US20140305145A1

US20140305145A1 - Household appliance, system and method of controling household appliances

Info

Publication number: US20140305145A1
Application number: US14/343,166
Authority: US
Inventors: Marcelo Zanelato; Marcos Roberto de Souza; Silvia Helena Pini
Original assignee: Whirlpool SA
Current assignee: Whirlpool SA
Priority date: 2011-09-06
Filing date: 2012-09-04
Publication date: 2014-10-16
Also published as: JP2014531884A; WO2013033796A3; BRPI1104773A2; KR20140057358A; CN103907258A; CO6920261A2; WO2013033796A2; MX2014002580A

Abstract

A control system and a control method for controlling input voltages (1) for household appliances having at least one electric motor in their set of electric charges or devices (5). This control is made by means of a processing unit (3), which can act selectively and independently on a set of output switches (4) and, therefore, act in different ways on each of the devices (5).

Description

The present invention refers to a system and method of controlling input voltages for household appliances that have at least one electric motor in their assembly of electric charges. This control is made by means of a processing unit that can act selectively and independently on the assembly of output switches, thus acting in different modes on each of the devices of the assembly of electric charges.

DESCRIPTION OF THE PRIOR ART

At present, a number of countries diverge with regard to the production and distribution of electric energy at different levels of voltage in each country. The vast majority of electronic apparatus, such as computers, television sets, stereo sets, among others, have a bi-voltage characteristic comprising automatic voltage control, which enables one to adjust various input voltage, usually 110V or 220V, for their perfect functioning at specific voltages. This characteristic is still little spread in the area of household appliances, since most of them need electric motors to function, limited by present-day techniques due to factors like power and control, among others.
In this regard, the few products that enable operation at bivoltage have manual switching made by the final user by means of a switch, which usually modifies the organization of coils of the devices for their functioning. However, few users have specific knowledge for these functions, which often causes functional errors, which entail burning of appliances and partial loss of functionality, causing drawbacks for these users, as well as risks for them depending on the level of protection of the apparatus.
For this reason, in order to prevent these drawbacks, besides increasing the protection for the user and prevent unnecessary use of guarantee services, thus reducing damage for the image associated to the maker, automatic changes of input voltage to acceptable levels of functioning of an apparatus have become compulsory practice.
Analogously, single-phase induction motors are widely used on household appliances by virtue of their simplicity, robustness and high performance. Since they are applied to various household appliances such as refrigerators, freezers, air conditioners, washing machines, among others, induction motors are usually provided with a cage-type rotor and a stator that has coils, generally composed of two windings used selectively for the state in which the induction motor is (start or run).
In this regard, during normal operation of the compressor, a run winding is fed by an alternating voltage, while the start winding is fed only during the first moments of functioning of the motor, since the beginning of the start motion needs higher power for accelerating the rotor. Therefore, the motors are designed and constructed specifically for actuation in certain limited voltage ranges, typically with possible variations not higher than 10% above or below the designed one. If these variations are higher than 10%, a new design and construction of the motor are necessary.
So, possible attempts to solve this problem have appeared in documents for design of bi-volt system. Document U.S. Pat. No. 4,415,964 presents a design in this regard, wherein a system is configured to adjust automatically the voltage output, independently of the input voltage, modifying the organization of coils of an output transformer upon altering the coils for configuration in parallel when turned on at 110V, thus bringing about a 110V output, and inversely upon altering the coils for configuration in series when turned on at 220V, thus repeating a 110V output. However, in this way the document limits possible charges to be turned on, as well as the control over them, since it uses a transformer at the output, not the direct organization of the devices on which it is actuating. Other information considered to be prior art can be found in document U.S. Pat. No. 5,001,623, which presents an automatic control system with a continuous current output, which, however, have the same drawbacks presented in the above-mentioned document, and document U.S. Pat. No. 7,528,734, which presents a system that indicates the input voltage, configured to let the user know whether the voltage present at that specific place is the desired one for the functioning of the apparatus, but without change or control of the output voltage.
Additionally, a DC power feeding system is disclosed in the document JP 2010 288387 with the objective for giving satisfactory usability to users while taking advantages of DC power feeding. Such system comprises a DC power feeding means of feeding a DC voltage, a voltage conversion means for converting the DC voltage provided in a feed line from the DC power feeding means to a load to a plurality of DC voltages having different operation voltages. The system further comprises a voltage setting means for setting a prescribed DC voltage converted by the voltage conversion means.
It should be noted that the documents presented are highly susceptible to oscillation transients and other disturbances in the feed lines, besides presenting enormous consumption of energy, as well as and manufacture and maintenance costs in comparison with the present invention. In this regard, low-power controls, like lamps and fans, require extra consumption of energy lost on transformers and other automatic control systems designed for re-configuring the input voltage used at present.
Differently, conventional household appliances that employ electric motors are usually designed for a specific voltage, since the high power of the electric motors makes it impossible to use transformers for actuation as voltage regulation sources, due to the large volume which they would have for the dimensioning in these applications.
In addition, household appliances used at present have various functionalities for comfort of the users. Documents like U.S. Pat. No. 7,716,937 demonstrate some of the functionalities found at present, such as dampers, fans, evaporators, condensers, motors, deicing resistances, lights, displays, temperature sensors, among others. These different types of devices have different actuation requirements, as well as may have different specifications for an optimized functioning.
Therefore, the control presented by this invention intends not only to automate the control of devices, by varying the forms of actuation on the input voltage to be delivered to the devices, as well as effecting optimization of all the devices to be controlled.

