WO2015101882A1

WO2015101882A1 - Electrical household appliance

Info

Publication number: WO2015101882A1
Application number: PCT/IB2014/067032
Authority: WO
Inventors: Alessio Beato; Stefano Frattesi; Luigi FAGNANO; Gabriele MERLONGHI
Original assignee: Indesit Company S.P.A.
Priority date: 2013-12-31
Filing date: 2014-12-17
Publication date: 2015-07-09
Also published as: ITTO20131100A1

Abstract

Described herein is a method for estimating electrical consumption levels of an appliance having a plurality of electrical loads (M, ELI, EL2, ELn) and a digital control system (ACS), which includes: - processing means (MC, MCI), configured for controlling the electrical loads (M, ELI, EL2, ELn) for the purposes of execution of an operating cycle; - sensor means (R1-R2, SS, SI, S2, Sn), for measuring quantities necessary for the processing means (MC, MCI) for controlling execution of the operating cycle; - nonvolatile-memory means (MEM), which contain program information (PD), used by the processing means (MC, MCI) for control of the electrical loads (M, ELI, EL2, ELn) during execution of the operating cycle, and information on individual consumption (CD) associated to respective first electrical loads (ELI, EL2, ELn), the information on individual consumption (CD) comprising a value representing electric power associated to the respective first electrical load (ELI, EL2, ELn). The control system (ACS) is pre-arranged for estimating at least one between values of instantaneous total power of the electrical appliance and values of consumption by the electrical appliance in a period considered, on the basis of estimated values of electric power associated to respective electrical loads. For at least some first electrical load, the corresponding estimated values of electric power are calculated by the processing means (MC, MCI) by applying to a value representing electric power at least one corresponding corrective parameter representing the instantaneous value of a corresponding quantity measured by the sensor means (R1-R2, SS, SI, S2, Sn).

Description

ELECTRICAL HOUSEHOLD APPLIANCE

DESCRIPTION

Field of the invention

The present invention relates to electrical household appliances and has been developed with particular reference paid to the issue of measurement of consumption of electrical energy.

Prior art

From EP 0 844 326 Al, based upon which is the preamble of Claim 1, there is known an electrical household appliance pre-arranged for making available to a user indications regarding consumption of resources by the appliance itself, amongst which electrical energy. This document describes in particular a laundry-washing machine having an electronic control system, comprising a main microcontroller and nonvolatile- memory means, encoded in which are data regarding the typical characteristics of consumption of the various electrical loads of the machine (pumps, solenoid valves, motors, resistances, warning lights, etc.). These data, which are the result of investigations and practical tests, form a "knowledge base" aimed at enabling identification of the consumption levels, per unit time, of the electrical loads referred to above. For this purpose, the control system is configured for obtaining the value of total consumption of electrical energy produced in the course of an operating cycle starting from calculation of the partial consumption levels produced by each individual load. These values of partial consumption are estimated by the control system, by multiplying an electric power absorbed by each load - as encoded in the memory means - by the period of time in which the load in question is rendered active during the operating cycle selected by the user, where this time is evidently known to the control logic that has the function of governing the various loads. The value of total consumption is then obtained by the control logic by adding up the individual values estimated. In this way, on a display of the machine, there may be presented an indication representative of the value of consumption of electrical energy determined by execution of an operating cycle carried out by the machine.

A drawback of the solution according to EP 0 844 326 Al is represented by the fact that the calculation of the values of consumption of electrical energy is in any case the result of estimates based upon essentially nominal values of consumption of the various electrical loads, where this calculation does not take into account variables independent of the selections that can be made by the user on the control panel of the machine.

In order to overcome the above drawback, WO 2010/049822 Al proposes a solution in which the electronic control system of an electrical appliance is purposely equipped with a device for measuring one or more electrical quantities associated to operation of the appliance itself. This measuring device - commonly known as "power meter" - is configured for supplying to the main microcontroller of the control system the value of the aforesaid electrical quantities, amongst which the consumption of electrical energy determined by execution of an operating cycle. Also in this case, the main microcontroller is pre-arranged for controlling representation of the information indicating the consumption of electrical energy, via suitable user-interface means.

