适用于双源能量收集的最大功率同步追踪电路

A Synchronous Maximum Power Point Tracking Circuit for Dual-Source Energy Harvesting System

针对多数传统能量收集系统的能量来源单一、现有多源能量收集系统的追踪效率较低、输入功率范围较窄等问题,提出一种双源最大功率同步追踪电路(DSS-MPPT)。该电路实时同步追踪两个环境能量源的最大输出功率,通过设计数字控制电路,MPPT电路中两个比较器可以共用单边延时电路,从而提高电路的能量转换效率。该数字控制电路可实时切换输入能量源,使得系统仅需一个电感,从而降低能量收集系统的体积以及电路的复杂度。基于0.18μm CMOS工艺的仿真表明,系统能量转换效率最高可达95.37%,并且在20μW^1 mW宽输入功率范围内追踪效率始终高于98.53%。

To solve the issues that most traditional energy harvesting systems had a single input source, and the existing multi-source energy harvesting systems had low tracking efficiency and narrow input power range, a dual-source synchronous maximum power point tracking(DSS-MPPT) circuit was proposed. The maximum power of dual sources was tracked synchronously by the proposed MPPT circuit. The input energy sources could be properly switched by the digital control circuit. Thus, only one inductor was needed in the system, thereby reducing the size of the energy harvesting system and the complexity of the circuit. Simulation verification based on a 0.18 μm CMOS process showed that the conversion efficiency of the designed DSS-MPPT could reach 95.37%, and its tracking efficiency was always higher than 98.53% in the input power range of 20 μW^1 mW.