An intelligent electronic device (IED) may obtain a residual flux of each phase of a transformer. The IED may determine a maximum difference (DIF) signal based on the residual flux and the prospective flux associated with potential close POWs of the corresponding phase. The TED may select a closing POW that results in a minimum DIF signal. The TED may send a signal to close a ganged switching device of the transformer at a time based on the selected closing POW.

Provided is a control module of a converter, in particular a power converter of a wind power installation, which is configured to control the converter in such a way that the converter emulates a behavior of a synchronous machine, comprising an, in particular internal, control loop which has an, in particular adjustable, virtual admittance by means of which the converter is controlled in order to emulate the behavior of the synchronous machine.

A method for limiting current in-rush in automotive lighting devices. By controlling the state of a switching circuit that is used to selectively connect a power supply to an automotive lighting device, the invention allows for selectively limiting the intensity of the current that is supplied to the lighting device. In accordance with preferred embodiments, this advantage is achieved by relying on electronic components that are nowadays used for different purposes.

A device for controlling a pre-charge current generated when electrically connecting a first terminal and a second terminal, according to one embodiment of the present invention, may comprise: a switch for controlling a magnitude of a current flowing between the first terminal and the second terminal; a first resistor for generating a base voltage of a first transistor in proportion to a magnitude of the pre-charge current flowing between the first terminal and the second terminal; the first transistor for limiting the magnitude of the pre-charge current when a voltage generated by the first resistor is equal to or greater than a predetermined threshold voltage; a photocoupler for receiving, in a state insulated from a first power source, an optical signal from the first power source and supplying power; a capacitor charged by the power supplied by the photocoupler; a second transistor for controlling the magnitude of the pre-charge current on the basis of a charging voltage of the capacitor; and a second resistor for controlling an operating time of the second transistor along with the capacitor.

A method for determining a transformer state on the basis of correction of dissolved gas data includes receiving, by a transformer state determination apparatus, dissolved gas data, determining, by the transformer state determination apparatus, a measurement error value which is a correction target in the dissolved gas data, correcting, by the transformer state determination apparatus, the measurement error value, and determining, by the transformer state determination apparatus, a transformer state on the basis of the dissolved gas data including the corrected measurement error value.

An inrush current suppression device is an inrush current suppression device that suppresses an inrush current flowing from a DC power supply through a mechanical switch, and includes: a first capacitor having one end connected to a positive terminal of the DC power supply through the mechanical switch; a semiconductor switching element connected to the other end of the first capacitor and a negative terminal of DC power supply between the other end of the first capacitor and the negative terminal of the DC power supply; a resistance element connected in parallel to the semiconductor switching element; and a control circuit for controlling the semiconductor switching element. The control circuit has a first output port, and controls ON time and OFF time of the semiconductor switching element by outputting a PWM signal from the first output port to the semiconductor switching element after the mechanical switch is closed.

An electronic device acting as a power receiving device and a control method. The electronic device includes a battery, a coil, a reception circuit electrically connected to the coil, a charger a current sensing circuit, and at least one control circuit. The charger supplies a specified voltage to a system and controls the state of charge of the battery by using the voltage supplied from the reception circuit. The current sensing circuit is configured to sense an inrush current caused by the system. The at least one control circuit is configured to transmit a first control signal for requesting to increase a transmission voltage supplied from an external electronic device when an inrush current is detected through the current sensing circuit.

An active inrush current limiter and method of limiting inrush current actively monitor line voltage and voltage drop across a current limiting resistance in a manner that eliminates the impact of fluctuations of line voltage on the decision of when to close a relay and bypass a current limiting resistance between the AC source and a group of power supplies. The active inrush current limiter includes a microcontroller connected to control the electronic switch and relay. The microcontroller is configured to sample the source AC power and detect a pattern of current flow through the electronic switch and current limiting resistance. A program executed in the microcontroller includes calculations that determine when to close the relay and bypass the current limiting resistance by detecting changes in power flow through the current limiting resistance that reliably correspond to a time when the capacitors in the power supplies have completed charging.

A method includes energizing a transformer from a deenergized state by turning on a solid-state transfer switch to conductively couple a power source on a first side of the solid-state transfer switch and a transformer on a second side of the solid-state transfer switch, and evaluating an inrush current to the transformer from the power source. The method includes turning off the solid-state transfer switch to conductively decouple the power source and the transformer in response to the inrush current meeting a first criterion, determining a recoupling timing for the solid-state transfer switch, and turning on the solid-state transfer switch in response to the recoupling timing effective to complete energization of the transformer with the inrush current to the transformer being limited by the first criterion.

Described is a system that includes a solid-state switch in series with a battery and a controller. The system also includes a capacitor coupled between a source and a gate of the solid-state switch and a resistor coupled between the gate of the solid-state switch and ground. The solid-state switch gradually transitions from an open state to a closed state over a time constant of the capacitor and the resistor upon application of power from the battery to the solid-state switch. The system further includes a first switching device that controls the application of power from the battery to the solid-state switch. Additionally, the system includes a second switching device that provides a discharge path of the capacitor upon completion of a task by the controller.