Patent Application
20130200880
The field of application of the invention is within the industrial sector of electrical energy in general, and more particularly in the field of reduction and saving of electrical consumption in linear and non-linear loads connected to the power grid which are in ‘standby’ or energy saving situation. The method and system of the invention are applicable in the industrial and tertiary sector, and in particular in the domestic field.
At present, a large quantity of electrical devices, such as videos, televisions, monitors, printers, photocopiers, etc., have an operating state mode known as waiting or ‘standby’ mode. Said state is similar for the user to a mode of disconnection of the apparatus, but, in fact, this is not the case, since the apparatus remains connected, consuming electrical energy.
Years ago, the disconnection of a piece of equipment literally meant this, the total disconnection of said equipment, and, therefore, that the consumption thereof was zero, or, in other words, the electricity meter did not record any consumption. Nowadays, however, the meters continue to record consumption, and the reason for this, among others, is the consumption of appliances in ‘standby’ mode’.
Increasingly frequently, electrical appliances are designed to be connected to electricity 24 hours a day, 7 days a week, and part of the electrical consumption of those appliances occurs when the apparatus is not really being used, but while the electrical appliance is in ‘standby’ mode’. In some products, such as printers or photocopiers, the ‘sleep’ or ‘standby’ mode entails an important saving. Even so, these appliances record the greatest consumption levels in ‘standby’ among office computer systems and other electrical appliances.
It is precisely the fact that the appliances are connected 24 hours a day which cause that, although the consumption in ‘standby’ of an apparatus is relatively low with respect to its consumption in normal or working mode, in absolute terms it is practically equivalent to it, since the number of hours that it consumes energy whilst it remains on ‘standby’ is much higher.
Various recent studies state that between 5 and 13 percent of electricity of domestic use consumed in developed countries may be attributed to appliances on ‘standby’, and it is forecast that this FIGURE will continue to increase due to the progressive increase in electrical appliances, computers and other electrical or electronic appliances, both in the home and in the office.
To avoid these consumptions arising from electrical appliances or other equipment provided with this ‘standby’ operating mode, there are solutions that in one or another way detect that the corresponding equipment is for a certain time in operating mode and after said time automatically disconnects.
The disadvantages of this type of solutions are varied, but the difficulty in the measurement or calculation of the power which determines that a piece of equipment is in ‘standby’ mode’ is especially notable, and consequently, the reliability and the response in its operation, i.e. the non-disconnection or the undue disconnection of the apparatus.
Other more imaginative solutions try to detect the presence of a user which theoretically is using the apparatus. In the case of solutions which whereby, for example a presence sensor, detect the presence of a user, and which therefore serves as criteria to determine when an appliance should be disconnected. As is evident, these solutions have, among others, the problem of reliably detecting when said user is present, since on many occasions, prolonged periods with absence of movement by the user could be interpreted as the absence thereof, and therefore, an erroneous disconnection could be determined. In turn, this type of solution also has the reverse problem, i.e. that the user is present in the place where the appliances are found but is not using them, for which reason, no type of energy saving is achieved.
A known method to detect that a piece of equipment has gone into ‘standby’ consists of calculating or measuring the current power that it is consuming, and to make said measurement of the power, it is necessary to differentiate between linear and non-linear loads.
A linear load, such as, for example, a water heater, as it is supplied by a sinusoidal voltage, will also consume a sinusoidal current. In this type of loads, the power calculation is relatively easy since it only depends on RMS values of voltage and current and on the power factor. The calculation of the RMS value is very simple since, as they are sinusoidal waves, the RMS value is the peak value of the wave divided by the root of two.
A non-linear load, with a sinusoidal supply voltage, will not consume a sinusoidal current but a distorted wave. In this case the calculation of the power consumed by these loads is complex since as they are not sinusoidal waves the power is not proportional to the product of the RMS values of voltage and current and the power factor. In this case, neither does the RMS value of the wave correspond to the maximum value divided by the root of two. Electronic equipment is typically non-linear loads since they integrate power sources to convert the sinusoidal voltage of 230Vrms of the grid in a DC voltage of values generally lower than 24Vdc.
Since these detection solutions of the ‘standby’ mode’ operate both with linear loads and non-linear loads, but especially with the latter since it is the electronic equipment which incorporates low consumption modes, the method of power calculation cannot be based on the measurement of RMS values and the power factor. A more sophisticated method of calculation based on the average of the instantaneous value of the power throughout a defined time period should be used:
This alternative ‘standby’ detection therefore demands instantaneous measurements of voltage and current as well as an important calculation power.
