US20150160675A1 - Demand response system - Google Patents

Abstract

A demand response (DR) system includes a DR control unit to generate different DR levels having different power rates for each power unit, and transmit a current DR level, and a household appliance to receive the DR level from the DR control unit, and differentially control energy output of a product in response to the received DR level so as to reduce power consumption of the product. As a result, the DR system reduces power consumption when power rates are high so as to reduce electricity bills.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a Continuation Application of U.S. Ser. No. 12/929,873 filed Feb. 22, 2011, and claims the benefit of Korean Patent Application No. 10-2010-0018627, filed on Mar. 2, 2010 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.
BACKGROUND
• 1. Field
• Embodiments relate to a demand response system for reducing power consumption during peak power rates so as to reduce electricity bills.
• 2. Description of the Related Art
• Generally, it is necessary for a power system to balance demand and supply. This requirement of the power system is of importance to rational utilization of limited energy resources.
• For the aforementioned reasons, demand management is a focus of attention, and a number of studies are underway into demand response (DR) systems for advanced demand management.
• Demand response (DR) can be defined as variation in consumption format depending on variation in power rates. In addition, demand response (DR) may be defined as incentive payment to restrict electricity consumption when power rates are high.
• Demand response (DR) may further include a procedure for changing consumption behavior in the same manner as in the aforementioned incentive payment. By means of the aforementioned two methods, the demand response (DR) of consumers may be derived. Consumers can reduce power consumption during a specific time interval of high power rates even if such reduction in power consumption during the specific interval causes inconvenience. For example, the consumer may temporarily stop an air-conditioner in midsummer so as to reduce power consumption when power rates are high.
• However, a conventional DR system has proposed an easy and simple control scheme dependent upon cost or price information. That is, the conventional DR system has been designed to limit the operation of household appliances in response to power rates, which may cause user inconvenience.
SUMMARY
• Therefore, it is an aspect to provide a demand response system to change energy output of a product in response to a demand response (DR) level having power rate information per power unit, thereby reducing peak power rates when power rates are high so as to reduce electricity bills.
• Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.
• In accordance with one aspect, a demand response system includes a demand response (DR) control unit to generate different DR levels having different power rates for each power unit, and transmit a current DR level; and a household appliance to receive the DR level from the DR control unit, and differentially control energy output of a product in response to the received DR level so as to reduce power consumption of the product.
• The household appliance may include a storage unit to store information associated with the energy output for each DR level of the household appliance, a receiving unit to receive a DR level from the DR control unit, a controller to change the energy output of the household appliance to an output value corresponding to the received DR level according to the DR level received through the receiving unit so as to reduce power consumption of the household appliance, and a load driving unit to drive a variety of loads of the household appliance in response to a control signal of the controller.
• The controller may reduce energy output as the received DR level increases.
• The household appliance may be an induction heating cooker including a working coil heating a container, and the controller may change an initial output level of the working coil to a level corresponding to the received DR level in response to the received DR level.
• The household appliance may be an air-conditioner, and the controller may change an initial set temperature of the air-conditioner to a temperature value corresponding to the received DR level in response to the received DR level.
• The household appliance may be a refrigerator, and the controller may change an initial freezing-chamber temperature of the refrigerator to a temperature value corresponding to the received DR level in response to the received DR level.
• The household appliance may be a refrigerator, and the controller may change an initial compressor operation rate of the refrigerator to an operation rate corresponding to the received DR level in response to the received DR level.
• The household appliance may include an input unit to receive a command from a user; and the controller may disable or enable energy output control in response to the DR level upon receiving the user command from the input unit.
• The input unit may include a first button to establish a time zone and a second button to establish the DR level, and the controller may maintain a DR level entered through the second button during a time zone entered through the first button.
• The input unit may include a first button to establish a time and a second button to establish the DR level, and the controller may maintain a DR level entered through the second button during a time entered through the first button.
• The household appliance may include a display unit, and the controller may display a currently operating DR level on the display unit.
• The controller may display information associated with power rates reduced by energy output control in response to the DR level on the display unit.
• The DR control unit may receive power rate information, accumulate the received power rate information in units of a predetermined time, i.e., one day, one week, one month, one year, or the like, and establish the plurality of DR levels using the accumulated power rate information.
