EP1944559A1

EP1944559A1 - Apparatus for setting Indoor snit groups of multi system air conditioner and method thereof

Info

Publication number: EP1944559A1
Application number: EP07109188A
Authority: EP
Inventors: Se Gee No. 404-1202 Chon
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2007-01-12
Filing date: 2007-05-30
Publication date: 2008-07-16
Also published as: KR20080066489A; CN101220984A; JP2008170141A

Abstract

There are provided an apparatus for grouping indoor units of a system air conditioner and a method thereof that are capable of setting the driving groups of the indoor units such that a cooling system is effectively operated without exceeding the peak value of power. A method of setting the groups of the system air conditioner having the plurality of indoor units includes the steps of extracting an amount of power observed from the plurality of indoor units during a predetermined period of time and grouping the plurality of indoor units such that a sum of an amount of power does not exceed a predetermined peak value of power based on data related to the extracted amount of power.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 2007-3980, filed on January 12, 2007 , in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates generally to a method of grouping the indoor units of a system air conditioner, and more particularly to an apparatus for setting the indoor unit groups of a system air conditioner, in which the driving groups of indoor units are set such that a cooling system can be effectively operated without exceeding the peak of power and a method thereof.

2. Description of the Prior Art

In general, an air conditioner is an apparatus used for cooling or warming a room. The air conditioner performs the cooling or warming operation by circulating a refrigerant between an indoor unit and an outdoor unit to absorb heat around the refrigerant when the liquid refrigerant is evaporated and to emit the heat when the refrigerant is liquefied.
In an air conditioner, one indoor unit is commonly provided in one outdoor unit. However, recently, user needs have increased for a multi system air conditioner that performs cooling or warming driving on a place in which a plurality of separated spaces exist like a school, a company, or a hospital by connecting a plurality of indoor units having various shapes and capacities to one or more outdoor units.
Since such a system air conditioner consumes a large amount of power, a consumer who installs the system air conditioner receives contract demand power from Korea Electric Power Corporation, an electric company, to drive various equipments (for example, a system air conditioner) in order to manage power. At this time, Korea Electric Power Corporation performs remote metering on main meters to grasp the amount of power consumption of each consumer. When the average amount of power consumption exceeds the amount of power determined by a contract in seasons (for example, from June to August) where the amount of power consumption significantly increases, an extra charge is imposed.
In order to prevent the extra charge from being imposed, the system air conditioner controls the peak of the amount of power so that the amount of power consumption of air conditioners does not exceed the amount of the contract demand power at the time zones where there is a large amount of power consumption. In order to control the peak of the amount of power, indoor units are effectively grouped to be driven.
The system air conditioner in which indoor units are grouped to be driven is disclosed in the Korean Publication No. 10-0531083 .
The system air conditioner disclosed in the above publication measures the power consumption of the entire load of a consumer who consumes power to perform control so that the power consumption of partial circulation groups among a plurality of circulation groups classified by an indoor unit is reduced and that the partial circulation groups are periodically changed into the remaining circulation groups when it is expected that the average amount of power consumption of the entire load to be consumed for a reference time exceeds the amount of reference power consumption to guarantee the effect of a cooling and warming system and to control the amount of power consumption of the consumer.
However, when controlling the peak power of the conventional system air conditioner, since a manager manually groups indoor units according to basic statistical values or intuition in consideration of the cooling and warming characteristics and various factors of the spaces in which the indoor units are arranged, in the case where the power consumption of the indoor units that belong to the same group is higher than the power consumption of the indoor units that belong the other groups on the average, when the group is driven, the power consumption may exceed the initially stipulated amount of power. In the case of a complicated system air conditioner, such a situation may be readily realized. Also, when the number of indoor units is no more than several hundreds and thousands, it is difficult for the manager to determine groups to assign the indoor units.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made to solve above-mentioned problems occurring in the prior art, and an object of the present invention is to provide an apparatus for setting the indoor unit groups of a system air conditioner capable of grouping indoor units, such that the sum of the amount of power does not exceed the peak value of power based on the amount of power obtained from the indoor units during a predetermined period of time and a method thereof.
