Embodiments of the disclosure include an electrical assembly. The electrical assembly can include a converter including a DC side and an AC side, the DC side configured for connection to a DC network, the AC side configured for connection to an AC network, the converter including at least one switching element; a circuit interruption device operably connected to the AC side of the converter; a DC voltage modification device operably connected to the DC side of the converter, the DC voltage modification device including a DC chopper; and a controller configured to selectively control the or each switching element, the circuit interruption device and the DC voltage modification device, wherein the controller is configured to be responsive to a converter internal fault by carrying out a fault operating mode.

A method identifies asymmetrical vibrations during the operation of an electric device which is connected to a high-voltage grid. Vibrations of the electric device are detected using vibration sensors which provide measured values on the output side. The measured values and/or values derived from the measured values are transmitted to a communication unit via a close-range communication connection. The measured values and/or the values are transmitted by the communication unit to a data processing cloud via a far-range communication connection. The measured values are separated into frequency components by the data processing cloud using a Fourier transformation, thereby obtaining a frequency spectrum. Odd and even frequency components of the frequency spectrum are ascertained based on a base frequency of the high-voltage supply grid and put into a ratio R relative to one another. The presence of asymmetrical vibrations is indicated if the ratio R exceeds a specified threshold.

Embodiments herein describe operating wind turbines in an offshore park to provide auxiliary power to a local AC grid or to an onshore grid during a grid malfunction. In one embodiment, the offshore park is coupled via a HVDC link to an onshore grid. When the HVDC link is down, a substation in the park includes a backup generator for creating a weak grid for powering auxiliary systems in a pilot turbine. The wind turbines in the park can switch to an auxiliary control system help power the auxiliary systems in the substation and in other turbines. In another embodiment, the offshore park is AC coupled to an onshore grid using a transformer in the substation. The wind turbines can participate in a brown or black start following a grid fault by switching to operating using the auxiliary control system.

The invention discloses a commutation failure protection method, and apparatus, computer device and storage medium thereof. The method comprises: collecting three-phase AC currents on a valve-side of a converter, a DC current on a high-voltage side and a DC current on a neutral terminal; selecting a minimum value of an absolute value of the three-phase AC currents on the valve side as an AC characteristic quantity, and selecting a maximum value of the DC current on the high-voltage side and the DC current on the neutral terminal as a DC characteristic quantity; according to the AC characteristic quantity and the DC characteristic quantity, constructing a minimum characteristic quantity; comparing the minimum characteristic quantity with a first preset threshold, and outputting a commutation judgment result; according to the commutation judgment result, constructing a commutation time interval; comparing the commutation time interval with a second preset threshold and a third preset threshold, and outputting a commutation failure protection judgment result to determine whether a commutation failure occurs. The invention uses minimum current sequence characteristics to track a commutation process of a converter valve, and when a commutation failure occurs, it may make timely, accurate and reliable judgment, thereby ensuring safe operation of valve equipment.

A microgrid with a high voltage direct current (HVDC) source for efficiently and safely distributing power to decentralized loads includes: at least a main HVDC power supply connectable in input to an AC grid and in output to a main DC distribution network and loads system in output, the main HVDC power supply having energy reserve means and a main switch-based fault isolator or main FI, the main DC distribution network and loads system including: a maintrunk bus, and subtrunks buses and/or front end local loads cells connected in parallel to the maintrunk bus, and at each branching of a subtrunk bus and a load or of a subtrunk bus of rank n−1 and a subtrunk bus of rank n, a local switch-based fault isolator or local FI, n being an integer comprised in the range [1, N]. A smart main controller including microcontrollers for smart operation is also included.

A method for controlling an electrical transmission network including a plurality of DC high-voltage lines and at least three AC/DC converters identified by a respective index i. For each of the converters having index i, the method includes recovering the setpoint active power value Pdci applied thereto, and recovering instantaneous voltage value Vi and voltage angle value θi of the buses having index i and modifying the setpoint active power Pdci of each of the converters having index i by a value including a term ΔPdcsi as a function of a sum of deviations of voltage angles multiplied by contribution adjustment parameters.

The present disclosure an include an electrical assembly comprising a power converter having an AC side and a DC side, the AC side for connection to an AC network; at least one power transmission medium connected to the DC side of the power converter; a dynamic braking system operably connected to the or each power transmission medium, the dynamic braking system including a dynamic braking control unit programmed to selectively control activation of the dynamic braking system to carry out a dynamic braking operation; a monitoring unit for monitoring an electrical parameter of the AC network; and a processing unit programmed to determine an operating state of the AC network from the monitored electrical parameter, wherein the dynamic braking control unit is programmed to be responsive to the determined operating state of the AC network by configuring the dynamic braking system to be activatable.

The present invention relates to an apparatus and a method for synchronizing a clock of VBE in a HVDC system capable of increasing reliability by synchronizing the clock of the VBE in the HVDC system to suppress harmonic generation and generate duplicate clock to supply stable clock to submodules. The apparatus for synchronizing the clock of the VBE in the HVDC system comprises an operation board for creating a reference clock and an interface board for controlling submodules on or off being synchronized to a reference clock.

A method can be used to synchronize time between nodes of a converter device for high voltage power conversion. The method is performed in a first node of the converter device and includes receiving a time reference from a second node of the converter device, obtaining a delay value for receiving time references from the second node, determining a compensated time by adding the delay value to the time reference, and setting a clock in the first node to be the compensated time.

A flow-guiding rod includes a cooling channel provided in a rod portion of the flow-guiding rod, and a coolant inlet pipe and a coolant outlet pipe provided on end(s) of the flow-guiding rod. The coolant inlet pipe and the coolant outlet pipe are communicated with the cooling channel.