• In accordance with another aspect, an induction heating cooking apparatus includes a load driving unit to drive a working coil heating a container, a receiving unit to receive a demand response (DR) level related to power rate information for each power unit, a storage unit to store output levels of individual DR levels, and a controller to confirm an output level corresponding to the DR level received through the receiving unit, change the output level established in the working coil to the confirmed output level, and control an operation of the load driving unit in such a manner that the working coil is operated at the changed output level.
• Information stored in the storage unit may be stored in a manner that the output level is reduced in proportion to the increasing DR level.
• In accordance with another aspect, an air-conditioner includes a load driving unit to drive a compressor, a receiving unit to receive a demand response (DR) level related to power rate information for each power unit; a storage unit to store temperature values of individual DR levels, and a controller to confirm a temperature value corresponding to the DR level received through the receiver, change a set temperature established in the air-conditioner to the confirmed temperature value, and control an operation of the load driving unit so that the set temperature value of the air-conditioner reaches the changed temperature value.
• Information stored in the storage unit may be stored in a manner that the temperature value increases in proportion to the increasing DR level.
• In accordance with another aspect, a refrigerator may include a load driving unit to drive a compressor, a receiving unit to receive a demand response (DR) level related to power rate information for each power unit, a storage unit to store freezing-chamber temperature values of individual DR levels, and a controller to confirm a freezing-chamber temperature value corresponding to the DR level received through the receiver, change a set freezing-chamber temperature established in the refrigerator to the confirmed freezing-chamber temperature value, and control an operation of the load driving unit so that the freezing-chamber temperature value of the refrigerator reaches the changed freezing-chamber temperature value.
• Information stored in the storage unit may be stored in a manner that the freezing-chamber temperature value increases in proportion to the increasing DR level.
• In accordance with another aspect, a refrigerator includes a load driving unit to drive a compressor, a receiving unit to receive a demand response (DR) level related to power rate information for each power unit, a storage unit to store compressor operation rates of individual DR levels, and a controller to confirm a compressor operation rate corresponding to the DR level received through the receiver, change a compressor operation rate established in the refrigerator to the confirmed compressor operation rate, and control an operation of the load driving unit so that the refrigerator is operated at the changed compressor operation rate.
• Information stored in the storage unit may be stored in a manner that the compressor operate rate is reduced in proportion to the increasing DR level.
BRIEF DESCRIPTION OF THE DRAWINGS
• These and/or other aspects of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
• FIG. 1 is a configuration diagram illustrating a demand response (DR) system according to an embodiment.
• FIG. 2 is a control block diagram illustrating a household appliance for use in a DR system according to an embodiment.
• FIG. 3 is a table illustrating initial output levels in response to DR levels of an induction heating cooker of a DR system according to an embodiment.
• FIG. 4 is a flowchart illustrating a method for controlling an induction heating cooker using a DR system according to an embodiment.
• FIG. 5 is a table illustrating temperature levels in response to DR levels of an air-conditioner for use in a DR system according to an embodiment.
• FIG. 6 is a flowchart illustrating a method for controlling an air-conditioner using a DR system according to an embodiment.
• FIG. 7 is a flowchart illustrating a method for controlling a refrigerator using a DR system according to an embodiment.
• FIG. 8 shows an induction heating cooker for use in a DR system according to an embodiment.
• FIG. 9 shows a message indicating a DR level operation and a message indicating reduced power rates that are displayed on a display panel of an induction heating cooker for use in a DR system according to an embodiment.
• FIG. 10 shows an operation panel for manually establishing a DR level of a household appliance for use in a DR system according to an embodiment.
• FIG. 11 shows another operation panel for manually establishing a DR level of a household appliance for use in a DR system according to an embodiment.
DETAILED DESCRIPTION
• Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
• FIG. 1 is a configuration diagram illustrating a demand response (DR) system according to an embodiment.
• Referring toFIG. 1, the DR system includes asmartmeter10 installed in a home to transmit and receive information to and from a power company; aDR control unit20 for receiving information about electric charges from thesmartmeter10; andrespective household appliances30 connected to theDR control unit20 over a network.
• Eachhousehold appliance30 performs a desired function using power received through a power line.
• Thehousehold appliance30 may include all kinds of electric household appliances, for example, an induction heating cooker, an air-conditioner, a refrigerator, a washing machine, etc.