Another object of the present invention is to provide an apparatus for setting the indoor unit groups of a system air conditioner capable of statically optimizing the amount of power consumption of the indoor units to manage the amount of power consumption of the indoor units such that a cooling system can be effectively operated without exceeding the initially stipulated amount of power and a method thereof.
In order to accomplish these objects, the present invention provides a method of setting groups of a system air conditioner having a plurality of indoor units, in which the method includes the steps of extracting an amount of power observed from the plurality of indoor units during a predetermined period of time and grouping the plurality of indoor units such that a sum of the amount of power does not exceed a predetermined peak value based on data related to extracted amount of power.
In extracting the amount of power from the plurality of indoor units, the amount of power periodically observed for a predetermined period of time from the plurality of indoor units is extracted.
In periodically extracting the amount of power, the amount of power is extracted from each indoor unit every time period obtained by dividing a predetermined time zone in which the amount of power consumption is large by a predetermined constant value (k).
The constant value (k) is the number of data required for obtaining Euclidean distance statistic values, in which the number corresponds to about 10 to 15.
The method further includes calculating the Euclidean distance statistic values between indoor units using the data on the amount of power periodically extracted with the lapse of time.
In calculating the Euclidean distance statistic values, the data on the amount of power periodically extracted with the lapse of time are substituted for the following Euclidean function [EQUATION 1] to calculate the amounts of power that are the distance statistic values between the indoor units. $\sum_{i - 1}^{k} (P_{ji} - P_{ii}), j \neq 1, 1 \leq j \leq n, 1 \leq l \leq n$
The method further includes arraying the calculated Euclidean distance statistic values in an ascending order and, in grouping the plurality of indoor units, the indoor units corresponding to the distance statistic values are grouped in one group so that the sum of the distance statistic values combined with each other in a group does not exceed a predetermined amount of peak power.
In combining the arrayed distance statistic values with each other in a group in the order of large values and small values, the distance statistic values are combined with each other in the group in the order of the first maximum value and the first minimum value, the second maximum value and the second minimum value except for the first maximum value and the first minimum value, and the third maximum value and the third minimum value except for the first and second maximum values and the first and second minimum values.
In grouping the plurality of indoor units, the sum of the combined distance statistic values is operated whenever the distance statistic values are combined with each other in the group to compare the operated sum of the distance statistic values with the amount of peak power and the distance statistic values are combined with each other in the group in the order of the maximum value and the minimum value until it is determined that the operated sum of the distance statistic values is smaller than the amount of peak power to group the indoor units.
An apparatus for setting groups of a system air conditioner having a plurality of indoor units includes a power amount extracting unit extracting an amount of power observed from the plurality of indoor units during a predetermined period of time and a group setting unit grouping the plurality of indoor units so that the sum of the amount of power does not exceed a predetermined amount of peak power based on the data related to the extracted amount of power.
The power amount extracting unit extracts the amount of power periodically observed from the plurality of indoor units during a predetermined period of time.
The apparatus further includes a power amount statistic unit calculating the Euclidean distance statistic values between the indoor units using data on the amount of power periodically extracted with the lapse of time.
The power amount statistic unit substitutes the data on the amount of power periodically extracted with the lapse of time for the following Euclidean function [EQUATION 1] to calculate the amounts of power that are the distance statistic values between the indoor units. $\sum_{i - 1}^{k} (P_{ji} - P_{ii}), j \neq 1, 1 \leq j \leq n, 1 \leq l \leq n$
The group setting unit combines the distance statistic values calculated by the power amount statistic unit with each other in the group in the order of large values and small values and groups the indoor units corresponding to the distance statistic values in one group so that the sum of the distance statistic values combined with each other in the group does not exceed the predetermined amount of peak power.
