Efficient portable stand-alone vaccine refrigerator for rural application

Vaccines are to be stored at a specific temperature to retain their potency. During the vaccination period, vaccines need to be taken to remote locations such as tribal areas. Here, there are two major challenges for community medicine employees to overcome, namely, (i) keeping the potency of the vaccine intact, and (ii) enough storage space for the vaccine. Often, the travel is by walk as there is a lack of facilities for transportation. The vaccines were usually taken in a portable carrier and an icepack was the only way to keep the vaccines cool; however, it would not be enough to maintain the vaccine temperature. A standalone mechanism is required, which would regulate the vaccine temperature, and the battery would be a part of it. Such a standalone mechanism is also essential during a power outage and in emergency conditions.

The objective of this project was to design and develop a prototype of 1.5 litres/3 litres storage capacity portable standalone refrigerator for vaccine storage. The key features of the developed refrigerator are refrigeration unit, DC–DC converter, Lithium (Li) ion battery, and battery charger. The Li-ion battery allows the refrigerator to run for 48 hours by maintaining the vaccine temperature between 2°C and 8°C, and it can be charged through a solar grid.

Impact and significance:

The refrigeration unit has USB communication that allows the user to download data such as temperature, door operation status, battery voltage, and state of charge. It is possible to charge the unit from either the grid or from standard solar photovoltaic panels. The ergonomic backpack type package weighing within 7 kg allows it to be easily carried on the shoulder to remote locations. Re-vaccination and the consequent economic loss can be avoided as the vaccine potency is preserved. The innovation is available as a transfer of Technology package from CDAC. Startups from Gujarat and Rajasthan expressed interest in using this for diagnostic lab sample collection from homes.

Publications:

2019. G. Subhash Joshi and V. John, “Circuit Parameter based Audiosusceptibility Model for Series Resonant Converter”, IEEE Trans. Power Electronics, vol. 34, no. 6, June 2019.

Shimul K Dam and V John, “High voltage resolution auxiliary power converter for online battery impedance measurement”, IEEE Energy Conversion Congress and Exposition (ECCE), 29 Sep–03 Oct 2019, Baltimore, USA.

Sugoto Maulik and V John, “Dodge Bridge Rectifier with low THD for Weak Grids”, 2019 IEEE Transportation Electrification Conference (TEC-India), 17–19 Dec 2019, Bengaluru.

1. K. Dam and V. John, “A Multi-Active- Half Bridge Converter based Soft-switched Fast Voltage Equalizer for Multi-cell to Multi-cell Charge Transfer”, 2019 IEEE Transportation Electrification Conference (TEC-India), 17–19 Dec 2019, Bengaluru.

Venkataramanan D and V John, “A Modified Common-Mode Filter with Enhanced Attenuation Performance in Single-Phase Grid-Tied Solar PV Inverters”, IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy (PESGRE 2020), 02–04 Jan 2020, Cochin.