• TheDR control unit20 receives power rate information from the power company through thesmartmeter10, and establishes different DR levels of individual power units using the received power rate information. The established DR level information is transmitted to eachhousehold appliance30.
• TheDR control unit20 records power rate information received from thesmartmeter10 at intervals of a unit time. For example, assuming that the unit time is set to one hour, the power rate information is recorded24 times each day. TheDR control unit20 establishes a plurality of DR levels representing different power rates of individual power units on the basis of the highest power rate and the lowest power rate using the power rate information. In this case, each DR level may be represented by power rates for every power unit.
• Using the power rate information, the DR level can be more accurately obtained by an average of power rate information accumulated in units of a predetermined time, for example, one day, one week, one month, one year, etc.
• FIG. 2 is a control block diagram illustrating a household appliance for use in a DR system according to an embodiment.
• Referring toFIG. 2, thehousehold appliance30 includes aninput unit31, a receivingunit32, asensing unit33, apower metering unit34, aload driving unit35, a transmittingunit36, adisplay unit37, astorage unit38, and acontroller39.
• Theinput unit31, for example, a keypad, a keyboard, a joystick, a touchpad, a button, etc., is used as an interface unit allowing a user to enter a desired command. Specifically, theinput unit31 may be integrated with thedisplay unit37, and may be configured in the form of a touchscreen.
• The receivingunit32 receives DR level information from theDR control unit20.
• Thesensing unit33 detects various states of a household appliance. If the household appliance is an induction heating cooker, thesensing unit33 includes a variety of sensors for sensing various states of the induction heating cooker, for example, a temperature sensor, a voltage sensor, etc. If the household appliance is an air-conditioner, thesensing unit33 includes a variety of sensors for sensing various states of the air-conditioner, for example, an indoor temperature sensor, an outdoor temperature sensor, an evaporator temperature sensor, etc. If the household appliance is a refrigerator, thesensing unit33 includes a variety of sensors, for example, an in-chamber temperature sensor, an evaporator temperature sensor, a discharge temperature sensor, etc.
• Thepower metering unit34 measures an amount of power consumed in a household appliance at intervals of a predetermined time, i.e., one day, one week, one month, one year, or the like.
• Theload driving unit35 drives a variety of loads of the household appliance.
• The transmittingunit36 transmits a variety of information of the household appliance to theDR control unit20. For example, the transmittingunit36 transmits an amount of household-appliance power consumption measured by thepower metering unit34 to theDR control unit20.
• Thedisplay unit37 displays an operation status of thehousehold appliance20, and displays messages associated with both the DR level operation and the power saving.
• Thestorage unit38 stores not only information related to an initial output level for each household appliance but also information related to a changed value of an initial output level for each DR level.
• Thecontroller39 controls individual elements constructing each household appliance.
• Thecontroller39 changes an initial output value established in a household appliance to another output value capable of reducing power consumption according to a DR level received from theDR control unit20. In this case, thecontroller39 reduces the initial output value in proportion to a current DR level, such that power consumption is reduced as the current DR level increases.
• In this case, if the household appliance is an induction heating cooker, thecontroller39 changes an initial output level value established in a working coil for heating a container of the induction heating cooker to another output level value capable of reducing power consumption according to the DR level received from theDR control unit20. In this case, thecontroller39 reduces the initial output value in proportion to a current DR level, such that power consumption is reduced as the current DR level increases.
• In addition, if the household appliance is an air-conditioner, thecontroller39 changes an initial set temperature value established in the air-conditioner to another output set temperature value capable of reducing power consumption according to the DR level received from theDR control unit20. In this case, thecontroller39 increases the initial set temperature value in proportion to a current DR level, such that power consumption is reduced as the current DR level increases.
• Further, if the household appliance is a refrigerator, thecontroller39 changes an initial freezing temperature value established in the refrigerator to another freezing temperature value capable of reducing power consumption according to a DR level received from theDR control unit20. In this case, thecontroller39 increases the initial freezing temperature value in proportion to a current DR level, such that power consumption is reduced as the current DR level increases. In this case, the initial refrigerating temperature value may be used instead of the initial freezing temperature value.
