JP2994277B2 - Power factor adjustment system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology of a power factor adjusting system having a function of preventing a so-called harmonic interference in a phase-advancing capacitor facility.

[0002]

2. Description of the Related Art FIG. 3 illustrates a conventional power factor adjusting system having a function of preventing a so-called harmonic interference, which is configured by combining a harmonic monitoring monitor for monitoring distortion of a harmonic voltage and a power factor adjusting device. FIG.

In FIG. 3, reference numeral 1 denotes a high-voltage trunk line of, for example, 6.6 kV, 2 denotes a high-voltage feeder, 31 and 32 denote transformers for power or electric light loads, and 61 denotes a reactor constituted by a phase-advancing capacitor 41a and a reactor 41b. A switch for opening and closing the power supply of the capacitor unit 41, for example, a high-voltage electromagnetic contactor.

Further, a reactor / condenser unit 4
Reference numerals 2 and 43 denote a phase-advancing capacitor 42a and a series reactor 42b and a phase-advancing capacitor 43a and a series reactor 43b, respectively, and switches 62 and 63 are provided corresponding to the reactor-capacitor units 42 and 43, respectively. The parallel body composed of the reactor / condenser units 41 to 43 constitutes a phase advance capacitor facility.

Further, the power factor adjusting device 7 is driven by inputting the secondary voltage of the instrument transformer 8 and the secondary current of the current transformer 9 for the instrument of the power receiving unit.

In such a power factor adjusting system, at the time of startup, the power is sequentially turned on for each reactor / capacitor unit in accordance with a predetermined startup sequence (sequence) of the ordinary power factor adjusting device 7, and the system is started.

The power factor adjusting device 7 includes switches 61 to 6
(3) An opening / closing control circuit for turning on / off a switch necessary for compensating for reactive power due to a load delay so that a predetermined power factor (usually 100%) is obtained by appropriately opening and closing each switch. 10 is output.

On the other hand, when the distortion rate of the harmonic voltage of the high-voltage main line 1 increases after the start-up (for example, when the distortion rate of the fifth harmonic voltage becomes 3.5% or more), particularly, the capacity of the series reactor is advanced. In the case of 6% of the capacity of the capacitor, since excessive harmonic currents due to series resonance flow into the reactor capacitor units 41 to 43, respectively, overheating, burning, or abnormal vibration of the phase-advancing capacitor or the series reactor. There is a possibility that so-called harmonic interference such as noise frequently occurs.

In view of this, as shown in FIG. 3, a current transformer 12 for a high voltage feeder for measuring the magnitude of the current flowing through the entire phase-advancing capacitor facility consisting of the parallel-connected reactor / capacitor units 41 to 43 is provided. The output of the current flowr 12 is input to the harmonic monitoring monitor 11, and when the magnitude and duration of the harmonic distortion rate of the current flowing through the entire phase-advancing capacitor equipment exceed predetermined values, the harmonic monitoring is performed. The monitor 11 outputs an alarm signal to the power factor adjusting device 7.

The alarm signal is, for example, an open command (open command) for opening the contacts of the switches 61 to 63,
Based on this opening command, the power factor adjusting device 7 and the opening / closing control circuit 10 perform a so-called sequence function so that the switches 61 to 61 are opened.
All 63 are forcibly opened (blocked), and as a result, the phase-advancing capacitor equipment can avoid so-called harmonic interference such as overheating, burning, or abnormal vibration or noise of the phase-advancing capacitor or the series reactor. ing.

When the return time of the harmonic monitoring monitor 11 exceeds a predetermined set time (for example, 30 minutes), the output of the alarm signal from the harmonic monitoring monitor 11 is released, and the forcibly opened and closed switch is opened. The units 61 to 63 are closed again, and the phase-advancing capacitor equipment returns to the original state before the forcible opening.

