The results of the ELR approach are quite remarkable – with total energy consumption being reduced by up to 93%. It also has a significant effect of unit’s size, cooling requirements and audible noise. Comparing a 120 kW ELR (comprised of 4-30kW rack units) with the 110 kW load bank, the ELR dissipates just 6 kW of heat!
Other benefits of dissipating less heat means smaller cooling fans, which dramatically reduces the audible noise. Regenerative loads are also 2-3 times higher power density compared to typical air-cooled loads, which results in less rack or bench space.
The secret to the implementation of a regenerative load bank is a back-end conversion system. As shown in Figure 4, DC energy flows into a DC-DC converter, which is tied into a DC-AC inverter (current source), and which then synchronizes with the distribution grid to recycle the energy. This technology is similar to grid-tied photovoltaic inverters (PVs).