown in the above equation (4), it is sufficient to store only the previously calculated value En (t) and the smoothing index α as the coefficient for obtaining the moving average value. A small memory capacity is required.

[Embodiment 10] In this embodiment, the case where the capacitors are composed of a plurality of capacitor banks will be described. Figure 11
Is a capacitor bank of the capacitors shown in FIG. 1 of the first embodiment. The case where the banks are switched to change the capacitor capacity will be described with reference to FIG.

Equations (5) and (6) are obtained by dividing equations (1) and (2) of the first embodiment by I1, respectively.

[0084]

[Equation 3]

(Icn / I1) is the harmonic content,
It is not affected by the capacitor capacity.

For example, if harmonics are used as a voltage source in the circuit, the equivalent circuit of FIG. 12 is obtained. When C1 is ON, the harmonic content is In / I1 ‥‥‥‥‥‥‥‥‥ (7) When both C1 and C2 are ON, the harmonic content is (In + In ') / (I1 + I1') (8) To simplify equation (8), set the capacitor capacity to C1 = C.
If 2, then 2In / 2I1 = In / I1 and equation (7) and equation (8) are the same.

That is, the contents (In / I1) and (In '/
I1 ') has the same ratio, and equations (7) and (8) are the same. Therefore, even if the bank is switched in the configuration of FIG. 11, it can be determined by the equations (1) and (2). Therefore, in the case of forming a capacitor bank also in the fourth and subsequent embodiments, when a con-capacitor is inserted in the system and the current flowing through the entire capacitor bank is detected, the equations (1) and (2) are used. Can determine the thermal overload state and the overvoltage state.

Eleventh Embodiment Although the tenth embodiment is applied to the case where the capacitor bank is configured and the capacitor bank is thrown into the system, the present embodiment is applied to the case where the capacitor bank is not thrown. In the case of form 2, etc.), the thermal overload state and the overvoltage state of the capacitor when the capacitor bank is turned on are predicted from the harmonics of the system voltage.

FIG. 13 is a configuration block diagram of a capacitor protection device according to an eleventh embodiment of the present invention. However, the signal (dotted line display) from the capacitor charging control device 8 to the monitoring alarm unit 25 is omitted. (Those which are not omitted are used in the twelfth embodiment.) FIG. 13 is almost the same as the capacitor bank shown in FIG. 4 of the fourth embodiment, and the capacitor capacity setting part 32 is a harmonic current calculating part. Other than 42, it is input to the monitoring alarm unit 25. Figure 1
4 (a) is a circuit diagram for considering the capacitor bank current,
FIG. 14B shows an equivalent circuit thereof.

In FIGS. 14A and 14B, the current In flowing in the system and the bus voltage Vn ' are: In = Vn / (nX0 + Za) Vn' = Vn-nX0In Therefore, the current flowing in each bank is

[0091]

The current (In1 to Inm) flowing through each capacitor bank is obtained because the system voltage Vn, series reactor reactance value XL, phase advancing capacitor reactance value Xc, upper system transformer reactance value Xo, etc. are known. be able to.

Therefore, the capacitor capacity setting unit 3 of FIG.
Each capacitor capacity at the time of switching the capacitor bank is set by 2, and Icn = Vn / (nXo + nXL- (Xc / n)) (3) Each capacitor is calculated by the following formula (3) of the second embodiment. The current of each harmonic for each bank switching can be predicted, and can be predicted by the determination formulas (1) and (2) of the first embodiment.

In this prediction, the calculation for each capacitor bank switching is sequentially and cyclically performed, and when it is determined that the thermal load state and the overvoltage state are caused by a certain bank switching, an alarm is displayed. Further, when it is predicted that the capacitor bank will be in a thermal load state or an overvoltage state, the control is performed so as to prevent the closing.

As described above, even in the case of a circuit constituted by a plurality of capacitor banks,
It is possible to determine a thermal load state and an overvoltage state for each bank switching.

