JP2611266B2 - Power factor automatic adjustment controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention detects a reactive power or the like and controls a power factor improving capacitor connected to the electric circuit in order to improve the power factor of the electric circuit. The present invention relates to a power factor automatic adjustment control device.

[Prior Art] For example, a conventional power factor automatic adjustment control device disclosed in Japanese Patent Publication No. 60-82323 is shown in FIG. In the figure, a power factor automatic adjustment controller (30) is amplified by a reactive power detector (4), an amplifier circuit (5) for amplifying a detection signal from the reactive power detector (4), and an amplifier circuit (5). Signal and closing level setting section (7) or cutoff level setting section (9)
Comparison circuit (6) for comparing with each set value set by (1)
And (8), first and second sequential circuits (23) and (24) for driving the relay circuit (25) by the output of the comparison circuit (6) or (8), and relay contacts (26a) ... ( Two
6n). The relay contact (26a) ... (26n) is connected via the control circuit (50) to the electromagnetic contactor (60a) ... (60c)
These electromagnetic contactors (60a) …… (60
c) The capacitor (62
a) Turn on or shut off (62c).

A measuring transformer (2) and a measuring current transformer (3) are connected to the electric circuit (1), and the voltage and current of the electric circuit (1) are detected. Reactive power is detected based on the voltage and the current, and power proportional to the detected reactive power is generated. The amplifier circuit (5) amplifies the output of the reactive power detector (4). The first comparison circuit (6) compares the output of the amplifier circuit (5) with the output of the input level setting section (7), and the output of the amplifier circuit (5) is higher than the output of the input level setting section (7). If it is high, it produces an output. The second comparison circuit (8) compares the output of the amplification circuit (5) with the output of the cutoff level setting section (9), and if the output of the amplification circuit is lower than the output of the cutoff level setting section (9), outputs the output. Occurs. The timer circuit (20) releases the reset state upon input from the OR gate (19), generates an output after the time set by the timer setting section (21) has elapsed, and thereafter returns to the reset state again. The first sequential circuit (23) is energized by the output of the first gate circuit (17), that is, the output of the first comparison circuit (6) and the output of the timer circuit (20), and is supplied to the electric circuit (1). The capacitor to be supplied is selected from the first to n-th capacitors (62a) (62c). The second sequential circuit (24) is energized by the output of the second gate circuit (18), that is, the output of the second comparison circuit (8) and the output of the timer circuit (20). Select the capacitor to shut off. The relay circuit (25) energizes the relay corresponding to the capacitor selected in the first sequential circuit (23) and deactivates the relay corresponding to the capacitor selected in the second sequential circuit (24). Relay contact (26a) ~ (26n) corresponds to the first to capacitor of the _{n (62a) ...... (62 c} ) ......, a relay contact that is energized or de-energized by a relay circuit (25).

[Problems to be Solved by the Invention] Since the conventional power factor automatic adjustment control device is configured as described above, all the capacitors connected to the power factor automatic adjustment control device are used for automatic power factor adjustment. And there is a problem that manual control for manually turning on or shutting off an arbitrary capacitor is impossible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an automatic power factor adjustment control device capable of manually controlling an arbitrary capacitor.

[Means for Solving the Problems] An automatic power factor adjusting apparatus according to the present invention automatically controls a plurality of capacitors which are turned on or off to an electric circuit, and each of the plurality of capacitors. Control mode setting means for setting whether to apply an automatic control mode or a manual control mode controlled manually, reactive power detection means for detecting reactive power of an electric circuit, and reactive power An input discriminating means for judging whether or not the power detected by the detecting means is below the input level for inputting the capacitor, and a control mode setting when the electric power is passing the input level in the input discriminating means. Means for applying only the capacitors that are subject to automatic control to the electric circuit, and means for the reactive power to cut off the capacitors. A breaking determination means for determining whether or not the breaking level has been exceeded; and, when the reactive power has exceeded the breaking level in the breaking determination means, only a capacitor which has been subjected to automatic control by the control mode setting means is removed from the electric circuit. Shut-off means for shutting off, and, for a capacitor which has been subjected to manual control by the control mode setting means, a manual control means for immediately shutting off when the capacitor is shut off, and for turning on the capacitor after a lapse of a predetermined time when turning on the capacitor, Is provided.