The solution according to WO 2010/049822 Al makes it possible to have available rigorous, and hence effective, measurements of the consumption of electrical energy determined by execution of an operating cycle, but presupposes that the control system of the electrical appliance is equipped with solid-state components that are additional to the components normally provided. These additional components, represented by the aforesaid device for measuring electrical quantities, determines a non-negligible additional cost, which is barely sustainable for low-range electrical household appliances.

Summary of the invention

Starting from the technique known from EP 0 844 326 Al, the object of the present invention is to provide a household electrical user device, in particular an electrical household appliance, the control system of which is able to provide more accurate values of instantaneous power and of energy consumed in a period considered (for example, an operating cycle or a fraction thereof) on the basis of the estimate of the consumption of individual loads and without the use of dedicated components for measuring power and energy, i.e., additional to the ones normally necessary for controlling operation of the electrical appliance.

The above purpose is achieved, according to the present invention, by a method for estimating electrical consumption levels in an electrical household appliance and an electrical household appliance having the characteristics specified in the annexed claims. The claims form an integral part of the technical teaching provided herein in relation to the invention.

Brief description of the drawings

Further objects, characteristics, and advantages of the invention will emerge clearly from the ensuing detailed description and from the attached Figure 1, which is provided purely by way of example and which illustrates a simplified block diagram of a digital control system for electrical household appliances, suitable for implementation of the invention.

Detailed description of preferred embodiments of the invention

Reference to "an embodiment" or "one embodiment" in the framework of the present description is intended to indicate that a particular configuration, structure, or characteristic described in relation to the embodiment is comprised in at least one embodiment. Hence, phrases such as "in an embodiment" or "in one embodiment" and the like that may be present in various points of the present description do not necessarily all refer to one and the same embodiment. Furthermore, the particular configurations, structures, or characteristics may be combined in any adequate way in one or more embodiments. The references used in what follows are provided merely for convenience and do not define the sphere of protection or the scope of the embodiments. It is moreover pointed out that in the sequel of the present description there only the elements useful for an understanding of the invention will be described.

For a better understanding of the present invention, illustrated in merely schematic form in Figure 1 is an example of digital control system of a household electrical user device suitable for implementation of the present invention, in particular an electrical household appliance: in what follows, it is assumed that the appliance is a machine for treatment of textile items, such as a laundry-washing machine or a washer- dryer, even though the invention may be applied to a wide range of digitally controlled electrical household appliances. It is to be noted that the circuit structure represented schematically in Figure 1 is the one typically adopted in machines of a known type, except for the specific modalities of control of consumption of electrical energy envisaged according to the invention.

In the control system represented, which is designated as a whole by ACS, the following functional parts may be distinguished: - a main microcontroller MC, which presides over management of the control system ACS;

- a stabilised power supply PS, which generates the low d.c. voltage necessary for supplying the control logic of the electrical appliance;

- sensors SI, S2, Sn, through which the microcontroller MC acquires information regarding the process that it is controlling; in the case of a laundry-washing machine or a washer-dryer, the sensors may for example comprise a level sensor, a water-conductivity sensor, a sensor for detecting the weight of the laundry to be treated, a motor-speed sensor, one or more temperature sensors, a humidity sensor, etc.;

- electrical loads ELI, EL2, ELn, used for executing a program of operation selected by a user; with reference to the example referred to of a laundry-washing machine or a washer-dryer, the loads ELI, EL2, ELn, may comprise a motor-driven pump, one or more solenoid valves, a resistance for heating the water, an electronic- control board, a series of warning lights, a motor-driven fan, a resistance for heating the drying air, a compressor, etc.;

- actuators Al, A2, An, by means of which the microcontroller MC manages the respective electrical loads of the electrical appliance, these actuators being, for example, represented by relays or by triacs;

- driving devices DRV1, DRV2, DRVn, for controlling the aforesaid actuators, these driving devices being, for example, represented by transistors;

- a user interface UI - interacting with the microcontroller MC via a communication line CL1 - through which the user selects the function that the electrical appliance has to carry out, and the possible options corresponding thereto, and by means of which the user can receive information on the process associated to the function selected, in particular through a display or other representation means; and

- the a.c. mains supply Vac, for example at 230 V rated voltage, with live and neutral designated, respectively, by L and N, which directly supplies the various electrical loads of the appliance and indirectly supplies, through the stabilised power supply PS, the low-voltage control logic of the appliance itself (as explained hereinafter, via the mains supply voltage Vac, a motor M is also supplied indirectly).

