A method for operating a multi-level bridge power converter includes providing a plurality of switching devices of the power converter in one of a neutral point clamped topology or an active neutral point clamped topology. The method also includes providing a plurality of deadtimes for the switching devices. Further, the method includes selecting one of the deadtimes for each of the switching devices such that at least two of the switching devices operate according to different deadtimes. Moreover, the method includes operating the switching devices at the selected deadtimes to allow a first group of the switching devices to switch slower than a second group of the switching devices such that the first group of the switching devices satisfy safe operating requirements while the second group of the switching devices switch faster than the first group.

A method for feeding electrical power into an electrical supply network having a network voltage with a network frequency by means of a converter-based generator, in particular by means of a wind power system, is provided. The method includes estimating a converter proportion of a network section of the electrical supply network. The converter proportion denotes a ratio of power fed in by means of converters to total power fed in. The method includes feeding the electrical power into the electrical supply network in a normal mode depending on the estimated converter proportion, activating a first support mode depending on the estimated converter proportion in accordance with a first activation condition, and activating a second support mode depending on the estimated converter proportion in accordance with a second activation condition, which is different than the first activation condition.

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.

A method for controlling a wind farm to damp low-frequency electrical oscillations, in particular subsynchronous resonances, in an electrical supply grid having a grid voltage with a nominal grid frequency is provided. The wind farm comprises at least one wind turbine connected to the electrical supply grid. The method includes sensing at least one low-frequency electrical oscillation of the electrical supply grid; determining an oscillation characteristic of each of the at least one sensed oscillation, the oscillation characteristic describing at least one property of the sensed oscillation; specifying an active-power damping signal and/or a reactive-power damping signal for damping the at least one low-frequency oscillation; feeding in an active power component in accordance with the active-power damping signal or a reactive power component in accordance with the reactive-power damping signal, the active-power damping signal and the reactive-power damping signal being specified in dependence on the determined oscillation characteristic.

Power generation devices and methods for use with toilets is disclosed. A number of power generation devices are provided that can be used in combination to power various features in a toilet which will be particularly useful for portable toilets that are off the grid. The power generation devices and methods include, for example, using a cell battery inside a toilet water source, a wind turbine, solar panels, and piezoelectricity. The features include, for example, lighting up the toilet with light-emitting diodes (LEDs) to make it easier for users to find the toilet, an audio/video setup for entertainment, and a toilet status light indicator to let the next user know when the toilet paper is out.

Methods and apparatuses for controlling reactive power of a wind turbine, and a wind farm are provided. An exemplary method includes: obtaining operation data of single wind turbines in a wind turbine group at the current time point; determining the total maximum capacitive reactive capacity and total minimum inductive reactive capacity, satisfying a safety constraint condition at the next time point, of the wind turbine group; calculating a deviation value of a wind turbine group reactive instruction at the current time point; and updating the wind turbine group reactive instruction on the basis of the acquired, determined, and calculated data so as to perform reactive power control.

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.

A method for forecasting wind power output of a target wind farm. The method includes normalizing, wind power output data for each wind farm of a group of wind farms, based, at least in part, on a respective installed capacity; transforming, the normalized power output data to yield transformed normalized wind power output data. Fitting, by the temporal module, each temporal model of at least one temporal model to model input data for each wind farm. The model input data corresponds to normalized wind power output data or transformed normalized wind power output data. The method further includes fitting, by a spatial module, a DVINE copula model for the group of wind farms, based, at least in part, on at least one residual value. Each residual value is determined based, at least in part on a selected fitted temporal model for each wind farm in the group.

A multimodal converter for use in electric vehicle charging stations for interfacing between at least one AC source and two DC sources (including the electric vehicle with onboard DC traction accumulator). The multimodal converter may also be applicable to other uses with a multitude of energy sources. For example, where the multimodal converter AC interface is for an electric motor, such as in a plug-in electric vehicle, an electric power tool, an electric water pump, a wind turbine, or the like, or interfacing with any DC sources such as an electrical battery apparatus, a solar panel array, a DC generator, or the like, whether for private, commercial or other use.

A direct current power system. The direct current power system includes a direct current bus system, a solar power system, an energy storage system and a wind power system. The solar power system is configured to supply a first direct current power. The energy storage system has an input electrically coupled to the solar power system and is configured to supply a second direct current power at 380 volts to the direct current bus system. The wind power system includes is electrically coupled to the energy storage system and is configured to supply a third direct current power.