Provided is a method for feeding electric power into an electricity supply grid via a connection node by way of a converter-controlled infeed unit, in particular by way of a wind power installation or a wind farm. The grid has a grid voltage and a grid frequency and is characterized by a grid nominal voltage and a grid nominal frequency. The grid voltage of the grid is acquired, a delayed differential angle is ascertained on the basis of the acquired grid voltage. The delayed differential angle corresponds to a difference between an acquired phase signal that indicates a temporal profile of a phase angle of the grid voltage and a phase signal that is delayed with respect to the acquired phase signal. A grid impedance effective for the connection node is acquired, and an infeed power is predefined based on the delayed differential angle and based on the impedance.

An inverter energy system supplies power to a site. The inverter energy system comprises a number of solar strings, each solar string including a solar panel(s) as a renewable energy source and an inverter. The inverter energy system is connected to a mains power supply (grid) and to a site load (sub circuits). The forward or reverse power flow into or out of the mains power supply is monitored at a monitoring point at the site. A rate limit is set for power flow into and/or or out of the mains power supply. The supply of power from the inverter energy system is controlled so that the power flow into or out of the mains power supply is within the set rate limit.

An aircraft propulsion system includes at least first and second electrical generators, each being configured to provide electrical power to a respective first and second AC electrical network. The system further comprises at least first and second AC electrical motors directly electrically coupled to a respective AC network and coupled to a respective propulsor, and a DC electrical network electrically coupled to the first and second AC networks via respective first and second AC to DC converters, and to a further electrical motor, the further electrical motor being coupled to a propulsor.

The present invention pertains to an energy management device 50 of a microgrid S1 which is associated with a power system 1 and is provided with a power storage device 15, the energy management device calculating a target value of received power of the microgrid, the target value optimizing the utilization efficiency of the energy of the microgrid S1, on the basis of power demand prediction in the microgrid S1 by taking, as constraint conditions, the upper and lower limits of the received power of the microgrid S1 and the upper and lower limits of output power of the power storage device.

A service management device is provided with a classification processing means that classifies and calculates, for each of a plurality of power supply apparatuses, details of input/output power in a service carried out using at least one of the power supply apparatuses; and a service recording means that records, for each classification performed by the classification processing means, details of an amount of power input/output as a result of execution of the service.

A service management device is provided with a classification processing means that classifies and calculates, for each of a plurality of power supply apparatuses, details of input/output power in a service carried out using at least one of the power supply apparatuses; and a service recording means that records, for each classification performed by the classification processing means, details of an amount of power input/output as a result of execution of the service.

A photovoltaic system includes an inverter, a controller, and at least two converters. An input terminal of each of the at least two converters are connected to a corresponding photovoltaic module, and output terminals of the at least two converters are connected in series and connected to an input terminal of the inverter. The controller is configured to set a voltage limiting value of at least one of the at least two converters, so that an output voltage of the at least one converter is less than or equal to the voltage limiting value when the converter works in a voltage limiting mode. The voltage limiting value of the at least one converter is proportional to an open circuit voltage of the photovoltaic module connected to an input terminal of the converter. Open circuit voltages of different photovoltaic modules vary with different parameters or models of the photovoltaic modules.

A photovoltaic system includes an inverter, a controller, and at least two converters. An input terminal of each of the at least two converters are connected to a corresponding photovoltaic module, and output terminals of the at least two converters are connected in series and connected to an input terminal of the inverter. The controller is configured to set a voltage limiting value of at least one of the at least two converters, so that an output voltage of the at least one converter is less than or equal to the voltage limiting value when the converter works in a voltage limiting mode. The voltage limiting value of the at least one converter is proportional to an open circuit voltage of the photovoltaic module connected to an input terminal of the converter. Open circuit voltages of different photovoltaic modules vary with different parameters or models of the photovoltaic modules.

This application provides a photovoltaic power generation system. The system includes at least one first photovoltaic module, a photovoltaic inverter, a first two-way DC/DC converter, and at least one first energy storage unit, and further includes at least one second photovoltaic module or at least one second energy storage unit. The photovoltaic inverter includes a DC/DC converter and a DC-AC inverter, where the DC/DC converter is electrically connected to the at least one first photovoltaic module, and the DC/DC converter is connected to the DC-AC inverter through a direct current bus. For the photovoltaic power generation system, photovoltaic arrays and energy storage devices can be configured flexibly to cope with peaks and troughs of power consumption.

This application provides a photovoltaic power generation system. The system includes at least one first photovoltaic module, a photovoltaic inverter, a first two-way DC/DC converter, and at least one first energy storage unit, and further includes at least one second photovoltaic module or at least one second energy storage unit. The photovoltaic inverter includes a DC/DC converter and a DC-AC inverter, where the DC/DC converter is electrically connected to the at least one first photovoltaic module, and the DC/DC converter is connected to the DC-AC inverter through a direct current bus. For the photovoltaic power generation system, photovoltaic arrays and energy storage devices can be configured flexibly to cope with peaks and troughs of power consumption.