[Operation] The plurality of capacitors advance the phase of the reactive power that is delayed by being supplied to the electric circuit, and adjust the power factor by delaying the phase of the reactive power that is advanced by being cut off.

The control mode setting means sets whether to apply the automatic control mode or the manual control mode to each of the plurality of capacitors.

 The reactive power detecting means detects the reactive power of the electric circuit.

The input determining means determines whether or not the reactive power is lower than the input level for inputting the capacitor. The input level is set to a fixed value when a plurality of capacitors have the same capacity, and when there are various capacities of each capacitor, the input level is calculated for each capacity.

The input means sets the capacitors to be controlled automatically when the reactive power goes around the input level, in the order of installation if the capacitors have the same capacity, Input to the electric circuit in descending order.

The interruption determination means determines whether the reactive power exceeds an interruption level for interrupting the capacitor. As with the shut-down level, a fixed value is set for the plurality of capacitors when the capacitors have the same capacity, and when the capacitors have various capacities, the calculation is performed for each capacity.

When the reactive power exceeds the cutoff level, the cutoff means replaces the capacitor set in the automatic control mode with
When the capacitors have the same capacity, the electric circuit is cut off in the order of application, and when there are various capacities of the capacitors, the capacitors are cut off in order of decreasing capacity.

The manual control means immediately cuts off the capacitor set in the manual control mode from the electric circuit when the capacitor should be cut off. When a capacitor is inserted into the electric circuit, the capacitor is inserted after a predetermined time sufficient to discharge the electric charge stored in the capacitor.

[Embodiment] An automatic power factor adjustment control device according to the present invention will be described with reference to Fig. 1 showing an embodiment and Fig. 2 showing a flowchart of automatic power factor adjustment control.

In FIG. 1, an electric circuit (1) is provided with a transformer for measurement (2) and a current transformer (3), and the output of these transformers is the reactive power of a power factor automatic adjustment controller (100). Input to the detector (101). Transformer (2), current transformer (3)
The reactive power detector (101) constitutes a reactive power detector. The power factor automatic adjustment control device (100) includes an arithmetic processing unit (hereinafter abbreviated as CPU) (102) including a microcomputer or the like, and a first storage unit that stores an arithmetic program and the like executed by the CPU (102). (Hereinafter abbreviated as ROM) (103) and a second storage for temporarily storing a reactive power value detected by the reactive power detection unit (101) and various input data input from the setting unit (105). (Hereinafter abbreviated as RAM) (104) and a setting unit (105) for inputting control data such as various control data such as an input level for inputting a capacitor and a shutoff level for shutting off a capacitor. A display unit (106) for displaying various operation data calculated by the CPU (102), and a relay control unit (107) for outputting a closing signal and a cutoff signal to the capacitor control unit (50). . Further, a control mode constituted by a changeover switch or the like, which acts as control mode setting means for setting whether to perform automatic control or manual control for each of the capacitors (62a), (62b), (62c). It has a setting unit (108). Each of the capacitors (62a), (62b), (62c) ... has a series reactor (61a), (61b), (61c) ...
… And the electromagnetic contactors (60a), (60b), (60c) …… are connected, and the electromagnetic contactors (60a), (60b), (60c)
The electric circuit (1) is turned on or off by the operation of... These capacitors (62a), (62b), (62
c) ... is the transformer (70a), (70b) and load (71a),
(71b) is connected in parallel. Each electromagnetic contactor (60
a), (60b), (60c) ... are the capacitor control units (50)
The capacitor control unit (50) operates each of the electromagnetic contactors (60a), (60b), (60c),... Based on the closing signal and the cutoff signal from the relay control unit (107).

