Electromagnetic Heating Frequency Control for Faster Frozen Food Thawing

The patent applies preliminary action by first determining a reference frequency before the actual thawing process. The system performs a preliminary frequency sweep to identify a reference frequency that provides good matching, then uses this reference as a starting point for subsequent optimization. This preliminary step avoids the need to traverse all frequencies during the actual thawing operation, significantly reducing the time required while maintaining thawing efficiency.

The frequency determination process is segmented into multiple stages: first determining a reference frequency through a preliminary sweep, then performing localized optimization around the reference frequency. This segmentation divides the broad frequency range into a preliminary exploration phase and a refined optimization phase, reducing the overall time required compared to exhaustive traversal of all frequencies.

The patent applies local quality by focusing the detailed frequency optimization only in the local region around the reference frequency, rather than uniformly across the entire frequency range. The system performs refined frequency sweeping and comparison within a limited range centered on the reference frequency, ensuring accurate determination of the optimal frequency while reducing the overall complexity of the process.

By performing a preliminary frequency sweep to establish a reference frequency before the main optimization process, the system reduces the complexity of the subsequent frequency determination. The preliminary action narrows down the search space, making the detailed accuracy-checking process simpler and less complex than traversing the entire frequency range.

The patent applies preliminary action by conducting the frequency determination and reflection parameter measurement at low power before the high-power heating process. This preliminary low-power measurement phase ensures accurate reflection parameter data is obtained without the data lag and thermal effects that occur during high-power operation. After determining the optimal frequency at low power, the system then switches to high-power heating mode, thus maintaining both measurement accuracy and heating efficiency.

The system uses periodic action by alternating between low-power measurement modes and high-power heating modes. During the measurement phase, low power is applied to accurately capture reflection parameters without significant thermal lag. Once the optimal frequency is determined, the system transitions to periodic high-power heating cycles, ensuring both accurate frequency selection and efficient heating performance.