KR20210051407A - Method for controlling power factor using energy storage system and apparatus thereof - Google Patents

Abstract

The present invention relates to a method for controlling a power factor at a network connection point, which comprises the following steps of: obtaining current time information in order to initiate control of a power factor at a network connection point; receiving information on power measurement at the network connection point from a power measuring device installed at the network connection point; calculating an instantaneous reactive power limit which reflects the characteristics of a power factor charge, based on the current time information and the information on power measurement; and calculating an instantaneous reactive power compensation at the network connection point, based on the instantaneous reactive power limit. According to the present invention, reactive power at the network connection point can be instantaneously compensated by using an energy storage system, thereby minimizing a power factor charge to general customers.

Description

Power factor control method using an energy storage device and its device {METHOD FOR CONTROLLING POWER FACTOR USING ENERGY STORAGE SYSTEM AND APPARATUS THEREOF}

The present invention relates to a power factor control method and an apparatus for controlling the power factor of a system connection point, and more particularly, to a power factor control method and apparatus based on an energy storage device reflecting power factor rate characteristics.

Currently, the amount of electricity used is increasing, but there is a limit to increasing the amount of power generation due to environmental issues. In order to solve this problem, the development of efficient power use and demand response is emerging as an important problem.

Demand management refers to reducing customer electricity bills by using a device capable of storing electricity. Electricity rates are composed of basic rates, electricity rates, and power factor rates. Therefore, in order to reduce the electric charge of the customer, it is necessary to reduce the power factor charge as well as the basic charge and the wattage charge.

The power factor (PF) refers to the ratio of the power supplied to the customer and the power actually used, and is used as an index of power use efficiency. Since improving the power factor improves energy efficiency, the country has applied various systems such as the KEPCO's power factor rate system and the Ministry of Land, Infrastructure and Transport's building energy efficiency rating certification system to induce power factor improvement on the power consumer side.

고전압으로 전기를 공급받는 일반용전력, 교육용전력, 산업용전력, 농사용전력, 임시전력 고객은 모두 역률을 일정 수치 이상으로 유지할 의무가 있으며 이를 위반할 시에는 역률 요금을 부과하도록 규정하고 있다.For example, in Chapter 5 of the Korea Electric Power Corporation's Electricity Supply Agreement,'Cooperation through Electricity Use' shows the contents of the power factor. A watt-hour meter that can measure reactive power is installed η General power, industrial power, agricultural power, temporary power, contract power of 20 kW or more,

General power, educational power, industrial power, agricultural power, and temporary power customers who receive electricity at high voltages are all obligated to maintain the power factor above a certain value, and in case of violating this, a power factor fee is stipulated.

In order to improve the power factor, there is a capacitor bank method as a power factor compensation method currently used in industrial sites. The capacitor bank method is a method of installing a plurality of capacitors in parallel in a circuit and then selectively injecting them according to the load. On the other hand, general customers use a method of adjusting the power factor by opening and closing the capacitor depending on the day and night. However, these power factor control methods have a problem that they do not reflect the characteristics of the power factor charge imposed by KEPCO.

It is an object of the present invention to solve the above and other problems. Another object is to provide a power factor control method and apparatus capable of minimizing power factor charges at general customers by instantaneously compensating for reactive power at a grid connection point through an energy storage device.

According to an aspect of the present invention in order to achieve the above or other objects, the steps of acquiring current time information for initiating power factor control at a grid connection point; Receiving power measurement information at the system connection point from a power measurement device installed at the system connection point; Calculating an instantaneous reactive power limit value reflecting a power factor rate characteristic based on the current time information and the power measurement information; And calculating an instantaneous reactive power compensation value at the system connection point based on the instantaneous reactive power limit value.

According to another aspect of the present invention, there is provided a basic information acquisition unit for acquiring current time information for initiating power factor control at a system linkage point; A measurement information collection unit for collecting power measurement information at the system connection point from the power measurement device installed at the system connection point; A power factor control calculator configured to calculate an instantaneous reactive power compensation value at the system connection point reflecting the power factor rate characteristic based on the current time information and the power measurement information; And a reactive power compensation unit for transmitting a control signal including information on the instantaneous reactive power compensation value to an energy storage device.

