A method for operating a wind turbine generator connected to a power network to account for recurring voltage faults on the power network caused by automatic reclosure of at least one circuit breaker following a short-circuit. The method comprises: identifying a deviation of voltage level of the power network from a normal operational voltage level of the network; determining that the identified deviation fulfils criteria for automatic reclosure; and operating the wind turbine generator in a recurring fault mode if automatic reclosure criteria are fulfilled. When operating the wind turbine generator in recurring fault mode, the method comprises: monitoring the recovery of the voltage level from the deviation; categorising the recovery of the voltage as one of at least a strong recovery or a weak recovery; and implementing a ride-through protocol according to the category of recovery.

The present disclosure relates to systems and methods for protecting against and mitigating the effects of over-excitation of elements in electric power systems. In one embodiment, a system consistent with the present disclosure may comprise a point pair subsystem to receive a plurality of point pairs that define an over-excitation curve for a piece of monitored equipment. The system may receive a plurality of measurements corresponding to electrical conditions associated with the piece of monitored equipment. A logarithmic interpolation subsystem may determine a logarithmic interpolation corresponding to one of the plurality of measurements based on the plurality of point pairs. An over-excitation detection subsystem may detect an over-excitation condition based on the logarithmic interpolation, and a protective action subsystem may implement a protective action based on the over-excitation condition.

A system and method for determining the optimal time to perform a pulse test to determine the presence of a fault after a switch opens to clear the fault to prevent generator instability. The method includes detecting the fault, opening a switch to clear the fault, determining an optimal time for performing the pulse test for determining the continued presence of the fault based on predetermined system data and parameters after the switch is opened so as to prevent the pulse test from occurring too early that could cause generator instability, and performing the pulse test at the optimal time to determine if the fault is still present. Determining the optimal time can use available system data and information, such as a priori knowledge or real-time behaviour. If the fault is not present, then the method determines a desired time to perform a reclose operation.

A system and method for determining the optimal time to perform a pulse test to determine the presence of a fault after a switch opens to clear the fault to prevent generator instability. The method includes detecting the fault, opening a switch to clear the fault, determining an optimal time for performing the pulse test for determining the continued presence of the fault based on predetermined system data and parameters after the switch is opened so as to prevent the pulse test from occurring too early that could cause generator instability, and performing the pulse test at the optimal time to determine if the fault is still present. Determining the optimal time can use available system data and information, such as a priori knowledge or real-time behaviour. If the fault is not present, then the method determines a desired time to perform a reclose operation.

An apparatus for managing a plurality of electric power generators is configured to receive measurements of a plurality of parameters related to performance of one or more of a plurality of generators and detect, based on the measurements, that values of at least two of the plurality of parameters measured for a first generator of the one or more generators do not match respective predetermined values of the at least two parameters for the first generator. In response to the detecting, the apparatus determines that the first generator is faulty and generates a signal to perform at least one of shutting down the first generator or disconnecting the first generator from at least one second generator of the plurality of generators, in response to determining that the first generator is faulty.

A high voltage DC (HVDC) system can include a generator configured to output alternating current (AC), a rectifier connected to the generator via AC phase lines, the rectifier configured to convert the AC to DC to output the DC to DC feeder lines, and a crowbar system. The crowbar system can include a switch module operatively connected to the AC phase lines to prevent AC from flowing to the rectifier in a cutoff state. The crowbar system can be configured to determine whether at least one cutoff condition exists. The at least one cutoff condition can be or include one or more of a DC overcurrent downstream of the rectifier, a DC overvoltage downstream of the rectifier, an AC overcurrent from the generator, or an arc fault. The crowbar system can be configured to control the switch module to the cutoff state if the at least one cutoff condition exists.

An aircraft with an electrical network including electrical subnetworks; a turbo generator including a gas turbine, an electricity generator with permanent magnets having phase groups respectively connected to the electrical subnetworks, and, for each phase group, an isolation device; and a control device designed to detect a short circuit in at least one of the phase groups, each phase group in which a short circuit is detected being described as defective and each other phase group being described as healthy and, in response to the detection of the short circuit, to disconnect this defective phase group from its associated electrical subnetwork and to command the shutdown of the gas turbine. The control device is also designed, in response to the detection of the short circuit, to keep each healthy phase group connected to its electrical subnetwork.

An aircraft with an electrical network including electrical subnetworks; a turbo generator including a gas turbine, an electricity generator with permanent magnets having phase groups respectively connected to the electrical subnetworks, and, for each phase group, an isolation device; and a control device designed to detect a short circuit in at least one of the phase groups, each phase group in which a short circuit is detected being described as defective and each other phase group being described as healthy and, in response to the detection of the short circuit, to disconnect this defective phase group from its associated electrical subnetwork and to command the shutdown of the gas turbine. The control device is also designed, in response to the detection of the short circuit, to keep each healthy phase group connected to its electrical subnetwork.

A system includes a converter for powering a synchronous electric machine to which it is connected by cables, an insulating device and a mechanism for short-circuiting phases of the machine. The system includes primary detectors for detecting an overcurrent in the converter and a securing device able to open the insulating device when receiving a primary detection signal emitted by the primary detector. The system also includes secondary detectors able to detect a short-circuit downstream from the insulating device and to emit a secondary detection signal toward the securing device, the latter actuating the closing of the mechanism for short-circuiting as long as they have already received a primary detection signal having led to the opening of the insulating device.

A variable-speed constant-frequency (VSCF) power converter includes a generator control operable to regulate an output voltage of a variable frequency generator at a variable frequency. The VSCF power generator also includes an inverter control operable to regulate a VSCF output voltage at a point-of-regulation at a constant frequency, where the generator control and the inverter control independently control a main line contactor of the point-of-regulation to provide redundant fault protection for an aircraft use.