A method for determining when a connection of a power system to a grid has been disconnected. The method includes the power system supplying a first amount of reactive power to the grid to which the power system is connected, and the power system determining if there is a frequency change within the grid. This includes if the frequency change does not exceed a predetermined threshold, the power system supplying a second amount of reactive power to the grid, and if the frequency exceeds a predetermined threshold, the power system supplying a first amount of reactive power to the grid.

Methods and apparatus for power generation and distribution according to various aspects of the present invention may operate in conjunction with a control system for controlling electrical power flowing between a main electrical grid providing main electrical grid power having a frequency, a supplemental power system, and a load. The control system may operate in conjunction with a switch system, wherein the switch system selectively connects the supplemental power system to the main electrical grid. A controller may be responsive to the main electrical grid power frequency and control the switch system. The controller may compare the main electrical grid power frequency to a first threshold and autonomously cause the switch system to connect the supplemental power system to the main electrical grid in response to the frequency of the main electrical grid power crossing the first threshold.

A method can be used to control a voltage source converter of a power supporting arrangement to act as a virtual synchronous machine. The method includes obtaining a measured power level of the converter, processing the measured power level using a differential equation of an angular velocity of the virtual synchronous machine in order to obtain a control contribution, providing a phase angle of a physical quantity used to control the converter based on the control contribution, monitoring the ability of the converter to act as a virtual synchronous machine, determining that the ability of the converter to act as a virtual synchronous machine is deemed insufficient, and adjusting the control contribution by increasing the damping term and/or decreasing the moment of inertia term in response to determining that the ability of the converter to act as a virtual synchronous machine is deemed insufficient.

A method can be used to control a voltage source converter of a power supporting arrangement to act as a virtual synchronous machine. The method includes obtaining a measured power level of the converter, processing the measured power level using a differential equation of an angular velocity of the virtual synchronous machine in order to obtain a control contribution, providing a phase angle of a physical quantity used to control the converter based on the control contribution, monitoring the ability of the converter to act as a virtual synchronous machine, determining that the ability of the converter to act as a virtual synchronous machine is deemed insufficient, and adjusting the control contribution by increasing the damping term and/or decreasing the moment of inertia term in response to determining that the ability of the converter to act as a virtual synchronous machine is deemed insufficient.

A method and system are provided for transferring a load between a primary power source and a secondary power source. In accordance with the disclosure, a controller senses, via a sensor, an electrical signal providing power from the primary power source to the load. The controller also detects a non-conforming power event by determining that a parameter of the electrical signal is either more or less than a first threshold value. Responsive to the detection of the non-conforming power event, the controller determines a quantity of non-conforming power events that occur during a first time interval. The controller further can compares the determined quantity of non-conforming power events to a second threshold value. Responsive to the determined quantity of non-conforming power events being either greater or lesser than the second threshold value, the controller initiates a control signal, such as a control signal to initiate a load transfer.

A method and system are provided for transferring a load between a primary power source and a secondary power source. In accordance with the disclosure, a controller senses, via a sensor, an electrical signal providing power from the primary power source to the load. The controller also detects a non-conforming power event by determining that a parameter of the electrical signal is either more or less than a first threshold value. Responsive to the detection of the non-conforming power event, the controller determines a quantity of non-conforming power events that occur during a first time interval. The controller further can compares the determined quantity of non-conforming power events to a second threshold value. Responsive to the determined quantity of non-conforming power events being either greater or lesser than the second threshold value, the controller initiates a control signal, such as a control signal to initiate a load transfer.

A microgrid arrangement includes a decentralized microgrid control system, a first microgrid and a second microgrid separated by a microgrid breaker. The first and second microgrids each include a number of assets, each asset being associated with a respective microgrid controller (MGC) of the microgrid control system. The control system can be operated by determining that the microgrid breaker is open, assigning a first MGC in the first microgrid to a first group of MGCs in the first microgrid, broadcasting information from the first MGC to other MGCs in the first group, determining that the microgrid breaker is closed, assigning the first MGC to a second group of MGCs in both the first microgrid and the second microgrid, and broadcasting information from the first MGC to MGCs in the second group.

A method is provided for power limiting in a power inverter configured to produce an output voltage and having a voltage regulator with a voltage setpoint defined for no load on an external bus line. The method includes determining a power level related to a load on the external bus line, determining an adjusted voltage setpoint based on the power level, including: decreasing the voltage setpoint to the adjusted voltage setpoint having a first value when the power level is above a maximum threshold, increasing the voltage setpoint to the adjusted voltage setpoint having a second value when the power level is below a minimum threshold, and slewing the adjusted voltage setpoint to the voltage setpoint so that the adjusted voltage setpoint has a third value when the power level is within a range defined by the maximum threshold and the minimum threshold.

A method is provided for power limiting in a power inverter configured to produce an output voltage and having a voltage regulator with a voltage setpoint defined for no load on an external bus line. The method includes determining a power level related to a load on the external bus line, determining an adjusted voltage setpoint based on the power level, including: decreasing the voltage setpoint to the adjusted voltage setpoint having a first value when the power level is above a maximum threshold, increasing the voltage setpoint to the adjusted voltage setpoint having a second value when the power level is below a minimum threshold, and slewing the adjusted voltage setpoint to the voltage setpoint so that the adjusted voltage setpoint has a third value when the power level is within a range defined by the maximum threshold and the minimum threshold.

The present invention relates to a method and plant of operating a grid forming power supply plant based on both a renewable energy, such as based on wind energy, solar energy, hydro energy, wave energy, and a carbon based energy, such as carbon based fuel. The grid includes a power input connection from a renewable power supply system and a power input connection from an carbon fuel engine based generator set. The generator set includes an engine for converting the carbon-based energy into motion energy, a generator, such as an alternator, for converting the motion energy into electrical energy, and a clutch for coupling and uncoupling of the engine with the generator. The system also includes a power buffer, such as a battery, subsystem for providing short term grid forming capacity and a plant grid forming controller for controlling grid parameters by means of controlling steps of a method. The plant grid forming controller includes interaction means for interacting with a control unit of the renewable power supply system, interaction means for interacting with a power buffer control unit, and interaction means for interaction with a control unit of the generator set.