The invention discloses an islanding detection method in DC microgrids based on MPPT trapezoidal voltage disturbance. The steps are as follows: start the MPPT strategy; set the starting signal threshold of disturbance; measure the output current of PVA at the maximum power; calculate the same environmental factor of PVA with different capacities under the same light intensity and temperature in real time; when the environmental factor is greater than the starting signal threshold of the disturbance, periodic trapezoidal disturbance is carried out to the PVA port voltage reference; if the PCC voltage Upcc exceeds the threshold set by the passive method, it is judged as islanding; otherwise, it is judged whether the change rule of Upcc is consistent with the change rule of the calculated PCC voltage Upccp under the trapezoidal disturbance; If it is consistent, it is judged as islanding; otherwise, it is pseudo islanding.

Method (300) of controlling a distribution network (1) and a microgrid controller (8) adapted for the method. The distribution network (1) comprises assets (3-7) in a first part (1a) and a second part (1b). which parts (1a, 1b) are selectively connected to each other into an interconnected state at a connection point

(PCC). The method comprises monitoring (301, 306) and controlling (310) the assets (3-7) of the distribution network (1). In a first control mode (310A), the first part (1a) is controlled by a distribution network controller (9) and the second part is controlled by the microgrid controller (8). Especially, the method includes selecting (303) between controlling (310) the distribution network (1) in the interconnected state in accordance with the first control mode (310A), and controlling (310) the distribution network (1) in the interconnected state in accordance with a second control mode (310B), in which second control mode (310B) the assets (3-7) of the both the first part (1a) and the second part (1b) are controlled by the distribution network controller (9).

A method of allocating power across a microgrid having a plurality of energy storage systems with different power and/or energy capacities, and different states of charge. The method includes allocating a total charge request and/or a total discharge request across the energy storage systems as a function of a usable energy capacity of each energy storage system.

A power generation system includes a power source that is configured to communicate with at least one of a downstream load or a downstream device by changing a voltage on a power bus between the power source and the at least one of the downstream load or the downstream device, while power source provides power on the power bus to the at least one of the downstream load or the downstream device.

A method of controlling output of an ESS depending on droop control according to frequency variation range of a power grid in the present invention may comprise steps of: monitoring the frequency variation range of the power grid; predicting frequency correction range resulting from regulation of an engine generator during a predetermined unit regulation time if the frequency variation range is determined to exceed a first reference value; controlling the output of the ESS with an output value determined by a frequency of the power grid according to a droop control algorithm set as a default if the predicted frequency correction range does not exceed a second reference value; and fixing the output of the ESS during the unit regulation time if the predicted frequency correction range exceeds the second reference value.

A method of allocating power across a microgrid having a plurality of energy storage systems with different power and/or energy capacities, and different states of charge. The method includes allocating a total charge request and/or a total discharge request across the energy storage systems as a function of a usable energy capacity of each energy storage system.

A method of allocating power across a microgrid having a plurality of energy storage systems with different power and/or energy capacities, and different states of charge. The method includes allocating a total charge request and/or a total discharge request across the energy storage systems; and limiting the charge and/or discharge of one or more energy storage systems to a submaximal value.

Devices and methods of allocating distributed energy resources (DERs) to loads connected to a microgrid based on the cost of the DERs are provided. The devices and methods may determine one or more microgrid measurements. The devices and methods may determine one or more real-time electricity prices associated with utility generation sources. The devices and methods may determine one or more forecasts. The devices and methods may determine a cost associated with one or more renewable energy sources within the microgrid. The devices and methods may determine an allocation of the renewable sources to one or more loads in the microgrid.

The present disclosure relates to a recloser control that provides autosynchronization of a microgrid to an area electric power system (EPS). For example, a recloser control may include an output connector that is communicatively coupled to a recloser at a point of common coupling (PCC) between the area EPS and the microgrid. The recloser control may include a processor that acquires a first set of measurements indicating electrical characteristics of the area EPS and acquires a second set of measurements indicating electrical characteristics of the microgrid. The recloser control may send synchronization signals to one or more distributed energy resource (DER) controllers to synchronize one or more DERs to the area EPS based on the first set of measurements and the second set of measurements.

A microgrid system includes first and second DC power sources electrically connected to respective first and second DC electrical power busses, a first uninterruptable power module electrically connected to the first DC electrical power bus and configured to be connected to an alternating current (AC) load, a second uninterruptable power module electrically connected to the second DC electrical power bus and configured to be connected to the AC load, a first bi-directional AC/DC inverter having a DC end and an AC end, where the first DC electrical power bus is connected to the DC end of the first bi-directional AC/DC inverter, a second bi-directional AC/DC inverter having DC and AC ends, where the second DC electrical power bus is connected to the DC end of the second bi-directional AC/DC inverter, and an AC electrical power bus electrically connected to the first and second bi-directional AC/DC inverters at their AC ends.