Test Equipment and Characterization for High Power Hybrid Vehicle Batteries and SuperCaps 2006-01-1243
Hybrid vehicles are becoming more and more attractive due to their reduced emissions and their higher fuel efficiency. Storage of electrical energy is the most critical aspect of hybrid automobiles. Therefore, an exact knowledge of the behavior of the battery and further electrical storage elements is mandatory. Their nonlinear characteristics over wide ranges of current magnitude, transient period, temperature and state of charge must be evaluated. Battery aging is another matter of increasing importance.
For this reason, an automated battery test bench has been developed which is capable of reproducing high dynamic loads in both charging and discharging direction. Pulse rise times are in the range of a few microseconds at maximum currents up to 1500 A. The quasi-static charge and discharge power can reach 20 kW. Optimized characterization programs enable a rapid extraction of battery behavior parameters as well as capacitor characteristics.
With this equipment various types of automotive batteries such as lead-acid and nickel-metal hydride batteries and all types of double-layer capacitors can be characterized.
For statistical analysis of several batteries in parallel, a compact version of the test bench with reduced current amplitudes and transient response times was developed. This stand-alone tester can be used for both stimulating aging effects and characterizing the most relevant battery parameters simultaneously.
The battery measurement equipment was successfully used to characterize different types of batteries. Parameterization of a battery model with high transient and amplitude dynamics for automotive applications was reached. This paper will show the complex analog and power electronics as well as the flexible data acquisition and load profile generation. Furthermore, measured data and model responses will be presented together with aging effects of double-layer capacitors.