Design and Power Generation Characteristics Analysis of a Self-adaptive Thermoelectric Power Generation System Based on LTspice

Thermoelectric power generation (TPG) is a novel method where carriers within a conductor migrate from the hot end to the cold end, generating a potential difference under a temperature gradient. Due to hysteresis, this potential difference fluctuates periodically with environmental temperature changes. Therefore, implementing a self-adaptive module during operation is crucial to enhance output voltage stability. Using LTspice, we simulated a TPG system, incorporating a boost module for a DC/DC boost circuit and a self-adaptive module with a logic-level controlled current electronic switch. Analysis results demonstrated nonlinear power generation growth with increasing temperature differences. Conversely, power generation decreased with rising internal resistance R0, thermal resistance Rq, and heat capacity Cq of the entire system. Notably, changes in R0 and Cq values had a more pronounced impact compared to Rq values. Under constant thermoelectric electromotive force conditions, a 1.5× growth in R0 led to a corresponding 1.5× power growth, while a 1.5× growth in Rq resulted in a 1.06× power growth. Furthermore, a 1.5× growth in Cq under the same Tcold value caused greater heat loss, subsequently reducing power output. After constructing the self-adaptive module, the TPG system effectively rectified and stabilized the floating potential difference within the voltage drop range of the field-effect transistor conduction tube, optimizing output to 50 from 600 ms. The self-adaptive TPG system designed in this research exhibits practical significance and potential applications in precision measurement instruments.