Single-phase inverter droop

Can a parallel inverter work with multiple low-power voltage source inverters?

However, to achieve Parallel operation of multiple lower-power voltage source inverters modules, the output voltage has to be strictly controlled to sustain the same amplitude, phase and frequency, otherwise large cross currents (AC and DC) can damage one or more of the parallel inverters .

Why do inverters produce a flow of reactive power?

Circulating currents produced due to the unequal magnitudes of inverter output voltages, presence of dc offset voltage in output inverter voltage and phase difference in output voltages of the inverter will be examined in this paper. Unequal voltage magnitudes among inverters result in a flow of reactive power among them.

How circulating current flows between inverters?

The circulating current flows between inverters due to DC-offset voltage and fluctuation of AC output voltages. This strategy uses the fundamental voltage and phase droop scheme to allow the inverters to share their load currents and uses a DC-offset droop scheme in order to eliminate DC circulating current.

How does DC offset droop work?

The output current is divided into two different currents by the controller, then it lets the inverters to bear the load current equally. Meanwhile, the DC cross currents are eliminated by applying the DC offset voltage droop method. The effectiveness of this method is shown in the result.