Another problem associated to this detection method is that it is necessary to define a power threshold value from which it is considered that a piece of equipment has entered in standby mode. The problem arises when we have to define this threshold value. On the one hand, the ‘standby’ consumption is quite different when we consider different types of appliances, for example, a television and a printer. On the other hand, furthermore, the ‘standby’ consumption is quite different within the same type of appliance according to their age, manufacturer, etc.
To all the above, we have to add that the circuits devoted to calculating power also have a residual consumption which in cases is quite considerable, which directly clashes with the objective for which they were created.
The objectives of the invention are achieved by a method in accordance with claim 1, a system in accordance with claim 20 and means of program coding in accordance with claim 22. The particular embodiments of the method object of the invention are defined in dependent claims 2 to 19, and of the system object of the invention in dependent claim 21.
More particularly, in order to resolve the aforementioned problem, the present invention provides, in a first aspect, a method for the detection of ‘standby’ state’ in linear and non-linear loads connected to the power grid and the automatic disconnection thereof, which comprises the following stages:
The method is based on the fact that whether it is a linear or non-linear load, the peak current consumed should undergo an important variation. This method has clear advantages with respect to the calculation method of the aforementioned power consumed: it is only necessary to sense the current consumed by the load and the calculation which is has to perform is minimum. These advantages are translated in a saving in components, space of printed circuit board and microprocessor price. Another advantages are that it is not necessary to define a threshold value if the equipment is capable of “learning” the value in normal operation and from this to detect an important variation.
In a particular embodiment, stage a) of the detection method of ‘standby’ state’, i.e. that corresponding to the production of the maximum value of the current in a load in normal operating state also comprises the following stages:
Advantageously, stages i) to iv) of the phase of production of the maximum current value in normal operating state is repeated a determined number of times and the average of all the means of the maximum current values obtained is achieved.
In a particular embodiment, stage b) of detection of entry in ‘standby’ mode’ of at least one load also comprises measuring of the maximum start-up current value in each load, and measuring of the maximum current value in each load at a specific moment, and after that the following stages,
Aforementioned stage v) is justified so that the method and system of the invention can act in the three cases described below.
It is detected that some loads, in general low power, do not modify the peak current consumed if it is in ‘standby’ at the time of the connection. This behaviour causes that the method of the invention does not disconnect said loads if said load or appliance is not used, i.e. it is not started and turned off (ON-OFF transition). Examples of this type of loads are satellite TV decoders, games consoles, etc. . . . Said behaviour is different in the case of computer screens, printers and other loads which, although they were in ‘standby’ operating mode at the time of connection, always have an important variation in the maximum value of the current.
When a load is supplied from the power grid:
Thus, on using the method and system of the invention, three cases may arise:
As has been indicated, said stage v) permits that the method and system of the invention can act in the three mentioned cases.
On the other hand, said stage v) of comparison, within stage b) of detection of entry in ‘standby’ mode’, permits contemplating five possible scenarios.
In first place, the method for the detection of ‘standby’ state’ establishes that, when the maximum current value measured at a specific moment in each load is greater than the maximum current value in the normal operating mode stored previously in the means of memory, the maximum current value measured at that specific moment replaces and is stored instead of that previous stored in the means of memory.
In the same way, the method establishes that, when the maximum current value measured at a specific moment in each load is less than the maximum current value in normal operating mode stored in the means of memory and greater than the determined percentage of the maximum current value of each load in the normal operating state, it is considered that the load is within the normal operating state.
On the other hand, the method establishes that, when the maximum current value measured at a specific moment in each load is less than the maximum current value in normal operating mode stored in the means of memory and below the determined percentage of the maximum value of the current of each load in the normal operating state, the load is considered in ‘standby’ state.
The method for the detection of ‘standby’ state’ also establishes that, when the maximum current value measured at a specific moment in each load is less than the maximum current value in normal operating mode stored in the means of memory and less than a specific value (reduced) of the current of each load in normal operating state, it is considered that the load is disconnected, or, in other words, there is no appliance or load connected to the system.
This condition obeys the need to not take into consideration the electric “noise” that any electrical appliance always has, and which logically does not correspond to a real consumption value in ‘standby’ mode’.