[0012]

In the conventional power factor adjusting system configured as described above, the power factor adjusting device 7 controls the switch 6 based on the alarm signal output from the harmonic monitoring monitor 11.
The opening / closing control circuit 10 issues an opening command for opening 1 to 63.
, And the reactor and conden units 41 to 43 in the closed state could be forcibly shut off.
After that, when the harmonic monitoring monitor 11 returns, the output of the alarm signal is released, and the power factor adjusting device 7 immediately outputs a closing command to the switching control circuit 10 for closing the switches 61 to 63, There is a problem that power is supplied to each reactor / capacitor unit at the same time, causing transient disturbance of the power supply system.

Further, the capacitors 41a to 43a are all connected between the time when the harmonic monitoring monitor 11 is operated and the time when it is restored, that is, from the time when the harmonic monitoring monitor 11 starts outputting the alarm signal to the time when the signal is released. Despite being shut off, the capacitor 41 is displayed on the operation display screen of the power factor adjuster 7.
a to 43a indicate that they are all in the closed state, and there is a problem that the actual operation state is not displayed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is based on the fact that when the monitoring monitor returns and the alarm signal is released, the power is simultaneously turned on to each of the reactor capacitor units. The purpose is to eliminate the occurrence of transient disturbances in the power supply system and to obtain a power factor adjustment system in which the operation display section displays the actual operation state even during the period from when the monitoring monitor operates until it returns. And

[0015]

A power factor adjusting system according to the present invention comprises a series combination of a phase-advancing capacitor and a series reactor connected to high-voltage feeders to which power is supplied from a high-voltage main line via switches. Several reactors
A high-voltage detecting device detects a current flowing from a parallel body of capacitor units, a transformer for a high-voltage main line provided on a high-voltage main line, a current transformer, and a parallel body of a reactor capacitor unit provided on a high-voltage feeder from the high-voltage main line. The magnitude and duration of the harmonic distortion rate of the current flowing through the current transformer for the feeder and the parallel body of the reactor and capacitor units based on the detection values of the current transformer for the high voltage feeder are predetermined values. A monitoring monitor that outputs an alarm signal when the power factor exceeds the threshold value, and a control signal for adjusting the power factor so that the specified power factor is obtained based on the detection values of the instrument transformer and current transformer for the high-voltage main line, and A power factor adjusting device for sending a forced opening control signal for forcibly opening all switches of a plurality of reactor / capacitor units when an alarm signal is received from the monitoring monitor. A power factor control system comprising: a switching control circuit that controls switching of a plurality of reactor / capacitor units according to a control signal sent from a power factor adjusting device. Input blocking means for temporarily blocking the input of the detected value of the detector to the power factor adjusting device, and the monitoring monitor operates the input blocking device at the time of outputting the alarm signal to temporarily stop the input of the detected value to the power factor adjusting device. In addition to this, the input blocking operation by the input blocking means is released when the alarm signal is released.

Further, the input blocking means is provided at least one of between the instrument transformer for the high voltage main line and the power factor adjusting device or between the current transformer for the high voltage main line and the power factor adjusting device. The monitoring monitor has a relay that is energized when an alarm signal is output to open the normally closed contact, and is demagnetized when the alarm signal is released to close the normally closed contact.

The input blocking means is provided between the high-voltage mains current transformer and the power factor adjusting device, and performs a bypass operation on the basis of an alarm signal from the monitoring monitor to thereby control the power factor adjusting device. This is a current conversion circuit that temporarily blocks the input of the detection value and stops the bypass operation when the alarm signal is released.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 FIG. 1 is an explanatory diagram of the power factor adjustment system according to the first embodiment. In FIG. 1, as a new configuration with respect to the conventional example, 13 is a power factor adjusting device 7 and an instrument transformer 8.
A b-contact (normally-closed contact) of, for example, an auxiliary relay (not shown) which opens and closes based on an alarm signal from the harmonic monitoring monitor 11.

