What is Katro half-bridge induction cooker solution

31 Jul.,2025

 

Analysis of the core circuit of induction cooker

The core circuit of induction cooker is a frequency conversion circuit, whose function is to convert low-frequency mains power of 50Hz or 60Hz into high-frequency electric energy of 20kHz, and supply it to the induction coil to generate a high-frequency magnetic field. Under the action of this magnetic field, eddy currents will be generated inside the metal pot, which will generate heat to achieve the purpose of cooking.

 

At present, there are three main forms of frequency conversion circuits for induction cookers: single-tube circuit, half-bridge circuit and full-bridge circuit. Household induction cookers generally use single-tube circuit or half-bridge circuit to achieve heating. The following is a brief introduction to single-tube circuit and half-bridge circuit:

 

1. Single-tube circuit

A single-tube circuit means that only one IGBT (insulated gate bipolar transistor) is responsible for opening and closing. When the IGBT is turned on, the current will quickly charge through the coil; when the IGBT is turned off, the current in the coil will charge the resonant capacitor, thereby generating a higher reverse voltage. If this voltage exceeds the withstand voltage of the IGBT, the IGBT may break down instantly, causing damage to the machine.

 

Under normal working conditions, the reverse voltage is usually between 1000-1100V. However, when the circuit is affected by interference or other unexpected factors, this voltage may increase, so protective measures must be taken in time.

 

There is also a disadvantage of the single-tube circuit. When the power is low, it may affect the working state of the IGBT, causing severe heating of the IGBT, shortening the service life or even breakdown. This is particularly obvious when the coil is close to the heated object. Therefore, the power that a single-tube induction cooker can continuously heat is usually greater than 50% of its maximum power. For example, an induction cooker with a maximum power of 2000W may use intermittent heating at a power below 1000W, which is not applicable in many cooking occasions.

What is Katro half-bridge induction cooker solution
What is Katro half-bridge induction cooker solution
What is Katro half-bridge induction cooker solution

2. Half-bridge circuit

The half-bridge induction cooker uses two IGBTs to turn on and off. When one IGBT is turned off, the other IGBT is turned on, thereby avoiding the problem of high reverse voltage, eliminating the hidden danger of overvoltage damaging the IGBT, and greatly improving the reliability of the product.

 

Another advantage of the half-bridge circuit is that the continuous power can be made very low, and there is no problem of low power affecting the working state of the IGBT. Theoretically, the half-bridge circuit can achieve continuous heating of all powers. However, due to the limitation of the operating frequency of components, it can generally achieve 20% of the maximum power, and even 10% of the maximum power under special design. That is, a 2000W induction cooker can also achieve continuous heating at a power of 200W, so that all fire gears can be heated continuously, greatly improving the practicality of the induction cooker.

 

Generally speaking, the maximum design power of the half-bridge circuit is about 20~30KW, which is far from the reach of a single-tube circuit. Different manufacturers will have different designs for half-bridge circuits. There are many different implementation methods from PWM generation, power control, phase control, current detection to IGBT drive. Therefore, there will be significant differences in product performance and reliability. Reasonable design becomes the most critical link.

 

Katro's already launched half-bridge induction cooker uses self-developed half-bridge technology, which achieves a qualitative leap in performance while achieving 20% ​​energy saving. The upgraded technology can detect pots as small as 8cm to meet the cooking needs of different user families. Technological advances make it possible to choose round or square coils, suitable for built-in products in sizes of 30cm, 60cm and 77/90cm. Most importantly, our costs are 10~15% lower than the industry level, giving our customers a more competitive advantage in the market.

 

If you want to know more about katro half-bridge induction cooker, contact us now!