The core of a commercial induction cooker's accurate identification of compliant cookware lies in the in-depth integration of electromagnetic induction principles with real-time parameter detection. This system leverages the magnetic coupling between the coil and the cookware, capturing electrical signal differences derived from magnetic field fluctuations to determine whether the cookware meets heating requirements. This prevents circuit failures caused by dry cooking or incompatible cookware.
During the initial detection phase, when the device is powered on, the coil generates a low-frequency alternating magnetic field. This magnetic field serves a primary purpose of "detection" rather than direct heating. If a compliant cookware (such as cast iron or magnetic stainless steel) is placed in the cookware, electromagnetic induction generates eddy currents, which react on the coil, causing specific patterns in electrical parameters such as inductance and impedance. The system's built-in detection circuit captures these parameter changes in real time. If there are no significant fluctuations (e.g., the cookware is absent or the cookware is made of non-magnetic material), the system determines that "no compliant cookware" is present and the heating process is not initiated, eliminating the possibility of dry cooking at the source.
To identify cookware materials, the system presets a magnetic permeability parameter range corresponding to compliant materials. The magnetic permeability of different cookware materials varies significantly. For example, non-magnetic materials like aluminum and copper have extremely low permeability, preventing them from effectively generating eddy currents. Consequently, the coil parameters will fluctuate far below the preset threshold. On the other hand, a compliant cast iron pot has high permeability, and its parameters will precisely fall within the preset range. By comparing the actual measured parameters with the preset range, the system quickly distinguishes compatible and non-compatible materials, preventing "false heating" caused by non-magnetic cookware's inability to absorb magnetic field energy. In this case, even when the device is running, the pot will not heat up, which can lead to long-term circuit load imbalance and component damage.
Checking the size and coverage area of the pot is also crucial. A compliant pot must have sufficient area to evenly absorb magnetic field energy. If the pot is too small (for example, only covering a small area in the center of the coil) or is placed significantly off-center (so that only the edges are in contact with the magnetic field), the magnetic field energy cannot be effectively transferred, resulting in localized energy concentration on the coil and abnormal fluctuations in electrical parameters. Some commercial induction cookers use a zoned coil plate detection design, using multiple detection points to determine the pot's coverage. If the coverage area doesn't meet the preset criteria, the system will determine the pot is "unsuitable" and refuse to start heating, preventing damage to the coil plate or micro-crystal plate due to local overheating.
Identifying a dry-boil condition relies on dual monitoring of temperature and electrical parameters. Even in a compliant cookware, if there is no medium (such as water or ingredients) inside, the temperature will rise rapidly during heating. A temperature sensor is installed below the micro-crystal plate or near the coil plate to measure the pot's bottom temperature in real time. When the temperature exceeds a safety threshold (such as a high temperature during a dry-boil condition), the sensor transmits a signal to the microcontroller (MCU), which immediately cuts off the heating power and triggers an alarm. Furthermore, the pot's thermal resistance changes significantly during dry-boil, causing the coil plate's electrical parameters to become abnormal again. The system uses this change to assist in the judgment, avoiding the potential delays associated with relying solely on the temperature sensor, which could lead to double dry-boil protection.
Dynamic load monitoring at the circuit level further enhances the identification mechanism. Empty cooking or use of incompatible cookware can cause load imbalance in the heating circuit. For example, non-magnetic cookware can cause the circuit current to be too low, while empty cooking can result in excessive current. The system monitors circuit current and voltage changes in real time through the IGBT module's driver circuit. When it detects that the load exceeds a safe range, the MCU quickly cuts off power output to prevent IGBT burnout due to overload or capacitor bulging due to voltage abnormalities. This creates a triple protection loop of "magnetic parameters, temperature, and electrical parameters," covering the entire process from cookware identification to operational monitoring.
The fault-tolerant design, tailored to commercial scenarios, ensures that identification is more tailored to actual usage needs. Considering that a chef may briefly jostle the cookware while stirring, causing temporary parameter abnormalities, the system implements a 1-2 second delay protection rather than an immediate shutdown. If the parameters return to normal within the delay, heating continues, avoiding frequent starts and stops that affect cooking. If the abnormality persists, a protection period is triggered. At the same time, the system will regularly calibrate detection parameters to offset component aging errors caused by long-term use, ensuring that compliant cookware from different batches and with slight wear can still be accurately identified, thereby ensuring the stability and safety of the commercial induction cooker during high-frequency use.