The group setting unit operates the sum of the combined distance statistic values whenever the distance statistic values are combined with each other in the group to compare the operated sum of the distance statistic values with the amount of peak power and combines the distance statistic values with each other in the group in order of first maximum and minimum values, second maximum and minimum values except for the first maximum and minimum values, and third maximum and minimum values except for the first and second maximum and minimum values until it is determined that the operated sum of the distance statistic values is smaller than the amount of peak power to group the indoor units.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a control block diagram of an apparatus for setting the indoor unit groups of a system air conditioner according to an embodiment of the present invention;
FIG. 2 is a block diagram for setting the indoor unit groups of a system air conditioner according to the present invention;
FIG. 3 illustrates processes of quantizing data on the amount of power observed by indoor units to cluster the data in the setting of the indoor unit groups of the system air conditioner according to the present invention; and
FIGs. 4A and 4B are flowcharts illustrating a method of setting the indoor unit groups of the system air conditioner according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a control block diagram of an apparatus for setting the indoor unit groups of a system air conditioner according to an embodiment of the present invention. A plurality of (for example, n) air conditioners 10 (hereinafter, indoor units) are provided. A demand controller 30 connected to a power line 20 of Korea Electric Power Corporation is provided in the plurality of indoor units 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n) in order to control peak power. A transmitter attached meter 40 for metering the amount of power consumption of a system air conditioner is provided between the demand controller 30 and the power line 20 to manage the amount of contract demand power by the same method as a conventional method.
Like a conventional apparatus for setting the indoor unit groups of a system air conditioner, the apparatus for setting the indoor unit groups of a system air conditioner according to the present invention is for managing the amount of contract demand power and for dynamically grouping the indoor units 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n) so that the total amount of power does not exceed the amount of peak power based on the amount of power obtained by the plurality of (n) indoor units 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n). The apparatus for setting the indoor unit groups of a system air conditioner includes a central controller 50 controlling the plurality of indoor units 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n) in the center by the command of a system manager. The central controller 50 receives the power consumption state of a system air conditioner from the demand controller 30 to generate packets controlling the plurality of indoor units 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n) and to transmit the packets to the corresponding indoor units 10.
Also, a manager input unit 60 inputting a control command for controlling the system air conditioner by the system manager and a group setting command for setting the groups of the indoor units 10 of the system air conditioner is connected to the central controller 50.
FIG. 2 is a block diagram for setting the indoor unit groups of a system air conditioner according to the present invention. In FIG. 2, the central controller 50 includes a power amount extracting unit 51 extracting power amount data obtained by the indoor units 10 for a predetermined time, a power amount storage unit 52 storing the power amount data periodically extracted by the power amount extracting unit 51 with the lapse of time, a power amount statistic unit 53 calculating Euclidean distances between the indoor units 10 using the power amount data stored in the power amount storage unit 52 to calculate power amount statistic values, a power amount arraying unit 54 arraying the Euclidean distance statistic values between the indoor units 10 that are calculated by the power amount statistic unit 53 in an ascending order, and a group setting unit 55 sequentially combining the maximum value S_t and the minimum value S₁ with each other in the distance statistic values S₁, S₂, S₃, ..., and S_t arrayed by the power amount arraying unit 54 in the ascending order to group the maximum value S_t and the minimum value S₁ sequentially combined with each other in one group (group 1, group 2, ..., and group M) until the sum of the maximum value S_t and the minimum value S₁ is smaller than a predetermined amount of peak power.
FIG. 3 illustrates processes of quantizing data on the amount of power observed by indoor units to cluster the data in the setting of the indoor unit groups of the system air conditioner according to the present invention.