Finally, the method for the detection of ‘standby’ state’ establishes that, when the maximum current value measured at a specific moment in the load is between the two following values: Maximum current value in Start-up minus an HS value, and, Maximum current value in Start-up plus the HS value, it is considered that the appliance or load is in ‘standby’ mode’ from when it was started. The HS value corresponds to a hysteresis which is entered to avoid that small noises in the measurement do not permit the action of the ‘standby’ detection system.
In a second aspect, the invention relates to a system for the detection of ‘standby’ state’ in linear and non-linear loads connected to the power grid and the disconnection thereof, which comprises:
In a particular embodiment, the system for the detection of ‘standby’ state’ also comprises means of reactivation of the system, which after ‘switching off’ or disconnection thereof when all the loads have gone into ‘standby’ operating mode during the determined time and established for that purpose, permit the reactivation or resetting of the system, i.e. the re-start up to be able to detect the ‘standby’ mode’.
In a last aspect, the invention relates to means of program coding adapted to execute one or several stages of the detection method in the described ‘standby’ mode.
In short, it can be concluded that the ‘standby’ detection method mode’ of the invention has a series of advantages which redound in a simplification of the method, less cost, both of the sensing elements and the associated microprocessor, and in particular, for an embodiment with mechanical reactivation means, the zero consumption of the detection device when this disconnects all the loads. In turn, the detection method by variation of the current peak consumed in the load or loads has the advantage that it is 100% automatic and it is only necessary to detect important current variations and that, therefore, it is not necessary to have great precision or a large calculation power.
To complement the description being made, and in order to help towards a better understanding of the characteristics of the invention, in accordance with a preferred and practical embodiment thereof, a single FIGURE is attached as an integral part of said description, wherein with an illustrative and non-limitative character, a flow chart has been represented which implements the ‘standby’ detection method of the present invention.
Below, a preferred embodiment of the ‘standby’ detection method of the invention is described by means of a functional diagram represented in
The method starts with two main parts a) and b). During the first part a) (stages i) to iv)) the maximum current value is sought, and it is stored as start-up peak value; then, the second part b) (stages v) to vi)) of the method start, where this “supervises” if the appliance or load enters in ‘standby’ mode. To do this, the maximum current value measured is sought and it is compared with the maximum value in normal operating state and with the maximum start-up current value.
More particularly, the first part of method a), comprises the following stages:
On the other hand, preferably, the value of the number of times N that stages 1 to 3 is repeated is between 20 and 200, and particularly N is 40.
To obtain a more precise maximum value, part a) of the method is repeated a number of times M and then the average is calculated. Preferably, the number of times M that part a) of the method is repeated is between 2 and 16, and particularly M is 8.
Part b) of the method, i.e. that relative to the “supervision” of whether the appliance or load enters in ‘standby’ mode comprises measuring of the maximum start-up current value in each load, and measuring of the maximum current value in each load at a specific moment, and after that the following stages,
The comparison made in stage v) of part b) of the method poses five possible scenarios:
Preferably, the value of P is between 30% and 50%, and particularly P is 50%. On the other hand, both the preferred value of U and that of HS is approximately 100 mA.
Subsequently, in the cases where it is considered that the load is in ‘standby’ mode or in ‘not connected’ mode, a timer T is started for each load.
Finally, the load and the means of detection are disconnected when value T of the timer is reached without the load having returned to normal operating state. One of the main advantages of the method and system of the invention is again underlined, i.e. the zero consumption of the system when the load is disconnected, as the means of detection are also disconnected. In said situation, the system reset is carried out by mechanical reactivation means, such as, for example the pushing of a button provided for said purpose.
When a load wherein ‘standby’ has been detected, and consequently the timer T had been started, goes on to normal operating state, the timer is reset.
This application is filed under the provisions of 35 U.S.C. §120 and is a continuation of U.S. patent application Ser. No. 12/600,680, filed on Nov. 18, 2009 and entitled “METHOD AND SYSTEM FOR DETECTION OF STANDBY STATUS IN LINEAR AND NON-LINEAR CHARGES CONNECTED TO THE ELECTRICITY MAINS AND AUTOMATIC DISCONNECTION THEREOF” in the name of Jesús BARTOLOMÉ GARCÍA, which claims priority to International Patent Application No. PCT/ES2007/000291, filed May 18, 2007, both of which are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12600680 | Feb 2010 | US |
| Child | 13568759 | US |
