A failure diagnosis system according to an embodiment includes a first power line, a second power line, a first main contact, a second main contact, a first electrical component, a second electrical component, and a control device. The first electrical component includes a first terminal electrically connected to a second part of the first power line and a second terminal electrically connected to a third part of the second power line. A state of the first electrical component is to be switched in a case where a voltage is applied between the first terminal and the second terminal. The control device is configured to determine whether an abnormality of the first main contact exists or not based on output of a control instruction relating to the first main contact and the state of the first electrical component.

A power device fault detection circuit includes a first fault detector configured to measure an output signal of at least one power device and output a first fault signal when a voltage of the output signal of the at least one power device exceeds a first voltage reference level after a first time period; and a second fault detector configured to measure an output signal of the at least one power device and output a second fault signal when a voltage of the output signal of the at least one power device exceeds a second voltage reference level after a second time period, where the first time period implemented by the first fault detector is shorter than the second time period implemented by the second fault detector.

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.

An active bridge rectifier circuit includes a rectifier unit and a control unit. The rectifier unit includes a first upper bridge switch, a second upper bridge switch, a first lower bridge switch, and a second lower bridge switch. The control unit includes a first signal comparator and a second signal comparator. The first signal comparator compares a live wire signal provided from a live wire end with a neutral wire signal provided from a neutral wire end to generate a first comparison signal. The second signal comparator compares the live wire signal with the neutral wire signal to generate a second comparison signal. The first comparison signal controls the first upper bridge switch and the first lower bridge switch. The second comparison signal controls the second upper bridge switch and the second lower bridge switch.

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 failure diagnosis system according to an embodiment includes a first power line, a second power line, a first main contact, a second main contact, a first electrical component, a second electrical component, and a control device. The first electrical component includes a first terminal electrically connected to a second part of the first power line and a second terminal electrically connected to a third part of the second power line. A state of the first electrical component is to be switched in a case where a voltage is applied between the first terminal and the second terminal. The control device is configured to determine whether an abnormality of the first main contact exists or not based on output of a control instruction relating to the first main contact and the state of the first electrical component.

A method manages a fault on a DC voltage side of a converter assembly including a modular multistage converter with switching modules having semiconductor switches and an energy store. Some switching modules are a first type and others are a second type. During operation, a positive switching module voltage, negative switching module voltage or zero voltage are generated at terminals of switching modules of the first type, and a positive switching module voltage or zero voltage are generated at terminals of switching modules of the second type. Upon detecting a DC voltage side fault, switching modules of the first type are actuated such that the polarity of their energy store voltages corresponds to the polarity of a fault current, and energy stores of switching modules of the first type are charged to a voltage exceeding their rated voltage. A converter assembly carrying out the method is also provided.

An example power supply for supplying electrical power to an electronic device includes an AC to DC converter, power factor correction (PFC) circuitry, and a controller. The AC to DC converter is configured to convert an input AC power signal into a DC power signal. The PFC circuitry is configured to correct a power factor of the DC power signal. The controller is configured to monitor an amount of correction () being applied to the DC power signal by the PFC circuitry and to shut down supply of power to the electronic device in response to being within a first threshold of zero degrees for a second threshold amount of time.

An example power supply for supplying electrical power to an electronic device includes an AC to DC converter, power factor correction (PFC) circuitry, and a controller. The AC to DC converter is configured to convert an input AC power signal into a DC power signal. The PFC circuitry is configured to correct a power factor of the DC power signal. The controller is configured to monitor an amount of correction () being applied to the DC power signal by the PFC circuitry and to shut down supply of power to the electronic device in response to being within a first threshold of zero degrees for a second threshold amount of time.

A system, a switch assembly and an associated method. The system includes a number of switch assemblies, each including a switch module, isolation circuits, a detection unit, and a drive unit. The switch module includes power switch devices connected in parallel. The switch modules are connected in series. The isolation circuits each are connected in series to a gate terminal of at least one corresponding power switch device of the power switch devices. Each isolation circuit includes a capacitor or a controllable switch. The detection unit detects faults in at least one of the power switch devices. The drive unit is coupled to the switch module via the isolation circuits for driving the power switch devices of the corresponding switch module, and when the fault is detected, the drive unit is for turning on the power switch devices parallel connected to the at least one of faulty power switch devices.