Exploring High Speed Regenerative DC Load System
High Speed Regenerative DC Load System
Chroma 63700H
Designed for testing AI server power supply equipment such as power racks and rack-mounted power systems. Available in two voltage versions, the 63700H Series supports both HVDC and DC-to-DC power system applications
Rated Power
80kW & 120kW
Voltage Range
80V & 1,000V
Current Range
Up to 2,650A
The 63700H High Speed Regenerative DC Load System is specifically designed for testing AI server power supply equipment such as power racks and rack-mounted power systems. Available in two voltage versions, the 63700H Series supports both HVDC and DC-to-DC power system applications.
The 63700H Series delivers excellent dynamic current response to meet the demands of Peak Power and EDPP (Electrical Design Peak Power) testing, while also delivering up to 80% energy recovery efficiency in steady state mode feeding power back to the grid. This significantly reduces heat generation in the test environment, lowers air-conditioning power consumption, cuts electricity costs associated with power conversion, and supports energy conservation and sustainability goals.
The 63700H Series has a rack-based architecture and is available in 80V and 1,000V models. The high-voltage 1,000V model further provides two voltage ranges suitable for 400V and 800V sidecar testing. The system delivers up to 120kW in steady state, with maximum current up to 2,650A per rack. Through synchronous dynamic master/slave control, configurations of up to ten 80V racks* or ten 1,000V racks* can be achieved with total maximum power up to 1,200kW.
The 63700H provides users with 256 programmable load sequences, supporting EDPP testing with multiple peak power profiles and including precise voltage and current measurement. The dedicated SoftPanel software provides an intuitive graphical interface for straightforward operation and setup.
The 63700H incorporates multiple safety mechanisms for AI server power testing, including over-current, over-power, and overtemperature protections as well as an overvoltage alarm. These safeguards enhance overall system reliability, making the 63700H a trusted solution for engineering validation and automated test system integration.
- Rated power: 80kW & 120kW
- Voltage range: 80V & 1,000V
- Current range: up to 2,650A
- Constant Current operating mode
- Synchronous dynamic master/slave control, up to 10 racks*
- Peak power capability: 160% of rated power (CCD) sustained for 1 ms; 140% for 50 ms; 120% for 30 sec.
- Current slew rate: up to 40 A/μs
- Energy recovery efficiency up to 80% (steady state)
- Dual voltage ranges on 1,000V models for 400V and 800V sidecar testing
- Programmable mode suitable for EDPP testing
- Smart fan control
- Protection functions: over-current, over-temperature, over-power protection, over-voltage alarm
- Standard LAN interface
- Applications: AI server Power Shelf, Power Rack, and BBU Shelf testing
Applications
The 63700H Series is specifically designed for testing AI server power equipment such as Power Shelf, Power Rack, and BBU Shelf systems, where transient response testing is a basic requirement. In the past, such testing typically relied on traditional linear loads, which dissipate absorbed power directly as heat and therefore place strict demands on installation space and temperature control. By combining high-speed dynamic response with energy regeneration capability, the 63700H enables both dynamic performance testing and long-duration reliability testing to be performed efficiently on a single system.
Key Features
Energy Recovery
The 63700H converts the absorbed DC load current and feeds it back to the facility grid as alternating current, with steady-state efficiency greater than 80%. The recovered energy can be reused by other equipment within the facility, reducing overall energy consumption and carbon emissions. This also effectively reduces heat generation from the electronic load, which in turn lowers air conditioning power consumption and facility operating costs.
Synchronous Dynamic Master/Slave Control
To keep pace with the rapid evolution of AI power systems, both power supplies and BBUs continue to scale upward in capacity. Power Shelves now exceed 100kW, and Power Racks can reach MW levels. To address these demands, the 63700H is built into a 41U system rack and features synchronous dynamic master/slave control. Multiple racks of the same model can be configured to operate as a single load. Users simply set test conditions via SoftPanel or command control, and the programmed load profile is automatically distributed to each rack for streamlined operation.
Dynamic Load Mode
Transient response testing is a fundamental requirement for power supply validation. Sudden load changes can cause output voltage overshoot or undershoot, leading to abnormal downstream system behavior or even component damage. To address this, the 63700H provides a programmable dynamic current load (CCD) mode with a current slew rate of up to 40 A/μs and a minimum current rise response time of 25μs. Programmable parameters include high/low current levels, T1/T2 timing, rise/fall slew rates, and run count. Repetition over a defined interval can also be set from 1 to 65,535 cycles. In addition, the 63700H 80V rack supports 160% @ 1ms, reaching 128kW, while the 1,000V rack supports 160% @ 1ms, reaching up to 192kW, making it ideal for simulating the instantaneous load capability of power supplies.
Constant Current Load Mode
The 63700H provides a Constant Current mode to satisfy basic test requirements. CC mode is commonly used for testing power supplies and DC-DC converters. By simulating real load conditions, it verifies whether the device under test can maintain stable output voltage under different load conditions, making it well suited for long-duration steady-state testing.
Programmable Load Sequence Function
The 63700H series comes with 256 built-in programmable load sequences. With parameters such as program number, repetition count, dwell time, and current settings, users can simulate a wide range of dynamic load current profiles, including multi-level dynamic current simulation with two or more current levels. This also supports Electrical Design Peak Power (EDPP) testing derived from GPU-level demands scaling to AI server workloads, including repetitive multi-step dynamic profiles (shown on the right) and oneshot load simulation.
SoftPanel Graphical Control Software
The 63700H is equipped with a LAN interface for remote control. Users can operate the system through SoftPanel, Chroma’s dedicated control software which is easy to learn and use. Remote control is also supported via DLL (Dynamic Link Library; supports CANoe, Python, C#, and other environments), allowing users to develop their own control programs and choose the operating method that best fits their workflow.
Model Options
| Model | Voltage | Current | Power |
| 63700H-80 | 80V | 2650A | 80kW |
| 63700H-1000 | 1000V | 710A / 235A | 120kW |
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