Abstract: In one aspect, the present subject matter discloses a method for overvoltage protection of an electrical system. The method may generally include detecting an overvoltage condition on an electrical system; and switching on, in response to the detected overvoltage condition, an impedance connected to the electrical system, wherein the impedance clamps voltage on the electrical system.

Abstract: Systems and methods for converting power are presented. The power conversion includes conducting load current through a first current path of multiple current paths in a power conversion unit using switches, diodes, or a combination thereof. The power conversion also includes blocking one or more additional current paths of the multiple current paths in the power conversion unit using one or more of the switches, one or more of the diodes, or a combination thereof. Furthermore, the power conversion includes reducing potential voltage stress on the one or more switches by using one or more voltage stress reduction switches to reduce a voltage that is blocked by the one or more blocking switches or diodes by connecting an end of each of the one or more switches opposite to a blocking edge to an intermediate voltage node.

Abstract: A system and method for estimating a remaining life period for a device. The system includes a sensor coupled to the device, wherein the sensor is configured to facilitate measuring an operating parameter of the device and generate a measurement signal that is representative of the operating parameter. The system includes a database comprising an upper limit value, a lower limit value and a reference parameter. A processor of system includes circuitry coupled to the sensor and coupled to the database The processor is configured to correlate measurements of the operating parameter with the reference parameter to facilitate estimating a remaining life period of the device.

Abstract: In one aspect, a method for protecting one or more electrical machines during a grid fault on an electrical system connected with the one or more electrical machines is provided. The method includes detecting a grid fault on an electrical system; taking one or more first actions from a first set of actions based on detected grid fault on the electrical system; detecting at least one operating condition of the electrical system after taking one or more first actions from the first set of actions based on the detected grid fault on the electrical system; and taking one or more second actions from a second set of actions based on the detected at least one operating condition of the electrical system.

Abstract: The present subject matter is directed to a system and method for controlling an electrical component, e.g. a power bridge, of a wind turbine using contingency communications. In one embodiment, the method includes receiving, by the electrical component, a standard set of commands for a first time frame. A next step includes receiving, by the electrical component, one or more contingency sets of commands for time frames beyond the first time frame. The method also includes determining if the standard set of commands is received within a start window of the first time frame. A further step includes implementing, by the electrical component, the standard set of commands during the first time frame if the standard set of commands is received within the start window. The method also includes implementing, by the electrical component, one of the contingency sets of commands received during a previous time frame if the standard set of commands is not received within the start window.

Abstract: The present subject matter is directed to a system and method for controlling an electrical component, e.g. a power bridge, of a wind turbine using contingency communications. In one embodiment, the method includes receiving, by the electrical component, a standard set of commands for a first time frame. A next step includes receiving, by the electrical component, one or more contingency sets of commands for time frames beyond the first time frame. The method also includes determining if the standard set of commands is received within a start window of the first time frame. A further step includes implementing, by the electrical component, the standard set of commands during the first time frame if the standard set of commands is received within the start window. The method also includes implementing, by the electrical component, one of the contingency sets of commands received during a previous time frame if the standard set of commands is not received within the start window.

Abstract: In one aspect, a method for protecting one or more electrical machines during an islanding event is provided. The method includes connecting one or more electrical machines to an alternating current (AC) electric power system, wherein the AC electric power system is configured to transmit at least one phase of electrical power to the one or more electrical machines or to receive at least on phase of electrical power from the one or more electrical machines; electrically coupling at least a portion of a control system to at least a portion of the AC electric power system; coupling at least a portion of the control system in electronic data communication with at least a portion of the one or more electrical machines; and detecting an islanding of the one or more electrical machines based on one or more conditions monitored by the control system.

Abstract: A power converter includes a plurality of power conversion modules. At least one power conversion module includes a plurality of power conversion devices defining a three-level bridge. A first power conversion module includes four terminals including one of a positive terminal and a negative terminal, an output terminal, a first neutral terminal, and a second neutral terminal. The first neutral terminal is coupled to a direct current (DC) link and the second neutral terminal is coupled to a second power conversion module.

Abstract: Systems and methods for power conversion are disclosed. The systems and methods use generation of a plurality of power levels approximately equal to multiples of one or more power supply voltage levels along with generation of one or more intermediate power levels between levels of the plurality of power levels via spanning reactor inductors. Furthermore, the method includes generating an output signal using the generated plurality of power levels and the one or more intermediate levels.

Abstract: Systems and methods for converting power are presented. The power conversion includes conducting load current through a first current path of multiple current paths in a power conversion unit using switches, diodes, or a combination thereof. The power conversion also includes blocking one or more additional current paths of the multiple current paths in the power conversion unit using one or more of the switches, one or more of the diodes, or a combination thereof. Furthermore, the power conversion includes reducing potential voltage stress on the one or more switches by using one or more voltage stress reduction switches to reduce a voltage that is blocked by the one or more blocking switches or diodes by connecting an end of each of the one or more switches opposite to a blocking edge to an intermediate voltage node.