In FIG. 3, the power amount extracting unit 51 divides a predetermined time zone (for example, a.m. 9 to p.m. 5) in which the amount of power consumption is large by a predetermined constant value (k; the number of data required for obtaining the Euclidean distance statistic values, about 10 to 15) to periodically extract the power amount data items (P₁₁, P₁₂, P₁₃, ..., and P_1k)(P₂₁, P₂₂, P₂₃, ..., and P_2k), ..., and (P_n1, P_n2, P_n3, ..., and P_nk) obtained by the respective indoor units 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n) every time period (about 32 to 48 minutes) and to store the power amount data (P₁₁, P₁₂, P₁₃, ..., and P_1k)(P₂₁, P₂₂, P₂₃, ..., and P_2k), ..., and (P_n1, P_n2, P_n3, ..., and P_nk) in the power amount storage unit 52.
The power amount statistic unit 53 calculates the values obtained by calculating the Euclidean distances between the indoors 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n), to be specific, between two indoor units (R₁, R₂)(R₁, R₃), ..., and (R₁, R_n), (R₂, R₁)(R₂, R₃), ..., and (R₂, R_n), ..., and (R_n-1, R_n), that is, power amount statistic values (R_1,2, R_1,3, ..., and R_1,n, R_2,1, R_2,3, ..., and R_2,n, ..., R_n-1,n) based on the power amount data (P₁₁, P₁₂, P₁₃, ..., and P_1k)(P₂₁, P₂₂, P₂₃, ..., and P_2k), ..., and (P_n1, P_n2, P_n3, ..., and P_nk) stored in the power amount storage unit 52.
The power amount statistic values (R_1,2, R_1,3, ..., and R_1,n, R_2,1, R_2,3, ..., and R_2,n, ..., R_n-1,n) calculated by the power amount statistic unit 53 are obtained by calculating the Euclidean distance statistic values between two indoor units 10 by the function of Euclidean geometry (in which all of mathematics are represented by geometry) that the straight line (the distance between two indoor units according to the present invention) that passes through two points (two indoor units according to the present invention) is single.
The power amount arraying unit 54 arrays the Euclidean distance statistic values (R_1,2, R_1,3, ..., and R_1,n, R_2,1, R_2,3, ..., and R_2,n, ..., R_n-1,n) between the indoor units 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n) that are calculated by the power amount statistic unit 53 in the ascending order (S₁, S₂, S₃, ..., and S_t). At this time, the number (t) of Euclidean distance statistic values arrayed in the ascending order is the number of cases in which the plurality of (for example, n) indoor units 10 are combined with each other by two.
The group setting unit 55 sequentially combines the maximum value S_t and the minimum value S₁ with each other in the distance statistic values arrayed by the power amount arraying unit 54 in the ascending order to group the maximum value S_t and the minimum value S₁ sequentially combined with each other in one group (the group 1, the group 2, ..., and the group M) until the sum of the maximum value S_t and the minimum value S₁ is smaller than the predetermined amount of peak power. For example, when the group 1 is grouped, the distance statistic values (S₁, S₂, S₃, ..., and S_t) arrayed in the ascending order are combined with each other in the group 1 in the order of the first maximum value S_t and the first minimum value S₁, the second maximum value S_t-1 and the second minimum value S₂ except for the first maximum value S_t and the first minimum value S₁, and the third maximum value S_t-2 and the third minimum value S₃ except for the first and second maximum value and the first and second minimum values. Whenever one distance statistic value enters the group 1, the sum of the distance statistic values that enter the group is compared with a predetermined amount of peak power so that the indoor units 10 are grouped in one group until the sum of the distance statistic values is smaller than the amount of peak power. The same indoor unit 10 can exist in different groups through such grouping.
The entire indoor units 10 are clustered to groups by repeating such a process. The system air conditioner controls the peak of the amount of power in accordance with the clustered indoor units 10. Such controlling of the peak of the amount of power operates till the next update point of time.
Hereinafter, the operating processes and effects of the apparatus for setting the indoor unit groups of the system air conditioner having the above structure and the method thereof will be described.