Represented in Figure 1 is a further electrical load of the appliance, and specifically a motor M, for example operatively coupled to a drive shaft of a laundry drum. The motor M may, for example, be an induction motor or a permanent-magnet motor that includes a plurality of phase windings. In the case exemplified, it may be assumed that the motor M is a three-phase induction motor, governed via an inverter circuit of a conception known in the sector. For this purpose, in the example of Figure 1, designated by RCT is a substantially constant voltage source, comprising an AC -DC rectifier circuit, which receives an input voltage Vac. The source RCT, which may, for example, include rectifier diodes in a bridge configuration, is coupled to a DC-AC inverter designated by INV, by way of a line Vdc constituting a so-called "d.c. bus". Downstream of the source RCT, preferentially provided on the line Vdc is a bulk capacitor (not shown), connected so that the inverter INV receives a constant d.c. voltage, for example of approximately 320 Vdc (for an input voltage to the source RCT of 230 Vac rated voltage). Basically, the source RCT rectifies the a.c. voltage and pre- charges the aforesaid capacitor, which improves the form factor of the d.c. voltage applied to the inverter INV, the latter then converting the d.c. voltage into a.c. voltage at the appropriate frequency.

In the case exemplified, the main microcontroller MC manages the motor M - in the programmed times and with the programmed modalities (speed, periods of rotation, periods of pause, possible reversal of rotation, etc.) by way of a dedicated microcontroller MCI, with which it is in signal communication via a suitable bus, designated by Bl . Thus, in a sense, the auxiliary microcontroller MCI performs functions like the ones of the driving devices DRV1, DRV2, DRVn for the other electrical loads ELI, EL2, ... , ELn of the appliance.

The auxiliary microcontroller MCI is programmed for driving the inverter INV as a function of commands received by the main microcontroller MC via the bus Bl so as to connect the power on the lines of the bus Vdc to the phases of the motor 5, according to a desired pattern. The inverter INV supplies the phase windings of the motor 5 with a desired voltage and frequency, so as to generate in the motor 5 the currents necessary for rotation of its rotor. Also associated to the microcontroller MCI is a sensor for detecting the speed of the motor M, here designated by SS. The frequency and amplitude of the output voltage of the inverter INV are regulated by the microcontroller MCI according to any technique known in the sector. It should be noted that the functions proper to the microcontroller MCI may possibly be integrated in the main microcontroller MC.

The control system ASC is moreover provided with means of its own for detecting the value of the a.c. mains voltage Vac that supplies the appliance. As normally occurs in the majority of electronically controlled electrical household appliances, this measurement may be made indirectly, for example using a simple resistive divider, represented schematically in Figure 1 by the resistances designated by Rl and R2. Via the divider R1-R2, the microcontroller MC receives on a purposely provided input of its own a voltage Vvac, which is proportional to the value of the a.c. mains voltage Vac, in order to derive with known modalities the RMS value of the mains voltage Vac. A circuit arrangement of this type is normally envisaged by the control system of various electrical household appliances, for example for detecting any possible interruptions of the mains supply voltage and/or for reasons of safety (an electrical household appliance does not normally have to be able to function outside an admissible range of mains voltages).

The control system ACS comprises nonvolatile-memory means operatively associated to the microcontroller MC, which in the example of Figure 1 are designated by MEM and represented separately. These memory means may in any case be integrated in the microcontroller MC and/or in the microcontroller MCI .

