Load bank control technology

New Adjustable Power Load Bank Technology: From 5kW Steps to 50W Fine Resolution

This technology adds fine power regulation to a conventional resistor load bank. It keeps the reliability of high-power resistor loading while allowing the load setting to approach the target test point with much finer resolution.

Why Conventional Step Loading Has a Limit

Conventional load banks usually control power by switching resistor groups. Each resistor group corresponds to a fixed power value, such as 5kW, 10kW, 25kW, or 50kW.

This structure is reliable and suitable for high-power loading, full-load testing, and long-duration operation. However, when a test requires a load point closer to a specific target value, fixed-step control can create load deviation.

The new adjustable power load bank technology adds fine regulation capability to a traditional resistor load structure. Taking a 5kW resistor module as an example, the newly developed power regulation board allows a single 5kW load section to achieve 50W load step resolution.

350kW Example total capacity of a liquid-cooled load bank.
5kW Typical base resistor module or minimum conventional load step.
50W Fine load step resolution achieved by the new regulation board.
The key improvement is not higher total power. It is higher load setting resolution. The load bank is no longer limited to switching a 5kW section fully on or off.

Example: 350kW Liquid-Cooled Load Bank

Assume a liquid-cooled load bank has a total rated capacity of 350kW, with a traditional minimum load step of 5kW.

If the target test load is 126.3kW, a conventional 5kW step system can only set 125kW or 130kW. If the target load is 188.75kW, the closest conventional setting is usually 190kW. If the target load is 242.6kW, the operator can only select 240kW or 245kW.

With 50W fine load regulation, the system can set the load much closer to these target values.

Target LoadConventional 5kW Steps50W Fine Regulation
126.30kW125kW / 130kW126.30kW
188.75kW190kW188.75kW
242.60kW240kW / 245kW242.60kW

For data center commissioning, CDU testing, UPS testing, power supply burn-in, and FAT/SAT procedures, a load point that is closer to the target value makes test data easier to compare, verify, and document.

Control Logic

This technology uses a combined structure of main load steps plus fine power regulation.

The main load is still handled by resistor modules. For example, 5kW modules provide the base high-power loading capacity. The fine regulation board is used to trim the load near the target power point.

The PLC calculates how many base load modules should be switched on, then controls the fine regulation board to compensate for the remaining power requirement.

Adjustable power load bank topology with 5kW load steps and 50W fine regulation board
Adjustable power load bank topology. The PLC combines 5kW main load steps with a 50W resolution regulation board, then uses voltage, current, and power feedback for control and reporting.
  1. The operator enters the target power on the HMI or PC software.
  2. The PLC calculates the required main load steps, such as the number of 5kW modules to energize.
  3. The fine power regulation board adjusts the selected 5kW resistor section in smaller increments.
  4. Voltage, current, and power feedback are returned to the PLC.
  5. The system records test data and exports CSV, Excel, or PDF reports.
  6. The liquid cooling system removes heat from the resistor section and records flow rate, pressure, inlet/outlet temperature, and alarm status.

Technical Value

This technology is suitable for test applications that require finer load control.

ApplicationTechnical Value
Data center commissioningSimulates IT load profiles more closely before servers are installed.
CDU liquid cooling testingProvides finer server heat load simulation for flow, pressure, and temperature response checks.
UPS testingVerifies output behavior at more accurate load ratios.
Inverter testingHelps observe output response under small load changes.
Power supply burn-inSupports long-duration operation at specific load points.
FAT / SATProvides more detailed test records and acceptance data.

Technical Boundary

50W is the load step resolution. It is not the complete system measurement accuracy.

Actual power accuracy is affected by voltage fluctuation, current sampling accuracy, power meter class, resistor temperature coefficient, cooling condition, cable voltage drop, control algorithm, and sensor calibration status.

A precise technical statement should be:

This technology provides 50W load step resolution, allowing the load setting to approach the target test power more closely. Actual power measurement accuracy should be confirmed based on the electrical measurement system and site test conditions.

Engineering Summary

The new adjustable power load bank technology is an important step from conventional resistor load banks toward controllable load simulation systems.

Using a 350kW liquid-cooled load bank as an example, a traditional 5kW minimum step is sufficient for many standard loading tests. However, when a project requires finer power curve simulation, CDU response verification, UPS load ratio matching, or more detailed FAT/SAT records, 50W load step resolution can significantly improve load control capability.

The core value is not larger capacity. It is more controllable load setting and test data that is closer to the engineering target.

Adjustable Power Load Bank FAQ

What is the difference between load step resolution and power measurement accuracy?

Load step resolution describes the smallest load adjustment the system can set. Power measurement accuracy depends on the electrical measurement circuit, sensors, meter class, calibration, wiring, and site conditions.

Why use 5kW main load steps with 50W fine regulation?

The 5kW modules provide stable high-power loading, while the 50W fine regulation board trims the load near the target power point. This combines robust resistor loading with finer control.

Is this technology only for liquid-cooled load banks?

No. The 350kW liquid-cooled load bank is used as an example. The same control concept can be applied to other resistor load bank designs when the electrical structure and thermal design support fine regulation.

Where is 50W load resolution most useful?

It is useful in data center commissioning, CDU testing, UPS testing, inverter testing, power supply burn-in, laboratory tests, and FAT/SAT procedures that require a load point close to a defined target value.

Specify the Test Target Before Selecting the Load Bank

For adjustable power load bank design, confirm the rated power, voltage, phase, frequency, minimum load step, fine regulation range, cooling method, control interface, feedback measurement, protection logic, and report format before quotation.