Method for measuring the mains frequency, and electrical appliance that implements said method
AssigneeIndesit Company S.p.A.
InventorsValerio Aisa, Enrico Smargiassi
Life of this patent
Estimating the term…
Abstract
A method for measuring the mains frequency by a digital control system of an electrical appliance, in particular an electrical household appliance, in which the digital control system is prearranged for performing rigorous measurements of the value of the mains frequency and of its variations through an operation of calibration of the means for measurement of the mains frequency performed prior to marketing of the product.
Claims21
1-20. (canceled)
Method for measuring the frequency of an a.c. mains voltage that supplies an electrical appliance, particularly an appliance pre-arranged for varying in a dynamic way its own absorption of electrical power, the electrical appliance including an electronic control system that includes a detector, the method comprising the steps of
- measuring, via the detector, a frequency value of the mains voltage;
- correcting the frequency value measured by the detector via the control system by reading a correction parameter representing systematic errors of the detector from a memory of the control system;
- and
- processing the measured frequency value on the basis of the correction parameter.
An electrical appliance including
- at least one electrical load adapted to be supplied with an a.c. voltage,
- means for the connection to a network for supply of the a.c. voltage, and
- an electronic control system adapted to manage said electrical load, the control system comprising
- measuring means for measuring a value of frequency of the mains voltage,
- a memory containing a parameter for correction of the frequency value measured by the measuring means, and
- at least one electronic microcontroller configured for correcting the measured frequency value using the correction parameter, in order to obtain a corrected frequency value that is not affected by systematic errors of the measuring means.
A method for the dynamic control of the electrical-power demand by an electrical appliance having at least one electrical load that is adapted to be supplied with an a.c. mains voltage, a means for connection to a network for supply of the a.c. voltage and an electronic control system adapted to manage said electrical load, the method comprising the operations of:
- i) measuring, via a measuring means of the control system, a frequency value of the mains voltage;
- ii) correcting the measured frequency value in order to obtain a corrected frequency value, the correcting operation being performed via a microcontroller of the control system on the basis of a correction parameter representing systematic errors of the measuring means by reading the correction parameter from a memory of the control system, said operation of reading being performed via the microcontroller;
- and
- iii) varying the power absorption associated with said electrical load as a function of the corrected frequency value.
A process for prearranging an electronic device for measuring the frequency of an a.c. voltage, the electronic device being of the type designed for connection to an a.c.-voltage electrical network and comprising a detector for detecting a value of frequency of the mains voltage, the detector having a respective precision or resolution of measurement of frequency, the process comprising the steps of:
- i) providing a frequency-measuring device having a precision or resolution of measurement higher than that of the detector of the electronic device;
- ii) electrically connecting the measuring device and the electronic device to the same a.c.-voltage electrical network;
- iii) obtaining a first value being indicative of the frequency of the mains voltage, on the basis of at least one measurement performed via the detector of the electronic device;
- iv) obtaining a second value being indicative of the frequency of the mains voltage, on the basis of at least one measurement performed via the measuring device;
- v) calculating, on the basis of the first and second values being indicative of the frequency, the value of a parameter for correction of frequency measurement, the correction parameter being in particular representative of systematic errors of the detector of the electronic device;
- vi) storing the value of the correction parameter in the electronic device;
- and
- vii) using the correction parameter for the purposes of subsequent measurements of the mains frequency performed via the respective detector means,
- wherein the steps i) to vi) are performed in the course of the manufacturing process of the electronic device or in a testing step thereof.
Dependencies are inferred from the claim text.