According to another aspect of the present invention, the process of acquiring current time information for initiating power factor control at a system linkage point; Receiving power measurement information at the system connection point from a power measurement device installed at the system connection point; Calculating an instantaneous reactive power limit value reflecting a power factor rate characteristic based on the current time information and the power measurement information; And a computer program stored in a computer-readable recording medium so that the process of calculating an instantaneous reactive power compensation value at the system connection point based on the instantaneous reactive power limit value is sequentially performed on the computer.

A power factor control method according to embodiments of the present invention and effects of the apparatus will be described as follows.

According to at least one of the embodiments of the present invention, there is an advantage in that the power factor charge at general customers can be minimized by temporarily compensating for reactive power at a system connection point through an energy storage device.

According to at least one of the embodiments of the present invention, based on the currently implemented power factor rate, the amount of reactive power compensation is minimized while satisfying the corresponding standard in the long term, thereby reducing the electricity bill of general customers and effectively compensating the power factor of nearby systems. It has the advantage of reducing the cost burden for power supply facilities.

However, the power factor control method according to the embodiments of the present invention and the effects that can be achieved by the apparatus are not limited to those mentioned above, and other effects not mentioned are from the following description in the technical field to which the present invention belongs. It will be clearly understood by those of ordinary skill.

1 is a view schematically showing the configuration of a customer power system according to an embodiment of the present invention;
2 is a flow chart illustrating a power factor control method according to an embodiment of the present invention;
3 is a diagram referred to for explaining a maximum reactive power accumulation limit value used in a power factor control technique;
4 is a diagram referred to for explaining a reactive power limit value for each unit time used in a power factor control technique;
5 is a diagram referred to for explaining an instantaneous reactive power limit value used in a power factor control technique;
6 is a view showing the configuration of a power factor control device according to an embodiment of the present invention.

Hereinafter, exemplary embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but identical or similar elements are denoted by the same reference numerals regardless of reference numerals, and redundant descriptions thereof will be omitted. The suffixes "module" and "unit" for constituent elements used in the following description are given or used interchangeably in consideration of only the ease of writing the specification, and do not themselves have a distinct meaning or role from each other. That is, the term'unit' used in the present invention means a hardware component such as software, FPGA, or ASIC, and the'unit' performs certain roles. However,'part' is not limited to software or hardware. The'unit' may be configured to be in an addressable storage medium or may be configured to reproduce one or more processors. Thus, as an example,'unit' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, Includes subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, database, data structures, tables, arrays and variables. The functions provided in the components and'units' may be combined into a smaller number of components and'units', or may be further divided into additional components and'units'.

In addition, in describing the embodiments disclosed in the present specification, when it is determined that a detailed description of related known technologies may obscure the subject matter of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are for easy understanding of the embodiments disclosed in the present specification, and the technical idea disclosed in the present specification is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention It should be understood to include equivalents or substitutes.

The present invention proposes a power factor control method and apparatus capable of minimizing a power factor charge at a general customer by instantly compensating for reactive power at a system connection point through an energy storage device. In the following specification, the present invention relates to general power, industrial power, agricultural power, temporary power, industrial power, agricultural power, and temporary contract power of 20 kW or more connected to a power system equipped with a power meter capable of measuring reactive power specified in Article 43, Paragraph 1 of the Electricity Supply Agreement of It is assumed that it is applied to general power, educational power, industrial power, agricultural power, and temporary power customers who receive electricity with electric power or high voltage.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the drawings.

1 is a diagram schematically showing the configuration of a customer power system according to an embodiment of the present invention.

Referring to Figure 1, the customer power system 100 according to an embodiment of the present invention is installed in the power load 120 connected to the power system 110, the system connection point (Point of Common Coupling, PCC, 115) The energy storage device 130, the power measurement device 140 installed at the system connection point (PCC, 115), the energy storage device 130, and the power factor control device 150 communicating with the power measurement device 140 Includes.

The power load 120 is a load located in a general customer, and may be any electronic device that consumes power supplied from an upper power system through a system connection point (PCC, 115).

Energy Storage System (ESS, 130) refers to any device that stores power and makes it available when needed. In general, the energy storage device 130 may perform a function of minimizing the demand for expensive peak power by storing power in a time period other than the power use peak time period and using the stored power in the power use peak time period. .

