A power supply circuit for an x-ray production system, which has an inverter circuit with an output for connecting the inverter circuit with an x-ray source of the x-ray production system, includes a rectifier circuit including an input to connect the rectifier circuit with a power supply network, the rectifier circuit further including an output to connect to an input of the inverter circuit; and a backup circuit including a plurality of electrical energy storage cells, the plurality of electrical energy storage cells being connectable in series between the input of the inverter circuit and the output of the rectifier circuit.

A system and a method for management of an electric grid. The system includes at least one monitoring server and at least one grid monitoring sensor communicably coupled to the at least one monitoring server. Herein the given grid monitoring sensor is installed to a given electrical utility pole of the electric grid. Each of the at least one grid monitoring sensor includes a magnetic sensor for measuring a time-variant magnetic field induced by current transients in the electric grid.

A method for determining synchronization transient stability of a power system and an electronic device are provided. The synchronous energy function corresponding to the power system model is determined; the synchronization convergence region is determined according to the synchronization energy function; it is determined whether the power system is transient stable according to the synchronization convergence region and the initial value of power system after fault; and adjusting parameters of the power system in response to determining that the power system is transient unstable.

A method which is suitable for a system having a frequency converter and a generator, both of which are connected to a power grid, includes obtaining sub-synchronous components of the grid voltage and determining damping current set points according to the sub-synchronous components to compensate for sub-synchronous resonances of the grid. Damping current set points are determined by receiving the sub-synchronous components of the grid voltage and returning damping current set points as outputs. A variable damping gain is adjusted according to the sub-synchronous frequency of the grid, such that the required compensation level can be adapted to the frequency converter for damping sub-synchronous resonance of the grid.

Disclosed are a voltage source converter based high voltage direct current (VSC-HVDC) high-frequency resonance suppression method, system, and device. The method includes: when an effective value of an actually input alternating current (AC) voltage is reduced from a normal value to meet a preset condition, making the virtual electrical quantity completely equal to the actual electrical quantity, and performing full real-time tracking for the actual electrical quantity to improve dynamic characteristics of a power system at the moment of a fault; and after performing the full tracking for a period of time, if the effective value of the actual AC voltage is less than a preset threshold, performing adaptive tracking until the actual electrical quantity recovers to a stable value. The present disclosure can reduce a risk of high-frequency resonance of a VSC-HVDC, avoid deteriorating dynamic characteristics of the VSC-HVDC, and improve safety of fault ride-through of the VSC-HVDC.

In various embodiments of the present disclosure, there is provided a method of operating a wind power plant in a weak grid environment in order to achieve desired system stability criteria and to support an electrical grid during small disturbances or faults, the wind power plant being coupled to an electrical grid, and including a power plant controller for controlling a plurality of wind turbine generators of the wind power plant, the method including: determining whether the electrical grid fulfils a weak grid criterion; setting the power plant controller to operate in a weak grid mode when the weak grid criterion is fulfilled, the weak grid mode including: reducing and providing an active power reference according to which the plurality of wind turbine generators are controlled, when a grid voltage deviates beyond a threshold voltage from a normal or recommended operating voltage range during steady state operation of a wind power plant; and generating a reduced amount of active power with each of the plurality of wind turbine generators based on the provided active power reference& controlling the active power ramp rates, when the electrical grid recovers from the voltage deviation or a fault. A corresponding wind power plant is further provided. The coordinated operation of the plant level control and WTG level control plays an important role.

A smart switch allows distributed generators to “ride through” non-three-phase faults by very quickly detecting a non-three-phase phase fault, locating the fault, identifying the “responsive sectionalizer switches” that will be involved in clearing or isolating the fault, and selecting one of the responsive sectionalizer switches to direct back-feed tie switch operations. The responsive sectionalizer switches trip only the faulted phase(s), and the selected sectionalizer switch instructs a back-feed tie switch to close to back-feed the distributed generators prior to conducting the typical fault response operation. This typically occurs within about three cycles, and is completed before the normal fault clearing and isolation procedures, which momentarily disconnect all three phases to the distributed generators from the normally connected feeder breaker. The looped connection to an alternate feeder breaker during these operations allows the distributed generators to “ride through” the normal fault clearing and isolation procedures.

Provided is a renewable power generation plant, a computer program product and method of controlling a renewable power generation plant including a power converter for connecting the renewable power generation plant to a power transmission network; a circuit breaker arrangement between the power converter and the power transmission network, including a circuit breaker for each phase of the renewable power generation plant; and a converter controller configured to generate control signals for the power converter and control signals for the circuit breaker arrangement; which method includes the steps of detecting the occurrence of a phase-to-ground fault event in one of the phases of the power transmission network; issuing control signals to the circuit breaker arrangement to keep the circuit breakers closed during the phase-to-ground event; and issuing control signals to the power converter to ride through the phase-to-ground fault event.

The present disclosure provides a dispatching method and a dispatching device for an integrated transmission and distribution network. The integrated transmission and distribution network include a transmission network and at least one distribution network. The method includes: establishing a dispatch model of the integrated transmission and distribution network; solving the dispatch model to obtain dynamic dispatch parameters for the integrated transmission and distribution network, in which the dynamic dispatch parameters comprise a boundary transferred power from the transmission network to each of the at least one distribution network, and power outputs of all generators in the transmission network and each of the at least one distribution network; and dispatching the integrated transmission and distribution network based on the boundary transferred power and the power outputs of all the generators in the transmission network and each of the at least one distribution network.

A method of controlling a power generation system following a transient grid event, and a system and controller to control the power generation system are described. The method includes sensing a rate of change of electrical frequency at terminals of a generator, determining a rate of change of shaft line acceleration, and identifying the transient grid event based on the rate of change of shaft line acceleration. The method also includes triggering an action to recover from the transient grid event when the rate of change of electrical frequency exceeds a first specified value and the rate of change of shaft line acceleration exceeds a second specified value for a specified duration.