Output Power Maximization in Energy Harvesting Applications

The project focuses on increasing the efficiency of an existing Energy Harvesting Integrated Circuit architecture developed by Prof. Shouri Chatterjee’s team in the ICE group at IIT Delhi. The project consists of two parts, each of which was undertaken in a separate semester long duration. The first part was an exploratory step taken in order to explore the possibility of using a Discrete Time Parametric Amplifier (DTPA) for boosting the charging speed of a DC-DC converter, in the Energy Harvesting IC. The DC-DC converter was explored & the functioning of the DTPA was thoroughly analyzed along with various simulations. Then an effort was made to integrate the DTPA with the existing DC-DC converter circuit in order to gain a faster clocking rate & hence increase the charging speed of the output capacitor. In the end though, the idea didn’t work out & it was mathematically proved that the DTPA can’t give any appreciable gains in the performance of the Harvesting circuit, rather it would only lead to a further deterioration. The second part focuses on maximum power point tracking for the Energy Harvesting IC. It involved developing an algorithm to track the frequency of charging cycles which would lead us to harness the maximum output power from the Energy source. This involved the development of a digital controller to implement the algorithm on-chip. Further, since the algorithm had lots of idle time in between various charge cycles, the algorithm was improved to incorporate charging from three different sources in parallel while sharing the maximum possible infrastructure & carefully arbitrating between the charging cycles of the three independent sources. The algorithm was successfully demonstrated with simulations in Virtuoso Analog Design Environment.