The determination of the thermal load state and the overvoltage state for each bank switching can be applied to the case where the second to fourth embodiments and the ninth embodiment are constituted by the capacitor banks. Also, when the impedance of each of the sixth to eighth embodiments is calculated and the harmonic current is calculated from the harmonic voltage, the impedance for each capacitor bank switching is calculated and stored, and the memory corresponding to the capacitor bank to be input is stored. The harmonic current can be calculated using the impedance.

Twelfth Embodiment In this embodiment, the setting of the capacitor capacity for each switching of the capacitor bank of the eleventh embodiment is derived from the current flowing through the capacitor when the capacitor is turned on or switched, and is automatically set.

The block diagram of the configuration is as shown in FIG. FIG. 15 is a flowchart for automatically setting the capacitor capacity, and the operation will be described based on this flowchart.

(1) The bank number m = 1 is set (step 501), and (2) the m-th capacitor (first for the first time) is turned on (step 502). (3) The current flowing through the capacitor is measured by CT7 (step 503). (4) Calculate the current value of the input bank (step 50)
4). In this case, as shown in the figure, the current value of each capacitor is calculated by subtracting the previous value from the current value.

(5) The capacitance of each capacitor is calculated by the equation shown in the figure (step 505). (6) The calculated capacitor capacitance value is stored in the memory (step 506). This capacitor capacity value is stored by providing a capacitor capacity setting table in the capacitor capacity setting unit 32 as shown in FIG. (7) If the bank number m is not the last (step 50
7), (8) The bank number is advanced by 1 (step 508) and the operation is repeated from step 502. (9) If the bank number is the last (step 507),
The capacity value setting operation ends.

As described above, the capacitor capacitance value can be automatically set. The automatic setting of the capacitor capacitance value is performed by predicting the capacitor current from the system voltage when the capacitors of the second embodiment, the fourth embodiment, the ninth embodiment, etc. are configured by a capacitor bank in addition to this embodiment. Applicable for cases.

Thirteenth Embodiment Although the above embodiment has been directed to the case of protecting the phase advancing capacitor, the embodiment of the present invention relates to the protection of the series reactor inserted in the phase advancing capacitor. Even if the phase advancing capacitor is not in a thermal load state or an overvoltage state, it is necessary to disconnect the phase advancing capacitor from the system when the series reactor is in a thermal load state or an overvoltage state for safety.

The operation will be described with the configuration of FIG. When the phase-advancing capacitor 4 is put into the system, the capacitor current flows in the series reactor 5. The harmonic component measuring unit 21 calculates each harmonic current from this capacitor current, and the thermal overload state or overvoltage state is calculated by "Electrical Joint Research Vol. 37, No. 3, page 79, Table 4-2-4". The following equation, which is more cited, is used.

This judgment formula is based on the condition that the thermal overload alarm generation condition of the series reactor is expressed by formula (9).
This is the case as shown in (10), in which either one of formula (9) or formula (10) is established. It should be noted that the equation (10) is converted into a fifth-order harmonic, and may be converted into another order of harmonics, but it is generally converted into a fifth-order harmonic.

[0105]

[Equation 4]

The condition for generating the overvoltage alarm of the series reactor is as shown in equation (11).

[0107]

[Equation 5]

According to this determination formula, an alarm is output as a thermal or overvoltage withstanding amount of the series reactor, or a signal for opening the phase advancing capacitor 4 is output. Note that these calculations are performed by the monitoring / warning unit 25. In addition, the above-mentioned conditional expression is referred to as “Electrical Joint Research Vol.
This is an expression that gives a guideline for the permissible limit, as shown in "No. 79, Table 4-2-4". "1.20""0.35"
The coefficient value of "16.7" may be changed. Alternatively, it may be variably set.

The thirteenth embodiment is similar to the fourth to ninth embodiments.
Can also be applied. That is, when the con-capacitor is put into the system and the current flowing through the entire capacitor bank is detected, the equations (9), (10), (1
In 1), the thermal overload state and overvoltage state of the series reactor can be determined.

In the case where the capacitor bank is composed of a plurality of capacitor banks as shown in FIG. 11 of the tenth embodiment, the formula (9) can be used regardless of the number of banks as described in the harmonic content ratio of the tenth embodiment. ), (10), and (11).

