A microgrid delay margin calculation method based on critical characteristic root tracking includes: establishing a microgrid closed-loop small-signal model with voltage feedback control amount including communication delay based on a static output feedback, so as to obtain a characteristic equation with a transcendental term, performing critical characteristic root locus tracking for the transcendental term of the system characteristic equation, searching for a possible pure virtual characteristic root, and further calculating the maximum delay time in a stable microgrid. The method studies the relationship between the controller parameters and delay margins, thereby guiding the design of the control parameters, effectively improving the stability and dynamic performance of the microgrid.

Provided in the present invention are a microgrid control system and a microgrid, the microgrid control system comprising: a grid-connected switch, an energy router, a first controller and a second controller; the first controller controls the grid-connected switch and sends a first control instruction; the second controller receives the first control instruction and responds to the first control instruction for controlling the energy router.

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 controlling a microgrid includes receiving, by a power management system, PMS, of the microgrid, operating point values for a plurality of controllable assets. The method includes determining, by the PMS, an asset headroom. The method includes determining, by the PMS, a modified operating point value that is dependent on the received operating point value of the controllable asset, the determined asset headroom of the controllable asset, and a total power offset of the microgrid. The method includes controlling, by the PMS, the controllable assets for which the modified operating point values have been determined in accordance with the modified operating point values.

A method of controlling a microgrid includes retrieving, by an energy management system, EMS, a forecast variable value for a forecast variable. The EMS determines an operating point value for a controllable asset that depends on the retrieved forecast variable value. The EMS determines an operating point shift value for the controllable asset, the operating point shift value representing a shift in operating point value in response to a variation in forecast variable value. The operating point value and the operating point shift value are provided to a power management system, PMS, of the microgrid.

A decentralized voltage control method for a microgrid based on nonlinear state observers, comprising the steps of step 10), establishing a large-signal model of distributed generations, a connection network and impedance-type loads in the microgrid; step 20), establishing a Luenberger-like nonlinear state observer for each distributed generation; step 30), estimating the dynamic characteristics of other distributed generations in real time based on the local measured values of each distributed generation; and step 40), implementing the decentralized voltage control based on the control requirements of reactive power sharing and voltage restoration. The control method realizes the voltage control of microgrid based on the decentralized state observers, which does not rely on communication transmission or remote measurement and avoids the adverse effects of communication latency and data drop-out on the control performance.

A microgrid control system including a plurality of distributed generators, loads and/or energy storages. The system includes a microgrid controller arrangement, and a network controller arrangement. The network controller is distributed and configured to perform measurements on the microgrid, send information to at least one other of the plurality of network controllers, and send information to the microgrid controller arrangement based on the performed measurements. The information sent to the microgrid controller arrangement relates to assets which are included in a segment of the microgrid with which the controller is associated. The microgrid controller arrangement is configured to control the plurality of assets by instructing respective converter controller of each of the plurality of assets.

A system architecture and method for enabling hierarchical intelligent control with appropriate-speed communication and coordination of control using intelligent distributed impedance/voltage injection modules, local intelligence centers, other actuator devices and miscellaneous FACTS coupled actuator devices is disclosed. Information transfer to a supervisory utility control is enabled for responding to integral power system disturbances, system modelling and optimization. By extending the control and communication capability to the edge of the HV power grid, control of the distribution network through FACTS based Demand response units is also enabled. Hence an integrated and hierarchical total power system control is established with distributed impedance/voltage injection modules, local intelligence centers, connected other actuator devices, miscellaneous FACTS coupled devices and utility supervisory all networked at appropriate speeds allowing optimization of the total power system from generation to distribution.

A medium-high voltage energy conversion system, and a control method and a controller therefor are provided. In the control method, an operation state of the medium-high voltage energy conversion system is acquired. In a case that the system is in a normal operation state, the system is controlled to operate in a first direct circuit current source mode. In a case that the system is in a first fault state in which a direct current grid voltage drops, the system is controlled to operate in a direct current voltage source mode. In a case that the system is in a second fault state in which a direct current grid voltage is in an overvoltage state, the system is controlled to operate in a second direct circuit current source mode.

A method performed by a network controller of an electrical microgrid having a plurality of energy storages. Each of the energy storages is associated with a respective storage controller. The method includes receiving information about a measurement made at a remote location in the microgrid. The method also includes obtaining respective participation factors in respect of the remote location for each of at least a first energy storage and a second energy storage of the plurality of energy storages. The method also includes obtaining respective states of charge for each of the at least first and second energy storages. The method also includes, for each of the at least first and second energy storages, calculating a reference value for the energy storage, and sending the reference value to the storage controller with which the energy storage is associated. The calculating includes calculating the reference value based on the obtained participation factors and the obtained states of charge.