KR20230002212A - Device for controlling power - Google Patents

Abstract

A device for controlling power, which controls the opening and input of a condenser connected to a load, according to an embodiment of the present invention comprises: a receiving part for receiving a first power factor which is a target power factor; a control part including a condenser capacity calculation part for setting the power factor of the load as the first power factor through the input or opening of the condenser, calculating a current capacity, which is the currently inputted capacity of the condenser, and calculating a first capacity, which is a condenser capacity necessary to achieve the first power factor, from the current capacity, and a condenser setting part for inputting or opening the condenser depending on the first capacity; and a monitoring part for monitoring a change in the power factor of the load. If the power factor of the load changes into a second power factor different from the first power factor, the condenser capacity calculation part calculates a second capacity, which is a condenser capacity necessary to re-achieve the first power factor, from the second power factor. The condenser setting part determines the input or opening of the condenser depending on the second capacity. The present invention can reduce power loss and power bills.

Description

Power control device {DEVICE FOR CONTROLLING POWER}

The present embodiment relates to an apparatus and method for controlling power, particularly reactive power.

Although electric power is a versatile and convenient energy source, the production and transmission of electrical energy is expensive, and costs can increase as demand for electricity increases. In order to reduce cost, it is necessary to increase power use efficiency or, conversely, to reduce power loss rate.

AC power is characterized by a phase relationship between current and voltage. If there is a lot of inductive load, that is, if the load is inductive, the current may lag behind the voltage. If there is a large capacitive load, that is, if the load is capacitive, the current may lead the voltage. The in-phase relationship can arise from a resistive load or from a balance between an inductive load and a capacitive load.

'Real' resistive power is generated from the common current, and 'apparent' reactive power is generated from the abnormal current due to the influence of the inductive reactance or capacitive reactance of the power circuit. Commonly used to measure the phase relationship between current and voltage is power factor, which corresponds to the cosine of the phase angle between voltage and current.

When the apparent power is Pa, the active power is P, the reactive power is Pr, the voltage is V, and the current is I, the relationship between power and power factor is as follows: Equation 1

[Equation 1]

The power factor is maximized at unit value when the phase relationship is resistive, less than 1 as a positive number when inductive, and less than 1 as a negative number when capacitive. Alternatively, the power factor may refer to a ratio of power (active power) used by a customer's electrical device (load) to power (apparent power) supplied by a power supplier.

Inductive loads such as motors and transformers tend to be more connected to power lines than capacitive loads. Power suppliers often charge customers a surcharge when the load causes a power factor below a certain value. To avoid this, users can improve the power factor of the inductive load and lower the power cost by connecting a power factor correction capacitor to the power line. That is, it may be possible to reduce power rates through power factor improvement.

However, although a capacitor is used to convert reactive power - unusable power generated by an inductive load - into operational power, the use of a capacitor can generate transient compensation according to load fluctuations - specifically, load power factor fluctuations. can For example, at night, when the inductive load is reduced (light load) or the inductive load is removed (no load), the power factor may change to a leading phase and the loss may increase as the capacitor operates as a load. This, too, can be an additional factor in electricity bills.

In this regard, the present embodiment is intended to provide a reactive power control technology that eliminates the occurrence of overcompensation for the power factor due to the input of the capacitor.

Against this background, one object of the present embodiment is a power control technology that monitors load fluctuations - load power factor fluctuations or reactive power fluctuations - and adjusts the closing or opening of capacitors in stages according to the amount of reactive power used. is to provide

Another object of the present embodiment is to provide a power control technology that automatically reads the closing or opening of a capacitor to implement optimal power factor control and protect the capacitor.