• In addition, thecontroller39 establishes an associated command in such a manner that an initial output in response to a DR level can be manually changed in response to a user command without being automatically changed. That is, thecontroller39 confirms a user command when an initial output is changed in response to a DR level, such that the initial output may be immediately changed or be changed from a reserved time or an output value to be changed may be changed to a user-input output value.
• In addition, thecontroller39 displays current DR level information so as to allow the user to recognize a current DR level. Also, thecontroller39 is operated at a current DR level so as to allow the user to recognize the power saving effect obtained by the DR level operation, such that it can display information indicating how much power rates are reduced as compared to another case in which thecontroller39 is not operated at the DR level.
• Detailed operations of thecontroller39 for each household appliance will hereinafter be described in detail.
• Hereinafter, operations of thecontroller39 on the assumption that the household appliance is an induction heating cooker will be given below.
• FIG. 3 is a table illustrating initial output levels in response to DR levels of an induction heating cooker of a DR system according to an embodiment.FIG. 4 is a flowchart illustrating a method for controlling an induction heating cooker using a DR system according to an embodiment.
• Referring toFIGS. 3 and 4, thecontroller39 receives a DR level from theDR control unit20 through the receivingunit32 atoperation100.
• After receiving the DR level from theDR control unit20, thecontroller39 determines whether the received DR level is a fourth DR level atoperation102.
• If the received DR level is the fourth DR level atoperation102, thecontroller39 confirms the initial output level of the working coil installed in the induction heating cooker atoperation104.
• After confirming the initial output level of the working coil, thecontroller39 changes the initial output level to another output level corresponding to the fourth DR level, which is less than the initial output level, atoperation106.
• For example, as shown inFIG. 3, if the confirmed initial output level is equal to or higher than the fourth DR level (i.e., PL≧4), thecontroller39 changes a new output level (NEW) to a value of (PL−3) indicating that a third DR level is deducted from the initial output level. If the confirmed initial output level is a third level (PL=3), thecontroller39 changes a new output level (NEW) to a value of (PL−2) indicating that a second DR level is deducted from the initial output level. In addition, if the confirmed initial output level is a second DR level (PL=2), thecontroller39 changes a new output level (NEW) to a value of (PL−1) indicating that a first level is deducted from the initial output level.
• Meanwhile, if the received DR level is not identical to the fourth DR level atoperation102, thecontroller39 determines whether the received DR level is a third DR level atoperation108.
• If the received DR level is not identical to the third DR level atoperation108, thecontroller39 confirms an initial output level of the working coil installed in the induction heating cooker atoperation110.
• After confirming the initial output level of the working coil thecontroller39 changes the initial output level to another output level corresponding to a third DR level, which is less than the initial output level, atoperation112.
• For example, as shown inFIG. 3, if the confirmed initial output level is equal to or higher than the third DR level (i.e., PL≧3), thecontroller39 changes a new output level (NEW) to a value of (PL−2) indicating that a second DR level is deducted from the initial output level. If the confirmed initial output level is a second level (PL=2), thecontroller39 changes a new output level (NEW) to a value of (PL−1) indicating that a first DR level is deducted from the initial output level.
• Meanwhile, if the received DR level is not identical to the third DR level atoperation108, thecontroller39 determines whether the received DR level is a second DR level atoperation114.
• If the received DR level is identical to the second DR level atoperation114, thecontroller39 confirms an initial output level of the working coil installed in the induction heating cooker atoperation116.
• After confirming the initial output level of the working coil thecontroller39 changes the initial output level to another output level corresponding to a second DR level, which is less than the initial output level, atoperation118.
• For example, as shown inFIG. 3, if the confirmed initial output level is equal to or higher than the second DR level (PL≧2), the new output level (NEW) is changed to a value of (PL−1) indicating that a first DR level is deducted from the initial output level.
• Meanwhile, if the received DR level is not identical to the second DR level atoperation114, thecontroller39 determines that the received DR level is the first DR level, and confirms an initial output level of the working coil installed in the induction heating cooker atoperation120.
• After confirming the initial output level, thecontroller39 maintains the initial output level atoperation122.
• As described above, thecontroller39 changes the initial output level to an output level corresponding to a DR level. The output level is determined according to a duty ratio of a PWM (Pulse Width Modulation) signal provided to the working coil. As the DR level is changed from the first DR level to the fourth DR level, thecontroller39 gradually reduces the duty ratio. As a result, power consumption of the working coil is reduced so that the peak demand is also reduced.
