Research On Power Conversion And Energy Matching Technology For Thermoelectiric Power Generation

In recent years,the use of new energy has been increasingly valued,waste heat as one of them,has huge reserves.Thermoelectric power generation technology can convert waste heat into electrical energy,with a wide range of energy,heat absorption and other advantages,can be used in the field of power electronic devices heat dissipation,at the same time generating thermoelectric energy.As a clean energy and cooling technology,thermoelectric power generation draw more and more attention from business and academia.As the basic element of thermoelectric power generation,the output voltage of thermoelectric generator is affected by temperature difference,it is unstable so it can not be directly supplied to the load.At the same time,as an independent power generation system,it has inherent energy mismatch problem.Aiming at the above problems,this paper designs a constant voltage output converter,which utilizes closed-loop control to realize constant voltage output.On the basis of power analysis,an energy matching system is designed,which uses power matching unit to improve the system cooling effect,achieving the energy matching.The specific research work in this paper includes:First,in order to determine the parameters of the converter and energy matching,the thermoelectric model of thermoelectric power generation is established by using five thermoelectric effect theories.On the basis of the experiment,the output characteristics of the thermoelectric generator are studied.According to this characteristic,the equivalent circuit model of the thermoelectric generator is established.The model can reflect the relationship between the circuit parameters of the thermoelectric wafer and the temperature difference and the load,and provide the data basis for the subsequent design of the appropriate converter.On this basis,in order to achieve constant load voltage,the design of low-voltage starting converter,in a larger input voltage and load range to achieve constant voltage output.In order to respond quickly to the input voltage fluctuation caused by the temperature change,the converter adopts feedforward-feedback control,and the reaction is rapid.At the same time,a controlled power source model is established for the energy mismatch in the thermoelectric power generation system.The mechanism of the energy mismatch of the thermoelectric power generation system is studied,and the optimal working area of the thermoelectric power generation system is obtained.In order to avoid entering the light load mismatch work area,the energy matching system is designed.The power consumption can balance the electric energy according to thedemand.In this process,the output voltage is limited,heat dissipation is enhanced.Finally,according to the theoretical analysis and design calculation results,this paper build test prototype.The energy consumption of the energy-matching circuit in the test prototype uses a DC-powered fan to facilitate further cooling of the air while consuming excess electricity.Experiments verify the rationality and effectiveness of theoretical analysis and the design of main circuit controller.