Research On Noise Improvement Technology Of Induction Hob

Electromagnetic induction heating technology is one of the most popular and important technologies.It has been widely used in civil,industrial and military fields.Especially civil,induction cooker,electromagnetic water heater,electromagnetic heating for floor has entered into thousands of households.As people have higher and higher requirement of quality of life,induction hob faces same noise problem as other home appliance.In this paper,the most common single-switch parallel resonant induction hob and half-bridge series resonant induction hob in the market are taken as examples to analyze and study the noise problem.Based on the analysis of the working principle of single-switch induction hob and halfbridge induction hob,the noise source of the induction hob is given.It mainly includes mechanical vibration noise caused by electromagnetic effect,noise caused by resonance anomaly,noise caused by coil,resonance capacitor and other key components,noise caused by cooling system,noise caused by PCB layout and wiring and other factors.In order to deal with the noise caused by key components and components,this paper through the selection of components,selection and improvement of the material,process and structure of coil,IGBT and resonant capacitor to improve the noise.To cope with the noise caused by key components and components,this paper improves the noise by selecting key components,choosing and improving the material,process and structure of coil,IGBT and resonant capacitor.In terms of the influence of cooling system on noise,the design and selection of fans and the full and half speed control of fans can minimize the noise of fans.By improving circuit and software design,optimizing PCB layout and wiring to improve the electromagnetic mechanical vibration and resonance caused by abnormal noise.On the circuit respect: through EMC filter circuit,IGBT drive circuit of single-switch induction hob,synchronous feedback circuit,IGBT voltage protection and surge protection circuit,and halfbridge IGBT drive circuit optimization,the anti-interference ability of the system is enhanced.On the software respect: based on the power grid frequency of 50 Hz,invent a new IGBT Mode(Free Running PWM Mode)different from the traditional single-switch induction hob;Then the IGBT pulse width was corrected by 50 Hz waveform,and the resonant energy was adjusted by fine-tuning IGBT pulse width according to the instantaneous voltage,so as to improve the noise.On PCB optimization design respect: optimize the PCB design layout of single-switch single zone induction hob,single-switch double-zone induction hob and half-bridge double-zone induction hob,and design reasonable PCB layout to avoid the noise problem.Finally,make a summary of the noise improvement technology and test.Comparison of fan half-speed and full speed,PCB optimization before and after,good coil and damaged coil,different loads,software optimization before and after,different structure design,high power and low power,etc.is carried out.The influence of each change on the noise is obtained.The noise improvement by software invention,hardware and PCB optimization is verified.