Abstract: A device includes a first thyristor element configured to be coupled to a first voltage line and a second voltage line, wherein the first voltage line is configured to transmit power in a first phase and the second voltage line is configured to transmit power in a second phase. The device includes a second thyristor element configured to be coupled to the second voltage line and a third voltage line, wherein the third voltage line is configured to transmit power in a third phase. The device includes a third thyristor element configured to be coupled to the first voltage line and the third voltage line.

Abstract: A neutral point clamped (NPC) power converter fault protection system is provided, and include a DC bus, a switching network, and a control module. The switching network is connected to the DC bus. The switching network includes at least two leg circuits. Each of the at least two leg circuits includes at least two switches connected in series and two NPC diodes. Each of the two NPC diodes corresponds to one of the at least two switches. Each of the at least two switches has an open position. The two NPC diodes are connected between a corresponding one of the at least two leg circuits and the DC bus. The control module is in communication with the switching network. The control module includes control logic for monitoring the switching network to detect a fault condition.

Abstract: A device includes a first thyristor element configured to be coupled to a first voltage line and a second voltage line, wherein the first voltage line is configured to transmit power in a first phase and the second voltage line is configured to transmit power in a second phase. The device includes a second thyristor element configured to be coupled to the second voltage line and a third voltage line, wherein the third voltage line is configured to transmit power in a third phase. The device includes a third thyristor element configured to be coupled to the first voltage line and the third voltage line.

Abstract: A midpoint voltage control system includes a power source, a generator coupled to the power source, a midpoint voltage controller coupled to the back-to-back converter configuration, a generator converter controller coupled to the midpoint power controller, a grid converter controller coupled to midpoint power controller, a first voltage converter coupled to the generator converter controller, the midpoint power controller and the generator, a second voltage converter coupled to the grid converter controller the midpoint power controller, the second voltage converter having a capacitor bank direct current (DC) bus midpoint and a transformer coupled to the second voltage converter and having a grid neutral midpoint, wherein the capacitor midpoint is interconnected to the grid neutral midpoint.

Abstract: A fault detection, identification, and protection system for a phase leg of a three-level neutral point clamped (NPC) power converter includes a fault detection circuit, the fault detection circuit configured to determine, based on signals received from the two inner switches and two outer switches via their respective gate drivers, the presence of a fault in the phase leg; a fault identification circuit, the fault identification circuit being configured to determine, based on signals from the fault detection circuit, a location of the fault in the phase leg; and a protection circuit, the protection circuit being configured to turn off at least one of the inner switches or outer switches in response to the identification of the location of the fault by the fault identification circuit.

Abstract: A fault detection, identification, and protection system for a phase leg of a three-level neutral point clamped (NPC) power converter includes a fault detection circuit, the fault detection circuit configured to determine, based on signals received from the two inner switches and two outer switches via their respective gate drivers, the presence of a fault in the phase leg; a fault identification circuit, the fault identification circuit being configured to determine, based on signals from the fault detection circuit, a location of the fault in the phase leg; and a protection circuit, the protection circuit being configured to turn off at least one of the inner switches or outer switches in response to the identification of the location of the fault by the fault identification circuit.

Abstract: A neutral point clamped (NPC) power converter fault protection system is provided, and include a DC bus, a switching network, and a control module. The switching network is connected to the DC bus. The switching network includes at least two leg circuits. Each of the at least two leg circuits includes at least two switches connected in series and two NPC diodes. Each of the two NPC diodes corresponds to one of the at least two switches. Each of the at least two switches has an open position. The two NPC diodes are connected between a corresponding one of the at least two leg circuits and the DC bus. The control module is in communication with the switching network. The control module includes control logic for monitoring the switching network to detect a fault condition.

Abstract: A wind turbine connected to a power grid is provided. The wind turbine is selectively activated to operate at a high-voltage ride through (HVRT) mode. The wind turbine includes a grid voltage circuit, a DC bus, a voltage source, and a dynamic brake. The grid voltage circuit monitors a fundamental voltage of the power grid and activates the HVRT mode if the fundamental voltage is at least about equal to a threshold voltage value. The DC bus has a DC bus voltage. The voltage source provides a DC bus rated voltage. The dynamic brake has a brake chopper and a resistive element. The dynamic brake is connected to the DC bus. The dynamic brake is connected to the voltage source if the HVRT mode is activated.

Abstract: A wind turbine connected to a power grid is provided. The wind turbine is selectively activated to operate at a high-voltage ride through (HVRT) mode. The wind turbine includes a grid voltage circuit, a DC bus, a voltage source, and a dynamic brake. The grid voltage circuit monitors a fundamental voltage of the power grid and activates the HVRT mode if the fundamental voltage is at least about equal to a threshold voltage value. The DC bus has a DC bus voltage. The voltage source provides a DC bus rated voltage. The dynamic brake has a brake chopper and a resistive element. The dynamic brake is connected to the DC bus. The dynamic brake is connected to the voltage source if the HVRT mode is activated.