In particular, the energy storage device 130 used in the present embodiment is a device capable of charging/discharging reactive power, and performing the charging/discharging operation of reactive power instantaneously according to the command of the power factor control device 150. I can. In this case, the energy storage device 130 may be installed at the system connection point (PCC) 115 to compensate for reactive power for power factor control at the system connection point (PCC) 115.

The most representative example of such an energy storage device is a battery-based energy storage system (BESS). Hereinafter, in the present specification, the energy storage device 130 may be referred to as a “reactive power charging/discharging device”.

The power measurement device 140 is installed at the system connection point (PCC, 115) of the power system 100, and is supplied to the customer through the system connection point (PCC, 115), the amount of active power (P), the amount of reactive power (Q) and power factor (PF) can be measured. The power measurement device 140 may provide power measurement information measured at the system connection point (PCC) 115 to the power factor control device 150.

The power factor control device 150 is connected to the power measuring device 140 and the energy storage device 130 through a communication line 160 to perform wired communication with the power measuring device 140 and the energy storage device 130. I can. Meanwhile, as another embodiment, the power factor control device 150 may perform wireless communication with the power measurement device 140 and the energy storage device 130 without a separate communication line connection.

The power factor control device 150 may receive power measurement information measured at the system connection point (PCC) 115 from the power measurement device 140. Here, the power measurement information may include active power (P) information, reactive power (Q) information, and power factor (PF) information.

The power factor control device 150 may determine a reactive power command value for power factor control of a customer based on the power measurement information received from the power measurement device 140. The power factor control device 150 may transmit a reactive power command value for power factor control to the energy storage device 130.

On the other hand, the power factor control device 150 according to the present invention determines a reactive power command value by reflecting the power factor rate characteristics prescribed by a power company (eg, Korea Electric Power Corporation), and based on the reactive power command value, the energy storage device 130 By controlling the operation of ), the power factor of the customer can be effectively managed.

고전압으로 전기를 공급받는 일반용전력, 교육용전력, 산업용전력, 농사용전력, 임시전력 고객은 모두 역률을 일정 수치 이상으로 유지할 의무가 있으며 이를 위반할 시에는 역률 요금을 부과하도록 규정되어있다.The characteristics of the power factor rate currently regulated by KEPCO are as follows. In Chapter 5 of the Korea Electric Power Corporation's electricity supply agreement,'Cooperation in the use of electricity' shows the contents of the power factor. A watt-hour meter that can measure reactive power is installed η General power, industrial power, agricultural power, temporary power, contract power of 20 kW or more,

Consumers of general power, educational power, industrial power, agricultural power, and temporary power who receive electricity at high voltage are all obligated to maintain the power factor above a certain value, and in case of violating this, a power factor fee is stipulated.

In addition, ① customers who have an watt-hour meter that can measure reactive power calculate the power factor by using the watt-hour meter as a cumulative metering value in units of 30 minutes. It is prescribed to calculate the power factor with the accumulated measurement value for 1 month. In the present invention, the method of calculating the power factor corresponding to the former is followed, and accordingly, the target of the present invention also targets customers with a watt hour meter capable of measuring reactive power.

According to KEPCO's electricity supply terms and conditions, the addition and reduction of power factor charges apply different standards depending on the daytime and nighttime. First, the addition or reduction of the charge according to the power factor during the daytime (from 09:00 to 23:00) is applied to the ground power factor. In this case, if the average power factor is less than 90%, add 0.2% of the basic charge for every 1% up to 60% below the power factor, and if the average power factor exceeds 90%, every 1 that exceeds 95% power factor. Decrease 0.2% of the basic rate per %. Here, the average power factor is calculated by averaging the power factor in units of 30 minutes for 1 month. However, if the power factor in units of 30 minutes is less than 60% of the ground power factor, it is regarded as 60%, and when the power factor exceeds 95%, it is regarded as 95%, and the average power factor for one month is calculated.

On the other hand, the addition or reduction of the charge according to the power factor in the night time (from 23:00 to 09:00 the next day) is applied to the true power factor. In this case, there is no separate reduction rule, and if the average power factor is less than 95%, 0.2% of the basic charge is added for every 1% that is not reached. Similarly, the average power factor is calculated by averaging the power factor in units of 30 minutes for 1 month. However, if the power factor in units of 30 minutes is less than the true power factor of 60%, the power factor is regarded as 60%, and in the case of the ground power factor, the power factor is regarded as 100% and the average power factor for one month is calculated.