Fourteenth Embodiment Although the thirteenth embodiment is applied when the capacitor is turned on in the system, in this embodiment, when the capacitor is not turned on (such as the case of the second embodiment), the system voltage of It is intended to predict a thermal overload state and an overvoltage state of a series reactor when a capacitor is turned on from harmonics.

For example, in the case of the configuration of FIG. 2, each harmonic component is derived from the system voltage, converted into each harmonic current component, and the converted harmonic components are used to obtain the formula shown in the thirteenth embodiment. The thermal overload state and the overvoltage state of the series reactor are predicted from (9), (10), and (11).

The determination of the thermal load state and the overvoltage state of this series reactor is performed in any of the second to fourth embodiments and the ninth embodiment.
Can also be applied.

Further, as shown in FIG. 13 of the eleventh embodiment, it is also applicable to the case of being composed of a plurality of capacitor banks. In this case, as described in the eleventh embodiment, the capacitor capacity at the time of switching the capacitor banks is set, the high frequency content rate is calculated for each capacity, and the determination formulas (9), (10), ( It can be determined in 11).
Further, the means for automatically setting the capacitor capacity of the twelfth embodiment can also be adopted.

Fifteenth Embodiment The protection of the series reactor is also applicable to the case where the so-called impedance shown in FIG. 6 of the sixth embodiment is obtained and the predicted value of the harmonic current value is derived from this impedance and the harmonic voltage value.

That is, in the phase advancing capacitor open state, the thermal overload state or the overvoltage state of the series reactor is determined from the above predicted values by the determination formulas (9), (10) and (11),
In the phase-advancing capacitor-on state, the thermal overload state or overvoltage state of the series reactor is determined from the measured harmonic current values using the determination formulas (9), (10), and (11).

Sixteenth Embodiment In the above embodiment, the warning signal and the like are output in the thermal overload state and the overvoltage state of the phase advancing capacitor and the series reactor, but only one of the “thermal overload state” and the “overvoltage state” is output. You may do it.

Further, in the ninth embodiment, the harmonic voltage of each order calculated by the “weighted moving average method (exponential smoothing method)” is used, but the harmonic current of each order is calculated in the first embodiment. Also in the case of obtaining, the harmonic current measurement value of each order may be used as the harmonic current of each order by performing the arithmetic processing by the “weighted moving average method (exponential smoothing method)”.

Further, the protection of the phase advancing capacitor and the protection of the series reactor may be performed by one protection device.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of a phase advancing capacitor protection device according to a first embodiment of the present invention.

FIG. 2 is a configuration block diagram of a phase advancing capacitor protection device according to a second embodiment of the present invention.

FIG. 3 is an operation principle diagram of impedance calculation according to the third embodiment of the present invention.

FIG. 4 is a configuration block diagram of a phase advancing capacitor protection device according to a fourth embodiment of the present invention.

FIG. 5 is a configuration block diagram of a phase advancing capacitor protection device according to a fifth embodiment of the present invention.

FIG. 6 is a configuration block diagram of a phase advancing capacitor protection device according to a sixth embodiment of the present invention.

FIG. 7 is a flowchart illustrating an operation according to the sixth embodiment of the present invention.

FIG. 8 is a configuration block diagram of a phase advancing capacitor protection device according to a seventh embodiment of the present invention.

FIG. 9 is a configuration block diagram of a capacitor protection device according to an eighth embodiment of the present invention.

FIG. 10 is a configuration block diagram of a capacitor protection device according to a ninth embodiment of the present invention.

FIG. 11 is a configuration block diagram of a capacitor protection device according to a tenth embodiment of the present invention.

FIG. 12 is an equivalent circuit diagram illustrating a harmonic content rate of a capacitor bank according to a tenth embodiment of the present invention.

FIG. 13 is a configuration block diagram of a capacitor protection device according to eleventh and twelfth embodiments of the present invention.

FIG. 14 is a circuit diagram and an equivalent circuit diagram for deriving a harmonic current of a capacitor bank according to an eleventh embodiment of the present invention.

FIG. 15 is an operation flowchart of automatic capacitor capacity setting according to a twelfth embodiment of the present invention.

FIG. 16 is a diagram of a capacitor capacity setting table according to a twelfth embodiment of the present invention.