In order to achieve the above object, an embodiment is a power control device for controlling the opening and closing of a capacitor connected to a load, comprising: a receiving unit for receiving a first power factor that is a target power factor; The power factor of the load is set as the first power factor through closing or opening of the capacitor, the current capacity, which is the capacity of the currently applied capacitor, is calculated, and the first capacity, which is the capacitor capacity required to achieve the first power factor, from the current capacity. a control unit including a capacitor capacity calculation unit that calculates and a capacitor setting unit that closes or opens the capacitor according to the first capacity; and a monitoring unit for monitoring a change in the power factor of the load, wherein the capacitor capacity calculation unit calculates the first power factor again from the second power factor when the power factor of the load changes to a second power factor different from the first power factor. The second capacitance, which is the capacitance required to achieve the required capacitance, is calculated, and the capacitance setting unit determines whether to turn on or open the capacitance according to the second capacitance.

In the apparatus, the first power factor has a value of 1, the second power factor is leading, and the monitoring unit changes the power factor of the load to the second power factor by a decrease in the inductive load. monitoring, the capacitor setting unit may open a capacitor having a capacitor capacity corresponding to the second capacity.

In the apparatus, the control unit determines whether the power factor of the load has changed from the second power factor to the first power factor, and the capacitor setting unit opens one of a plurality of capacitors included in a capacitor bank, but the power factor of the load Other capacitors may be opened one by one until the first power factor is reached from the second power factor.

In the above device, the capacitor setting unit selects another capacitor of a lower order from the capacitor bank when there is no capacitor corresponding to the first capacity or the capacitor corresponding to the second capacity in the capacitor bank, and inserts the selected capacitor. or open.

In the above device, the capacitor setting unit, if there is no capacitor corresponding to the first capacity or a capacitor corresponding to the second capacity in the capacitor bank, combines two or more capacitor capacities, and sets two or more capacitor capacities corresponding to the two or more capacitor capacities. The above capacitors may be selected from among the capacitor banks, and the selected capacitors may be closed or closed.

In the apparatus, a storage unit for storing a combination value generated from a combination of a plurality of capacitances is included, and the capacitor setting unit includes a first combination value corresponding to the first capacitance or a second combination corresponding to the second capacitance. A value may be read from the storage unit, and a plurality of capacitors having the capacitance used for the first or second combination value may be selected from the capacitor bank and inserted.

In the device, the capacitor capacity calculation unit includes a microprocessor, and the microprocessor calculates reactive power corresponding to a power factor, and calculates the first capacity and the second capacity according to the reactive power. .

The device includes an input unit for receiving an operation for the power control device from a user and transmitting the input to the receiver, wherein the receiver converts the operation by the user into digital data and transmits the digital data to the control unit. can do.

In the device, the input unit may receive power factor, active power, reactive power, monitoring of power factor, and operation for closing or opening a condenser.

In the device, a display unit for displaying the operation of the power control device, the current power factor, the current active power, the current reactive power, the current status of the closed or opened capacitor, the current voltage, the current current, and the current reduction factor. can include

In the device, a plurality of capacitor terminals connected to a plurality of capacitors included in the capacitor bank, a neutral terminal connected to a neutral line, a ground terminal connected to an earth line, and a hot line connected. and a terminal part controlled by the condenser setting part.

As described above, according to the present embodiment, by adjusting the closing or opening of the capacitor according to the change in load, it is possible to reduce power loss and power charges by removing reactive power.

In addition, according to the present embodiment, it is possible to reduce the overcompensation of the power factor by the capacitor according to the load variation and the resulting power loss.

1 is a configuration diagram of a power control device according to an embodiment.
2 is a diagram illustrating reduction of reactive power and power factor correction through input of a capacitor according to an embodiment.
3 is a diagram illustrating resolution of power factor transient compensation through opening of a capacitor according to an exemplary embodiment.
4 is a diagram illustrating a connection between a terminal unit and a capacitor bank according to an exemplary embodiment.
5 is a flowchart illustrating an operation of a power control device according to an exemplary embodiment.
6 is a first diagram illustrating an actually manufactured power control device according to an embodiment.
7 is a second diagram illustrating an actually manufactured power control device according to an embodiment.
8 is a third diagram illustrating an actually manufactured power control device according to an embodiment.
It is revealed that the accompanying drawings are illustrated as references for understanding the technical idea of the present invention, and thereby the scope of the present invention is not limited thereto.

