Research On Characteristics And Applications Of Thermoelectric Power Generator

With the progress of global economics and the improvement of living standards, the increasing demand of traditional energy has brought about serious energy shortage, as well as severe pollution of environment. In addition to the development and use of clean renewable energy, thermoelectric power technology has been getting more and more global attention. It takes advantage of low-grade energy as a heat source such as industrial and automotive waste heat. And making use of temperature difference, it turns the heat into electricity with a number of advantages such as green compliant, simple structure, safety and reliability. Therefore, thermoelectric power technology is quite an effective way to solve the global energy crisis and environmental pollution.The thermoelectric power generation system has been studied in this thesis. Firstly, the basic theory of thermoelectric power generation is introduced. The characteristics and parameters of thermoelectric power generator (TEG) are also derived. In addition, a simple test platform is build to test the characteristics and parameters of TEG under laboratory conditions. Secondly, various DC-DC boost converters suitable for TEG are comparatively analyzed based on above analysis and test results, and high step-up boost converter with switched-capacitor network is proposed. For the converter, its various working modes are analyzed in detail. What’s more, the steady state operating point of main circuit is derived and its small-signal model is established with state-space averaging method. Thirdly, the system is divided into two operation modes based on the state of battery. And a comprehensive energy management strategy is designed in order to achieve full utilization of low-grade heat energy, which could achieve smooth switching between two different operating modes. Besides, in the maximum power point tracking control mode, improved perturbation and observation method with variable step is designed to make TEG provide as much energy as possible with good efficiency and accuracy. Finally, simulation verification is conducted by software of PSIM, and experiment verification is carried out based on a100W prototype with digital control system of DSP28035. Simulation and experimental results show the rationality of the circuit parameter design and effectiveness of the energy management strategy.