An electrical system includes a plurality of synchronous electrical machines, and an electronic control unit structured to controllably trip a circuit breaking mechanism such as a relay coupling together the electrical machines. The control unit executes control logic to select trip options responsive to slip frequency between the synchronous electrical machines that is induced by a power swing.

An electrical system includes a plurality of synchronous electrical machines, and an electronic control unit structured to controllably trip a circuit breaking mechanism such as a relay coupling together the electrical machines. The control unit executes control logic to select trip options responsive to slip frequency between the synchronous electrical machines that is induced by a power swing.

A relay protection method against LC parallel circuit detuning faults comprises the steps of: a relay protection device samples a current of a parallel LC, that is, a reactor and a capacitor, and samples a total current flowing through the whole LC; convert the current of the reactor into a current of an equivalent capacitor; calculate amplitudes of the current of the equivalent capacitor and a current of a realistic capacitor and calculate an amplitude of the total current flowing through the LC; calculate a current amplitude ratio of the equivalent capacitor to the realistic capacitor; and when the amplitude of the total current flowing through the LC is large enough, send an alarm signal or a trip after a setting time delay if the current ratio exceeds a preset upper and lower limit range. Also provided is a corresponding relay protection device.

A relay protection method against LC parallel circuit detuning faults comprises the steps of: a relay protection device samples a current of a parallel LC, that is, a reactor and a capacitor, and samples a total current flowing through the whole LC; convert the current of the reactor into a current of an equivalent capacitor; calculate amplitudes of the current of the equivalent capacitor and a current of a realistic capacitor and calculate an amplitude of the total current flowing through the LC; calculate a current amplitude ratio of the equivalent capacitor to the realistic capacitor; and when the amplitude of the total current flowing through the LC is large enough, send an alarm signal or a trip after a setting time delay if the current ratio exceeds a preset upper and lower limit range. Also provided is a corresponding relay protection device.

Embodiments of the disclosure relate to transient event mitigating systems and methods that can be incorporated into a power generation system. The power generation system can include an exciter coupled to an alternating current (AC) generator that provides electric power to power lines. The transient event mitigating system can include an automatic voltage regulator that detects a transient event in one or more of the power lines and configures a power converter to respond to the transient event by increasing an amount of direct current (DC) voltage coupled into the power converter. The power converter can provide the increased DC voltage to an exciter coil of the exciter for a transitory period of time in order to adjust the electric power generated by the AC generator and mitigate adverse effects of the transient event.

A generator protection unit is provided including a central processing unit including at least one programmable device configured to utilize an Ethernet communication protocol. The central processing unit may be configured to synchronize a first signal generated by a generator electrically coupled to the generator protection unit to a second signal including an electrical power grid parameter of an electrical power grid, the first signal and the second signal having a phase offset. The generator protection unit may also include a plurality of multimeters, each electrically coupled to the electrical power grid and the central processing unit, and at least one display filter electrically coupled to the central processing unit and configured to separate a defined portion of a protection parameter signal, such that a remaining portion of the protection parameter signal is transmitted to the central processing unit. The generator protection unit may further include a user interface coupled to the central processing unit and configured to relay at least the remaining portion of the protection parameter signal to an operator of the generator protection unit.

A generator protection unit is provided including a central processing unit including at least one programmable device configured to utilize an Ethernet communication protocol. The central processing unit may be configured to synchronize a first signal generated by a generator electrically coupled to the generator protection unit to a second signal including an electrical power grid parameter of an electrical power grid, the first signal and the second signal having a phase offset. The generator protection unit may also include a plurality of multimeters, each electrically coupled to the electrical power grid and the central processing unit, and at least one display filter electrically coupled to the central processing unit and configured to separate a defined portion of a protection parameter signal, such that a remaining portion of the protection parameter signal is transmitted to the central processing unit. The generator protection unit may further include a user interface coupled to the central processing unit and configured to relay at least the remaining portion of the protection parameter signal to an operator of the generator protection unit.

A generator system includes a generator controller for monitoring the operation of generator cable. The generator controller is configured to receive a first signal indicative of a generator output and a first connection of a generator cable and a second signal indicative of a second connection of the generator cable. The generator controller is configured to calculate a characteristic value for the generator cable based on the first signal and the second signal and compare the characteristic value for the generator cable to a threshold value. A generator status message or a generator command is generated in response to the comparison. The characteristic value may be resistance of the generator cable.

A generator system includes a generator controller for monitoring the operation of generator cable. The generator controller is configured to receive a first signal indicative of a generator output and a first connection of a generator cable and a second signal indicative of a second connection of the generator cable. The generator controller is configured to calculate a characteristic value for the generator cable based on the first signal and the second signal and compare the characteristic value for the generator cable to a threshold value. A generator status message or a generator command is generated in response to the comparison. The characteristic value may be resistance of the generator cable.

A wind turbine includes a wind rotor, a generator, and a converter. The generated electric power is fed from the converter by means of a feed to a turbine transformer for delivery to a grid. The feed is designed as a double branch including a power-branched power circuit breaker unit having a first feed line and a second feed line connected in parallel, wherein a separate low-voltage winding of the turbine transformer and a separate power circuit breaker at the connector of the converter is associated with each feed line.