In accordance with at least one aspect of this disclosure, a system includes a generator control relay configured to electrically connect a generator and an exciter switch drive to drive an exciter switch. A first processor is operatively connected to control a state of the generator control relay to control the electrical connection between a generator and the exciter switch drive. The system includes an exciter drive configured to generate excitation current for field windings of a generator system based on a state of the exciter switch. A second processor is operatively connected to control the exciter drive and to communicate with the first processor during a fault event to place the generator control relay in an open state, disconnecting the generator from the exciter switch drive to prevent generation of excitation current. In certain embodiments, the first processor can include a microcontroller and the second processor can include a voltage regulation processor.

The present application discloses a flexible excitation system and a method for controlling the same. The flexible excitation system consists of a plurality of groups of flexible excitation power units connected in parallel, a deexcitation circuit unit and a flexible excitation control unit. The method for controlling the flexible excitation system includes: realizing the internal fault-tolerant operation control of the flexible excitation power units by cooperatively controlling AC circuit breakers and DC circuit breakers of the flexible excitation power units and a deexcitation switch; dynamically controlling ceiling voltage when terminal voltage drops by using the fast response control ability of the flexible excitation system, so as to improve the forced excitation output capacity of the self-shunt excitation system. Aiming at the possible overload problem of an excitation transformer during the operation of flexible excitation, an excitation transformer overload limiter for the flexible excitation system is provided to limit the operation state of the excitation transformer within an allowable overload operation range of equipment.

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.

In accordance with at least one aspect of this disclosure, a method can include measuring a voltage across a DC link of a generator system when a generator exciter is inactive and a generator permanent magnet is active, and detecting a short or open permanent magnet generator (SOPMG) fault condition in the generator system with a DC link monitor operatively connected to measure the voltage across the DC link.

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 generator control unit (GCU) includes a fault detection system configured to generate a direct current (DC) voltage signal based on a difference of a DC-equivalent voltage between the positive and negative exciter gate drive signals. The fault detection system further outputs a fault detection signal indicating the fault status of the gate drive integrated circuits based on a comparison between the DC average voltage signal and a threshold value.

The method of control according to the invention slaves a DC voltage generated by the alternator to a predetermined setpoint value by controlling an excitation current flowing in an excitation circuit comprising an excitation winding of a rotor of the alternator. The excitation current is controlled by means of a semiconductor switch, in turn controlled by a control signal having a predetermined period. The method comprises a detection of a failure of the excitation circuit. At least one short-circuit of the excitation winding is detected. According to another characteristic of the method, the control signal is generated on the basis of a combination of a setpoint signal formed by pulses of the predetermined period exhibiting a duty ratio representative of the setpoint value and of a detection signal indicative of the short-circuit.

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 differential protection method for generating a fault signal includes measuring current measurements at least at two different measuring points of a multiphase transformer for each phase. The current measurements for each phase are used to form differential current values and stabilization values. The fault signal is generated if it is determined during a trigger region check that a measurement pair of at least one of the phases, being formed by using one of the differential current values and the associated stabilization value in each case, is in a predefined trigger region. In order to be able to selectively and reliably distinguish an external fault from an internal fault, the transformer has a grounded star point and a zero system current flowing through the star point is used to form the stabilization values. A corresponding differential protection device is provided for performing the differential protection method.

Described is a method including monitoring a point of regulation voltage input to a generator control unit and monitoring a generator output voltage as a backup point of regulation voltage input. The method also includes detecting an overvoltage fault at the point of regulation voltage input, the backup point of regulation voltage input, or both. Additionally, the method includes opening a first solid-state switch (110) in response to detecting the overvoltage fault. Opening the first solid-state switch (110) prevents provision of an input signal (104) to a generator excitation field (102). Further, the method includes opening a generator excitation field relay (112) in response to detecting the overvoltage fault. Opening the excitation field relay (112) also prevents provision of the input signal (104) to the generator excitation field (102).