FIGs. 4A and 4B are flowcharts illustrating a method of setting the indoor unit groups of the system air conditioner according to the present invention.
First, when a system manager inputs a group setting command for setting the groups of the indoor units 10 through the manager input unit 60 (S100), the central controller 50 starts to drive the system air conditioner in order to optimally group the plurality of (n) indoor units 10 in accordance with the group setting command input by the manager (S102).
At this time, the power amount extracting unit 51 of the central controller 50 starts to extract the amounts of power consumption (P11, P21, ..., and Pn1) observed by the plurality of (n) indoor units 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n) (S104). The power amount extracting unit 51 divides the predetermined time zone (for example, a.m. 9 to p.m. 5) in which the amount of power consumption is large by the predetermined constant value (k; the number of data required for obtaining the Euclidean distance statistic values, about 10 to 15) to periodically extract the power amount data items (P₁₁, P₁₂, P₁₃, ..., and P_1k)(P₂₁, P₂₂, P₂₃, ..., and P_2k), ..., and (P_n1, P_n2, P_n3, ...; and P_nk) obtained by the plurality of (n) indoor units 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n) every time period (for example, a time period when 8 hours from a.m. 9 to p.m. 5 is divided by 10 to 15; about 32 to 48 minutes) and to store the power amount data (P₁₁, P₁₂, P₁₃, ..., and P_1k)(P₂₁, P₂₂, P₂₃, ..., and P_2k), ..., and (P_n1, P_n2, P_n3, ..., and P_nk) in the power amount storage unit 52.
The Euclidean distances between the indoors 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n), to be specific, between two indoor units (R₁, R₂)(R₁, R₃), ..., and (R₁, R_n), (R₂, R₁)(R₂, R₃), ..., and (R₂, R_n), ..., and (R_n-1, R_n) are calculated using the power amount data (P₁₁, P₁₂, P₁₃, ..., and P_1k)(P₂₁, P₂₂, P₂₃, ..., and P_2k), ..., and (P_n1, P_n2, P_n3, ..., and P_nk) stored in the power amount storage unit 52.
In a method of calculating the Euclidean distances between the indoor units (R₁, R₂)(R₁, R₃), ..., and (R₁, R_n), (R₂, R₁)(R₂, R₃), ..., and (R₂, R_n), ..., and (R_n-1, R_n), the power amount data (P₁₁, P₁₂, P₁₃, ..., and P_1k)(P₂₁, P₂₂, P₂₃, ..., and P_2k), ..., and (P_n1, P_n2, P_n3, ..., and P_nk) periodically extracted with the lapse of time are substituted for the following Euclidean function [EQUATION 1] to calculate the amounts of power that are the Euclidean distance statistic values (R_1,2, R_1,3, ..., and R_1,n, R_2,1, R_2,3, ..., and R_2,n, ..., R_n-1,n) between the indoor units (R₁, R₂)(R₁, R₃), ..., and (R₁, R_n), (R₂, R₁)(R₂, R₃), ..., and (R₂, R_n), ..., and (R_n-1, R_n) by the power amount statistic unit 53 (S108). $\sum_{i - 1}^{k} (P_{ji} - P_{ii}), j \neq 1, 1 \leq j \leq n, 1 \leq l \leq n$
Then, the calculated Euclidean distance statistic values (R_1,2, R_1,3, ..., and R_1,n, R_2,1, R_2,3, ..., and R_2,n, ..., R_n-1,n) between the indoor units 10 (R₁, R₂, R₃, R₄, R₅, R₆, ..., and R_n) are arrayed by the power amount arraying unit 54 in the ascending order (S₁, S₂, S₃, ..., and S_t) (S110). At this time, the number (t) of Euclidean distance statistic values (S₁, S₂, S₃, ..., and S_t) arrayed in the ascending order is the number of cases in which the plurality of (n) indoor units 10 are combined with each other by two as represented in the following [EQUATION 2]. $t = \frac{n! (n - 2)!}{2!}$
As illustrated in FIG. 3, the maximum value S_t and the minimum value S₁ in the distance statistic values (S₁, S₂, S₃, ..., and S_t) arrayed in the ascending order start to be sequentially combined with each other in one group (for example, the group 1) (S112) and the sums of the distance statistic values of the maximum value S_t and the minimum value S₁ combined with each other are operated whenever the maximum value and the minimum value in the distance statistic values (S₁, S₂, S₃, ..., and S_t) are combined with each other in the group (the group 1) (S114) to determine whether the operated sums of the distance statistic values are less than the predetermined amount of peak power (S116).