Contained in the memory means MEM is program information PD and information on individual consumption CD. The program information includes the set of encoded instructions that the microcontroller MC uses for control of the various electrical loads of the appliance during execution of the operating cycles, also on the basis of the physical and/or electrical quantities measured via the sensor means SI, S2, Sn, SS. The information of consumption includes, instead, values representing the characteristics of consumption of the various electrical loads of the appliance, for example, the loads designated by ELI, EL2, ... , ELn. This information may include the value of electric power of the loads and/or their value of resistance, in the case of loads of a resistive type. These values may be nominal values or else, preferably for the most significant loads, values obtained on the basis of tests and experimental investigations, as in the approach envisaged in EP 0 844 326 Al .

As mentioned previously, the control system of the electrical appliance forming the subject of the invention is pre-arranged for making accurate estimates of consumption of electrical energy associated to its operation.

In the case of the invention, the estimate of absorption of at least some electrical loads is based not only upon values stored, but also upon the measurement of physical and/or electrical quantities that the control system in any case has to make, via the sensor means R1-R2, SS, SI, S2,... , Sn, for the purposes of execution of an operating cycle. The values of these quantities hence come to form a parameter that the control system sets in relation with the values representing electric power of certain electrical loads during execution of the operating cycle of the appliance. These quantities are here defined for simplicity as "corrective parameters", in so far as the corresponding values are used for refining pre-stored values, preferably encoded in tabular form in the memory MEM. For this reason, the information on individual consumption CD regarding at least some electrical loads includes, in addition to the corresponding values representing electric power, also the formulas that express the relation existing between such a value and the corresponding corrective parameter or parameters.

In one embodiment, the control method according to the invention, envisages different degrees of precision of the estimate of the consumption levels of the various loads, which depend upon the contribution that the loads in question make to the total consumption of the electrical appliance. In a preferred embodiment, the loads of an electrical household appliance that yield a non-negligible energy contribution may be classified from the standpoint of consumption levels in the categories listed below.

1. Fixed-consumption loads

These are electrical loads having a consumption that can be affected by external factors but the variability of which is negligible and the contribution of which to the overall consumption of the appliance is modest, such as for example the electronic- control board of the appliance, solenoid valves, small actuators, and/or similar loads with modest consumption. In general, falling within this category are loads that have a power not higher than a relatively low predefined threshold, for example 5 W, and a fixed consumption value can be assigned to them, which may correspond to their rated- power value. For these loads, then, a table encoded in the memory MEM includes the corresponding rated power, and the microcontroller MC can deduce the corresponding energy consumption within the treatment cycle via the simple formula: "activation time" x "rated power". 2. Loads with consumption depending upon a parameter

These are loads that yield a non-negligible energy contribution over the total consumption of the appliance and the consumption of which may be affected significantly by an external factor. For each of these loads, a table encoded in the memory MEM contains the value representative of the consumption of the load in question and its relation with the corresponding corrective parameter. Preferentially, the value of consumption expressed in the table is a value based upon experimental tests, for example conducted during a step of testing of the appliance.

An example in this sense may be made in relation to a resistance for heating the water or the drying air in a machine for treatment of garments. The rated power value of a resistance of this sort, which may range, for example, between 1500 W and 2200 W, usually has tolerances of 7-8%, so that it is preferable - for example, in the step of testing of the appliance - to detect the effective power or the effective value of resistance, with the datum thus detected that is stored in a table.

The precision of estimation of consumption of the resistance within an operating cycle of the appliance is further increased, according to the invention, using the value of the corresponding corrective parameter: in the example here considered, this parameter is represented by the supply voltage Vac, which the control system ACS in any case has to measure during the operating cycle, as clarified above, for example using the divider R1-R2. In such an example, the formula in the table may be of the type W_a = V²/R_e, where W_a is the refined estimated power, V² is the square of the RMS value of the supply voltage Vac detected by the microcontroller MC, and R_e is the stored value of resistance of the load in question.

An approach similar to the one exemplified may be applied in general to all the loads of a resistive type.