OBJECTIVES OF THE INVENTION

Thus, an objective of the present invention is to provide an automatic voltage control device, with simple and robust topology, besides a reduced cost, which enables use on a large scale and reduction of models required for meeting a determined family of products for markets of different voltages.
Another objective of this invention is that the electronic control of these devices should have negligible consumption of energy.
Another objective of this invention is that the electronic control should be less susceptible to oscillation transient or disturbances coming from the feed network. A further objective of this invention is the optimized control of various devices that have different requirements for actuation, as well as the control of various functionalities for comfort of the user and interaction with interfaces of household appliances.

BRIEF DESCRIPTION OF THE INVENTION

One first embodiment of the invention presents control system for household appliances, the system comprising at least one input voltage, a processing unit, a set of output switches and a set of electric charges including an electric motor and having an operation voltage, wherein the processing unit is configured for detecting the input voltage and actuating on the set of output switches to actuate the devices, and to be configured for conforming the input voltage detected to the device operation voltage, acting on the set of output switches in different ways to conform the voltage independently on each of the devices of the set of electric charges.
The invention also presents a control method for household appliances having a set of electric charges that include an electric motor, comprising the steps of:

- a. detecting an input voltage;
- b. defining an operation voltage of devices of the set of electric charges;
- c. defining the mode of actuation on output switches; and
- d. being configured for actuation on the set of output switches of in different ways to conform the voltage independently on each of the devices of the set of electric charges.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described in greater detail on the basis of an example of embodiment represented in the drawings. The figures show:

FIG. 1 is a representation of the block diagram of the preferred embodiment of the invention;

FIG. 2 is a block diagram representing possible controls effected in the preferred embodiment of the invention;

FIG. 3 is a graph of one of the device control modes, by complete cycles with input voltage of 110V;

FIG. 4 is a graph of one of the device control modes, by complete cycles with input voltage of 220V;

FIG. 5 is a graph of one of the device control modes, by phase, with input voltage of 110V;

FIG. 6 is a graph of one of the device control modes, by phase, with input voltage of 220V;

FIG. 7 is a graph of one of the device control modes, by organization of charges, with input voltage of 110V; and

FIG. 8 is a graph of one of the device control modes, by organization of charges, with input voltage of 220V.

