Bi-directional DC power supplies and regenerative DC loads test fuel cells
Bi-directional DC power supplies and regenerative DC loads are offered by EA Elektro-Automatik (EA) for fuel cell stack testing.
Test engineers must conduct a series of characterisation, performance and durability tests on fuel cells which are characterised by determining their resistance. Fuel cell performance is usually indicated via polarisation curves by measuring its voltage and current. A durability test is conducted when a fuel cell stack reaches operating conditions and is subjected to a continuous series of charge/discharge cycles to ensure that it will work safely and reliably.
“Fuel cells are included in power generation for commercial vehicles such as buses and forklifts, backup power generation systems, and for other power sources. To ensure the design and manufacturing of quality fuel cells, EA Elektro-Automatik offers its EA-PSB 10000 2-quadrant power supplies and EA-ELR 10000 series electronic loads. Both the EA-PSB power supplies and the EA-ELR loads sink up to 30kW and feed the energy back to the grid to enable testing of any size fuel cell stack, said EA.
Both the PSB power supplies and the ELR electronic loads have built-in function generators that include arbitrary waveform generation, which simplifies characterisation, performance, and durability testing of fuel cells. Unlike other loads that need a separate AC instrument, the ELR load, with its built-in waveform generator, can perform the perturbation test to determine fuel cell resistance. Both the PSB supplies and the ELR loads, with built-in waveform generators can subject the fuel cell-under-test to dynamic load variations for performance and durability testing.
The PSB DC supply also has an internal X-Y generator that allows the supply to simulate the output of a fuel cell. At various voltages, the PSB supply can vary its output resistance to generate a current characteristic of the fuel cell at the programmed voltage. The PSB supply can emulate the three phases of a fuel cell’s characteristic output. The PSB supply can add ripple and noise onto its output to determine how well a fuel-cell powered device can perform under a wide range of conditions.
Both the PSB series supplies and the ELR loads offer true auto-ranging performance. The PSB supplies have a constant power characteristic output that allows for a wider range of voltage and current output with one instrument. The supplies can have ranges from 0 to 60V up to 0 to 2,000V. Current outputs can be up to 1,000A at 30V with the 30kW supply. Similarly, the ELR loads can sink up to 2,000V or 1,000A with the 30kW load. Auto-ranging power supplies and loads enable users to obtain higher voltages and currents without having to oversize the supply or the load.
The PSB series power supplies have a two-quadrant instrument, allowing it to function as both a source and a load. As a load, both the PSB supplies and the ELR loads are regenerative loads and can return the absorbed power to the grid with more than 96 per cent efficiency. That significantly reduces the cooling requirements on the instrument, says EA. Less cooling enables saving space with a smaller instrument for a given power capacity and saves on power consumption costs. Fan noise is also significantly reduced, says the company.
The PSB series supplies and the ELR loads have USB and Ethernet as standard interfaces. Optional interfaces, including RS-232, Profibus, CAN bus, and ModBus, to allow control from a PC or a programmable controller.
The supplies and the load have a multi-coloured touchscreen display that shows all programmed and measured values and only two control knobs. Language choices are English, Spanish, French, German, Chinese and Russian.