In the power factor adjusting system according to the first embodiment configured as described above, the amount of accumulated harmonic inflow into the entire phase-advancing capacitor equipment increases, and the alarm signal is output from the harmonic monitoring monitor 11 to the power factor adjusting device. 7, based on the output from the power factor adjusting device 7 to the switching controller 10, the switches 61 to 63 are all opened by the same sequence operation as in the above-described conventional example, and the phase advance capacitor equipment is forcibly shut off. Is done.

In this case, the alarm signal is output to the power factor adjusting device 7 and the coil of the auxiliary relay (not shown) is excited to open the b-contact 13, so that the reactor-capacitor units 41 to 43 are forcibly operated. Similarly to the cutoff, the voltage input from the secondary side of the instrument transformer 8 to the power factor adjusting device 7 is also blocked.

Accordingly, since the apparent input power of the power factor adjusting device 7 becomes zero, the capacitor input command signal in the power factor adjusting device 7 is sequentially released. For example, when about 1 to 5 minutes elapse, The capacitor input display on the operation display screen of the power factor adjusting device 7 also completely disappears.

Thereafter, a predetermined set time (for example, 30 minutes)
And the contact 13 is closed based on the output of the harmonic monitoring monitor 11b.
That is, the power factor adjusting device 7 is in an initial startup state. Therefore,
Power is sequentially supplied to the phase-advanced capacitor equipment that has been forcibly shut off for each reactor / capacitor unit in accordance with a predetermined startup sequence of the ordinary power factor adjusting device 7.

Therefore, according to the first embodiment, the high-voltage feeder 2 to which power is supplied from the high-voltage main line 1 is connected in series via the switches 61 to 63 with the phase-advancing capacitor and the series reactor. Of a plurality of reactor / condenser units 41 to 43, a high-voltage main line instrument transformer 8 and a current transformer 9 provided in the high-voltage main line 1.
And a current transformer 12 for a high voltage feeder for detecting a current flowing from a high voltage main line 1 to a parallel body of reactor condenser units 41 to 43 provided in the high voltage feeder 2, and detection of the current transformer 12 for the high voltage feeder A monitor 11 for outputting an alarm signal when the magnitude and duration of the harmonic distortion rate of the current flowing in the parallel body of the reactor / capacitor units 41 to 43 exceed a predetermined value based on the value; When a control signal for power factor adjustment is transmitted so as to have a specified power factor based on the detection values of the instrument transformer 8 and the current transformer 9 for the high voltage main line, and an alarm signal is received from the monitoring monitor 11, A power factor adjusting device 7 for transmitting a forced opening control signal for forcibly opening all the switches 61 to 63 of the plurality of reactor / condenser units 41 to 43;
The switches 6 of the plurality of reactor / condenser units 41 to 43 according to the control signal sent from the power factor adjusting device 7
In a power factor adjusting system including an open / close control circuit 10 for opening and closing 1 to 63, an instrument transformer 8 for a high-voltage main line is provided.
Alternatively, an input blocking means for temporarily blocking the input of the detection value of the current transformer 9 to the power factor adjusting device 7 is provided, and the monitor 11 operates the input blocking device at the time of outputting the alarm signal to the power factor adjusting device 7. Is temporarily blocked, and the input blocking operation by the input blocking means is released when the alarm signal is released. In particular, the input blocking means comprises the high-voltage trunk line instrument transformer 8 and the power factor adjusting device. The monitoring monitor 11 includes a relay that excites when the alarm signal is output to open the normally closed contact and demagnetizes when the alarm signal is released to close the normally closed contact. As a result, the secondary voltage input from the instrument transformer 8 to the power factor adjusting device 7 is blocked based on the alarm signal from the harmonic monitoring monitor 11, and the driving of the power factor adjusting device 7 is temporarily stopped. As a result, the harmonic monitoring monitor 11 returns When the alarm signal is released, it is possible to eliminate the occurrence of the transient disturbance of the power supply system due to the simultaneous power-on of each reactor / capacitor unit, and to return after the harmonic monitoring monitor 11 operates. A power factor adjustment system having a reasonable harmonic interference prevention function in which the operation display unit can display the actual operation state even in the time period before the operation can be obtained.

