Study On The Control Technique Of Inductively Coupled Power Transfer System And Its ZCS Soft Switching

As a new type of electric power transmission technology, Inductively CoupledPower Transfer (ICPT) technology transfers electric power on the principle of thespace magnetic field coupling. Contrast to traditional power transmission technology,ICPT technology can deliver power over electrical isolation and the absence ofmechanical contact between the power supply and the load, with advantages of lowmaintenance cost, high reliability, and the ability to operate in all kinds ofinflammable and explosive environment. This technology is increasingly used indigital device, wireless power supply to home appliances, medical use and contactlessbattery charging for electric vehicles.This paper mainly studied on the Control Technique of Inductively CoupledPower Transfer System and its ZCS Soft Switching. The main operation principle,research status and development trends are first introduced.The working principle ofthe ICPT system is summarized. The ZCS Soft Switching Technique is introduced.Energy injection circuit topology and its working principle is analyzed, then putsforward the control method of energy injection which is improved, change theswitching cycle of energy injection mode and resonant mode form an integer times ofthe resonance cycle into semi-integer times of the resonance cycle, thus the systemcould switch between modes more quickly. By changing the duty cycle of energyinjection to adjust the working mode of the primary side of the inverter dynamically,achieve the purpose of controlling the output voltage. Analyzes the impact of changesin the load on the system performance parameters, calculates the duty cycle of energyinjection. Simply analyzes the system’s frequency bifurcation phenomenon, proposesthe control strategy.The system is simulated by using MATLAB/Simulink. The phenomenon offrequency bifurcation is demonstrated by the simulation results which show that thecontrol method of energy injection makes the inverter working in ZCS soft switchstate, while dynamically adjusting the duty cycle when the load resistance changes.The experimental device including the main circuit, the detection circuit and thedriver circuit has been designed, and debugging is passed. Finally, experiment resultsverify the control method of energy injection.