Implementation of Automatic Battery Charging Temperature Compensation on a Peak-Shaving Energy Storage Equipment

This paper presents the implementation of an automatic temperature compensation for the charging of Lead-Acid batteries on a peak-shaving equipment. The equipment is composed by a multilevel converter, controlled by DSP, in a cascaded H-bridge topology and injects active power from the batteries into the grid in order to provide support to the system during peak times. When the energy price is lower, the batteries are charged from the grid, preparing for the next cycle. During charge times, the batteries floating voltages must be compensated as a function of temperature, in order to preserve their lifetime. The temperature information is provided by an RTD amplifier board, that communicates with the DSP via SPI bus. The paper presents the details of SPI communication on the TMS320F28335 DSP and the implementation of its control algorithm that sets the reference floating voltage for the batteries. Experimental results are presented.