Embodiment 2 FIG. FIG. 2 shows Embodiment 2 of the present invention.
It is explanatory drawing of the power factor adjustment system which concerns on. In FIG. 2, as a new configuration with respect to the conventional example and the first embodiment of the present invention, a reference numeral 14 flows from the current transformer 9 as a power receiving unit to the power factor adjusting device 7 based on an alarm signal from the harmonic monitoring monitor 11. This is a current conversion circuit as input blocking means capable of blocking the input of the secondary current of the current transformer 9.

Here, the current conversion circuit 14 is composed of, for example, a timed relay, and converts the secondary side current of the current transformer 9 from the current transformer 9 to the power factor adjusting device 7 via a normally closed contact (not shown). An input may be performed.

When a signal is input to the timed relay, the normally closed contact is opened after a predetermined time (for example, one second), and the current transformer 9 sends the signal to the power factor adjusting device 7. The input of the secondary current of the current transformer 9 may be blocked.

In the power factor adjusting system according to Embodiment 2 configured as described above, when the harmonic inflow accumulation amount of the entire phase-advancing capacitor equipment becomes large and the harmonic monitoring monitor 11 outputs an alarm signal, Conventional Example and Embodiment 1
The power supply to all the phase advance capacitor equipment is forcibly cut off by the same sequence operation as in (1).

In this case, the above-mentioned alarm signal is simultaneously output not only to the power factor adjusting device 7 but also to the current conversion circuit 14, and the current conversion circuit 14 performs the reactor
Similarly to the forced cutoff of the capacitor units 41 to 43, the current input from the secondary side of the current transformer 9 to the power factor adjusting device 7 is forcibly blocked (in this case, if the secondary side of the current transformer 9 is open).
A bypass circuit configuration (not shown ) is provided so as not to be present .

Therefore, since the apparent input power of the power factor adjusting device 7 becomes zero, the capacitor input command signal in the power factor adjusting device 7 is sequentially released. For example, when about 1 to 5 minutes elapse, On the operation display screen of the power factor adjusting device 7, the display of turning on the capacitor completely disappears.

Thereafter, a predetermined time (for example, 30 minutes)
, The output of the alarm signal from the harmonic monitoring monitor 11 is also released, and the current conversion circuit 14 sends the signal from the secondary side of the current transformer 9 to the power factor adjusting device 7. The forced input blocking of the current input is also released, and the current conversion circuit 14 also returns to the original state based on the output of the harmonic monitoring monitor 11b, that is, the power factor adjusting device 7 enters the initial startup state. Then, the power is sequentially supplied to the phase-advanced capacitor equipment that has been forcibly shut off for each reactor / capacitor unit in accordance with a predetermined startup order of the ordinary power factor adjusting device 7.