In the description of the present invention, if it is determined that a related known function may unnecessarily obscure the subject matter of the present invention as an obvious matter to those skilled in the art, the detailed description thereof will be omitted.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are assigned the same reference numerals and overlapping descriptions thereof are omitted. do it with

1 is a configuration diagram of a power control device according to an embodiment, FIG. 2 is a view illustrating reduction of reactive power and power factor correction through input of a capacitor according to an embodiment, and FIG. 3 is a diagram according to an embodiment. It is a diagram explaining the elimination of power factor transient compensation through the opening of the capacitor.

Referring to FIG. 1, the power control device 100 includes an input unit 110, a receiver 120, a control unit 130, a terminal unit 140, a capacitor bank 150, and a monitoring unit 160. ) and a display unit 170.

The input unit 110 may receive a manipulation of the power control device 100 from a user and transmit the input to the receiver 120 . As manipulations for the power control device 100, the user may input manipulations for power factor, active power, reactive power, power factor monitoring, and closing or opening of the condenser.

Here, manipulation of the power factor may include inputting a power factor value when the user wants to set a different power factor from the current power factor of the load. Operation of the active power or reactive power may be inputting an active power value or a reactive power value when the user wants to set another active or reactive power from the current active or reactive power of the load. An operation for monitoring the power factor may be inputting a set value for whether or not the power control device 100 detects a change in load. An operation for closing or opening a capacitor may be inputting a set value for which capacitor to close or open among a plurality of capacitors included in the capacitor bank 150 or how many capacitors to close or open. there is.

The receiving unit 120 may generate digital data by digitizing a signal input from the outside. In particular, the receiving unit 120 may receive a signal according to a user's manipulation from the input unit 110 and convert it into digital data. The receiver 120 may transmit the converted digital data to the controller 130. For example, the receiver 120 may be connected to a current transformer (CT) to receive a current signal from the current transformer. The receiving unit 120 may convert the current signal into digital data and transmit the converted digital data to the controller 130 .

The control unit 130 includes a capacitor capacity calculation unit 131 and a capacitor setting unit 132 included therein, and may compensate for a power factor of a load by opening or closing a capacitor. Here, the input of the capacitor can be understood as connecting the capacitor in parallel with the load. The connected condenser can reduce total reactive power of the load by supplying reactive power absorbed by the inductive load. Opening the capacitor can also be understood as disconnecting the capacitor from the load in parallel. The capacitor separated from the load can increase the total reactive power of the load by stopping the supply of reactive power.

The capacitor capacity calculation unit 131 may calculate the capacity of the capacitor. The capacitor capacity calculation unit 131 may calculate the capacity of the input capacitor at a point in time. For example, the capacitor capacity calculation unit 131 may calculate the capacity of the capacitor connected to the current load (hereinafter referred to as 'current capacity'). The capacitor setting unit 132 may set the closing or opening of a plurality of capacitors included in the capacitor bank 150. Data on the setting may be received from The capacitor capacity calculation unit 131 may calculate the current capacity by summing the capacities of at least one input capacitor.

Also, the capacitor capacity calculation unit 131 may calculate the capacity of the capacitor required for the load to achieve a work power factor. For example, the capacitor capacity calculator 131 may receive a target power factor input from a user. The capacitor capacity calculation unit 131 may calculate the capacity (hereinafter referred to as 'first capacity') of the capacitor required for the load to achieve a target power factor.

The capacitor capacity calculation unit 131 may use the calculation of reactive power to calculate the first capacity. For example, the capacitor capacity calculation unit 131 calculates the reactive power according to the current reactive power and the target power factor, calculates the difference between the current reactive power and the reactive power according to the target power factor, and the capacitor capacity required to compensate for the difference. The first dose can be calculated.

The capacitor setting unit 132 may select at least one or more of a plurality of capacitors included in the capacitor bank 150 to open or insert the capacitor. The capacitor setting unit 132 may receive the required capacitance value of the capacitor from the capacitor capacity calculating unit 131 and select at least one capacitor corresponding to the required capacitance value of the capacitor.