To summarize the above, the power factor calculated by the cumulative weighing value of 30 minutes during the day time (from 09:00 to 23:00) is maintained at 90% or more above the ground through the power factor control for each unit time, and at night time (from 23:00). The power factor fee is not charged if the power factor calculated by the cumulative measurement value in 30-minute increments is maintained above 95%. However, since the average power factor for one month is used to calculate the power factor rate, the power factor of the customer can be controlled while minimizing the amount of charging/discharging of reactive power if calculated by reflecting the change in the power factor for one month to the power factor reference value of the unit time. .

In accordance with these power factor rate characteristics, the power factor control technique used in the power factor control device 150 according to the present invention is to satisfy the average power factor for a month within the power factor maintenance criteria so that the power factor rate is not charged. It is a method of deriving the optimal reactive power charging/discharging command value for power factor control instantaneously by changing the power factor reference value for each unit time. Such a power factor control technique can be effectively applied when an energy storage device (ESS) capable of charging/discharging reactive power has already been constructed, when the reactive power load fluctuates severely or when precise power factor control is required. Hereinafter, a power factor control technique used in the power factor control apparatus 150 according to the present invention will be described in detail.

2 is a flowchart illustrating a power factor control method according to an embodiment of the present invention.

Referring to FIG. 2, the power factor control device 150 according to the present invention includes information on a system linkage point (PCC, 115) subject to power factor control, and current date information according to a power factor control start command from a system operator. And time information, etc. may be obtained (S210). In this case, the information may be input from the system operator, but is not limited thereto. On the other hand, depending on the embodiment, information on the system connection point (PCC, 115) may be omitted.

_{The power factor control device 150 is a voltage, current, instantaneous active power (P pcc} ), instantaneous reactive power at the grid linking point (PCC, 115) from the power measuring device 140 installed at the grid linking point (PCC, 115). Information about (Q _pcc ) and power factor (PF _i ) may be received (S220).

Based on the current time information, the power factor control device 150 checks whether the current power factor rate time zone is a day time zone (from 09:00 to 23:00) or a night time zone (from 23:00 to 09:00 the next day) ( S230). This is because the power factor charge in the daytime is applied to the ground power factor, and the power factor charge in the night time is applied to the true power factor.

Check the results of the 230 phase, the no if the current power factor charge time is daytime, the power factor controller 150 is to set an absolute value for the instantaneous reactive power (Q _pcc), the instantaneous reactive power (Q _pcc) Based on this, the instantaneous reactive power compensation value is calculated.

On the other hand, as a result of the confirmation in step 230, when the current power factor rate time zone is the night time zone, the power factor control device 150 _{sets an absolute value for instantaneous reactive power Q pcc} , and the instantaneous reactive power in which the absolute value is set. An instantaneous reactive power compensation value is calculated based _on (Q pcc) (S240). That is, in the case of the leading power factor, the instantaneous reactive power Q _pcc is negative, so the absolute value is taken to calculate the instantaneous reactive power compensation value.

Hereinafter, for convenience of description, a case in which the current power factor rate time zone is a day time zone will be described.

The power factor control device 150 averages 30 minutes based _{on information about the power factor average (PF month ) in units of 30 minutes for a month and the power factor average (PF now} ) in units of 30 minutes up to the current time (time point). The power factor reference value (PF _{limit_30} ) may be calculated (S250).

The power factor control device 150 may calculate a _{power factor average (PF month} ) in units of 30 minutes for a month using Equation 1 below. This is because the power factor for calculating the power factor rate is determined as the monthly average value of the calculated power factor by measuring active/reactive power in units of 30 minutes.

Here, PF _i is the power factor calculated by the cumulative weighing value of 30 minutes, and N is the number of 30 minute intervals from 09:00 to 23:00 for a month. For example, N for a month with 30 days in a month is 28*30=840, and N for a month with 31 days is 28*31=868. Hereinafter, in the present embodiment, for convenience of description, it is assumed that one month is 30 days.

If the power factor average (PF _month ) in units of 30 minutes for a month is predetermined (for example, PF _month = 0.9), the power factor control device 150 uses Equation 2 below to calculate the value for one month from the current time when the K-th time has elapsed. It is possible to calculate _{the average power factor reference value (PF limit_30} ) in 30-minute increments that must be maintained until the end of this operation.

