An isolated switched-mode power converter converts power from an input source into power for an output load. Power switches within a primary-side power stage control the amount of power input to the power converter and, ultimately, provided to the output load. A digital controller on the secondary side of the power converter generates signals to control the power switches. This controller also senses a rectified voltage on the secondary side of the power converter and uses this sensed voltage to detect fault conditions of the primary side. For example, the sensed rectified voltage is used to detect undervoltage or overvoltage conditions of the input power source of the power converter, or faulty power switches within the primary-side power stage.

A method and a device provide protection for a multi-terminal HVDC grid against faults. The method includes measuring a DC displacement voltage having a polarity and a value, determining if a short circuit fault exists by comparing the DC displacement voltage with a threshold displacement voltage and identifying a fault type based on the polarity and the value of the DC displacement voltage. The disclosed device contains a converter having a positive pole and a negative pole, a DC-switch substation, a DC line connecting the converter and the DC-switch substation and a transient fault detector. The transient fault detector contains a positive voltage sensor sensing a positive transient voltage of the positive pole and a negative voltage sensor sensing a negative transient voltage of the negative pole and a control unit which is adapted to derive a DC displacement voltage from the positive and the negative transient voltages.

A power receiving device includes: a power receiving unit configured to wirelessly receive power from a power transmitting unit of a power transmitting device; a rectifier circuit; a charging relay provided between the rectifier circuit and the power storage device; a voltage sensor configured to sense a voltage applied from the power receiving unit to the rectifier circuit; and a charging ECU configured to wirelessly communicate with the power transmitting device via a communication device. After wireless communication with the power transmitting device is established before a power request is output to the power transmitting device, the charging ECU closes the charging relay and also performs a short-circuit determination process, by using a value of a voltage sensed by the voltage sensor with the charging relay closed, to determine whether the rectifier circuit has a short circuit fault.

A protection device for a power converter provided between an AC system and a DC power transmission system is configured to: receive an input of an AC current value obtained between a transformer connected to the AC system and the power converter capable of converting AC power into DC power; receive an input of a change rate of a direct current detected by a Rogowski coil provided between a DC line and the power converter, the DC line receiving DC power from the power converter; determine based on the AC current value and the change rate whether a fault occurs or not in one of the power converter and the DC line; and output information for protecting the power converter based on a determination result.

A rectifier includes a first input, a first output, and a first pair of diodes. The first input is configured to receive a first alternating current (AC) voltage. The first pair of diodes is electrically coupled in series between the first input and the first output. The first pair of diodes is configured to rectify the first AC voltage. The first output is configured to output the first rectified AC voltage.

A converter apparatus and methods of operation thereof are disclosed. In an example, a converter unit of a bipole converter apparatus comprising a neutral connection having a breaker switch is disclosed. In the event of a DC fault, the fault condition may be monitored and it is determined whether a breaker switch operation condition is met. The breaker switch is opened when the breaker switch operation condition is met. In one example, the breaker switch operation condition may comprise a current level.

A switching power supply (switched-mode power device) includes a rectifier for a mains connection and for rectifying a three-phase AC voltage, a first converter and a second converter, the input voltage of which forms an intermediate circuit voltage, where the first converter regulates the intermediate circuit voltage such that the voltage substantially corresponds to a predefinable output voltage of the second converter multiplied by a load-independent transformation ratio on operation of the second converter with a resonant frequency, where upon forced reduction of the output voltage from the second converter, the first converter can set an, on average, sufficiently low intermediate circuit voltage such that the second converter can be operated substantially with the resonant frequency for a load-independent transformation ratio, where a signal for closed-loop control of the first converter stage can be derived from voltage and/or current information from the second converter.

A control method allows the control of an installation for transmitting electricity comprising a DC transmission network including a group of electricity transmission lines that are linked to one another. The method allows the opening of at least one N-1 safety system, for each safety system being opened, the contribution to the flow of current through the group of transmission lines, originating from the converter station associated with the safety system that is opened, is removed. Furthermore, the method also allows a search for the short-circuit fault in order to identify the faulty transmission line, and an operation, implemented after identification of the faulty transmission line by the search step, of isolating the faulty transmission line by opening the line circuit breakers of the faulty transmission line.

A method detects a working voltage collapse by use of an electric component, in which the exceeding of a critical characteristic of the working voltage is monitored and an excess is detected as a collapse. Accordingly, in order to recognize the collapse breakdown in a simple trouble-free manner, a model voltage generated by a model circuit is used as the critical characteristic.

The invention relates to an on-board electrical system supply system (1), having a DC/DC converter (11) with at least one semiconductor rectifier element (4), having two supply connections (9a, 9b) for an on-board electrical system, which supply connections are connected at the output end to the DC/DC converter (11), having an isolating switch (5) which is coupled between one of the supply connections (9a, 9b) and the DC/DC converter (11), and having an on-board electrical system isolating circuit (10) which is designed to determine a reverse voltage (U, Ua, Ub) across at least one of the semiconductor rectifier elements (4), and to actuate the isolating switch (5), in order to decouple the on-board electrical system from the DC/DC converter (11), depending on a value of the determined reverse voltage (U, Ua, Ub).