Single Source Multi-Frequency AC-AC Converter for Induction Cooking Applications

Abstract

In recent years, induction heating (IH) applications aided by electronic power control have gained significance. Particularly, for cooking applications, an appropriate control technique is required to feed power from a single source to multiple loads with minimum switching losses. Additionally, when multiple loads are used, it requires independent control and operation for each of the loads. The main idea of this work is to develop a single-stage AC-AC converter topology to feed power to multiple loads independently with a single source, with a reduced number of switching devices and with minimum switching losses. The proposed topology uses a frequency bifurcation concept to feed power to multiple loads by placing the transmitting coil and work coil at a distance of 3 cm. The source is resonated at a 25 kHz switching frequency, with the designed bifurcated frequencies of 20 kHz and 33 kHz. The resonant capacitors are appropriately chosen to operate at those frequencies. For real-time applications, simultaneous and independent power control are inevitable in multi load-fed IH applications. This is achieved through a pulse density modulation scheme with minimum switching losses. The simulation of the proposed system is performed in MATLAB/Simulink, and also the 1 kW system is validated using a PIC16F877A microcontroller. The real-time thermal variation in the load is also recorded using a FLIR thermal imager. The experimental and simulation results are observed, and the obtained efficiency of the system is plotted for various duty cycles of pulse density modulation control.

Investigation on Performance of Various Power Control Strategies with Bifilar Coil for Induction Surface Melting Application

“…The pulse density modulation-based control scheme shows optimal performance with respect to heat rate, output variation, and efficiency (maximum of 89.6%). This trend is similar to that of the work published for cooking applications [17,19,[31][32][33]. • Asymmetric duty cycle control can be applied to a system where a wide range of ZVS operations are required.…”

Induction Heating in Domestic Cooking and Industrial Melting Applications: A Systematic Review on Modelling, Converter Topologies and Control Schemes

“…To increase the efficiency of the system topology and to reduce the number of components, single-stage AC-AC resonant converters have been proposed [24,26,[67][68][69][70][71][72][73][74][75][76]. Figure 7 shows the general block diagram of the single-stage power conversion topology.…”

Review on single‐phase high‐frequency resonant inverters for current sharing in multiple inverter system

“…Compared to conventional heating technology, IH does not cause pollution, so it is widely used in industry, and it is also favored by domestic cooking. [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] In microgrid systems, SPHFRI has potential for application because the use of high-frequency voltages makes harmonic filtering easier. 40,41 High-frequency transformers and other passive components are also smaller, which will significantly reduce the system cost of microgrids.…”

“…In IH systems, SPHFRI serves as a key component to convert electrical energy into safe and controllable thermal energy in a contactless and efficient manner. Compared to conventional heating technology, IH does not cause pollution, so it is widely used in industry, and it is also favored by domestic cooking 23–39 . In microgrid systems, SPHFRI has potential for application because the use of high‐frequency voltages makes harmonic filtering easier 40,41 .…”