Eaton Variable Module Management System

In some multi-UPS parallel systems used with lighter loads, the system maximises the load percentage of the UPSs by putting the UPSs that are not needed to power the load into idle mode. This results in partial energy savings and is limited to multi-UPS systems, with no efficiency improvements for -single-UPS systems.

• Maximised energy efficiency:

• VMMS optimally employs uninterruptible power modules (UPMs) in the UPS to achieve higher efficiencies in double-conversion mode in order to maximise the percentage load level of the remaining active UPMs by switching UPMs that are not needed to ready state

• This is calculated according to the UPMs’ VMMS load threshold – 80% by default – and the system configuration (redundancy requirements). This results in maximised energy savings

• VMMS is only possible thanks to Power Xpert 9395P UPS modularity.

• VMMS can also be applied in multimodule single-UPS systems

• In “ready state”, the UPM rectifies the DC-link, generates logic level PWM (Pulse Width Modulation) signals and filters EMI and lightning spikes

• Extensive configurability

Customers can decide how to configure their system, establishing the number of redundant UPMs and the max percentage load level per UPM allowed in VMMS setting other UPM’s in ready state. VMMS can be used in all multi-module (multiple-UPM) Power Xpert 9395P systems:

• Single 9395P units from 550 kVA to 1100 kVA
• All parallel 9395P systems

• Existing installations can also be upgraded with VMMS capability:

• VMMS maintains redundancy and achieves higher efficiency by intelligently controlling the load levels of UPMs
• Number of redundant UPMs can be selected (N+0, N+1, N+2, N+X)
• UPMs in ready state can be used as redundant units (N+0)

• No compromise on reliability 

When a disturbance or load increase occurs on a critical bus, all the UPMs in ready state are able to react quickly, immediately switching back to double-conversion mode connecting the existing PWM signals to the IGBT gates. In VMMS, all UPMs will switch to double-conversion if:

• The output voltage fluctuates by more than 3% for any reason
• Any UPM reaches its current limit or discharges its battery
• Battery recharge is necessary

Once the above conditions are resolved, the system switches back to VMMS, after a customer-preset time delay (1 to 60 hours): once the load stabilises, Eaton proprietary design and algorithms allow the system to determine which UPMs to switch back to ready state to maximise efficiency according to the new operating conditions.