DETAILED DESCRIPTION OF THE FIGURES

FIG. 1 shows the preferred embodiment of the present invention. Thus, FIG. 1 presents a processing unit 3, which is fed by an input voltage 1 by means of a rectifier 2. The processing unit 3 may also be fed by the input voltage 1 and is configured for detecting the dimensions of this input voltage 1 applied to the system. The detection in the system may be made either directly, the input voltage 1 being directly sent to the processing unit 3, which calculates and defines the voltage values, or indirectly, the input voltage 1 feeding a voltage-level sensor 6, which detects the dimensions of this input voltage 1 and supplies this information to the processing unit 3 for analysis, the processing unit 3 being thus responsible for calculating and defining the values of the input voltage 1.
In this regard, the processing unit 3 is configured for defining various modes of selective actuation on the set of output switch 4, which preferably comprise electromechanical switches (such as relays or solenoids) or electronically controlled switches (such as static switches, TRIACs or transistors), also fed by the input voltage 1. These switches of the set of output switches 4 are configured for actuating in different ways on devices (which have a determined operation voltage, preferably 127V) of the set of electric charges 5, so that the input voltage 1 can be adjusted to the operation voltage of the various devices of the set of electric charges 5, this actuation means being defined not only by the input voltage 1, but also by the type of device of the set of electric charges 5 to be controlled.
Thus, the processing unit 3 is configured for detecting the input voltage 1, either directly or by means of a voltage-level sensor 6, and also defining the best means of actuation on the set of output switches 4. FIG. 1 also demonstrates that the processing unit 3 is configured for receiving information from a control interface 7, by means of buttons and temperature sensors, for instance, thus obtaining information necessary for managing the devices of the system in an optimized way, besides providing information to the user of the household appliance by means of the control interface 7, which may use displays or leds, among others, for communication with the user.
In this regard, FIG. 2 presents a block diagram with possible devices to be controlled. It should be noted that the processing unit 3 is configured for controlling, independently and in different ways, various types of devices of the set of electric charges 5, which may have various elements, as for instance, compressors 8, deicing resistances 9, lamps 10, different motors 11 to open and close ports or other types of automation, vanes 15, in addition to one or more outputs for any other type of signal 12, such as loud-speakers for alarms, for instance.
Analogously, the processing unit 3 is also configured for receiving information from various elements, which may be sensors inside the cooling system, inside the processing unit 3 or out of the cooling system, as for instance port sensors 13, temperature sensors 14 or the control interface 7 of the household appliances, for optimization of the functioning of the devices to be controlled, which may be buttons, displays or screens with LCD or LED, touch-screens, voice commands, among others.
Thus, it should be noted that the processing unit 3 may contain a program that is configured to manage simultaneously all the devices in an optimum way, upon defining not only the mode of actuation on the set of output switches 4 for selecting specific voltages for each element, but also the time for turning each switch on/off, so that the cooling system can function according to its technical specifications, so as to carry out all the necessary operations in correct times, further bringing about energy saving by virtue of the functionalities of the operation program.
An example of management of the actuation that may be given is the operation of devices in an inverse manner, for charges that undergo interference from each other, as for instance, the lamp and deicing resistance 9. Upon opening the port of the cooling system when this deicing resistance 9 is on, it is possible to notice a flicker on the lamp 10 (blinking light, instead of constant light). This is due to the drop in voltage in the cycles in which the deicing resistance 9 is on. So, the processing unit 3 may be configured for detecting the problem and, if the deicing resistance 9 is on, upon opening the cooling-system port, it is turned off during the time in which the port is kept open. When the port is closed, the deicing resistance 9 is turned on again.
FIGS. 3 to 8 shows possible modes of control for management of the devices of the present invention. In a preferred mode, the devices of the set of electric charges 5 are dimensioned for 127V, and these devices vary from lamps, fans, resistances to motors. It should be noted that in the preferred embodiment of the present invention the motor used has a specific construction, which will be explained in greater details later.
