2.5 kW DC/DC energy storage converter is bi-directional

March 31, 2015 // By Graham Prophet
TDK-Lambda’s EZA2500-32048 bi-directional converter suitable for energy storage systems with rechargeable batteries. This 2500W digitally controlled, compact 1U power supply can automatically change conversion direction from high voltage dc sources, powered by solar or wind, to 48Vdc batteries and vice versa.

In addition to small to medium sized energy storage, applications also include lithium-ion battery testing as well as the utilisation of regenerated energy from robots, cranes, autonomous ground vehicles and lifts. For example, the EZA2500 can replace the large power resistors currently used for lift braking and instead use that previously dissipated energy to charge batteries. That storage can then be used to either provide peak power for high torque demands or as battery back-up for power cuts.

The EZA2500 operates from, or supplies, either a 36 to 60V or 300 to 380V DC voltage with maximum currents of ±52A or ±7.8A respectively. The output voltage and current can be programmed and monitored using the RS-485 communications port. For larger systems, multiple units can be operated in parallel by setting the unit to “droop mode” current share via the RS-485 interface. A variety of alarm signals is also accessible, as well as remote on/off and under/over voltage functions. The EZA2500 will operate at full load in an ambient temperature of -10 to +40C.

Internally, the twin DC-DC converter design enables continuous transitional switching between charge and discharge states to maintain the stability of the bus voltage. Operating efficiencies of up to 94% are achieved with the use of full digital control. The converters are isolated – 3 kVAC from the high voltage (grid) to low voltage (battery) input/outputs, 2 kVAC from grid to ground and 500 VAC from battery to ground. Measuring 43.6mm (1U) high, the unit is 423 mm wide and 400 mm deep. Certifications include UL/CSA 60950-1, EN 60950-1, carries the CE mark for the LVD and RoHS2, and has a five-year warranty.

TDK-Lambda; www.uk.tdk-lambda.com/eza