• When receiving a new DR level at the same level during a predetermined time (e.g., 5 seconds), thecontroller39 recognizes the received DR level as a valid or effective value.
• An override function indicates that an initial output level is maintained without changing the initial output level, irrespective of the received DR level. Thecontroller39 maintains the initial output level irrespective of a DR level when a user enters this override function.
• The relationship between the DR level and the initial output level is shown inFIG. 3. For example, provided that the user sets an initial output level to ‘4’, if the DR level is set to 1,level 4 is maintained without change. However, if the DR level of 2 is used, the initial output level is changed from 4 to 3. In addition, if the DR level of 3 is used, the initial output level is changed from 4 to 2. If the DR level of 4 is used, the initial output level is changed from 4 to 1.
• As described above, the higher the DR level, the lower the initial output level. As a result, the DR system according to the embodiments can reduce power consumption during the high-DR-level interval, resulting in reduction in electricity bills.
• Operations of the DR system when the household appliance is an air-conditioner will hereinafter be described in detail.
• FIG. 5 is a table illustrating temperature levels in response to DR levels of an air-conditioner for use in a DR system according to an embodiment.FIG. 6 is a flowchart illustrating a method for controlling an air-conditioner using a DR system according to an embodiment.
• Referring toFIGS. 5 and 6, thecontroller39 receives a DR level from theDR control unit20 through the receivingunit32 atoperation200.
• After receiving the DR level from theDR control unit20, thecontroller39 determines whether the received DR level is a fourth DR level atoperation202.
• If the received DR level is the fourth DR level atoperation202, thecontroller39 confirms the initial set temperature of the air-conditioner atoperation204.
• After confirming the initial set temperature of the air-conditioner, thecontroller39 changes the initial set temperature to another set temperature corresponding to the fourth DR level less than the initial set temperature at operation206.
• For example, as shown inFIG. 5, if the confirmed initial set temperature is equal to or higher than 25° C. (i.e., TL≦25° C.), thecontroller39 changes a new set temperature (NEW) to a temperature value of (TL+3° C.) indicating that a temperature of 3° C. is added to the initial set temperature. If the confirmed initial set temperature is a temperature of 26° C. (i.e., TL=26° C.), thecontroller39 changes a new set temperature (NEW) to a temperature value of (TL+2° C.) indicating that 2° C. is added to the initial set temperature. In addition, if the confirmed initial set temperature is a temperature of 27° C. (i.e., TL=27° C.), thecontroller39 changes a new set temperature (NEW) to a temperature value of (TL+1° C.) indicating that 1° C. is added to the initial set temperature.
• Meanwhile, if the received DR level is not identical to the fourth DR level atoperation202, thecontroller39 determines whether the received DR level is a third DR level atoperation208.
• If the received DR level is identical to the third DR level atoperation208, thecontroller39 confirms an initial set temperature of the air-conditioner atoperation210.
• After confirming the initial set temperature of the air-conditioner, thecontroller39 changes the initial set temperature to another set temperature corresponding to a third DR level less than the initial set temperature atoperation212.
• For example, as shown inFIG. 5, if the confirmed initial set temperature is equal to or higher than 26° C. (i.e., TL≦26° C.), thecontroller39 changes a new set temperature (NEW) to a temperature value of (TL+2° C.) indicating that 2° C. is added to the initial set temperature. If the confirmed initial set temperature is 27° C. (i.e., TL=27° C.), thecontroller39 changes a new set temperature (NEW) to a temperature value of (TL+1° C.) indicating that 1° C. is added to the initial set temperature.
• Meanwhile, if the received DR level is not identical to the third DR level atoperation208, thecontroller39 determines whether the received DR level is a second DR level atoperation214.
• If the received DR level is identical to the second DR level atoperation214, thecontroller39 confirms an initial set temperature of the air-conditioner atoperation216.
• After confirming the initial set temperature of the air-conditioner, thecontroller39 changes the initial set temperature to another set temperature corresponding to a second DR level less than the initial set temperature atoperation218.