In this regard, FIG. 3 shows a control mode for managing the devices of the present invention, called control by phase, in which the devices of the set of electric charges 5 are controlled by the processing unit 3, which detects the input voltage 1 with a value of approximately 110V, with a preferred range of actuation of the present invention of 90V to 170V. thus, the processing unit 3 acts on the set of output switches 4 so that every wave of the input voltage 1 is supplied to the electric charge of the set of electric charges 5. In this way, the voltage applied to the devices has the value of the voltage of operation of the devices and, therefore, these devices have 100% the input voltage 1 applied to them (approximately 127V).
In an analogous way, FIG. 4 demonstrates this control mode, by phase, acting on the devices with an input voltage that has a value of about 220V, with a preferred range of actuation of the present invention from 170V to 260V. Thus, the processing unit 3 detects the input voltage 1 and defines that it should be modified before being supplied to the devices of the set of electric charges 5 and, therefore, effects a cut in the wave cycles by acting on the set of output switches 4. It should be noted that this cut by phase provides a final voltage to be supplied to the devices of half the value of the operation voltage and, therefore, about 127V. In this way, the system transmits to the devices the operation voltage, even when the input voltage 1 is different from the operation voltage of the devices of the set of electric charges 5. It should be pointed out that this control uses the Flicker rule and, therefore, is generally used for deicing resistances, fans without velocity control, among others.
FIG. 5 presents a control system for managing the devices of the set of electric charges 5 that has an operation voltage of 127V, wherein the mode called complete cycle control, in which the processing unit 3 detects that the input voltage is of about 110V. Thus, it should be noted that the processing unit 3 acts on the set of output switches 4 in such a way that the whole input voltage wave is supplied to the charge.
FIG. 6 presents the same control mode of the present invention, by complete cycle control, when the set of electric charges 5 has an operation voltage of 127V and the processing unit 3 detects the input voltage of about 220V. In this regard, the processing unit defines that the best mode of controlling certain devices that have low power and non-expressive levels of harmonics, as for instance incandescent lamps, use the complete cycle control. It should be noted that for certain occasions, as in the case of lamps, the application of whole wave cycles and cut of complete cycles may not be used, because this would result in a visible variation of the light intensity and, for this reason, one uses this control mode that produces a non-sine wave upon making physical cuts during the wave cycles.
In a different way, FIGS. 7 and 8 present devices of the set of electric charges 5 having elements that can be organized so as to be selectively actuated for operations at different voltages. Thus, FIG. 8 presents a combination of charges of the devices of the set of electric charges 5 in parallel, wherein the processing unit 3 detects an input voltage 1 with value of about 110V, while FIG. 7 inversely demonstrates a combination of charges of the devices of the set of electric charges 5 in series, wherein the processing unit detects an input voltage 1 with value of about 220V. It should be noted that the set of output switches 4 acts directly on this combination of the charges of the devices of the set of electric charges 5. This control is usually applied to devices that have high power, like electric motors usually employed on compressors, having coils that may be combined in different ways.
These electric motors are preferably induction motors usually comprising at least one stator that has one or more run windings and one or more start windings, besides a preferably cage-type rotor. These induction motors may also be of the type of controlled variable velocity, besides other types that were not cited but may be constructed with the configurations specified. In a preferred embodiment of the present invention, the coils of these induction motors are organized in T-connection, which comprises a main coil divided into two parts, which may be combined either in series or in parallel, and an auxiliary start coil connected in parallel to one of the parts of the main coil.
Finally, it is important to point out that in the technique used by this invention there is no extra consumption of power when the devices are off, since they do not use transformers, and there are various other control modes that can be cited, as for example, pulse modulation (PWM), voltage generators, converters with rectifiers and voltage multipliers (or dividers). Robust controls like those presented in the invention may therefore be used in a wide range of voltage (preferably from 90V to 260V). Thus, various types of devices can be controlled simultaneously, independently and in different ways by the present invention.
A preferred example of embodiment having been described, one should understand that the scope of the present invention embraces other possible variations, being limited only by the contents of the accompanying claims, which include the possible equivalents.