When it is determined that the sums of the distance statistic values are less than the amount of peak power, after the indoor units 10 (for example, the distance statistic values) corresponding to the distance statistic values combined in the group (the group 1) are grouped in one group (the group 1) (S118), the distance statistic values are sequentially combined with each other in one group (the group 1) in the order of the first maximum value S_t and the first minimum value S₁, the second maximum value S_t-1 and the second minimum value S₂ except for the first maximum value S_t and the first minimum value S₁, and the third maximum value S_t-2 and the third minimum value S₃ except for the first and second maximum values and the first and second minimum values. in the distance statistic values (S₁, S₂, S₃, ..., and S_t) arrayed in the ascending order (S120) to compare the sum of the distance statistic values combined with each other in the group (the group 1) is compared with the amount of peak power whenever one combination of the distance statistic values enters the group (the group 1) (S122).
When it is determined that the sum of the distance statistic values is less than the amount of peak power, the process returns to the S118 so that the distance statistic values are combined with each other in one group (the group 1) until the sum of the distance statistic values is smaller than the power of peak power to group the indoor units 10.
On the other hand, when it is determined that the sum of the distance statistic values is no less than the amount of peak power, the distance statistic values are combined with each other in the group (the group 1) until the sum of the distance statistic values is smaller than the amount of peak power to group the indoor units 10 corresponding to the distance statistic values (S124).
After the indoor units 10 are grouped in one group (the group 1) through the above processes, the next group (for example, the group 2) is grouped (S126). Then, in the grouping of the next group (the group 2), the processes of sequentially combining the maximum value and the minimum value with each other in the remaining distance statistic values excluding the distance statistic values combined with each other in the previous group (the group 1) are performed to compare the sum of the distance statistic values that enter the group (the group 2) with the amount of peak power whenever one combination of distance statistic values enters the next group (the group 2) like in the previous group (the group 1) and to group the indoor units 10 in the group (the group 2) until the sum of the distance statistic values is smaller than the amount of peak power. Such grouping is the same as the grouping of the previous group (the group 1). The same indoor unit 10 can exist in different groups through such grouping.
When the grouping of the entire indoor units 10 is completed by repeating the above processes (S128), the system air conditioner controls the peak of the amount of power in accordance with the clustered groups of the indoor units 10 and such controlling of the peak of the amount of power continues till the next update point of time.
As described above, in the apparatus for setting the indoor unit groups of the system air conditioner according to the present invention and the method thereof, it is possible to group the indoor units so that the sum of the amount of power does not exceed the peak of the amount of power based on the amount of power obtained from the indoor units during a predetermined period of time.
Also, according to the present invention, the amount of power consumption of the indoor units is statically optimized to manage the amount of power consumption of the indoor units so that it is possible to effectively operate a cooling system without exceeding the initially stipulated amount of power.

Claims

A method of setting groups of a system air conditioner having a plurality of indoor units, the method comprising:
extracting an amount of power observed from the plurality of indoor units during a predetermined period of time; and

grouping the plurality of indoor units such that a sum of an amount of power does not exceed a predetermined peak value of power based on data related to the extracted amount of power.
The method as claimed in claim 1, wherein, in extracting the amount of power from the plurality of indoor units, the amount of power periodically observed from the plurality of indoor units during a predetermined period of time is extracted.