• For example, as shown inFIG. 5, if the confirmed initial set temperature is equal to or higher than 27° C. (i.e., TL≦27° C.), thecontroller39 changes a new set temperature (NEW) to a temperature value of (TL+1° C.) indicating that 1° C. is added to the initial set temperature.
• Meanwhile, if the received DR level is not identical to the second DR level atoperation214, thecontroller39 determines that the received DR level is a first DR level, such that it confirms the initial set temperature of the air-conditioner atoperation220.
• After confirming the initial set temperature of the air-conditioner, thecontroller39 maintains this initial setup temperature atoperation222.
• As described above, the DR level is sub-divided into several steps, such that power consumption corresponding to each level is controlled. If a compressor is operated at a user-desired temperature, power consumption is maximized. If the DR level is increased, a user-desired temperature is gradually increased to reduce the operation time of the air-conditioner, resulting in reduced power consumption and reduced peak load.
• When the new DR level is received at the same level during a predetermined time, the DR level is changed. Upon receiving a new level during the predetermined time, the DR level is maintained at a previous level.
• In the same manner as in the induction heating cooker, the air-conditioner has an override function for maintaining the initial set temperature. If the user enters the override function, thecontroller39 continuously maintains the initial set temperature irrespective of a DR level.
• Thecontroller39 can display the corresponding DR level on thedisplay unit37 when a DR level is changed, and can display the reduced power rates caused by the corresponding DR level operation.
• If the user does not want to control the operation of the air-conditioner in response to the DR level, thecontroller39 may release the operation control of the air-conditioner in response to the DR level upon receiving a command from the user.
• The relationship between the DR level and the initial set temperature is shown inFIG. 5. For example, in an ordinary case, the user sets an initial set temperature to 18° C. If the DR level is changed during the operation of the air-conditioner, the initial set temperature is compulsorily increased by +2° C. Thereafter, if the DR level of 1 is used, the initial user setup information is maintained. However, as the DR level is increased, the initial set temperature is increased in increments of +2° C.
• Instead of changing the initial set temperature, the DR system according to the present invention compulsorily adjusts the compressor operation rate in proportion to the increasing DR level, resulting in reduction of power consumption. That is, the DR system gradually reduces the air-conditioner operation time in proportion to the increasing DR level. For example, if the DR level of 1 is used, the compressor operation of the air-conditioner is 50-minutes operation mode→10-minutes stop mode. If the DR level of 2 is used, the compressor operation of the air-conditioner is 40-minutes operation mode→20-minutes stop mode. If the DR level of 3 is used, the compressor operation of the air-conditioner is 30-minutes operation mode→30-minutes stop mode. If the DR level of 4 is used, the compressor operation of the air-conditioner is 20-minutes operation mode→40-minutes stop mode.
• Through the above-mentioned scheme, the higher the DR level, the lower the initial set temperature. Alternatively, the higher the DR level, the lower the compressor operation rate. As a result, power consumption can be reduced during a high-DR-level interval, resulting in reduction of power rates.
• Operations of the DR system when the household appliance is a refrigerator will hereinafter be described in detail.
• FIG. 7 is a flowchart illustrating a method for controlling a refrigerator using a DR system according to an embodiment.
• Referring toFIG. 7, thecontroller39 receives a DR level from theDR control unit20 through the receivingunit32 atoperation300.
• After receiving the DR level from theDR control unit20, thecontroller39 determines whether the received DR level is a fourth DR level atoperation302.
• If the received DR level is the fourth DR level atoperation302, thecontroller39 confirms the initial freezing-chamber temperature of the refrigerator atoperation304.
• After confirming the initial freezing-chamber temperature of the refrigerator, thecontroller39 changes the initial freezing-chamber temperature to a freezing-chamber temperature corresponding to the fourth DR level, which is less than the initial freezing-chamber temperature atoperation306.
• For example, thecontroller39 changes a new freezing-chamber temperature (NEW) to a temperature of (TL+6° C.) indicating that 6° C. is added to the initial freezing-chamber temperature.
• In addition, thecontroller39 powers off a defrosting heater to defrost an evaporator, and at the same time displays a current DR level (fourth DR level) atoperation308.
• Meanwhile, if the received DR level is not identical to the fourth DR level atoperation302, thecontroller39 determines whether the received DR level is a third DR level atoperation310.