3) Loads with consumption depending upon different parameters

Also in this case, these are electrical loads that yield a non-negligible energy contribution over the total consumption of the appliance, but the consumption of which may be affected by a number of external factors. Consequently, for these loads, a table encoded in the memory means MEM sets in relation the value of power or representative of the power with the corrective parameters of interest, measured by the control system ACS in the state of activation of the load in question. Also in this case, the value regarding the power that is stored in the table is preferably based upon experimental tests, for example conducted during a step of testing of the appliance.

The formula expressed in the table may be of the type W_a = i(Wd, Pi, P₂, ), where W_a is the refined estimated power, Wd is the stored power of the load in question and Pi and P₂ are the values of the corrective parameters detected by the microcontroller MC via the sensor means R1-R2, SS, SI, S2, ... , Sn.

An example of a load of this sort is a compressor, which in the case of electrical household appliances may equip a refrigeration apparatus or a machine for treatment of textile items provided with a heat pump. External parameters that significantly affect the consumption of a compressor are the temperature of the evaporator associated to the compressor and the supply voltage of the latter. Experimentally, it may in fact be noted that the consumption of electrical energy of a compressor depends not only upon the supply voltage, but also upon the temperature of a different part of the refrigerating circuit to which the compressor belongs, and specifically the temperature of the evaporator, which is a function of the pressure inside the circuit and indicates a greater or smaller stress of the compressor itself. From the temperature detected on the evaporator and from the supply voltage Vac - which are measurements that the control system in any case has to make for managing operation of the electrical appliance -the stored value representing the power of the load can thus be corrected.

Obviously, the number "n" of the corrective parameters could be higher than two, with the formula that may be generalized as W_a = i(Wd, Pi, P₂, ...Pn,). An example of electrical load the value of consumption of which may be correlated to various parameters is a universal motor, for example used instead of a three-phase motor for driving a laundry drum or for driving devices such as pumps and fans. The consumption of such a motor depends not only upon the supply voltage, but also upon the r.p.m. and the phase angle, which are quantities that can in any case be detected by the control system ACS for managing normal operation of the electrical appliance. The value of Vac, as has been said, may be detected by the microcontroller MC via the sensor Rl- Rl, the value of speed of the motor may be detected via a corresponding speed sensor forming part of the sensor means SI, S2, Sn (for example, a tachometer or an encoder), whereas the phase angle can be calculated by the microcontroller MC on the basis of the measurement of the supply voltage and current (also the total value of the a.c. mains current absorbed instant by instant by an electrical appliance is normally detected by its control system, usually via a suitable measuring resistor traversed by the aforesaid current).

4) Loads with dedicated control

These are complex loads, which yield a non-negligible energy contribution over the total consumption of the appliance and management of which is entrusted to an additional microcontroller of the control system of the electrical appliance. In these cases, the estimate of the value of power and/or energy is made directly by the microcontroller which controls the load in question and then transmits this value to the main microcontroller of the control system, which then aggregates it with the consumption levels of all the other loads.

A typical example in this sense is represented by a three-phase motor, such as the one designated by M, operation of which is managed by the dedicated microcontroller MCI . Also for loads of this type the estimates of power and/or energy are made by the dedicated microcontroller by measuring quantities that are in any case already available to the control system, and specifically - with reference once again to the example of the motor M - the supply voltage, the phase current, and the r.p.m. of the motor, which must in any case be known to the auxiliary microcontroller MCI for managing the motor M.

Also in the case of the motor M, in fact, the microcontroller MCI makes a measurement of the d.c. supply voltage Vdc via a resistive divider. On the other hand, the phase currents of the motor M can be detected by the microcontroller MCI using, for example, one or more resistors with extremely low values of resistance for converting the value of the current into a voltage value proportional thereto.

The microcontroller MCI can then communicate the information of estimated power and/or estimated energy to the central microcontroller MC via the bus B l . Obviously, if control of the complex load is made directly by the microcontroller MC, there is no need for an auxiliary microcontroller or the corresponding communication bus.

On the basis of the state of the various electrical loads, the purposely programmed microcontroller MC aggregates the contributions thereof in terms of power and thus updates the estimates of the instantaneous total power and the total energy.

