METHOD AND ARRANGEMENT FOR SUPPLYING POWER TO SEVERAL INDUCTION COILS IN AN INDUCTION APPARATUS
First Claim
1. A method for supplying power to a plurality of induction coils in an induction apparatus, each said induction coil having a respective frequency converter and being supplied with said power by means of said respective frequency converter operating at a given frequency, wherein during simultaneous operation of the plurality of said induction coils, said frequencies of said frequency converters are set as a function of said power provided with respect to a frequency difference between said frequencies according to one of the following operating modes:
- a) said frequency difference is less than 10 Hz, b) said frequency difference is less than 1 kHz, or c) said frequency difference is between 15 kHz and 25 kHz.
1 Assignment
0 Petitions
Accused Products
Abstract
An arrangement for controlling induction coils of an induction cooking hob so as to minimize noise production resulting from intermodulation of certain frequencies of operation. The induction coils are operated in two modes, with a first mode at the same frequency fg so to produce a low intermodulation or differential frequency, or at a second mode having a high differential frequency of about 18 kHz. Alternating back and forth between said modes of operation makes it possible to reach predefined average values for the power of the induction coils for a given time period, while at the same time minimizing development of disturbing noise.
-
Citations
16 Claims
-
1. A method for supplying power to a plurality of induction coils in an induction apparatus, each said induction coil having a respective frequency converter and being supplied with said power by means of said respective frequency converter operating at a given frequency, wherein during simultaneous operation of the plurality of said induction coils, said frequencies of said frequency converters are set as a function of said power provided with respect to a frequency difference between said frequencies according to one of the following operating modes:
-
a) said frequency difference is less than 10 Hz, b) said frequency difference is less than 1 kHz, or c) said frequency difference is between 15 kHz and 25 kHz. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A system for controlling an induction hob having at least two separately controllable induction coils comprising:
-
a first induction coil associated with a first frequency converter capable of being supplied with a first power level;
a second induction coil associated with a second frequency converter capable of being supplied with a second power level;
a power source configured to supply said first power level and said second power level;
a controller configured to control over a first time period a first frequency of said first frequency converter and a second frequency of said second frequency converter, wherein the first frequency and said second frequency are set so that the first power level and the second power level add to a desired total power level, wherein further maintaining a frequency difference between said first frequency and said second frequency such that said frequency difference is;
a) less than 1 khz, or b) between 15 kHz and 25 kHz. - View Dependent Claims (10, 11, 12, 13, 14)
-
-
15. A controller comprising computer readable software configured to perform the steps of:
-
controlling a first frequency converter associated with a first induction coil to supply a first power level (P1(fg1)) to the first induction coil at a first frequency (fg1) during a first time period (tg);
controlling a second frequency converter associated with a second induction coil to supply a second power level (P2(fg2)) to the second induction coil at a second frequency (fg2) during said first time period (tg);
controlling the first frequency converter to supply a third power level (P1(fv1)) to the first induction coil at a third frequency (fv1) during a second time period (tv);
controlling the second frequency converter to supply a fourth power level (P2(fv2)) to the second induction coil during the second time period (tv), wherein a difference between the first frequency (fg1) associated with the first induction coil and the second frequency (fg2) associated with the second induction coil in the first time period (tg) is less than 1 kHz, and a difference between the third frequency associated with the first induction coil (fv1) and the fourth frequency (fv2)associated with the second induction coil in the second time period (tv) is between 15 kHz and 25 kHz. - View Dependent Claims (16)
-
Specification