Therefore, according to the second embodiment, the series reactor of the phase-advancing capacitor and the series reactor connected to the high-voltage feeder 2 to which power is supplied from the high-voltage main line 1 via the switches 61 to 63 respectively. Of a plurality of reactor / condenser units 41 to 43, a high-voltage main line instrument transformer 8 and a current transformer 9 provided in the high-voltage main line 1.
And a high-voltage feeder current transformer 12 for detecting a current flowing from the high-voltage main line 1 to a parallel body of the reactor condenser units 41 to 43 provided in the high-voltage feeder 2, and a detection value of the high-voltage feeder current transformer 12. Based on the reactor
A monitor 11 that outputs an alarm signal when the magnitude and duration of the harmonic distortion rate of the current flowing through the parallel body of the capacitor units 41 to 43 exceed a predetermined value.
And a control signal for adjusting the power factor so that the specified power factor is obtained based on the detection values of the instrument transformer 8 and the current transformer 9 for the high-voltage main line, and an alarm signal is received from the monitoring monitor 11. In such a case, a power factor adjusting device 7 for sending a control signal for forced opening for forcibly opening all the switches 61 to 63 of the plurality of reactor / condenser units 41 to 43, and a control sent from the power factor adjusting device 7 Switches 61 to 43 of a plurality of reactor / condenser units 41 to 43 according to signals
In a power factor adjustment system including an opening / closing control circuit 10 that controls the opening and closing of the power supply 63, an input for temporarily blocking the input of the detection value of the high-voltage main line instrument transformer 8 or the current transformer 9 to the power factor adjustment device 7 Blocking means is provided, and the monitor 11 operates the input blocking means at the time of outputting the alarm signal to temporarily block the input of the detection value to the power factor adjusting device 7, and at the time of canceling the warning signal, the input blocking by the input blocking means. The operation is canceled. In particular, the input blocking means is provided between the high-voltage mains current transformer 9 and the power factor adjusting device 7 to perform a bypass operation based on an alarm signal from the monitoring monitor 11. , The input of the detection value to the power factor adjusting device 7 is temporarily stopped, and the current conversion circuit 14 stops the bypass operation when the alarm signal is released. Secondary current input high The input is blocked by the current conversion circuit 14 based on the alarm signal from the wave monitoring monitor 11, and the drive of the power factor adjusting device 7 is temporarily stopped, so that the harmonic monitoring monitor 11 returns and the alarm signal is released. In this case, it is possible to eliminate the occurrence of transient disturbance of the power supply system caused by the simultaneous power supply to each reactor / capacitor unit, and to reduce the time period from when the harmonic monitoring monitor 11 operates to when it returns. In addition, it is possible to obtain a power factor adjustment system having a reasonable harmonic interference prevention function in which the operation display unit can display the actual operation state.

[0032]

According to the present invention, there are provided a plurality of reactor / capacitor units which are connected in series to a high voltage feeder to which power is supplied from a high voltage main line via a switch, and which are formed of a series body of a phase advance capacitor and a series reactor. Parallel bodies,
A high-voltage main line instrument transformer and current transformer provided on the high-voltage main line, and a high-voltage feeder current transformer for detecting a current flowing from the high-voltage main line to a parallel-connected reactor / capacitor unit provided on the high-voltage feeder. An alarm signal is generated when the magnitude and duration of the harmonic distortion rate of the current flowing through the parallel-connected reactor-capacitor unit exceed a predetermined value based on the detection value of the current transformer for the high-voltage feeder. A monitor signal to be output and a control signal for adjusting the power factor so that the specified power factor is obtained based on the detection values of the instrument transformer and current transformer for the high voltage main line, and an alarm signal is received from the monitor monitor. In this case, a power factor adjusting device that sends a control signal for forced opening that forcibly opens all switches of a plurality of reactor / condenser units, and a control signal that is sent from the power factor adjusting device And a switching control circuit for controlling the switching of the plurality of reactor / condenser units according to the power factor adjustment system. Input monitoring means for temporarily blocking input of the power factor adjustment device, the monitoring monitor operates the input blocking means at the time of output of the alarm signal to temporarily block the input of the detection value to the power factor adjusting device, and at the time of canceling the alarm signal, Since the input blocking operation by the blocking means is cancelled, the input from either the instrument transformer or the current transformer to the power factor adjusting device is blocked based on the alarm signal from the monitoring monitor. When the drive of the power factor adjustment device was temporarily stopped, the monitoring monitor returned and the alarm signal was released, the power was turned on to each reactor and capacitor unit at the same time. Reasonable harmonic interference that eliminates the occurrence of transient disturbances in the source system and allows the operation display unit to display the actual operation state even during the period from when the monitoring monitor operates to when it returns. A power factor adjustment system having a prevention function can be obtained.

In particular, the input blocking means is provided in at least one of between the high-voltage main line instrument transformer and the power factor adjusting device or between the high-voltage main line current transformer and the power factor adjusting device. The monitoring monitor has a relay that excites and opens the normally closed contact when an alarm signal is output and demagnetizes and closes the normally closed contact when the alarm signal is released. The secondary voltage input from the instrument transformer to the device is blocked based on the alarm signal from the monitoring monitor and the input of the secondary side voltage input is blocked and the drive of the power factor adjustment device is temporarily stopped. Is released, eliminates the occurrence of transient disturbance in the power supply system caused by the simultaneous power-on of each reactor capacitor unit,
In addition, to obtain a power factor adjustment system having a reasonable harmonic interference prevention function in which the operation display unit can display the actual operation state even in the time period from when the monitoring monitor operates to when it returns. Can be.

