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Smart cooking: A new application for power electronics.

The basic principle of induction heating is to create a time-variable magnetic field by means of Ampere’s law:

The magnetic field is then utilized to create a time-variable magnetic flux which creates an inducted electrical voltage by means of the Faraday-Neumann-Lenz law:

The inducted voltage is converted in electrical current by means of Ohm’s law:

Finally the electrical current can be converted in heating power according to Joule’s effect:

Electronics technology is betting on these physical effects to produce heat from electric power converted and applied by a set of power integrated switches like IGBTs (acronym for insulated-gate bipolar transistors, see Figure 1):

‘“ELECTROHEAT describes any heating process where electricity is the primary energy source”. I.e. an electromagnetic field (or electromagnetic radiation) interacts with the part to be heated (otherwise known as “the work-piece”), and causes it to be heated. Generally, the frequency of the electromagnetic field interacting with the work piece characterizes the heating process. The frequency of the electromagnetic radiation can stretch from DC to beyond daylight. … Recently (within the last 5 or so years), design emphasis has moved from thyristor bases inverters to IGBT based inverters. IGBTs offer three principal advantages over thyristors: The first advantage is that, unlike thyristors, IGBTs turn off when their gate signal is removed. Once turned on, a thyristor will remain conducting until it is reverse biased. This means that the power-electronic topology of an IGBT-based inverter can be considerably simpler. The second major advantage of an IGBT over a thyristor is the packaging technology is considerably easier to use. These two improvements make the manufacturing costs of the inverter considerably lower. The final improvement that IGBTs offer is that they can have considerably faster switching speeds, so the operating frequency range of an IGBT based system will be extended.’ (Source: Induction Heating Basics by Alee López )

The utilization of the IGBT in an electronic circuit shows its advantages in terms of integration offered by electronics technology to build an induction heating system:

“The principle of induction heating is simple. Coil generates high frequency magnetic field and the metal object in the middle of the coil induces eddy currents that heat it. In parallel with the coil is plugged resonance capacity to compensate its inductive nature. Resonance circuit (coil-capacitor) must be driven at its resonant frequency. Excitation current is much smaller than the current, which flows through the coil. The circuit works as a “double half bridge” with four IGBT STGW30NC60W controlled using circuit IR2153. Double half bridge is able to deliver the same power as full bridge, but the gate driver is simpler. Big double diode STTH200L06TV1 (2x 120A) works as antiparallel diodes. Much smaller diodes (30A) will be enough. If you use the IGBT with built-in diodes (e.g. STGW30NC60WD), you won’t have to use them” (Source: danyk.cz)

Figure 1

Click here for larger image 'The schematic diagram of the induction heater with IGBT's' (Source: danyk.cz)

 

“The schematic diagram of the induction heater with IGBT’s” (Source: danyk.cz)

 

Do you like the induction heating solution? Do you think this type of system will be adopted in the near future in the industry and also to cook food in restaurants, for example?

1 comment on “Smart cooking: A new application for power electronics.

  1. Popularityseo
    March 28, 2019

    Yes, i am pretty sure this type of system will be adopted in the near future.

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