FIG. 17 is a configuration block diagram of a conventional harmonic current monitoring device.

[Explanation of symbols]

1 Upper system transformer, 4 Phase-advancing capacitor, 5 Series reactor 6 Electromagnetic contactor, 7 CT, 8 Capacitor injection control device, 9 PT 20 Phase-advancing capacitor protection device, 21 Harmonic component measuring unit 22, 40 A / D conversion Meter, 23 FFT, 25 Monitoring alarm unit 27 Signal inversion circuit, 30 Condition setting unit, 36 Withstanding coefficient setting unit 41 Harmonic voltage measuring unit, 42 Harmonic current calculating unit 38, 43 Changeover switch, 45 Comparative impedance calculating unit 46 Memory Memory, 47 AND circuit, 49 timed timer, 50 harmonic voltage trend calculator

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02H 3/50-3/52 H02H 3/08-3/10 H02H 3/20 H02J 3/00-5 / 00

Claims (23)

(57) [Claims] 1. In a power system in which a phase advancing capacitor is turned on / off, a harmonic current of a predetermined order flowing through the phase advancing capacitor is measured, and the phase advancing capacitor is thermally activated based on the measured value. A means to judge whether it is in an overload state or an overvoltage state and output a phase advancing capacitor open signal or an alarm signal according to the judgment result, and to judge whether the phase advancing capacitor is in a thermal overload state or an overvoltage state. A phase advancing capacitor protection device provided with a means for changing at least one of a thermal overload withstand amount (allowable limit value) and an overvoltage withstand amount (allowable limit value), which are judgment reference values for carrying out. 2. A power system in which a phase advancing capacitor is turned on and off, for converting a harmonic voltage of a predetermined order included in the power system into a harmonic current of each order flowing through the phase advancing capacitor. Set various conditions such as the capacity of the phase-advancing capacitor and the capacity of the transformer of the upper system, measure the harmonic voltage of the predetermined order included in the power system,
Calculate the predicted value of the harmonic current of a predetermined order that flows in the phase advancing capacitor from this measured value and the conditions set above,
A phase advancing capacitor protection device that determines whether the phase advancing capacitor is in a thermal overload state or an overvoltage state based on the predicted value, and outputs a phase advancing capacitor closing prohibition signal or an alarm signal according to the determination result. 3. In a power system in which a phase advancing capacitor is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, the phase advancing capacitor is converted from the harmonic voltage of a predetermined order included in the power system. The various conditions such as the phase-advancing capacitor capacity and the host system transformer capacity for converting into the harmonic current of each order flowing in are set for each bank switching, and the harmonic voltage of the predetermined order included in the power system is set. Measure,
From this measured value, the phase advancing capacitor capacity, and the conditions set above, a predicted value of the harmonic current of a predetermined order flowing through the phase advancing capacitor is calculated for each bank switching, and the phase advancing capacitor is calculated based on this predictive value. A phase advancing capacitor protection device that determines whether the bank is in a thermal overload state or an overvoltage state at each bank switching and outputs a phase advancing capacitor bank closing prohibition signal or an alarm signal according to the determination result. 4. A power system in which a phase advancing capacitor is turned on and off, for converting a harmonic voltage of a predetermined order included in the power system into a harmonic current of each order flowing through the phase advancing capacitor. Set various conditions such as the capacity of the phase-advancing capacitor and the capacity of the transformer of the host system, measure the harmonic voltage of a predetermined order included in the power system with the phase-advancing capacitor open, and set this measurement value and the above setting. The predicted value of the harmonic current of a predetermined order that flows in the phase advancing capacitor is calculated from the above conditions, and it is determined whether the phase advancing capacitor is in a thermal overload state or overvoltage based on this predictive value. Depending on the result, the advance capacitor input prohibition signal or alarm signal is output, and the harmonic current of a predetermined order that flows through the phase advance capacitor is measured in the advance capacitor input state. A phase-advancing capacitor protection device that determines whether the phase-advancing capacitor is in a thermal overload state or an overvoltage state and outputs a phase-advancing capacitor open signal or an alarm signal according to the determination result. 