SoC-Based In-Cycle Load Identification of Induction Heating Appliances

Abstract

The equivalent load of an induction hob is strongly dependent on many parameters such as the switching frequency, the excitation level, the size, type and material of the vessel, etc. However, real-time methods with the ability to capture the variation of the load with the excitation level have not been proposed in the literature. This is an essential issue as most of the commercial induction hobs are based on an ac bus voltage arrangement. This paper proposes a method based on a phase sensitive detector that offers an online tracking of the equivalent impedance for this type of arrangements. This algorithm enables advanced control functionalities such as clustering of vessels, material recognition and premature detection of ferromagnetic saturation, among others. After simulation and experimental validation, the method is implemented into a prototype with a system-on-chip (SoC) to verify its real-time behavior. The proposed approach is applied to different real-life situations which prove its great performance and applicability.

Conductance Control for Electromagnetic-Compatible Induction Heating Appliances

“…Additionally, this model assumes that the resistance and the inductance are constant. However, the equivalent impedance varies with the excitation level so that, even if a constant f sw is applied to the inverter, the impedance would vary due to the considered ac bus voltage arrangement [5], [18]. Nevertheless, to apply the method presented in the following section and to achieve the pursued objective, the presented model is completely valid.…”

“…One of the most challenging characteristics of DIH is that the equivalent impedance R − L varies with many parameters such as the temperature, the excitation level applied to the load, the distance between the pot and the inductor, the ferromagnetic material of the pot, the switching frequency, etc. [5]. This fact is quite relevant because even the control action (f sw ) leads to an intrinsic variation of the load.…”

Load Estimation for Induction Heating Cookers Based on Series RLC Natural Resonant Current

“…[22] detected equivalent parameters by using the power factor and the absolute amplitude of the impedance |Z|. As IHCs based on quasi-resonant converters have the shortage of high-voltage stress on the power transistors [23], many studies [24][25][26][27][28][29][30] have focused on estimation methods for HBSRCs; specifically, these studies have proposed estimation methods based on single values or the average value of feedback electrical signals within a bus voltage cycle [24][25][26][27]. One of these studies [24] used a phase-sensitive detector, the inputs of which are multiplied by sine and cosine signals of the feedback voltage and current, respectively, and calculated R eq and L eq by using a low-pass filter.…”

“…A study also determined the EHCR of cookware by using deep learning [28]. Two studies [29,30] have considered the influence of bus voltage variations on R eq and L eq estimations. Furthermore, another study [31] executed power control by changing the operating frequency; the study used the DFT to calculate the equivalent impedance from the resonant voltage and current in an area with a relatively high DC-link voltage in order to achieve favorable power control.…”

EMI Reduction Via Resonator Coils in Glassless Integrated Domestic Induction Systems

“…Nowadays, an intense research activity is still detected in this field, mainly focused on improving the performance and reducing the cost of current cooktops. This research activity encompasses power electronics converters for an efficient use of the energy [2], [3], coil arrangements for the improvement of the user flexibility [4], [5], [6], load identification systems [7], [8], sensing functionalities [9], [10], [11], inductor PCB implementations [12], magnetic materials [13], robotized mobile inductors [14], or adapting non-metallic cookware for induction cooktops [15].…”