EnTON – Energy Transfer Optimizing Circuits for Energy Harvesting Applications

能量收集能够将环境能量转换为电能，以便为否则将由电池或电缆驱动的设备提供电力。例如，考虑到工业4.0或物联网等应用，许多传感器必须安装在分散的位置以执行状态监控。通过电缆或电池为这些设备供电既需要维护，又需要成本，因此能量收集是此类应用的关键技术。该研究项目的目标是首次评估能量收集方法恒定负载仿真的完全集成实施，其动力来自其经过数学验证的100%效率。本研究将集中在一个匹配的负载电阻的基础上的输入和输出电压的函数的重点。虽然通常被忽略，只有两种情况下可以容忍这种简化：升压降压转换器在不连续导通模式和升压转换器在边界模式。对于一般的适用性，输入以及输出的依赖性，必须考虑到，以避免降低效率，为了达到这一目标，创新的电路设计技术将进行探索和评估，以减少功耗与最大功率点跟踪（MPPT）和开关模式转换器的最新技术相比。考虑到两种MPPT方法，算术负载匹配和爬山，计算方法将使用基于MOS晶体管的电压-电流特性的超低功耗模拟电路导出。算术负载匹配需要输入和输出电压相关占空比的超低功耗计算技术。对于爬山方法，设想一个超低功耗模拟电路来计算转换的能量。此外，创新的电路设计技术将被开发，以减少开关延迟和零电流检测器的功耗，从而在一个高性能的开关转换器。总体而言，使用几百微亨的现成电感实现紧凑且节能的收获系统将因此变得可行。在理论评估之后，所有方法都将被实现，并且通过特定应用的CMOS集成电路验证其性能。

Energy Harvesting enables the conversion of ambient energy into electrical energy in order to provide power to devices that otherwise would be battery or cable driven. Considering applications like Industry 4.0 or the Internet of Things, numerous sensors must be mounted in decentralized locations to perform condition monitoring, for example. Powering these devices by cables or batteries is both maintenance and cost intensive which is why energy harvesting is a key technology for such applications.Motivated by its mathematically proven efficiency of 100%, the objective of this research project is to evaluate for the first time a fully-integrated implementation of the energy harvesting approach Constant Load Emulation. This research will focus on a matched load resistance with the emphasis on a function based on both the input and the output voltage. Although usually neglected, only two cases can tolerate this simplification: the boost buck converter in discontinuous conduction mode and the boost converter in boundary mode. For a general applicability, the input as well as the output dependence must be considered to avoid a reduction in efficiency.To meet this objective, innovative circuit design techniques will be explored and evaluated in order to reduce the power consumption compared with the state of the art for both the maximum power point tracking (MPPT) and the switch-mode converter. Considering the two MPPT-approaches, Arithmetic Load Matching and Hill Climbing, calculation methods will be derived using ultra-low-power analog circuits based on the voltage-to-current characteristic of the MOS transistor. An ultra-low-power calculation technique for an input and output voltage-dependent duty cycle is required for the Arithmetic Load Matching. For the Hill Climbing approach, an ultra-low-power analog circuit is envisioned for calculating the converted energy. Furthermore, innovative circuit design techniques will be developed to reduce both the switching delay and the power consumption of the zero-current detector resulting in a high performance switching converter. Overall, the implementation of compact and energy-efficient harvesting systems using off-the-shelf inductances of a few hundred micro-henry will thus become feasible.After a theoretical evaluation, all approaches will be implemented and their performance verified by means of an application-specific CMOS integrated circuit.