Here, PF _{limit_30} is the average power factor in units of 30 minutes to be maintained from the current time, PF _now is the average of the power factor in units of 30 minutes from the initial (initial) time to the current time, and PF _month is the power factor in units of 30 minutes for a month. It is the average, and K is the number of elapsed time in 30 minutes from the start time to the current time.

The power factor control device 150 may calculate an instantaneous reactive power limit value Q _{inst based on information on the average power factor reference value PF limit_30 in} units of 30 minutes (S260).

First, the average power factor (PF ₃₀ ) within 30 minutes is calculated as a short-circuited active power and a reactive power, as shown in Equation 3 below.

Here, PF ₃₀ is the average power factor calculated as the cumulative metered value within 30 minutes, P _{sum_30} is the cumulative amount of active power within 30 minutes, and Q _{sum_30} is the cumulative amount of reactive power within 30 minutes.

Since the average power factor (PF ₃₀ ) within 30 minutes must be maintained higher than the average power factor reference value (PF _{limit_30} ) derived in 30 minutes, the power factor control device 150 uses the following Equation 4 to determine the current time within the 30 minute interval. The maximum reactive power accumulation limit (Q _{sum_limit} ) at (T _now ) can be calculated. That is, the power factor control device 150 is based on the cumulative amount of active power up to the current time (P _sum ) in the 30-minute section and the average power factor reference value (PF _{limit_30} ) in 30-minute intervals at the current time (T _now ) within the 30-minute section. The maximum reactive power accumulation limit (Q _{sum_limit} ) can be calculated.

Here, P _pcc is the instantaneous active power, P _sum is the cumulative amount of active power up to the current time in the 30-minute interval, Q _pcc is the instantaneous reactive power, and Q _sum is the cumulative amount of reactive power up to the present time in the 30-minute interval, PF _{limit_30} is the standard value of the average power factor per 30 minutes.

For example, as shown in FIG. 3, the maximum reactive power accumulation limit value (Q _{sum_limit ) at the current time (T now} ) within a 30-minute section can be calculated through Equation 4, and accordingly, within a 30-minute section. The instantaneous reactive power at the system connection point may be compensated so that the accumulated amount of reactive power at the current time T _{now does not exceed the maximum reactive power accumulation limit Q sum_limit.}

The power factor control device 150 may calculate the _{reactive power limit Q limit for each unit time using Equation 5 below.} That is, if the Q _{sum_limit} value is divided by the current time (T _now ), the reactive power limit value (Q _limit ) for each unit time can be calculated. For example, as shown in FIG. 4, the reactive power limit value Q _{limit for each} unit time is a value that varies over time.

Here, T _now is the current time within the 30 minute interval, and Q _{sum_limit} is the maximum reactive power accumulation limit at the _{current time (T now} ) within the 30 minute interval.

The power factor control device 150 may calculate an _{average reactive power value Q avg using Equation 6 below. That is, by dividing the accumulated reactive power value (Q sum} ) up to the current time by the total time (T _total ), the average reactive power value (Q _avg ) can be calculated. Likewise, as shown in FIG. 4, the average reactive power value Q _avg is a value that varies over time.

The difference between the reactive power limit value for each unit time calculated through Equation 5 (Q _limit ) and the reactive power average value (Q _avg ) calculated through Equation 6 above is the reactive power difference average value (Q _margin ). Accordingly, the average value of the reactive power difference Q _margin may be calculated as in Equation 7 below.

_{The difference between the total} time (T total) and the current time (T _now ) is the remaining time (T _rest ). Therefore, the remaining time (T _rest ) can be calculated as in Equation 8 below. For example, as shown in FIG. 4, the relationship between the _{current time T now} and the total time T _total and the remaining time T _{rest can be checked.}

)과 제2 면적에 해당하는 무효전력 누적량(

)이 동일하다는 점을 이용하여 남은 시간 동안의 순시 무효전력 제한치(Q_inst)를 계산할 수 있다.The power factor control device 150 may calculate _{an instantaneous reactive power limit value Q inst} for the remaining time from the current time by using Equation 9 below. That is, the power factor control device 150 may calculate _{an instantaneous reactive power limit value Q inst} for the remaining time based on information about the _{reactive power difference average value Q margin} . For example, as shown in FIG. 5, the accumulated amount of reactive power corresponding to the first area 510 (

) And the accumulated amount of reactive power corresponding to the second area (

Using the fact that) is the same, the instantaneous reactive power limit (Q _inst ) for the remaining time can be calculated.