5. In a power system in which a phase advancing capacitor is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, the phase advancing capacitor is converted from the harmonic voltage of a predetermined order included in the power system. In order to convert the harmonic current of each order into the harmonic current of each order, set various conditions such as the phase-advancing capacitor capacity and the host system transformer capacity for each bank switching. The harmonic voltage of the order is measured, and the predicted value of the harmonic current of the predetermined order that flows in the phase advance capacitor is calculated for each bank switching from this measured value and the conditions set above, and based on this predicted value. Whether or not the phase advancing capacitor is in a thermal overload state or an overvoltage state is determined for each bank switching, and a phase advancing capacitor closing prohibition signal or an alarm signal is output according to the determination result, and the phase advancing With the capacitor turned on, measure the harmonic current of a specified order that flows in the turned-on phase advancing capacitor, and based on this measurement value, determine whether the turned-on phase advancing capacitor is in a thermal overload state or an overvoltage state. A phase advancing capacitor protection device that makes a judgment and outputs a phase advancing capacitor opening signal or an alarm signal according to the judgment result. 6. The phase advancing capacitor protection device according to claim 4 or 5, wherein one harmonic measuring unit is configured to measure both a harmonic current and a harmonic voltage of a predetermined order. A phase-advancing capacitor protection device that measures the harmonic current when the phase capacitor is turned on, and measures the harmonic voltage when the phase capacitor is open. 7. In a power system in which a phase advancing capacitor is turned on / off, in a state where the phase advancing capacitor is turned on, a harmonic current of a predetermined order flowing through the phase advancing capacitor and the predetermined value included in the power system. The harmonic voltage of the same order as the order is measured, and the impedance corresponding to each order is obtained, and whether the phase-advancing capacitor is in a thermal overload state or an overvoltage state based on the measured harmonic current of each order. It is determined whether or not, the advance capacitor open signal or alarm signal is output according to this determination result, the high frequency voltage of the predetermined order included in the power system is measured in the advance capacitor open state, and this measured value From the obtained impedance, the predicted value of the harmonic current of each order flowing in the phase advancing capacitor is calculated, and the phase advancing capacitor is subject to thermal overload or Determines whether an overvoltage condition, the determination result phase advancing capacitor feeding inhibition signal or power capacitor protection device for alarm output in response to. 8. In a power system in which a phase advancing capacitor is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, the phase advancing capacitor is turned on and flows to the phase advancing capacitor at each bank switching. A harmonic current of a predetermined order and a harmonic voltage of the same order as the predetermined order included in the power system are measured, and the impedance corresponding to each order is obtained for each bank switching, and the input is performed. Measures the harmonic current of a predetermined order that flows in the phase-advancing capacitor, and determines whether the phase-advancing capacitor is in a thermal overload state or an overvoltage state based on the measured value and the input capacity of the phase-advancing capacitor. Then, depending on the result of this judgment, a phase advancing capacitor open signal or an alarm signal is output, and in the phase advancing capacitor open state, the high frequency voltage of the above-mentioned predetermined order included in the power system is measured. The predicted value of the harmonic current of each order flowing in the phase advancing capacitor is obtained from this measured value and the impedance obtained at each bank switching, and the phase advancing capacitor is thermally overloaded based on this predictive value. Alternatively, a phase advancing capacitor protection device that determines whether or not it is in an overvoltage state for each bank switching, and outputs a phase advancing capacitor closing prohibition signal or an alarm signal according to the determination result. 9. The phase-advancing capacitor protection device according to claim 3, wherein when setting a capacitor capacity, a current is measured for each capacitor bank switching, and the capacitor is based on the measured value. A phase-advancing capacitor protection device provided with means for obtaining and setting the capacity. 10. The phase-advancing capacitor protection device according to claim 2, wherein the phase-advancing capacitor is open and the determination result is that the phase-advancing capacitor is not in a thermal overload state or an overvoltage state. , A phase-advancing capacitor protection device provided with means for canceling a phase-advancing capacitor closing prohibition signal or an alarm signal. 11. The phase-advancing capacitor protection device according to claim 2, wherein when the determination result indicates that the phase-advancing capacitor is in a thermal overload state or an overvoltage state, an operation from another device or another device is performed. A phase-advancing capacitor protection device provided with a means for blocking the phase-advancing capacitor input signal by. 12. The phase-advancing capacitor protection device according to any one of claims 2 to 11, wherein after measuring a harmonic voltage of a predetermined order included in the power system, the measured harmonic voltage of each order is measured. A phase-advancing capacitor protection device which is provided with means for performing respective weighted moving average processing, and calculates a predicted value of the harmonic current of each order flowing through the phase-advancing capacitor from the harmonic voltage of each order after the averaging processing. 