The Design And Realization Of The Electronic Control System For High Power Induction Cooker

High-power induction cooker is a kind of heating equipment which is used for heating and cooking food in the kitchen. It uses the high frequency alternating current to produce the alternating magnetic field when it runs through the coil. Alternating magnetic field in the bottom of a ferric pan will generation induction currents named eddy current, which causes the pan to heat with high speed. High-power induction cooker has a series of advantages such as heating speed, high efficiency, uniform heating, sanitation, environmental protection and energy-saving. It is one of household electrical appliances whose development is quickest and the market growth rate is highest at the present. This paper designed the control system based on the principle of induction heating and completed the control system's hardware and the software design of the high-power induction cooker. The main content is as follows:In this paper, the heating principle of the high-power induction cooker is introduced briefly. It researched the load equivalent circuit and ensured the entire solution for the control system. This solution use PIC18F458 as the core processor, three-phase uncontrolled rectifier circuit and single-phase bridge voltage model inverter circuit as the main circuit on hardware level and pulse frequency modulation(PFM) as the mode to adjust the output power.The hardware platform of the high-power induction cooker, including the main circuit, the main controller, Voltage, current, temperature signal detection, IGBT insulating driving and protecting circuit, human-machine interface is described clearly in chapter 3. Due to the request of driving circuit for IGBT, the insulating driving circuit, the Over current Protection circuit and the measure of anti-jamming for IGBT are researched. Integrated driving module EXB841 is used to drive IGBT. The hardware dead time control circuit and the improvement of the IGBT driving circuit are enhanced the security and the reliability for IGBT.Constant power output control strategy is put forward based on fuzzy -PI compound control of quasi-voltage, current dual-closed-loop control in the chapter 4. The merits of fuzzy control, PI control and quasi-voltage, current double close-loop control are used in the pulse frequency modulation. So the system has good performance of the transient and steady-state performance and complete the constant power output for each gears. The output power is always follow the input power and maintain the stability of firepower.In the software design, it uses the ideas of modularized program design to carve up and design each function module in the high-power induction cooker. The soft of the power control strategy based on fuzzy-PI compound control is designed in this chapter. Intelligent cooker testing technology enhances the rapid detection and accuracy for the pan and reduces electromagnetic pollution and saving electricity.Finally, the equipment is entire assembled and debugged. After many times testing and running, it has proven that this system features with reasonable, output power steady, safety and reliable.