Microgrid inverter mode switching

What is a microgrid inverter?

One of the main characteristics of microgrids (MGs) is the ability to operate in both grid-connected and islanding modes. In each mode of operation MG inverters may be operated under current source or voltage source control.

How droop control a microgrid inverter?

Among them, there are two ways of droop control, one is to take reactive–frequency (Q–f) and active–voltage (P–V) droops to control the microgrid inverter under grid-connected conditions, and since it is a grid-connected mode, the voltage and frequency of the system are mainly considered and the reference value of the output power is calculated.

Can a microgrid inverter control a current source?

Most of the microgrid inverters in current-source mode use phase-locked loop to control , and the grid-connected inverter based on phase-locked loop can be equated to a current source.

How a microgrid can switch between modes?

However, switching between the modes is majorly executed according to the protectional control of the microgrid. The two challenging scenarios concerned with the protection and mode switching of microgrid are: Synchronized reclosing of a microgrid with the utility (i.e. switching from autonomous to grid-connected mode).

What is the difference between grid-connected and islanding mg inverters?

In grid-connected mode, MG inverters typically operate under a current source control strategy, whereas in islanding mode MG inverters operate under a voltage source control approach. Smooth transfer between the grid-connected mode and the islanding mode is one of the main challenges of MG activity.

Can parallel inverters share power during a microgrid transition?

Similarly, in order to achieve equal power sharing among parallel inverters during the transition of a microgrid (without significant oscillations, overshoots, or circulating currents between inverters), a novel hybrid control scheme was proposed.