• If the received DR level is identical to the third DR level atoperation310, thecontroller39 confirms an initial freezing-chamber temperature of the refrigerator atoperation312.
• After confirming the initial freezing-chamber temperature of the refrigerator, thecontroller39 changes the initial freezing-chamber temperature to another freezing-chamber temperature corresponding to the third DR level, which is less than the initial freezing-chamber temperature atoperation314.
• For example, thecontroller39 changes a new freezing-chamber set temperature (NEW) to a temperature value of (TL+4° C.) indicating that 4° C. is added to the initial freezing-chamber temperature.
• The defrosting heater is powered off and at the same time the current DR level (third DR level) is displayed atoperation316.
• Meanwhile, if the received DR level is not identical to the third DR level atoperation310, thecontroller39 determines whether the received DR level is identical to the second DR level atoperation318.
• If the received DR level is identical to the second DR level atoperation318, thecontroller39 confirms the initial freezing-chamber temperature of the refrigerator atoperation320.
• After confirming the initial freezing-chamber temperature of the refrigerator, thecontroller39 changes the initial freezing-chamber temperature to another freezing-chamber temperature corresponding to the second DR level indicating a low freezing-chamber temperature less than the initial freezing-chamber temperature atoperation322.
• For example, thecontroller39 changes a new freezing-chamber temperature (NEW) to a temperature of (TL+2° C.) indicating that 2° C. is added to the initial freezing-chamber temperature.
• Meanwhile, if the received DR level is not identical to the second DR level atoperation318, thecontroller39 determines that the received DR level is a first DR level and confirms the initial freezing-chamber temperature of the refrigerator atoperation326.
• After confirming the initial freezing-chamber temperature of the refrigerator, thecontroller39 maintains this initial freezing-chamber temperature atoperation328.
• In addition, the current DR level (first DR level) is displayed atoperation330.
• As described above, as the DR level is increased, the initial freezing-chamber temperature decided by the user is also gradually increased to reduce the compressor operation time of the refrigerator, such that power consumption is reduced and peak load is also reduced.
• Upon receiving a new DR level at the same level during a predetermined time, the DR level is changed. Otherwise, upon receiving a different level instead of the same level during a predetermined time, the DR level is maintained at a previous level.
• In the same manner as in the induction heating cooker and the air-conditioner, the refrigerator also has an override function capable of maintaining the initial freezing-chamber temperature irrespective of the DR level. If the user enters the override function, thecontroller39 maintains the initial freezing-chamber temperature irrespective of the DR level.
• If the DR level displayed on thedisplay unit37 is changed, thecontroller39 displays the corresponding DR level on thedisplay unit37, and can display power consumption corresponding to the new DR level.
• In addition, if the user does not want to control the operation of the refrigerator in response to the DR level, thecontroller39 may release the operation control of the refrigerator in response to the DR level upon receiving a command from the user.
• If the DR level of2 is used, thecontroller39 increases the initial freezing-chamber temperature by 2° C. For example, if the initial freezing-chamber temperature is set to −20° C., the initial freezing-chamber temperature is changed to −18° C., resulting in reduction in compressor operation time. In this case, the defrosting heater is normally operated.
• If the DR level of 3 is used, thecontroller39 increases the initial freezing-chamber temperature by 4° C. For example, if the initial freezing-chamber temperature is set to −20° C., the initial freezing-chamber temperature is changed to −16° C., resulting in reduction in compressor operation time. In this case, the defrosting heater is not operated.
• In addition, if the DR level of 4 is used, thecontroller39 increases the initial freezing-chamber temperature by 6° C. For example, if the initial freezing-chamber temperature is set to −20° C., the initial freezing-chamber temperature is changed to −14° C., resulting in reduction in compressor operation time. In this case, the defrosting heater is not operated.
• Through the above-mentioned scheme, the higher the DR level, the higher the initial freezing-chamber temperature, such that the operation time of the compressor of the refrigerator is reduced. As a result, power consumption can be reduced during a high-DR-level interval, reducing power consumption.
• FIG. 8 shows an induction heating cooker for use in a DR system according to an embodiment.
• Referring toFIG. 8, theinduction heating cooker30 for use in the DR system according to the embodiment includes two heating coils L1 and L2 that are installed under a cooking board on which a container is put so as to provide heat to the cooking board.