13. The phase-advancing capacitor protection device according to claim 1, wherein a harmonic current of a predetermined order flowing through the phase-advancing capacitor is measured, and then the measured harmonics of each order. Means for performing weighted moving average processing for each current are provided, and it is determined whether the phase advancing capacitor is in a thermal overload state or an overvoltage state based on the harmonic current of each order after this averaging processing. Capacitor protection device. 14. The phase-advancing capacitor protection device according to claim 2, wherein when the phase-advancing capacitor is open, it is determined that the phase-advancing capacitor is not in a thermal overload state or an overvoltage state. A phase-advancing capacitor protection device provided with delay means for releasing the phase-advancing capacitor closing prohibition signal or the alarm signal after a lapse of time. 15. The phase advancing capacitor protection device according to claim 1, wherein the phase advancing capacitor is determined to be in a thermal overload state or an overvoltage state, and if this state continues for a predetermined time, the phase advancing A phase-advancing capacitor protection device provided with delay means for outputting a capacitor opening signal or an alarm signal. 16. The phase-advancing capacitor protection device according to claim 2, wherein the phase-advancing capacitor is a thermal reference that is a reference value for determining whether the phase-advancing capacitor is in a thermal overload state or overvoltage. A phase advancing capacitor protection device provided with means capable of changing at least one of load withstand capacity (allowable limit value) and overvoltage withstand capacity (allowable limit value). 17. In a power system in which a phase advancing capacitor connected with a series reactor is turned on / off, a harmonic current of a predetermined order flowing through the phase advancing capacitor is measured, and based on this measurement value, the harmonic current is measured. A means for determining whether the series reactor is in a thermal overload state or an overvoltage state and outputting a phase advancing capacitor open signal or an alarm signal according to the determination result, and whether the series reactor is in a thermal overload state or an overvoltage state. A phase advancing capacitor protection device provided with means capable of changing at least one of a thermal overload withstand amount (allowable limit value) and an overvoltage withstand amount (allowable limit value), which are determination reference values for determining whether or not. 18. A power system in which a phase-advancing capacitor connected to a series reactor is turned on and off, and harmonics of respective orders flowing from the harmonic voltage of a predetermined order included in the power system to the phase-advancing capacitor. Set various conditions such as the capacity of the phase-advancing capacitor and the capacity of the host system transformer for converting into current, and measure the harmonic voltage of the predetermined order included in the power system,
Calculate the predicted value of the harmonic current of a predetermined order that flows in the phase advancing capacitor from this measured value and the conditions set above,
A series reactor protection device that determines whether or not the series reactor is in a thermal overload state or an overvoltage state based on the predicted value, and outputs a phase advancing capacitor closing prohibition signal or an alarm signal according to the determination result. 19. In a power system in which a phase advancing capacitor is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, the phase advancing capacitor is converted from the harmonic voltage of a predetermined order included in the power system. The various conditions such as the phase-advancing capacitor capacity and the host system transformer capacity for converting into the harmonic current of each order flowing in are set for each bank switching, and the harmonic voltage of the predetermined order included in the power system is set. Measure,
From this measured value, the phase advancing capacitor capacity, and the conditions set above, a predicted value of the harmonic current of a predetermined order flowing through the phase advancing capacitor is calculated for each bank switching, and the phase advancing capacitor is calculated based on this predictive value. A series reactor protection device that determines whether the bank is in a thermal overload state or an overvoltage state at each bank switching and outputs a phase advancing capacitor bank closing prohibition signal or an alarm signal according to the determination result. 