Research And Implementation Of Contactless Power Supply Led Drive Power Supply

Wireless power transmission technology can make the electrical isolation,get rid of the shackles of the transmission line.So the application of electric energy is more broad and more flexible.With the continuous development of people's demand,the advantages of wireless power transmission technology,such as safety,reliability,convenience and flexibility will be more obvious.Therefore wireless power transmission technology will not only have a more broad application prospects,but also have great research significance and application value.In this thesis,the research of LED power supply is a practical application of wireless power transmission technology in the field of life.In this thesis,based on the flyback topology,the circuit is designed to realize the wireless energy transmission.The transmission coil in the circuit can be regarded as the actual deformation of tight coupled transformer.Using the analysis method of similar tight coupled transformer,combined with the transmission coil's own characteristics,transmission coil in the circuit is modeled and analyzed.Then the T equivalent model and mutual inductance model is given.According to the theoretical analysis of the transmission coil,the equivalent circuit of T is designed and the equivalent circuit is obtained.The working process of the circuit is analyzed,and the circuit is divided into four stages,and each stage is analyzed in time domain or transform domain.The design of control loop circuit adopts the primary loop control strategy.Small resistance is used to sample the current of main circuit.The differential circuit detects the main circuit current when it is zero,then produces synchronous pulse.Thereby MOS driving pulse circuit is synchronized,and the stable resonant state of the the main circuit be maintained.The average value of the main circuit current is controlled by an integral circuit.By controlling the turn-on time of the switch,the power of the main circuit can be kept stable.In order to meet the requirements of the frequency,MOS tube drive circuit is transformed in the two output of the SG3525.In this way,the two ends together control MOS tube opening or closing.In the actual design and manufacture of the hardware,according to the theoretical basis of the transmission coil,the coil are designed and fabricated.Then the actual parameters of the transmission coil is measured by the bridge.The parameters of components in the circuit are put into the circuit theory model,and the Matlab is used to analyze the circuit.According to the circuit principle diagram,PCB is designed and the hardware circuit is made.Debugging in the hardware circuit,the actual waveform of the circuit is measured by the oscilloscope.Compared with the theoretical and simulation waveform,the correctness and feasibility of the circuit design is verified.