• In order to operate individual heating coils L1 and L2, one side of the main body of theinduction heating cooker30 includes not only a plurality ofoperation panels50 for entering corresponding commands but also adisplay panel40 for displaying information.
• Therefore, the user puts the container on the cooking board, confirms the positions of the heating coils L1 and L2 used to heat the container through thedisplay panel40, and presses theoperation panel50 to enter initial output levels of individual heating coils L1 and L2, such that high-frequency power source is provided to the heating coils L1 and L2 on which the container is placed, thereby heating the container.
• Theoperation panel50 includes afirst button51 and asecond button52. Thefirst button51 is a ‘Start Now’ button, and thesecond button52 is a ‘Start on DR’ button. The ‘Start Now’ button is adapted to establish an override function, and the ‘Start on DR’ button is adapted to release the function (i.e., override function) for automatically executing the energy output control in response to the DR level.
• If the user operates the induction heating cooker when the DR level is high and power rates are high, this operation of the induction heating cooker is considered to be inefficient. Therefore, in this case, the user may immediately operate the induction heating cooker as needed, or may also optionally operate the induction heating cooker at the power saving mode as needed. For reference, these buttons can be applied to all household appliances, for example, induction heating cookers, air-conditioners, refrigerators, washing machines, etc.
• FIG. 9 shows a message indicating a DR level operation and a message indicating reduced power rates that are displayed on a display panel of an induction heating cooker for use in a DR system according to an embodiment.
• Referring toFIG. 9, thecontroller39 displays the currently-operating DR level information so as to allow the user to recognize a current DR level through thedisplay unit37. In addition, thecontroller39 is operated at a current DR level so as to allow the user to recognize the power saving effect obtained by the DR level operation, such that it can display information indicating how much power rates are reduced as compared to another case in which thecontroller39 is not operated at the DR level.
• FIG. 10 shows an operation panel for manually establishing a DR level of a household appliance for use in a DR system according to an embodiment.FIG. 11 shows another operation panel for manually establishing a DR level of a household appliance for use in a DR system according to an embodiment.
• Theoperation panels60 and70 through which the user can freely change a DR level or the like are mounted to the household appliance, such that the user can adjust theoperation panels60 and70 as necessary.
• For example, the user may enable or disable the energy output control in response to the DR level using the ON/OFF button62 contained in theoperation panel60 or70 having the DRlevel set button63. In this case, the input DR level is maintained through the DRlevel set button62 during the time zone entered using the time-zone set button61.
• In addition, if the user enters a desired time through the time setbutton61 contained in theoperation panel70 and enters a DR level through the DRlevel set button72, the DR level entered through the DRlevel set button72 is maintained during the input time entered through the time setbutton71. If the input time has elapsed after the expiration of a timer, the manual DR level control is ended and energy output may be controlled in response to the DR level received from theDR control unit20.
• Through the above-mentioned scheme, the common DR control shortcoming in which the household appliance is unable to perform its own performance of 100% can be eliminated, such that the DR level can be more reasonably controlled.
• As is apparent from the above description, the DR system according to the embodiment changes an initial output level of a household appliance in response to different DR levels having different power rates per power unit, thereby reducing power consumption when power rates are high so as to reduce electricity bills.
• Although a few embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims (4)

What is claimed is:

1. An air conditioner comprising:

a compressor configured to compress refrigerant; and

a controller configured to control an operation of the compressor based on a difference between a set temperature input from a user and stored therein and a current room temperature, receive information about a current power rate through a network, and store a table including initial set temperatures matched to respective power rates,

wherein when the air conditioner is turned on, the controller controls the operation of the compressor based on the difference between the initial set temperature and the current room temperature, if the set temperature input and stored is lower than the initial set temperature corresponding to received current power rate.

2. The air conditioner ofclaim 1, wherein the table defines a plurality of levels corresponding to respective power rate range, and stores a plurality of initial set temperatures matched to the respective level.

3. The air conditioner ofclaim 2, wherein a first difference between an initial set temperature of the table matched to an N level and an initial set temperature of the table matched to an N+1 level is equal to a second difference between an initial set temperature of the table matched to an N−1 level and the initial set temperature matched to the N level.

4. The air conditioner ofclaim 3, wherein the difference is a unit temperature.

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