Abstract: A system for commissioning a wind turbine is provided. The system includes a test wind turbine, one or more additional wind turbines coupled to the test wind turbine, and a control system. The control system includes a first control module for controlling the one or more additional wind turbines to act as a power source and provide power to the test wind turbine. The control system also includes a second control module for controlling the one or more additional wind turbines to act as a load for dissipating test power generated by the test wind turbine.

Abstract: A system for operating a power generation system within a battery storage/discharge mode includes a power convertor having a DC link, a switching module coupled to the DC link, a storage device, and a filter coupled between the storage device and power converter. The filter may correspond to a normal mode filter configured to limit normal mode voltage from being applied to the storage device. A common mode filter may be associated with the storage device. The storage device may correspond to one or more batteries while the power generation system may correspond to a wind-driven generator.

Abstract: A load commutated inverter (LCI) drive system for a synchronous electrical machine is provided. The system may include a first supply bridge and a second supply bridge, each of which may include an alternating current to direct current (AC-to-DC) source side converter, a DC link circuit, and a DC-to-AC load side inverter. The system may include a controller for selectively controlling at least one of the first supply bridge and the second supply bridge by selective firings of silicon controlled rectifiers (SCRs). The electrical power outputted from the first supply bridge and the second supply bridge may be combined by an output delta-wye electric power transformer and supplied to the electrical machine. The LCI drive system may further include one or more input electric power transformers configured to supply an input electric power to the first supply bridge and the second supply bridge.

Abstract: High performance gate drives and methods for driving semiconductor switching elements, such as insulated gate bipolar transistors (IGBTs), are provided. The gate drive can control the voltage applied to the gate of the IGBT to one or more intermediate voltages near the threshold voltage of the IGBT to control dv/dt of the collector-emitter voltage during and the di/dt of the collector current turn off. For instance, a voltage level between the turn on voltage and the turn off voltage can be applied for a first time period to control dv/dt of the collector-emitter voltage and di/dt of the collector current during turn off. Another voltage level between the turn on voltage and the turn off voltage can be applied for a second time period during reverse recovery of a freewheeling diode coupled in parallel with the IGBT.

Abstract: Magnetic components that can be used to provide normal mode and common mode inductance in a power system, such as a wind-driven doubly fed induction generator system, are provided. The magnetic components can include a structure that combines both normal mode inductors and common mode inductors on a common core. In particular, the magnetic components can include specific winding and core arrangements which couple a common mode inductor and a normal mode inductor onto a single core with at least three legs. The structure of the magnetic components can be smaller in size, can have lower weight, and can have a lower cost than typical solutions to providing common mode and normal mode inductance in a power system.

Abstract: The present subject matter is directed to apparatus and methods for producing a variable frequency output waveform from a power converter for use in a power generation system, such as a wind turbine power generation system. A voltage divider is employed to provide plural voltage levels to which a multi-level bridge circuit employing selectively activated switches in pairs of switches is coupled. The switches are operated in such a fashion as to produce a generally sinusoidal waveform that may be easily filtered by low cost filters due to the plural voltage levels to produce a generally smooth sine wave from the converter. Such converters may be used in various environments including in pairs in multi-phase power converters.

Abstract: A method and system for reducing a disturbance of an electric grid signal in a wind turbine is provided. The method includes providing a generator for the wind turbine system, and, coupling a power converter to the generator, the power converter. The power converter is configured to monitor at least one of a negative sequence component and a positive sequence component of a signal transmitted from an electric grid, determine if a disturbance exists based on the monitored signal, determine at least a portion of a magnitude of the negative sequence component of the signal, and, orient a voltage of the signal based on the determined magnitude negative sequence component to modify the instantaneous power flow through the power converter.

Abstract: Disclosed is a mechanical layout for a half-bride power module that is optimized for low inductance. In one embodiment, a first power module and a second power module are mounted on each side of a heat sink. An inductance cancelling bus bar is wrapped around the heat sink, the first power module and the second power module in a loop.

Abstract: A method and system for a control circuit are provided. The circuit includes an integrating counter coupled to a process wherein the integrating counter is configured to integrate over time a process parameter signal received from the process and to generate a trigger signal when the integrated signal equals a predetermined count. The control circuit also includes a transition controller electrically coupled to a respective control element and configured to receive the trigger signal generated by the integrating counter.

Abstract: A power conversion system includes a first converter effectively connected in series to a second converter. Each converter has a plurality of output levels. A phase-shifted transformer is coupled to the converters. The phase-shifted transformer has a delta-wound winding and an open star winding. The first converter is coupled to the open star winding and the second converter is coupled to the delta winding. The open star winding is configured for direct connection to either of a load or the open star winding of a second phase-shifted transformer, having a delta winding connected to a third converter. One or more DC voltage sources are each connected to the first and second converters by a respective DC link capacitor. Each DC voltage source is connected to a common power grid by an isolated multiphase transformer winding.