Bidirectional · Regenerative · Programmable
Bidirectional & Regenerative DC Power Supplies: The Buyer's Hub
One instrument that both sources and absorbs power, returns recovered energy to the grid, and runs your full test sequence under remote control. Here is how the range is structured, what each model class delivers, and how to get a configured quote.
Source & sink in one
One instrument both supplies and absorbs DC — no separate load needed.
Energy recovered
Up to 93% of absorbed power is returned to the grid, not burned as heat.
Battery & PV simulation
Built-in battery emulation and solar-array (PV) simulation for real-world test.
Programmable & remote
SCPI, Modbus-RTU and CANopen for ATE automation and sequencing.
What this range actually is
A bidirectional, regenerative DC power supply replaces two boxes with one. It behaves as a fully programmable DC source and as an electronic DC load, switching between sourcing and sinking current smoothly across the zero-current boundary. When it sinks, it does not burn the absorbed power as heat in a resistor bank, it inverts that energy and feeds it back to the AC mains.
The platform covered here is the N35500 series built by Ultra Power Systems. A single 3U chassis delivers up to 42 kW; units parallel in master/master configuration to reach multi-megawatt levels for full battery-pack lines and inverter test floors. Output spans 0-2250 V with 0.02% F.S. accuracy and a command-to-output response of ≤5 ms.
Because the design is genuinely two-quadrant, the same hardware serves charge and discharge test, regenerative loading, battery emulation and PV array emulation, all without rewiring the rack.
Why bidirectional plus regenerative matters
Traditional setups pair a unidirectional supply with a dissipative load. That works, but every watt you sink during a discharge test becomes heat your facility must remove, and you pay for that energy twice: once to generate it and again to air-condition it away. A regenerative architecture recovers up to 93% of the absorbed energy back to the grid.
On a continuously cycling battery line, that recovery turns the electricity bill and the HVAC load from a running cost into a near-non-issue. Fewer heat-rejection problems also mean denser racks and quieter labs. See the dedicated regenerative DC power supply page for the cost math.
Model classes from 360 V to 2250 V
Pick the voltage class by your highest device-under-test bus voltage, then size power by your cycle rate. The platform scales in both dimensions.
| Class | Voltage | Typical use | Per-chassis power |
|---|---|---|---|
| Low / mid bus | 0-360 V | Cell & module cycling, 48 V/automotive low-voltage | up to 42 kW (3U) |
| EV traction bus | 0-1000 V | EV battery packs, 800 V architectures, OBC/BOBC | up to 42 kW (3U) |
| String / ESS | 0-1500 V | PV strings, ESS/PCS/BESS, utility inverters | up to 42 kW (3U) |
| High voltage | 0-2250 V | High-voltage stacks, aerospace/ATE, research | up to 42 kW (3U) |
Need more current or power than one chassis? Parallel multiple units to MW scale. The high-voltage class guide breaks down form factors per voltage.
Simulation and control built in
Beyond plain CC/CV/CP/CR operation, the range adds firmware that turns the supply into a test instrument. The NS81000 battery-simulation option ships with 7 model libraries plus custom curve import and tracks SoC against OCV. The NS91000 solar/PV option runs EN50530 static and dynamic profiles and Sandia MPPT tests. Every unit speaks LAN/RS232/RS485/CAN with SCPI, Modbus-RTU and CANopen, so it drops into existing ATE without custom drivers.
Ready to scope a system? Request a quote from Ultra Power Systems or email Ultra Power Systems with your voltage, power and channel count.
Frequently asked questions
What is a bidirectional regenerative DC power supply?
What voltage and power range does the N35500 platform cover?
How do I get pricing?
Get a configured quote
Tell us your voltage, power, application and timeline and get a configured quote from Ultra Power Systems.