Effective Voltage Sag Ride-Through using Ultra Capacitor for Armored Fighting Vehicle Application - A Case Study

This paper presents a case study of design, development and testing of Ultra Capacitor (UC) based energy storage system for effective voltage ride-through in Armored Fighting Vehicle (AFV) applications. It also presents the test results of UC module delivering full load of AFV. AFV is powered with 24 V, 400 Ah battery bank and 28 V, 20 kW generator located in hull. Source is connected to the load through common single wire DC bus and chassis is the return path. DC bus voltage drops down to 16 V, during starting of heavy load. As the entire mission related sensitive systems are also connected to same DC bus, voltage sag in DC bus creates undesirable effects. Due to advancement in the field of double layer capacitor, UC module based ride-through system is developed and tested. Total capacitance of 23 F, 35.1 V UC modules was developed using 13 cells of Faradigm UCs. Dynamic voltage equalization circuit is connected across all the cells to protect the cells against over voltage. Rugged interface module was developed to house the UC. The module was integrated in AFV and tested in actual load condition. Voltage after ride-through system is always more than 26 V during starting of the main engine or operation of heavy load like hydraulic motor, though the DC bus voltage drops to 16 V. Field trials were carried out to ascertain the performance of the module and the results are satisfactory.