Here, T _rest is the remaining time, T _total is the total time, and Q _margin is the average value of the reactive power difference.

The power factor control apparatus 150 may _{compare information on} the instantaneous reactive power Q pcc and the instantaneous reactive power limit Q _inst at the current point in time (S270).

As a result of the comparison of step 270, when the instantaneous reactive power Q _pcc at the present time is less than the instantaneous reactive power limit Q _inst , the power factor control device 150 does not need to control the power factor at the grid connection point. The process is terminated.

On the other hand, as a result of the comparison in step 270, when the instantaneous reactive power Q _pcc at the current point is greater than the instantaneous reactive power limit Q _inst , the power factor control device 150 controls the power factor using Equation 10 below. An instantaneous reactive power compensation value (Q _comp ) for may be calculated (S280). That is, the power factor control device 150 may calculate the instantaneous reactive power compensation value Q _{comp based on the information on the instantaneous reactive power limit Q inst} and the instantaneous reactive power Q pcc at the present time. .

Here, Q _pcc is the instantaneous reactive power at the present time, and Q _inst is the instantaneous reactive power limit.

The power factor control device 150 may transmit a reactive power command value (ie, a charge/discharge control signal) including information on the _{instantaneous reactive power compensation value Q comp to the energy storage device 130 (S290 ).} The energy storage device 130 receiving this may perform a charging/discharging operation according to the _{instantaneous reactive power compensation value Q comp.} If the instantaneous reactive power (Q _pcc ) at the present time is greater than the instantaneous reactive power limit (Q _inst ), the power factor is likely to be violated, so the energy storage device 130 compensates for the difference between the two and the system connection point 115 Reactive power in can be controlled.

In general, the energy storage device 130 performs a discharging operation according to the reactive power command value in the case of a day time zone, and performs a charging operation according to the reactive power command value in the night time period. Meanwhile, in the present embodiment, a method of compensating the ground power factor in the daytime period is described in detail, but the true power factor in the night time period may be compensated using the same method.

As described above, the power factor control method according to the present invention can minimize the power factor charge at a general customer by temporarily compensating for reactive power at a system connection point through an energy storage device.

6 is a diagram showing the configuration of a power factor control apparatus according to an embodiment of the present invention.

6, the power factor control apparatus 200 according to an embodiment of the present invention includes a basic information acquisition unit 210, a measurement information collection unit 220, a power factor control operation unit 230, and a reactive power compensation unit 240. ).

The basic information acquisition unit 210 may acquire information on a system linkage point (PCC, 115) subject to power factor control, current date information, time information, and the like. In this case, the basic information acquisition unit 210 may receive the corresponding information from the system operator or may automatically detect it. On the other hand, depending on the embodiment, information on the system connection point (PCC, 115) may be omitted.

_{The measurement information collection unit 220 is a voltage, current, instantaneous active power (P pcc} ), instantaneous invalidation at the system connection point (PCC, 115) from the power measurement device 140 installed at the system connection point (PCC, 115). It is possible to collect information about power (Q _pcc ) and power factor (PF _{i ).} In this case, the measurement information collection unit 220 may collect the corresponding information in a predetermined time unit (periodically).

The power factor control operation unit 230 may calculate an instantaneous reactive power compensation value for power factor control at a system linkage point based on the information received from the basic information acquisition unit 210 and the information received from the measurement information collection unit 220. have.

First, the power factor control operation unit 230 is based _{on the information on the power factor average (PF month ) in units of 30 minutes for a month and the power factor average (PF now} ) in units of 30 minutes up to the current time. (PF _{limit_30} ) can be calculated. Then, the power factor control operation unit 230 is the active power to within the current hour and 30 minutes interval accumulation (P _sum), and based on the 30 minutes, the average power factor reference value (PF _{limit_30)} per unit time by the reactive power limit value calculating (Q _limit) I can.