In particular, the input blocking means is provided between the current transformer for the high-voltage mains and the power factor adjusting device, and performs a bypass operation based on an alarm signal from the monitoring monitor to the power factor adjusting device. While temporarily blocking the input of the detection value of
The current conversion circuit stops the bypass operation when the alarm signal is released, so the input of the secondary current from the current transformer to the power factor adjuster is blocked by the input blocking means based on the alarm signal from the monitoring monitor. When the power of the power factor adjusting device is temporarily stopped and the monitoring monitor returns and the alarm signal is released, the power supply system transients due to the simultaneous power-on of each reactor / capacitor unit. The operation display unit has a reasonable harmonic failure prevention function that can display the actual operation state even during the period from when the monitoring monitor operates to when it returns to normal operation, while eliminating the occurrence of dynamic disturbance. Power factor adjustment system can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a power factor adjustment system according to a first embodiment.

FIG. 2 is an explanatory diagram of a power factor adjustment system according to a second embodiment.

FIG. 3 is an explanatory diagram of a power factor adjustment system having a conventional harmonic interference prevention function.

[Explanation of symbols]

13 Contact b of auxiliary relay (normally closed contact) 14 Current conversion circuit.

Claims (3)

(57) [Claims] 1. A parallel body of a plurality of reactor / capacitor units each comprising a series body of a phase-advancing capacitor and a series reactor connected to a high-voltage feeder to which power is supplied from a high-voltage main line via a switch, respectively. An instrument transformer and a current transformer for the high-voltage main line provided on the main line, and a reactor and a power supply provided from the high-voltage main line to the high-pressure feeder.
A current transformer for a high voltage feeder for detecting a current flowing in a parallel body of the capacitor units, and a harmonic distortion factor of a current flowing in the parallel body of the reactor and capacitor units based on a detection value of the current transformer for the high voltage feeder. A monitor that outputs an alarm signal when the magnitude and duration of the power supply exceed a predetermined value, and a power factor specified based on the detected values of the high-voltage trunk line instrument transformer and current transformer. A power-factor adjustment control signal is transmitted so as to satisfy the following condition.When an alarm signal is received from the monitoring monitor, a forced-opening control signal for forcibly opening all of the switches of the plurality of reactor / capacitor units is issued. A power factor adjusting device to be sent, and an opening / closing control circuit that controls opening / closing of the switches of the plurality of reactor / condenser units according to a control signal sent from the power factor adjusting device. In the power factor adjustment system comprising, provided input blocking means for temporarily blocking the input of the detection value of the instrument transformer or current transformer for the high-voltage mains to the power factor adjustment device, the monitoring monitor, When the alarm signal is output, the input blocking means is operated to temporarily block the input of the detection value to the power factor adjusting device, and when the alarm signal is released, the input blocking operation by the input blocking means is released. Characteristic power factor adjustment system. 2. The power supply system according to claim 1, wherein the input blocking means is at least one of between the high-voltage main line instrument transformer and the power factor adjusting device or between the high-voltage main line current transformer and the power factor adjusting device. The monitoring monitor is energized when the alarm signal is output to open the normally closed contact, and is demagnetized when the alarm signal is released to close the normally closed contact. The power factor adjusting system according to claim 1, further comprising a relay. 3. The input blocking means is provided between the high-voltage mains current transformer and the power factor adjusting device, and performs a bypass operation based on the alarm signal from the monitoring monitor. 2. The power factor adjusting system according to claim 1, wherein the current factor converting circuit temporarily blocks input of a detection value to the power factor adjusting device and stops the bypass operation when the alarm signal is released.