In general, a capacitor bank composed of a plurality of capacitors can be categorized into two types: a capacitor bank composed entirely of capacitors having the same capacitance, and a capacitor bank composed of capacitors having different capacitances. When the capacitor banks are all composed of capacitors of the same capacity, cyclic control is performed in which the capacitors are cut off in the order in which they are arranged, and the capacitors are turned on in the order in which the capacitors were cut off. On the other hand, when the capacitor bank is composed of a plurality of capacitors having different capacities, priority control or the like is performed, for example, in which control is performed in order from a capacitor having a smaller capacity. In the latter case, if the load is extremely light or heavy, a large-capacity or small-capacity capacitor that has almost no effect on the actual load even when actually turned on or shut off is always turned on or off by manual control in advance. It is more efficient to cut off. The control mode setting unit (108) sets each of the capacitors (62a), (62b), (62c)... Constituting the capacitor bank to the automatic control mode or the manual control mode. The capacitor set in the automatic control mode is automatically controlled by the CPU (102) based on the flowchart shown in FIG. On the other hand, the capacitor set in the manual control mode is further operated by a switch in the control mode setting section (108), through the CPU (102), the relay control section (107), and the electric circuit (1) via the capacitor control section (50). As a result of the operation of the electromagnetic contactor (for example, 60a) directly connected to the electric circuit, the electric circuit (1) is turned on and cut off. At this time, the CPU (102) or the like acts as a manual control means, and immediately shuts off the capacitor to be manually controlled from the electric circuit (1). In addition, the capacitors targeted for manual control are connected to an electric circuit (1).
When the capacitor is supplied to the electric circuit (1), it is necessary to discharge the electric charge that had been charged when the capacitor was previously supplied to the electric circuit (1). Therefore, the CPU (102) outputs a closing signal after confirming that the clock time starting counting from the previous interruption has passed a sufficient time necessary for discharging.

Next, the operation in the automatic control mode will be described with reference to the flowchart shown in FIG.

When the power factor automatic adjustment control is started (1000), the reactive power of the electric circuit is measured by the reactive power detecting means such as the transformer (2), the current transformer (3), and the reactive power detector (101). You. In addition, the input level and the cutoff level previously input by the setting unit (105) and stored in the RAM (104) or the calculation data for calculating these values is a CP.
It is read into U (102) (1001).

If there are various capacitor values, CPU (102)
According to a program previously written in the ROM (103), the cutoff level and the cutoff level are determined based on the capacity of each capacitor and the above-described operation data, such as the combined transformation ratio and hunting prevention coefficient of the transformer (2) and the current transformer (3). Calculate the input level for each capacitor capacity type (100
2). If the capacitors (62a), (62b), (62c)... Have the same capacity, this step can be omitted.

The composite transformation ratio is the product of the transformer ratio on the primary side / secondary side of the transformer (2) and the transformer (3) described above. What is actually measured is the secondary output of the transformer (2) and the current transformer (3), and the combined transformation ratio is used to convert the reactive power and the like of the actual electric circuit from these measured values. . The hunting prevention coefficient is a constant value to prevent the malfunction of turning on or off the capacitor again as soon as the capacitor is turned on or off due to a measurement error, etc. This is a safety factor for setting the time and target adjustment width to be relatively wide.

Next, the CPU (102) determines whether or not the phase of the measured reactive power is advanced (1003).

If the reactive power phase is advanced, the CPU (10
2) acts as a cutoff determining means and determines whether or not the reactive power exceeds the cutoff level (1004). If it does not exceed this value, no operation command is output and the step (10
Return to 01). When the reactive power exceeds the cutoff level, first, n = 1 is set (1005), and it is determined whether or not the capacitor having the first control order is set to the automatic control mode (1006). If the first capacitor is set to the automatic mode, it is next determined whether or not the first capacitor is in the cutoff state (1008). If the first capacitor is already cut off,
n = n + 1 is set (1007), and the same determination operation step (1006) is repeated for the capacitor having the second control order. When the first capacitor is on,
The CPU (102) acts as a breaking means and outputs a breaking signal (1009). The shutoff signal output from the CPU (102) is sent to the relay control unit (107) and the capacitor control unit (50).
The electromagnetic contactor (60a) is driven to cut off the first capacitor (for example, 62a) via (1010), and the process returns to step (1001). If the first capacitor is not set to the manual control mode, set n = n + 1 (10
07), Step for the second capacitor (1006)
Is repeated.

