40kVA Parallel UPS System with Four 10kVA Rack-Mounted UPS Units

Project Overview

TAFENG ran four 10kVA rack-mounted UPS units in parallel as a 40kVA system. The test showed how the units synchronize, share load, and respond when one unit is disconnected, and provided data to tune the parallel control parameters and firmware.

What We Tested

We ran the four units in parallel across a 20%–100% load range, monitoring output voltage, frequency synchronization, and per-unit current to check load sharing.

We then simulated a unit loss under load. The remaining three kept supplying the load and redistributed it without overloading the remaining units.

The test also let us refine several control functions:

• Parallel synchronization — tightened the synchronization response between units.
• Current sharing — adjusted parameters for a more even load split.
• ECO mode — measured efficiency reached up to 99.8% under the test conditions.
• Protection — reviewed input-voltage, overload, and parallel-protection settings for multi-unit operation.

Result

The four 10kVA units passed verification as a 40kVA UPS system. The data refined the parallel control logic and firmware for multi-unit operation.

Application

The 10kVA rack-mounted UPS runs standalone or links with additional units as capacity grows. A four-unit build provides 40kVA of installed capacity and can be configured for N+1 redundancy, depending on the actual load requirement.

Typical uses include small data centers, communication rooms, network equipment, industrial control systems, and other rack-based power systems.