The capacitor setting unit 132 may select and open or insert a capacitor having a capacitor capacity corresponding to the first capacity. For example, if the power factor of the load is lagging power factor and the target power factor is 1 to completely remove reactive power, the capacitive component and reactive power of the load should not exist. The capacitor setting unit 132 may select and insert a capacitor having a capacity corresponding to the first capacity from the capacitor bank 150 . When the selected condenser is connected to a load, the fluidity component of the load may decrease and the reactive power of the load may also decrease.

Referring to FIG. 2 , when a capacitor corresponding to the first capacity is input, the reactive power of the load may be reduced. The input capacitor can reduce the reactive power of the load by supplying reactive power to the load. So, the load that absorbs the initial reactive power (Q) can absorb the remaining reactive power (Q') except for the first reactive power (Qc1) supplied by the input capacitor. The input capacitor can reduce the amount of reactive power absorbed by the load by the first reactive power Qc1. This is the result of the loaded capacitor compensating for the power factor of the load.

Returning to FIG. 1 again, the monitoring unit 160 may continuously detect a change in the power factor of the load. A load is composed of a resistance component and a reactance component, and the reactance component may be inductive or insoluble. Inductive reactance may be generated by an inductor, and dissolving reactance may be generated by a capacitor, respectively. When the load changes, the reactance component changes, and when the reactance changes, the power factor of the load may change. Thus, the monitoring unit 160 may detect a change in power factor through a change in load. When the monitoring unit 160 detects a change in the power factor of the load, it transmits a detection signal to the control unit 130, and the control unit 130 can operate the capacitor capacity calculation unit 131 and the capacitor setting unit 132.

When the power factor of the load changes, the capacitor capacity calculation unit 131 calculates the capacitor capacity required to achieve the original power factor again, and based on this, the capacitor setting unit 132 can open or close the capacitor. For example, the monitoring unit 160 may detect that the power factor of the load changes to a second power factor different from the first power factor after being set to a first power factor that is a target power factor. The capacitor capacity calculation unit 131 may calculate a capacitor capacity (hereinafter referred to as 'second capacity') required to achieve a first power factor at a load power factor from a second power factor. The capacitor setting unit 132 may select a capacitor from the capacitor bank 150 according to the second capacity, and may close or open the selected capacitor.

Referring to FIG. 3 , the monitoring unit 160 may detect a change in the power factor of the load according to a decrease in the inductive load after compensating for the power factor of the load. For example, in I, the capacitor setting unit 132 may set the power factor of the load to a first power factor having a value of 1 by inputting a capacitor. In II, the monitoring unit 160 may detect that the power factor of the load changes from a first power factor having a value of 1 to a second power factor of a leading phase due to a decrease in the inductive load. In this case, the capacitance of the capacitor inputted by the capacitor setting unit 132 for the first power factor may be excessive in the second power factor of the leading phase. That is, it can be understood that too many capacitors input for the first power factor are input for the second power factor. So, the capacitor must be opened as much as it is excessively charged. In III, the capacitor capacity calculation unit 131 calculates the second capacity required to achieve the first power factor again from the second power factor, and the capacitor setting unit 132 has a capacitor capacity corresponding to the second capacity. Capacitors can be opened.

Returning to FIG. 1 again, the power control device 100 may also input or open the capacitor step by step until the power factor of the load reaches the target power factor. The power control device 100 may repeat closing or opening of the capacitor until the power factor of the load reaches the target power factor.

For example, in order to achieve the first power factor, the capacitor setting unit 132 may input one of a plurality of capacitors included in the capacitor bank 150. The controller 130 may determine whether the power factor of the load has reached the first power factor. If the power factor of the load is not the first power factor, the capacitor setting unit 132 may input other capacitors one by one until the power factor of the load becomes the first power factor.

As another example, when the power factor of the load changes from a first power factor having a value of 1 to a leading second power factor, the capacitor setting unit 132 may select one of a plurality of capacitors included in the capacitor bank 150. can be opened. The controller 130 may determine whether the power factor of the load has reached the first power factor. If the power factor of the load is not the first power factor, the capacitor setting unit 132 may open other capacitors one by one until the power factor of the load becomes the first power factor.

