Battery charger control system

A battery charger control system and method for maximizing output power to a battery. This is achieved by ensuring operation at either the maximum allowable input current or the thermal limit imposed by the battery charger using an on-line controller. In the invention, the thermal limit is determined by the junction temperatures of the two main IGBT's. Because direct measurement of these temperatures is impractical, they must be calculated by a computer algorithm that uses various on-line measurements. Test results for a 8 kW battery charger indicate reduction in the bulk charging time from conventional battery chargers of about 26% when charging a set of NiFe batteries.
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Abstract/Description: A battery charger control system and method for maximizing output power to a battery. This is achieved by ensuring operation at either the maximum allowable input current or the thermal limit imposed by the battery charger using an on-line controller. In the invention, the thermal limit is determined by the junction temperatures of the two main IGBT's. Because direct measurement of these temperatures is impractical, they must be calculated by a computer algorithm that uses various on-line measurements. Test results for a 8 kW battery charger indicate reduction in the bulk charging time from conventional battery chargers of about 26% when charging a set of NiFe batteries.
Subject(s): 323/282
307/64
323/222
323/271
Date Issued: 1998-12-01