Patent Application
20140232315
The present invention relates to a method and a system for controlling input voltages for charges that have selective organization of electric components for more than one voltage, preferably for induction motors used on cooling compressors.
At present, several countries diverge as to the production and distribution of electric energy, with different voltage levels in each country. Thus, the great majority of electronic apparatus, such as computers, television sets, stereos, among others, have a bi-voltage characteristic comprising an automatic voltage control that enables the adjustment of input voltages for its perfect functioning at specific voltages. This characteristic is still little known in the area of household appliances, because most of them need electric motors to function, being limited by present-day techniques due to factors like power and control, among others.
In this regard, the few of these products that enable functioning at bi-voltage have manual switching made by the final user by means of a switch, which usually modifies the organization of coils of the charges for its functioning. However, few users have specific knowledge for these functions, which often causes functional errors, as partial loss of functionality, or even blowing the product. Additionally, it may cause hazards to the user, depending on the level of protection of the apparatus.
In order to prevent these hazards, and increase the protection to the user and avoid unnecessary maintenance by guarantee services, thus decreasing losses in the image associated to the product manufacturer, the automatic changes in input voltage to the acceptable level of functioning of the apparatus become compulsory practice.
Analogously, single-phase induction motors are widely used on refrigerators by virtue of their simplicity, robustness and high performance. Specially applied in various household appliances like refrigerators, freezers, air conditioners, washing machines, among others, induction motors are usually provided with a cage-type rotor and a stator having coils that are usually composed of two windings, which are selectively used for the state (start or run) in which the induction motor is.
In this regard, during normal operation of the compressor a run winding is fed by an alternating voltage, while a start winding is only fed during the first moments of functioning of the motor, since the beginning of the movement need higher power for accelerating the motor. Therefore, motors are designed and built specifically to function at certain limited ranges of voltage, typically with variations not higher than 10% above and below the designed level. If these variations are higher than 10%, a new design and construction of the motor are required.
For this reason, possible attempts to solve this problem appear in documents that disclose bi-voltage systems. Document U.S. Pat. No. 4,415,964 describes a design in this sense, which provides a system capable of adjusting automatically the voltage output, regardless of the input voltage, modifying the organization of coils of an output transformer, upon altering the coils to a configuration in parallel, when it is turned on 110V, thus causing a 110V-output, and, in a contrary manner, altering the coils to a configuration in series when it is turned on 220V, thus repeating a 110V-output. However, in this construction the document limits possible charges to be fed, as well as the control over them, since it uses a transformer as the output, rather than the direct organization of the charges at which it is actuating.
Additional information that is considered in the prior art is presented in document U.S. Pat. No. 5,001,623, that describes a system for automatically controlling the voltage output with a direct-current, which, however, has the same problems as the above-mentioned document, and document U.S. Pat. No. 7,528,734, that describes a system that indicates the input voltage, capable of warning the user about whether the voltage present at that specific point is the desired one for the functioning of the apparatus, but without changing or controlling the output voltage.
It should be noted that all the documents presented are greatly susceptible of oscillation transients and other disturbances on the feed lines, besides presenting enormous consumption of energy and manufacture/maintenance costs, in comparison with the present invention.
Thus, it is an objective of the present invention to provide a device for automatic voltage control, with simple and robust topology, in addition to reduced cost, which enables use on a large scale and reduction of models required for a given family of products for markets of different voltages.
It is another objective of this invention that the electronic control over these devices should have negligible consumption of energy.
A further objective of this invention is that the electronic control should be less susceptible to oscillation transients or disturbances from the feed network.
It is a further objective of this invention that the electronic control should be capable of adjusting induction motors or electric charges automatically and without the need to change of manual switches.
Another objective of this invention is to provide a specific organization capable of providing electronic protection of charges by monitoring the voltages applied to them, the currents and/or temperatures thereof.
Still another objective of this invention is to provide a specific system for integrated assembly of motors.
One first embodiment of the invention presents a system for controlling input voltage in electric charges, the electric charges having a coil arrangement that can be selectively actuated for operation at different levels of input voltage, the system comprising at least one processing unit and the a set of output switches. The processing unit is configured to detect the input voltage and to actuate on the set of output switches for carrying out the selective actuation of the electric charge, so that the electric charges will operate at the level of the input voltage detected by the processing unit. The system for controlling input voltage in charges may also comprise a network sensor that supplies the input-voltage values to the processing unit in a different configuration. Preferably, this system is configured to operate an inductive motor that comprises a set of claims that can be modified for actuation in series for the input voltage with value of 220V or in parallel for input voltage with value of 110V.
In another embodiment, the invention adds to the system for controlling input voltage in electric charges a protection sensor capable of supplying information on current, voltage and/or temperature to the processing unit. One should also consider an embodiment in which the system comprises a control reference unit capable of supplying references of current, voltage and/or temperature to the processing unit.
The invention also relates to a method for controlling input voltage ion electric charges, the electric charges having an arrangement of coils that can be selectively actuated for operation at different levels of input voltage, which comprises first step of detecting the input voltage and second step of actuating a set of output switches depending on the input voltage detected in the first step. Additionally, the method comprises a third step which modifies the arrangement of coils in the electric charges for operation at the level of input voltage detected in the first step. This method is also applied preferably for modifying the coil arrangements of an inductive motor, preferably actuating in series when the first step results in a value of 220V or in parallel when the first step results in a value of 110V.
Another method of controlling input voltage in electric charges presented is comprises a fourth step of detecting current, voltage and/or temperature of the electric charges for carrying out fifth step of protecting the electric charges, which prevents the functioning of the electric charges if the values detected in the first step are considered out of standard. The fourth step may further be configured so as to carry out the comparisons with respect to reference values established previously for specific states of the electric charges.
The present invention will now be described in greater detail with reference to an embodiment represented in the drawings. The figures show:
The electric charges 5, preferably used by this system, are single-phase induction motors, which comprise at least one stator having one or more run windings and one or more start windings, besides a rotor, preferably of the cage type. These induction motors may also be of the type of controlled variable velocity, in addition to others that were not cited but that can be built with the specified configurations.
In this regard, the system for controlling input voltage comprises an input voltage 1 that feeds a source of direct current 2 capable of supplying energy for the functioning of the processing unit 3, also fed by the input voltage 1, configured for detection of the dimensions of this input voltage 1 applied to the system. The detection of the system is made directly, the input voltage 1 being sent directly to the processing unit 3, which calculates and defines the voltage values.
Thus, the processing unit 3 is capable of actuating selectively on the set of output switches 4, which preferably comprise electromagnetic switches (such a relays or solenoids) or electronically controlled switches (such as static, TRIACs or transistors), also fed by the input voltage 1 and is capable of actuating so as to reconfigure the organization of the electric charges 5, so that the electric charges 5 will be better organized for the functioning at the input voltage 1 detected. Thus, the set of output switches 4 selects preferably an organization of coils in parallel for input voltages 1 of value 110V, while reversely selects an organization of coils in series for input voltages 1 of value 220V.
Analogously,
Thus, the processing unit 3 is capable of actuating selectively on the set of output switches 4, also fed by the input voltage 1. The set of output switches 4 is then capable of actuating so that the electric charges 5 will be better organized for the functioning at the input voltage 1 detected.
Similarly,
In this regard,
It should be noted that only
A preferred 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.
| Number | Date | Country | Kind |
|---|---|---|---|
| PI1102466-6 | May 2011 | BR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/BR2012/000153 | 5/24/2012 | WO | 00 | 4/17/2014 |