In addition, if there is no capacitor corresponding to the first capacity or the capacitor corresponding to the second capacity in the capacitor bank, the capacitor setting unit 132 selects another capacitor of the lower order from the capacitor bank and closes or opens the selected capacitor. there is. Here, the ranking may be based on an order pre-input by the user. For example, the capacitance may be selected sequentially from the smallest capacitor or the largest capacitor.

In addition, if the capacitor bank does not have a capacitor corresponding to the first capacity or a capacitor corresponding to the second capacity, the capacitor setting unit 132 combines the capacities of two or more capacitors, and selects two or more capacitors corresponding to the capacities of the two or more capacitors as described above. A selection is made among the capacitor banks, and the selected capacitor can be closed or closed. For example, if the capacities of the five capacitors included in the capacitor bank 150 are 64㎌, 64㎌, 32㎌, 16㎌ and 8㎌, and the first or second capacity is 128㎌, the capacitor setting unit 132 ) can select two capacitors with 64㎌.

The capacitor setting unit 132 may select a capacitor according to a pre-stored combination value. The combination value may be previously stored in a storage unit (not shown). For example, when the capacities of the five capacitors included in the capacitor bank 150 are 64㎌, 16㎌, 32㎌, 16㎌ and 8㎌, the capacitor setting unit 132 sets the first capacitor in the storage unit (not shown). The combination value can be read, and a 32 μF capacitor can be selected according to the first combination value. Alternatively, the capacitor setting unit 132 may read the second combination value from a storage unit (not shown) and select two 16 μF capacitors according to the second combination value.

The terminal unit 140 is electrically connected to the capacitor bank 150 and can turn on or turn off the electrical connection of the capacitor as set by the capacitor setting unit 132. When the terminal unit 140 turns on the electrical connection, the capacitor may be input and connected to the load. When the terminal unit 140 turns off the electrical connection, the capacitor is opened and can be separated from the load.

Also, the terminal unit 140 may be electrically connected to a hot line (L). The terminal unit 140 may mediate the hot line (L) so that the capacitor of the capacitor bank 150 is connected to the hot line (L). The hot line L may be a path through which current generated by electric power flows.

Also, the terminal unit 140 may be electrically connected to a ground line (G) and/or a neutral line (N). The terminal unit 140 may intermediate the ground line (G) and the neutral line (N) so that the capacitor of the capacitor bank 150 is connected to the ground line (G) and/or the neutral line (N). Alternatively, the ground wire (G) may be directly connected to the controller 130 and the neutral wire (N) may be directly connected to the terminal unit 140 .

The capacitor bank 150 may include at least one capacitor therein. The capacitor bank 150 may block electrical contact with the outside by casing at least one capacitor. The capacitor bank 150 may include a positive electrode electrically connecting an internal capacitor and an external terminal. The capacitor bank 150 may include a negative terminal connected to a ground wire or a neutral wire.

The display unit 170 may display information to the user. The display unit 170 may receive image data generated to display information from the controller 130 and display the image data on the screen. The information displayed by the display unit 170 includes the operation input through the input unit 110, the current power factor, the current active power, the current reactive power, the current status of the closed or opened capacitor, the current voltage, and the current current. and a current reduction rate.

4 is a diagram illustrating a connection between a terminal unit and a capacitor bank according to an exemplary embodiment.

Referring to FIG. 4, the terminal unit 140 includes a plurality of capacitor terminals 1 to 8 connected to a plurality of capacitors included in the capacitor bank 150, a neutral terminal connected to a neutral wire N, and a neutral terminal connected to the ground wire N'. It may include a ground terminal (not shown), and a three-phase terminal L' connected to the hot line L. The terminal unit 140 receives the terminal setting value from the condenser setting unit, and terminals according to the terminal setting value. The terminal setting value may include a capacitor setting value for selecting at least one of the plurality of capacitor terminals 1 to 8.