The value of the instantaneous total power is calculated by the microcontroller MC by adding up the estimated values of electric power associated to the respective active electrical loads of the electrical appliance. The value of total energy consumption in a given period, which may for example refer to an operating cycle of the electrical appliance or to a fraction thereof (for example, the washing step, the spinning step, the drying step, etc.), is instead obtained by the microcontroller MC through the estimate of partial levels of consumption of electrical energy, produced by the electrical loads that have been activated in the period considered, these partial consumption levels being then added up.

At least for the electrical loads of the sets previously indicated as having consumption levels 1), 2) and 3), these partial consumption levels are obtained by multiplying the corresponding estimated value of electric power by the period of time in which the load has been activated in during the period considered.

The aforesaid estimated values of electric power are obtained by the microcontroller MC on the basis of the information on individual consumption CD associated to a corresponding electrical load.

In the case of the loads of type 1), the information on individual consumption is practically represented by a stored value (which may, as has been said, be a value representing the rated power). For these loads, then, the estimated value of electric power is obtained without applying any corrective parameter.

In the case of the loads of type 2) and type 3), instead, the information on individual consumption CD comprises, in addition to the corresponding stored value representing electric power (which may, as has been said, be the fruit of experimental tests), also the mathematical formula that expresses the relation existing between this value and one or more corresponding corrective parameters. For the loads of type 2) and type 3), then, the estimated values of electric power are calculated by the microcontroller MC by applying to the aforesaid stored value one or more corresponding corrective parameters, each of these parameters representing the value, for example the instantaneous value, of a corresponding quantity measured by the sensor means R1-R2, SI, S2, Sn, SS (with reference to the examples described, the quantities in question are voltage, temperature, speed, phase angle). Finally, as regards loads of type 4), the corresponding estimated values of electric power and the corresponding value of partial consumption of electrical energy are directly calculated by the dedicated microcontroller MCI or, in the absence of this, by the microcontroller MC, via processing of the values of a plurality of quantities detected via the sensor means (with reference to the examples described, the quantities in question are phase voltage and current).

In one embodiment, the value of total energy is calculated by multiplying the value of instantaneous total power by the duration of the cycle or of the fraction of interest, or in any case of the period considered. More precisely, with reference to an operating cycle of an appliance with discontinuous supply, the value of total energy can be obtained by multiplying the value of instantaneous total power by the period during which the appliance is turned on, given that the device remains supplied - for a more or less lengthy time - both prior to start-up and after the end of the cycle (consumption before and after the cycle may, however, be considered negligible).

The above embodiment is, from the processing standpoint, the simplest.

Each of the values of the quantities that constitute the corrective parameters can be an instantaneous value, for example the one detected by the control system ACS at the instant where calculation of the instantaneous total power is required. For the calculation regarding the total energy, the value of each corrective parameter may be the one detected at a predefined instant or when a predefined operating condition of the load is reached (for example, immediately after start-up of the cycle for the voltage, after a certain period of activation of the compressor for the temperature, immediately after start-up of the universal motor for r.p.m. and phase angle, etc.). It is also possible, once again for the purposes of calculation of the total energy, to pre-arrange the microcontroller MC in order to make an average of a number of measurements of the quantities of interest, and then use the average value as corrective parameter used for calculation of the estimated value of electric power to be multiplied by the time of activation of the load concerned.

In a different embodiment, which is particularly advantageous in the case where it is desired to have available a precision of estimation that is even more accurate, the microcontroller MC is programmed for estimating the value of energy consumption in a given period (the cycle or a fraction thereof) by adding values of instantaneous total power: in a particularly advantageous embodiment, this is obtained by calculating the integral of the instantaneous total power of the entire appliance, or else by calculating the integrals of the estimated values of electric power of the various loads, and then adding them together.