The method as claimed in claim 2, wherein, in periodically extracting the amount of power, the amount of power is extracted from each indoor unit every time period, which is obtained by dividing a predetermined time zone where the amount of power consumption is large by a predetermined constant value (k).
The method as claimed in claim 3, wherein the constant value (k) is a number of data required for obtaining Euclidean distance statistic values, and the number corresponds to about 10 to 15.
The method as claimed in claim 2, further comprising calculating the Euclidean distance statistic values between indoor units using the data related to the amount of power periodically extracted during a predetermined period of time.
The method as claimed in claim 5, wherein, in calculating the Euclidean distance statistic values, the data related to the amount of power periodically extracted during the predetermined period of time are substituted for the following Euclidean function [EQUATION 1] to calculate the amounts of power that are the distance statistic values between the indoor units. $\sum_{i - 1}^{k} (P_{ji} - P_{ii}), j \neq 1, 1 \leq j \leq n, 1 \leq l \leq n$
The method as claimed in claim 5, further comprising arraying the calculated Euclidean distance statistic values in an ascending order,
wherein, in grouping the plurality of indoor units, the indoor units corresponding to the distance statistic values are grouped in one group such that the sum of the distance statistic values combined with each other in a group does not exceed a predetermined peak value of power.
The method as claimed in claim 7, wherein, in combining the arrayed distance statistic values with each other in a group in an order of large and small values, the distance statistic values are combined with each other in the group in an order of first maximum and minimum values, second maximum and minimum values except for the first maximum and minimum values, and third maximum and the minimum values except for the first and second maximum and minimum values.
The method as claimed in claim 7, wherein, in grouping the plurality of indoor units, the sum of the combined distance statistic values is operated whenever the distance statistic values are combined with each other in the group to compare an operated sum of the distance statistic values with the amount of peak power and the distance statistic values are combined with each other in the group in an order of maximum and minimum values until it is determined that the operated sum of the distance statistic values is smaller than the amount of peak power to group the indoor units.
An apparatus for setting groups of a system air conditioner having a plurality of indoor units, the apparatus comprising:
a power amount extracting unit extracting an amount of power observed from the plurality of indoor units during a predetermined period of time; and

a group setting unit grouping the plurality of indoor units such that a sum of an amount of power does not exceed a predetermined peak value of power based on data related to the extracted amount of power.
The apparatus as claimed in claim 10, wherein the power amount extracting unit extracts the amount of power periodically observed from the plurality of indoor units during a predetermined period of time.
The apparatus as claimed in claim 10, further comprising a power amount statistic unit calculating the Euclidean distance statistic values between the indoor units using data related to the amount of power periodically extracted during a predetermined period of time.
The apparatus as claimed in claim 12, wherein the power amount statistic unit substitutes the data related to the amount of power periodically extracted during a predetermined period of time according to following Euclidean function [EQUATION 1] to calculate amounts of power that are the distance statistic values between the indoor units. $\sum_{i - 1}^{k} (P_{ji} - P_{ii}), j \neq 1, 1 \leq j \leq n, 1 \leq l \leq n$
The apparatus as claimed in claim 12, wherein the group setting unit combines the distance statistic values calculated by the power amount statistic unit with each other in the group in an order of large and small values and groups the indoor units corresponding to the distance statistic values in one group such that a sum of the distance statistic values combined with each other in the group does not exceed the predetermined peak value of power.
The apparatus as claimed in claim 14, wherein the group setting unit operates the sum of the combined distance statistic values whenever the distance statistic values are combined with each other in the group to compare the operated sum of the distance statistic values with the amount of peak power and combines the distance statistic values with each other in the group in an order of first maximum and minimum values, second maximum and minimum values except for the first maximum and the minimum values, and third maximum and minimum values except for the first and second maximum and minimum values until it is determined that the operated sum of the distance statistic values is smaller than the peak value of power to group the indoor units.