20. In a power system in which a phase advancing capacitor connected with a series reactor is turned on / off, a harmonic of each order flowing from the harmonic voltage of a predetermined order included in the power system to the phase advancing capacitor. Set various conditions such as the phase-advancing capacitor capacity and host system transformer capacity for converting to current, measure the harmonic voltage of the predetermined order included in the power system with the phase-advancing capacitor open, and Calculate the predicted value of the harmonic current of a predetermined order that flows through the phase-advancing capacitor from the measured value and the set conditions, and based on this predicted value, determine whether the series reactor is in a thermal overload state or an overvoltage state. The phase-advancing capacitor closing prohibition signal or the alarm signal is output according to the judgment result, and the harmonic current of a predetermined order that flows through the phase-advancing capacitor is output in the phase-advancing capacitor closing state. And a series reactor protection device that determines whether the series reactor is in a thermal overload state or an overvoltage state based on the measured value and outputs a phase advancing capacitor open signal or an alarm signal according to the determination result. . 21. In a power system in which a phase advancing capacitor connected with a series reactor is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, harmonics of a predetermined order included in the power system In order to convert the voltage to the harmonic current of each order flowing in the phase-advancing capacitor, set various conditions such as the phase-advancing capacitor capacity and the host system transformer capacity for each bank switching, and with the phase-advancing capacitor open, The harmonic voltage of a predetermined order included in the power system is measured, and the predicted value of the harmonic current of a predetermined order flowing in the phase advancing capacitor is calculated for each bank switching from the measured value and the set condition. Based on this predicted value, it is determined whether or not the series reactor is in a thermal overload state or an overvoltage state for each bank switching, and in accordance with the determination result, the phase advance capacitor closing prohibition signal or Or an alarm signal is output, the harmonic current of a predetermined order that flows in the advanced capacitor that is input is measured while the advanced capacitor is turned on, and based on this measurement value, the thermal transient of the input series reactor is exceeded. A series reactor protection device that determines whether it is a load state or an overvoltage state and outputs a phase advancing capacitor open signal or an alarm signal according to the determination result. 22. A power system in which a phase advancing capacitor connected with a series reactor is turned on and off, wherein a harmonic current of a predetermined order flowing through the phase advancing capacitor in a state where the phase advancing capacitor is turned on, and the power system. The harmonic voltage of the same order as the predetermined order contained in is measured, and the impedance corresponding to each order is obtained, and the thermal overload of the series reactor is based on the measured harmonic current of each order. State or overvoltage state is determined, and a phase advancing capacitor open signal or alarm signal is output according to the result of the determination, and the high frequency voltage of the above specified order included in the power system is measured in the phase advancing capacitor open state. Then, the predicted value of the harmonic current of each order flowing through the phase-advancing capacitor is calculated from this measured value and the calculated impedance, and based on this predicted value, the series current Determines whether a thermal overload or overvoltage conditions Akutoru, the determination result phase advancing capacitor feeding inhibition signal or series reactor protection system for alarm output in response to. 23. In a power system in which a phase advancing capacitor to which a series reactor is connected is turned on and off, and when the phase advancing capacitor is composed of a plurality of banks, the phase advancing capacitor is turned on and each bank is switched. A harmonic current of a predetermined order flowing through the phase-advancing capacitor and a harmonic voltage of the same order as the predetermined order included in the power system are measured, and the impedance corresponding to each order is calculated for each bank switching. Along with, measure the harmonic current of a predetermined order that flows in the input phase advancing capacitor, and based on this measurement value and the input phase advancing capacitor capacity, the thermal overload state or overvoltage state of the series reactor. It is determined whether or not the phase advancing capacitor open signal or alarm signal is output according to the result of the judgment, and the phase advancing capacitor open state is included in the power system. The high-frequency voltage of a predetermined order is measured, the predicted value of the harmonic current of each order that flows in the phase-advancing capacitor is obtained from this measured value and the impedance obtained at each bank switching, and the series value is calculated based on this predicted value. A series reactor protection device that determines whether the reactor is in a thermal overload state or an overvoltage state at each bank switching, and outputs a phase-advancing capacitor closing prohibition signal or an alarm signal according to the determination result.