In one embodiment, for example, the cycle time (or a fraction thereof) is divided into a number of intervals, that are sufficiently short as to enable, within each of them, measurement of the instantaneous power, with the modalities explained above, the instantaneous power being then assumed as constant within the interval itself. The instantaneous power may be the total power or the power calculated for each active load. The instantaneous power detected in each interval is multiplied by the length of the interval itself, and the products of all the intervals are added up: in this way the value of the energy consumed by the entire appliance or by the individual load is obtained, and in the latter case the values of energy of all the loads are then added together. The calculation is approximate, and the approximation improves when the number of the intervals increases.

This is particularly advantageous when the quantity of interest is liable to significant fluctuations in the short term, i.e., during the period of activation of the load to which it is correlated. In this case, there may consequently be made a succession in time of measurements of the quantities of interest, for example once every second, so as to estimate with greater precision the evolution in time of the instantaneous power and be able to make the calculation of the energy with an operation of integration of the power in time.

The estimated values according to the invention are advantageously rendered explicit, for example communicated to the user through the interface UI that the appliance has available. In addition or as an alternative, there may be envisaged the possibility of providing indications on the consumption levels through an interface device external to the appliance, or else communicating these indications to a remote centre, in the case where the appliance is pre-arranged for this purpose, according to modalities in themselves known.

The value of instantaneous total power may, for example, be represented at intervals on a display of the interface means or represented continuously and updated in a cyclic way. The value of energy consumption may, for example, be displayed at the end of an operating cycle of the electrical appliance selected and started by the user and/or at the end of a fraction thereof that is considered. Obviously, the control logic may be prearranged for displaying values of energy consumption referred to different periods, for example values that can be set by the user from among a plurality of possible options, such as for example the consumption starting from when the appliance has been installed, or a different reference period (a week, a month, a year, etc.). Likewise, the control system ACS can be pre-arranged for displaying on the interface means the progressive consumption of energy, i.e., by updating in time real the value displayed, from start-up to the end of the current operating cycle and/or of the different period of interest.

From the foregoing description there emerge clearly the characteristics of the present invention and its advantages, which are mainly represented by the greater accuracy of estimation of the values of instantaneous power and of energy consumed as compared to what is described in EP 0 844 326 Al, but without thereby implying the need to use dedicated components for measuring power and energy in addition to the ones normally necessary for controlling operation of the electrical appliance, as is instead the case of WO 2010/049822 Al.

It is clear that, for the person skilled in the art, numerous variations may be made to the method and the electrical appliance described herein by way of example, without thereby departing from the scope of the invention as defined in the ensuing claims.

Claims

1. A method for estimating electrical consumption levels of an electrical household appliance designed for execution of at least one operating cycle, the electrical appliance having a plurality of electrical loads (M, ELI, EL2, ELn) and a digital control system (ACS), which includes:

- processing means (MC, MCI), configured for controlling the electrical loads (M, ELI, EL2, ELn) for the purposes of execution of the operating cycle;

- sensor means (R1-R2, SS, SI, S2, Sn), for measuring quantities necessary for the processing means (MC, MCI) for controlling execution of the operating cycle; and

- nonvolatile-memory means (MEM), which contain program information (PD), used by the processing means (MC, MCI) for control of the electrical loads (M, ELI, EL2, ELn) during execution of the operating cycle, and information on individual consumption (CD) associated to respective first electrical loads (ELI, EL2, ELn), the information on individual consumption (CD) comprising a value representing electric power associated to the respective first electrical load (ELI, EL2, ELn),

wherein the control system (ACS) is pre-arranged for estimating at least one of:

- values of instantaneous total power of the electrical appliance, obtained by adding up estimated values of electric power associated to respective electrical loads (M, ELI, EL2, ELn) of the electrical appliance; and

- values of energy consumption by the electrical appliance in a period considered, obtained on the basis of the estimate of partial levels of consumption of electrical energy produced by the electrical loads (M, ELI, EL2, ELn) of the electrical appliance, at least some of said partial consumption levels being obtained by multiplying an estimated value of electric power associated to a respective first electrical load (ELI, EL2, ELn) by the period of time during which said load is rendered active during the period considered, said energy consumption by the electrical appliance being obtained from the sum of said partial consumption levels,

and wherein at least some of the estimated values of electric power are obtained by the processing means (MC, MCI) on the basis of the information on individual consumption (CD) associated to a corresponding said first electrical load (ELI, EL2, ELn),

the method being characterized in that for at least some of said first electrical loads (ELI, EL2, ELn) the corresponding estimated values of electric power are calculated by the processing means (MC, MCI) by applying to the value representing electric power associated to a first electrical load (ELI, EL2, ELn) at least one corresponding corrective parameter representing the value of a corresponding quantity measured by the sensor means (R1-R2, SS, SI, S2, Sn).

