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.

An automatic switching interface box for generators in residential dwellings and small commercial applications provides a breaker box transfer switch for generators powering one or more electrical loads. In power blackout situations, the breaker box transfer switch uses a power control relay to keep the load power on, which eliminates the need for a hot generator plug, because the plug in box is not powered. The generator power output cord is plugged onto the male plug of the interface box, or hard wired thereto. If the auxiliary generator had been started and is at rated voltage, the load is immediately and automatically switched from the utility connection to the generator as electrical source. The relay keeps the prongs of the male plug safely unpowered until the generator is attached since the relay coil is powered by the generator output and the plug is connected to the normally open contacts.

An output of a generator may vary according to the speed of the engine, physical characteristics of the engine, or other factors. A profile for a generator that describes a periodic fluctuation in an operating characteristic for the generator is identified. A field current of an alternator associated with the generator is modified based on the profile for the generator in order to counter variations in the output of the generator.

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.

Overvoltage protection device for a variable-speed and constant-frequency electrical energy generation system includes at least one DC current generator connected, via a DC current bus to the input terminals of at least one inverter and to at least one regulation module for regulating the output voltage of the at least one inverter. The device includes a circuit including at least one switch in series with a resistor, the circuit being connected between the input terminals of the at least one inverter, at least one measurement sensor for measuring the DC voltage across the input terminals of the at least one inverter, a control circuit connected to the at least one measurement sensor and able to receive a voltage measured by the at least one measurement sensor, compare the measured voltage against a threshold and command the closure of the at least one switch if the measured voltage is greater than the threshold, and command opening thereof if not.

Overvoltage protection device for a variable-speed and constant-frequency electrical energy generation system includes at least one DC current generator connected, via a DC current bus to the input terminals of at least one inverter and to at least one regulation module for regulating the output voltage of the at least one inverter. The device includes a circuit including at least one switch in series with a resistor, the circuit being connected between the input terminals of the at least one inverter, at least one measurement sensor for measuring the DC voltage across the input terminals of the at least one inverter, a control circuit connected to the at least one measurement sensor and able to receive a voltage measured by the at least one measurement sensor, compare the measured voltage against a threshold and command the closure of the at least one switch if the measured voltage is greater than the threshold, and command opening thereof if not.

Relay devices and methods of use for detecting and reacting to subsynchronous oscillation events in electrical energy generation and transmission systems, such as but not limited to, subsynchronous control interactions between wind-turbine generators and series-compensated transmission lines.

A method for protecting a permanent magnet generator of a wind turbine with a multiphase generator, and n number of isolated converters, the multiphase generator including a rotor carrying permanent magnets and n number of independent multiphase sub-stators comprising a plurality of windings, each converter being connected to an independent multiphase sub-stator and configured to control the plurality of windings of the multiphase sub-stator comprises determining an asymmetrical short circuit current in one of the sub-stators, which generates a first oscillating torque, disconnecting the converter linked to the sub-stator with an asymmetrically short circuited group of windings, and injecting an asymmetrical current with the remaining connected converters, wherein said injected asymmetrical current generates a second oscillating torque that is substantially opposed in phase to the first oscillating torque so that the first oscillating torque is at least partly compensated is disclosed. Permanent magnet generators are also disclosed.

A method for protecting a permanent magnet generator of a wind turbine with a multiphase generator, and n number of isolated converters, the multiphase generator including a rotor carrying permanent magnets and n number of independent multiphase sub-stators comprising a plurality of windings, each converter being connected to an independent multiphase sub-stator and configured to control the plurality of windings of the multiphase sub-stator comprises determining an asymmetrical short circuit current in one of the sub-stators, which generates a first oscillating torque, disconnecting the converter linked to the sub-stator with an asymmetrically short circuited group of windings, and injecting an asymmetrical current with the remaining connected converters, wherein said injected asymmetrical current generates a second oscillating torque that is substantially opposed in phase to the first oscillating torque so that the first oscillating torque is at least partly compensated is disclosed. Permanent magnet generators are also disclosed.

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.