If the phase of the reactive power is not advanced (or delayed) in step (1003), the CPU (102) acts as the input determining means and determines whether the reactive power is below the input level ( 1011) If not, the CPU (102) returns to step (1001) without outputting any operation command. When the reactive power value is lower than the input level, assuming that the total number of capacitors constituting the capacitor bank is k, n = k is set (1012), and the CPU (1012)
2) It is determined whether or not the k-th capacitor is set to the automatic control mode (1013). If the k-th capacitor is set to the automatic control mode, it is next determined whether or not this capacitor has already been turned on (1015). When the k-th capacitor is not turned on, the CPU (102) acts as a closing means, counts a predetermined time (1016), and then generates a closing signal (1017). CP
The closing signal output from U (102) is
It is transmitted to the capacitor control unit (50) via 7). The capacitor control unit (50) operates the electromagnetic contactor (eg, 60a) to feed the kth capacitor (eg, 62a) to the electric circuit (1). When the k-th capacitor is set to the manual operation mode or when the k-th capacitor is already turned on, n = n-1 is set (1014), and the same discrimination operation step as for the k-1st capacitor is performed (1014). 1013) and step (1015) are repeated.

While the power factor automatic adjustment control is being performed, the control mode setting unit (108) is operated to change the setting of the capacitor set in the manual control mode to the automatic control mode, or conversely. The setting of the capacitor set in the automatic control mode may be changed to the manual control mode. In these cases, since the setting of the control order of each capacitor is incorrect, it goes without saying that the power factor automatic adjustment control is temporarily released, and the process is started from step (1000) again.

[Effects of the Invention] As described above, the power factor automatic adjustment control device according to the present invention can arbitrarily set the closing and closing of each capacitor that is switched on and off to the electric circuit in the automatic control mode and the manual control mode. This has the effect that the capacitor can be manually controlled.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a power factor automatic adjustment control device according to the present invention, FIG. 2 is a flowchart showing a program executed in a CPU (102), and FIG. It is a figure showing an apparatus. In the figure, (101) is a reactive power detector, (102) is a CPU, and (10)
8) is a control mode setting section.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-5618 (JP, A) JP-A-64-55620 (JP, A) JP-A-63-290127 (JP, A)

Claims (2)

(57) [Claims] An automatic control mode to be automatically controlled is applied to each of a plurality of capacitors to be turned on or off to an electric circuit and each of the plurality of capacitors, or manually. Control mode setting means for setting whether to apply the controlled manual control mode, reactive power detecting means for detecting reactive power of the electric circuit, and reactive power detected by the reactive power detecting means turns on a capacitor. The input mode for the automatic control by the control mode setting means when the reactive power is below the input level, and Input means for inputting only a capacitor to the electric circuit; and reactive power detected by the reactive power detection means is a capacitor. A cut-off determining means for determining whether or not a cut-off level for a cut-off has been exceeded; and, if the reactive power exceeds the cut-off level in the cut-off determining means, the control mode setting means sets the control mode as an automatic control target. A shutoff means for shutting off only the capacitor from the electric circuit, and a capacitor which is to be manually controlled by the control mode setting means, immediately shuts off when the capacitor is shut off, and a predetermined time when the capacitor is turned on. A power factor automatic adjustment control device comprising: 2. The method according to claim 1, wherein when the capacitor set in the automatic control mode is switched to the manual control mode by the control mode setting means, or when the capacitor set in the manual control mode is switched to the automatic control mode, the power factor is automatically controlled. 2. The power factor automatic adjustment control device according to claim 1, wherein the adjustment control is temporarily released, and the power factor automatic adjustment control is started again from the beginning.