2. The method according to Claim 1, wherein the information on individual consumption (CD) comprises a formula that expresses the relation existing between the value representing electric power associated to one of said first electrical loads (ELI, EL2, ELn) and the at least one corresponding corrective parameter.

3. The method according to Claim 1 or Claim 2, wherein the estimated values of electric power are calculated by the processing means (MC, MCI) by applying to the value representing electric power associated to a first electrical load (ELI, EL2, ELn) at least one further corrective parameter representing the value of a corresponding further quantity measured by the sensor means (R1-R2, SS, SI, S2, Sn).

4. The method according to any one of the preceding claims, wherein the processing means (MC, MCI) are prearranged for estimating the value of energy consumption of the electrical appliance in the period considered by adding up values of instantaneous total power.

5. The method according to Claim 4, wherein the value of energy consumption of the electrical appliance in the period considered is obtained by calculating the integral in the period considered of the value of the instantaneous total power of the electrical appliance, or else by calculating the integrals in the period considered of the estimated values of electric power and then by adding them up.

6. The method according to any one of the preceding claims, wherein at least one corrective parameter is the value of the supply voltage (Vac) of the electrical appliance.

7. The method according to any one of the preceding claims, wherein, for one or more first predetermined electrical loads of the electrical appliance, in particular first electrical loads having power not higher than a predefined threshold, the information on individual consumption (CD) is constituted by a stored value; i.e., the corresponding estimated value of electric power is obtained by the processing means (MC, MCI) without applying any corrective parameter.

8. The method according to any one of the preceding claims, wherein the estimated value of electric power and/or the value of partial consumption of electrical energy of one or more second electrical loads (M) of the electrical appliance is calculated by the processing means (MC, MCI) on the basis of the values of a plurality of quantities measured by the sensor means (R1-R2, SS, SI, S2, Sn).

9. The method according to Claim 8, wherein the estimated value of electric power and/or the value of partial consumption of electrical energy of a said second electrical load (M) is calculated by a dedicated microcontroller (MCI) pre-arranged for managing operation of said second electrical load (M) and is communicated to a main microcontroller (MC) of the control system (MC) on a corresponding communication line (Bl).

10. An electrical household appliance that implements the method according to one or more of the preceding claims, comprising a plurality of electrical loads (M, ELI, EL2, ELn) and a digital control system (ACS) which includes:

- nonvolatile-memory means (MEM), which contain program information (PD), used by the processing means (MC, MCI) for control of the electrical loads (M, ELI, EL2, ELn) during execution of the operating cycle, and information on individual consumption (CD) associated to respective first electrical loads (ELI, EL2, ELn), the information on individual consumption (CD) comprising a value representing electric power associated to the respective first electrical loads (ELI, EL2, ELn),

wherein the control system (ACS) is pre-arranged for calculating the estimated values of electric power of at least some of said first electrical loads (ELI, EL2, ELn) by applying to the value representing electric power associated to the corresponding first electrical load (ELI, EL2, ELn) at least one corrective parameter representing the value of a corresponding quantity measured by the sensor means (R1-R2, SS, SI, S2, Sn).

11. The electrical appliance according to Claim 10, wherein the memory means (MEM) contain, for each first electrical load (ELI, EL2, ELn), the corresponding value representing electric power and a formula that expresses the relation existing between said value and the at least one corresponding corrective parameter.

12. The electrical appliance according to Claim 10 or Claim 11, further comprising interface means (UI), for rendering explicit said values of instantaneous total power and/or said values of energy consumption of the electrical appliance in the period considered.