In parallel-connected inverter systems, it’s crucial to maintain consistent voltage, frequency, and phase among units to prevent disruptive “cross-currents.”

Different methods, like the central control and master/slave approaches, have been used for parallel inverter connections. However, these methods, while suitable for capacity expansion, often lack high reliability.

The SANUPS A11M takes a fresh approach by omitting central control units. Instead, it employs autonomous control circuits for individual units, allowing each unit to independently manage parallel inverter operation. This autonomous control includes monitoring input and output voltages, calculating momentary frequency and phase, and making necessary adjustments.

Communication lines link the units, enabling start/stop commands and data sharing. Importantly, synchronization happens within each unit, reducing dependence on inter-unit communication. This ensures consistent parallel operation during both AC and backup scenarios.

For example, with 8 parallel units, they can collectively handle up to 8 kVA loads. If the load is 7 kVA or lower, one unit’s surplus capacity ensures redundancy, maintaining operation even if one unit malfunctions. This innovative design highlights how the SANUPS A11M achieves robust redundancy via parallel operation control while minimizing reliance on shared components.