One of the capacitor terminals (1, 8) at both ends can be connected to the neutral wire (N) through the neutral terminal (N'). The other can be connected to the hot line (L) through the three-phase terminal (L'.

The plurality of capacitor banks 150-1 to 150-4 may include at least one or more capacitors 201 to 205 therein. In general, one capacitor may be included, but two or more capacitors may be included.

At least some of the plurality of capacitor terminals 2 to 6 may be electrically connected to the plurality of capacitor banks 150-1 to 150-4. At least some of the plurality of capacitor terminals 2 to 6 and the plurality of capacitor banks 150-1 to 150-4 may be connected one-to-one. The condenser banks 150-1 to 150-3 that encase one condenser may be connected to the condenser terminal one-to-one. The capacitor bank 150-4 casing two or more capacitors may be connected to two or more capacitor terminals. Each of the capacitor banks 150-1 to 150-4 may include a positive terminal connected to the capacitor terminal and a negative terminal connected to the neutral terminal (N'). The number of positive terminals depends on the number of capacitors included therein. can match

5 is a flowchart illustrating an operation of a power control device according to an exemplary embodiment.

Referring to FIG. 5 , a method of controlling reactive power by a power control device by closing or opening a capacitor is shown.

The power control device may receive the target power factor through the receiver (step S501). When the power control device receives a user's manipulation including the target power factor through the input unit, the receiving unit may convert the target power factor into digital data and transmit the digital data to the control unit.

The power control device may calculate the current capacity through the capacitor capacity calculator (step S503). Further, the power controller may calculate the first capacity, which is the capacitor capacity required to achieve the first power factor, which is the target power factor, from the current capacity through the capacitor capacity calculator (step S505).

The power control device may input or open the capacitor according to the first capacity through the capacitor setting unit (step S507).

The power control device may monitor the change in the power factor of the load through the monitoring unit (step S509).

If there is no change in the power factor, the power control device may repeat monitoring for the change in the power factor of the load (NO in step S511). If there is a change in the power factor, the power control device may calculate a new capacitor capacity to return to the compensated power factor through the capacitor capacity calculator (step S513). For example, when the power factor of the load changes from the first power factor to the second power factor, the capacitor capacity calculator may calculate the second capacity required for the power factor of the load to change from the second power factor to the first power factor.

The power control device may input or open the capacitor through the capacitor setting unit (step S515). For example, the power control device may open one of a plurality of capacitors included in the capacitor bank. The power control device may determine whether the power factor of the load changes from the second power factor to the first power factor, and open the other capacitors one by one until the power factor of the load changes from the second power factor to the first power factor.

6 is a first diagram illustrating an actually manufactured power control device according to an embodiment.

Referring to FIG. 6, real objects of a neutral wire (N), a hot line (L), and a ground wire (G) connected to the power control device are shown. The neutral line (N), hot line (L), and ground line (G) coming from the outside can pass through the housing of the power control device and lead to the terminal unit (140 in FIG. 1) (see 610 in FIG. 6).

7 is a second diagram illustrating an actually manufactured power control device according to an embodiment.

Referring to FIG. 7 , a real object of the display unit ( 170 in FIG. 1 ) included in the power control device appears. The display unit ( 170 in FIG. 1 ) may be installed on the outer wall of the housing of the power control device so that the user can view information (see 710 in FIG. 7 ). The displayed information may include user's operation, current power factor, current active power, current reactive power, current input or open capacitor status, current voltage, current current, and current reduction rate.

For reference, a plurality of power control devices may be implemented. Each power control device is connected to different loads and can adjust the closing and opening of each capacitor bank to detect and compensate for reactive power and power factor. In this drawing, it is composed of three power control devices, and three display units corresponding to each power control device may be installed.

8 is a third diagram illustrating an actually manufactured power control device according to an embodiment.

