Power supply device for a household appliance and an operating method thereof

A household appliance comprising:

• a power supply device comprising:
• a switching converter that comprises a rectifying stage electrically connected with a main power supply;
• a bus capacitor electrically connected in parallel with at least one output terminal electrically connected with the rectifying stage;
• a first resonant tank and a second resonant tank electrically connected with at least a terminal of bus capacitor;
• a first switching device has a first switching period and is electrically connected with the first resonant tank;
• a second switching device which has a second switching period and is electrically connected with the second resonant tank;
• and
• a control means configured to control the first switching device and the second switching device;
• wherein the control means operates the first switching device independently from an operating condition of the second switching device, so that at least one first electric quantity related to the operation of the first switching device follows at least one corresponding reference first waveform, and a first reference value;
• wherein the control means operates the second switching device depending on an operating condition of the first switching device and based in part on a desired power output of the power supply device, so that the first switching device and the second switching device work according to an interleaved mode and the second switching period is kept constantly equal to the first switching period, and a delay between initiating operation of the first switching device and initiating operation of the second switching device is based in part on the desired power output of the power supply device;
• and
• wherein the control means operates the first switching device, so that the at least one first electric quantity related to the operation of the first switching device varies within first predefined limits.

A method for operating a household appliance power supply device, comprising the steps of:

• connecting a power supply device electrically to a household appliance;
• configuring the power supply device with a switching converter;
• electrically connecting a rectifying stage to the switching converter;
• electrically connecting the rectifying stage with a main power supply input and a bus capacitor;
• electrically connecting the bus capacitor in parallel with at least one output terminal of the rectifying stage;
• electrically connecting a first resonant tank and a second resonant tank with at least a terminal of the bus capacitor;
• electrically connecting a first switching device and a second switching device with the first resonant tank and the second resonant tank, wherein the first switching device and the second switching device have respectively a first switching period and a second switching period;
• normally operating the first switching device independently from the operating conditions of the second switching device, so that one or more first electric quantities related to the operation of the first switching device follow corresponding first reference waveforms and/or first reference values;
• operating the second switching device depending on the operating conditions of the first switching device and based in part on a desired power output of the power supply device, so that the first switching device and the second switching device work according to an interleaved mode, the second switching period is kept constantly equal to the first switching period, and a delay between initiating operation of the first switching device and initiating operation of the second switching device is based in part on the desired power output of the power supply device.