Study On Key Technologies Of Wireless Power Supply For Household Appliances

A high stability, good load compatibility and high efficiency wireless power supplysolution for household appliances is studied in this paper. Such solution can realize thata variety of household appliances receive energy safely and reliably within a commonenergy launch platform. Considering the actual need of the transmission power andefficiency, the resonant network parameters design with the characteristics ofconstant-frequency; constant-current; constant-voltage, the object efficiencyoptimization and the relevant protection circuits design are researched.The main works of this paper include:①Based on the stroboscopic mapping method and fixed points theory, therelationships between the operating frequency, the primary resonant current, the loadoutput voltage and load are analyzed. Meanwhile, constrains of constant primaryresonant current, constant operating frequency and constant load output voltage arediscussed. Consequently, an integrated design process for parameters of resonant tank isproposed, such method can realize that the primary resonant current, operatingfrequency and load voltage keep constant without any closed-loop control andadditional switching circuits in the designed load conditions. Therefore, the good loadcompatibility, low EMI and high stability can be achieved.②Due to the low efficiency of the wireless power supply platform under somelight loads, the main losses of designed ICPT system for household appliances areintroduced. Thus, an efficiency calculation model is presented, with the aid of suchmodel, the designed online capacitor array and the detection values of the injectioncurrent pouring into the inverter, the control strategy of the object efficiencyoptimization, namely the segmented optimal frequency dynamic tracking method has beenproposed. This method can maintain a high efficiency under all loads. However, thereliability and stability aren’t declined.③Finally, there is a detailed introduction to the protection circuit such as switchessnubber, over-voltage, over-current, over-temperature and no-load protection circuit.