Claims

1.-26. (canceled)

27. A control system for a refrigerator, the refrigerator comprising at least one door and the control system comprising:

an input voltage (1);

a processing unit (3) configured to detect the input voltage (1); and

a set of electric devices (5) having an operation voltage, the set of electric devices (5) comprising at least a deicing resistance (9), wherein:

the processing unit (3) is configured to turn off the deicing resistance (9) while the door of refrigerator is open if the processing unit (3) detects that the deicing resistance (9) is turned on upon opening of the refrigerator door, and

the processing unit (3) is further configured to turn on again the deicing resistance (9) when the refrigerator door is closed.

28. A control system for a refrigerator according to claim 27, wherein the set of electric devices (5) further comprises a lamp (10), the processing unit (3) being configured to detect a drop in the operation voltage of the lamp (10) when the deicing resistance (9) is on.

29. A control system for a refrigerator according to claim 27, further comprising a voltage-level sensor (6), which provides information about the input voltage (1), so that the processing unit (3) can be configured for conforming the input voltage (1) detected to the operation voltage of each of the set of electric devices.

30. A control system for a refrigerator according to claim 27, wherein the processing unit (3) acts in a range of input voltage (1) from 90 V to 260 V.

31. A control system for a refrigerator according to claim 27, wherein the processing unit (3) acts on a set of output switches (4) for conforming the input voltage (1) to an operation voltage of 90 V to 127 V on each of the set of electric devices (5).

32. A control system for a refrigerator according to claim 27 wherein the processing unit (3) is configured for managing the devices of the set of electric charges (5) according to a control interface (7) of the refrigerator.

33. A control system a refrigerator according to claim 27, wherein the processing unit (3) is configured for managing the set of electric devices (5) by means of a control of phase of the input voltage (1).

34. A control system for a refrigerator according to claim 27, wherein the processing unit (3) is configured for managing the devices of the set of electric devices (5) by controlling complete cycles of the input voltage (1).

35. A control system for a refrigerator according to claim 27, characterized in that the processing unit (3) is configured for managing the devices of the set of electric devices (5) by pulse width modulation (PWM).

36. A control system for a refrigerator according to claim 27, wherein the processing unit (3) uses voltage grader, converters with rectifiers, multipliers and/or voltage dividers.

37. A control method for a refrigerator, the refrigerator comprising at least one door, a processing unit (3) configured to detect an input voltage (1) and a set of electric devices (5) having an operation voltage, the set of electric devices (5) comprising a deicing resistance (9), the control method comprising:

turning off the deicing resistance (9) while the door of the refrigerator is open if the processing unit (3) detects that the deicing resistance (9) is turned on upon opening of the refrigerator door; and

turning on the deicing resistance (9) when the refrigerator door is closed.

38. A control method for a refrigerator according to claim 37, wherein the set of electric devices also comprises a lamp (10), the control method further comprising detecting a drop in an operation voltage of the lamp (10) when the deicing resistance (9) is turned on.

39. A control method for a refrigerator according to claim 37, further comprising the step of providing information about the input voltage (1), so that the processing unit (3) can be configured for conforming the input voltage (1) detected to the operation voltage of each of the devices of the set of electric devices (5).

40. A control method for a refrigerator according to claim 37 further comprising the step of acting on a set of output switches (4) for conforming the input voltage (1) to an operation voltage of 90 V to 127 V on each of the devices of the set of electric devices (5).

41. A control method for a refrigerator according to claim 37 further comprising managing the devices of the set of electric devices (5) according to a control interface (7) of the refrigerator.

42. A control method for a refrigerator according to claim 37 further comprising managing the devices of the set of electric devices (5) by means of a control of phase of the input voltage (1).

43. A control method for a refrigerator according to claim 37 further comprising managing the devices of the set of electric devices (5) by controlling complete cycles of the input voltage (1).

44. A control method for a refrigerator according to claim 37 further comprising managing of the devices of the set of electric devices (5) by pulse width modulation (PWM).