The power factor control operation unit 230 may calculate _{an instantaneous reactive power limit Q inst} for the remaining time from the current time based on the _{reactive power limit Q limit} and the average reactive power Q _avg for each unit time. In addition, the power factor control operation unit 230 may calculate an instantaneous reactive power compensation value Q _{comp based on the instantaneous reactive power limit value Q inst} and the instantaneous reactive power Q pcc at the present time.

_{The reactive power compensation unit 240 generates a charge/discharge control signal including information on the instantaneous reactive power compensation value Q comp} received from the power factor control operation unit 230, and generates the generated charge/discharge control signal. It can be transmitted to the energy storage device 130. Accordingly, the energy storage device 130 may perform an operation of charging/discharging reactive power to the system connection point (PCC) 115 according to the charging/discharging control signal received from the reactive power compensating unit 240.

As described above, as described above, the power factor control apparatus according to the present invention can minimize the power factor charge at a general customer by temporarily compensating for reactive power at a system connection point through an energy storage device.

The present invention described above can be implemented as a computer-readable code on a medium on which a program is recorded. The computer-readable medium includes all types of recording devices that store data that can be read by a computer system. Examples of computer-readable media include hard disk drives (HDDs), solid state disks (SSDs), silicon disk drives (SDDs), ROMs, RAM, CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, etc. There is this. Therefore, the detailed description above should not be construed as restrictive in all respects and should be considered as illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

100: customer power system 110: power system
120: power load 130: energy storage device
140: power measuring device 150/200: power factor control device
210: basic information acquisition unit 220: measurement information collection unit
230: power factor control operation unit 240: reactive power compensation unit

Claims (10)

Acquiring current time information for initiating power factor control at the grid connection point;
Receiving power measurement information at the system connection point from a power measurement device installed at the system connection point;
Calculating an instantaneous reactive power limit value reflecting a power factor rate characteristic based on the current time information and the power measurement information; And
And calculating an instantaneous reactive power compensation value at the system connection point based on the instantaneous reactive power limit value. The method of claim 1,
The power measurement information includes at least one of voltage, current, instantaneous active power, instantaneous reactive power, and power factor at the system connection point. The method of claim 1,
And determining whether a current power factor rate time zone is a day time zone or a night time zone based on the current time information. The method of claim 1, wherein the calculating the instantaneous reactive power limit value comprises:
Calculating an average power factor reference value in a predetermined time unit;
Calculating a reactive power limit value for each unit time based on the average power factor reference value; And
And calculating the instantaneous reactive power limit value based on the reactive power limit value and the reactive power average value for each unit time. The method of claim 4,
The power factor control method, characterized in that the average power factor reference value (PF _{limit_t) of the predetermined time unit is calculated through the following equation.}
[Equation]

Here, PF _{limit_t} is the average power factor reference value in a predetermined time unit (t) that must be maintained from the current time, PF _now is the average power factor in a predetermined time unit (t) from the initial calculation time to the current time, and PF _month is one. It is the power factor average of the predetermined time unit (t) over the month, and K is the number of elapsed time in the predetermined time unit (t) from the start time to the current time. The method of claim 1,
The power factor control method, characterized in that the instantaneous reactive power limit is calculated through the following equation.
[Equation]

Here, T _rest is the remaining time, T _total is the total time, and Q _margin is the difference between the reactive power average value from the reactive power limit value per unit time. The method of claim 1,
The instantaneous reactive power compensation value is a power factor control method, characterized in that calculated through the following equation.
[Equation]

Here, Q _pcc is the instantaneous reactive power at the present time, and Q _inst is the instantaneous reactive power limit. The method of claim 1,
And transmitting a control signal including information on the instantaneous reactive power compensation value to an energy storage device. A computer program stored in a computer-readable recording medium such that the method according to any one of claims 1 to 8 is performed on a computer. A basic information acquisition unit that acquires current time information for initiating power factor control at the system connection point;
A measurement information collection unit for collecting power measurement information at the system connection point from the power measurement device installed at the system connection point;
A power factor control calculator configured to calculate an instantaneous reactive power compensation value at the system connection point reflecting the power factor rate characteristic based on the current time information and the power measurement information; And
Power factor control device comprising a reactive power compensation unit for transmitting a control signal including information on the instantaneous reactive power compensation value to the energy storage device.

Images