Referring to FIG. 8 , the actual terminal unit 140 included in the power control device is shown. The terminal unit 140 may be implemented on a PCB. One end of the plurality of condenser terminals (1 to 8) may be connected to the neutral terminal (N' and the neutral line (N). The other end of the plurality of condenser terminals (1 to 8) is connected to the 3-phase terminal (L' and the hot line ( L) Among the plurality of condenser terminals (1 to 8), six of them can be connected to the condenser bank.

The protection scope of the present invention is not limited to the description and expression of the embodiments explicitly described above. In addition, it is added once again that the protection scope of the present invention cannot be limited due to obvious changes or substitutions in the technical field to which the present invention belongs.

Power control device 100 input unit 110
Receiving unit 120 Control unit 130
Terminal part 140 Condenser bank 150
Monitoring unit 160 Display unit 170
Condenser capacity calculation unit (131)
Condenser setting unit (132)
Multiple capacitor banks (150-1 to 150-4)
Condenser (201~205)

Claims (2)

In a power control device including a capacitor connected to a load, the load includes an inductive load and changes to have a lagging power factor or a leading power factor according to a change in the inductive load,
a receiving unit receiving a first power factor having a value of 1 as a target power factor;
A capacitor bank including a plurality of capacitors;
Setting the power factor of the load to be close to the first power factor through the closing or opening of at least one of the plurality of capacitors, calculating the current capacity, which is the capacity of the currently closed capacitor, and achieving the first power factor from the current capacity a control unit including a capacitor capacity calculation unit that calculates a first capacity, which is the capacity of a capacitor to be input for the purpose, and a capacitor setting unit that inputs at least one of the plurality of capacitors according to the first capacity;
a monitoring unit that monitors a change in the power factor of the load and monitors a change in the power factor of the load from the first power factor to a leading second power factor as the inductive load decreases;
Combination value serving as a criterion for selecting at least one of the plurality of capacitors when the capacitor bank does not have a capacitor corresponding to the second capacitance, which is the capacitor capacitance to be opened, to achieve the first power factor again from the second power factor. a storage unit previously stored by the user; and
A plurality of capacitor terminals connected to the plurality of capacitors included in the capacitor bank, a neutral terminal connected to a neutral line, a ground terminal connected to an earth line, and three connected to a hot line. Including an upper end, including a terminal part controlled by the condenser setting unit,
The capacitor capacity calculation unit calculates the second capacity when the power factor of the load changes from the first power factor to the second power factor;
The capacitor setting unit selects and inserts at least one of the plurality of capacitors according to the order input in advance by the user when there is no capacitor corresponding to the first capacity in the capacitor bank, and inserts the capacitor corresponding to the second capacity. If is not in the capacitor bank, selects and opens at least one of the plurality of capacitors according to the combination value,
The combination value includes a capacity obtained by combining capacities of two or more capacitors among the plurality of capacitors and information on one or two or more capacitors necessary for the combination among the plurality of capacitors,
The terminal unit receives a terminal setting value from the capacitor setting unit - the terminal setting value selects at least one of the plurality of capacitor terminals - and turns on or turns off the terminal according to the terminal setting value,
One of both ends of the plurality of condenser terminals is connected to the neutral wire through the neutral terminal, and the other is connected to the hot line through the three-phase terminal,
Terminals other than both ends of the plurality of condenser terminals are connected one-to-one with the first to third condenser banks casing one condenser, and the fourth condenser bank casing two or more condensers is connected through two or more condenser terminals, ,
The first to fourth capacitor banks have a positive terminal connected to any one of the plurality of capacitor terminals - the positive terminal corresponds to the number of capacitors included in the first to fourth capacitor banks - and a negative terminal connected to the neutral terminal. including,
The capacitor capacity calculation unit includes a microprocessor,
The microprocessor calculates reactive power corresponding to a power factor, and calculates the first capacity and the second capacity according to the reactive power,
An input unit for receiving an operation for the power control device from a user and transmitting it to the receiving unit;
The power control device of claim 1 , wherein the receiving unit converts an operation by the user into digital data and transmits the digital data to the control unit. According to claim 1,
The input unit is a power control device that receives an operation for monitoring power factor, active power, reactive power, power factor, and closing or opening a capacitor.

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