Abstract: A method for controlling a plurality of series connected switch modules each including at least two parallel connected electronic switches, the method includes the step of, in response to failure of any electronic switch of one or more switch modules, turning on any non-faulty electronic switch of one or more faulty switch modules when the electronic switches of other non-faculty switch modules are controlled to be turned on.

Abstract: A drive system includes a current sensor configured to generate a first current signal representative of a current flowing in one or more electrical devices electrically coupled together through a power supply bus, a power output bus, and a common ground. The drive system also includes a voltage sensor configured to generate a first voltage signal representative of a voltage with respect to the common ground in the one or more electrical devices. The drive system further includes a ground fault detection controller configured to determine a ground fault in the one or more electrical devices based on a change in at least one of the first current signal and the first voltage signal.

Abstract: The present disclosure relates to a snubber circuit which comprises a static snubber unit, connected in parallel with the switch, for balancing a static voltage sharing across a switch when the switch is in a state of turn-on or turn-off; and a dynamic snubber unit for balance a dynamic voltage sharing across the switch when the switch is in a process of turn-on or turn-off, comprising a dynamic voltage sharing capacitor connected in parallel with the switch and having a relationship between a capacitance and a voltage of the dynamic voltage sharing capacitor; and a controller for controlling the capacitance of the dynamic voltage sharing capacitor to be in a predetermined working area of capacitance rising while the voltage across the switch is increasing. The present disclosure also relates to a power semiconductor device.

Abstract: A power converter includes primary and secondary bridges, a transformer, and a controller configured to generate a switching mode map that correlates each of a plurality of switching modes to a respective set of value ranges of system parameters of the power converter. The sets of system parameter value ranges are contiguous and non-overlapping across the switching mode map, each of the plurality of switching modes includes gate trigger voltage timings for commuting at least one of the primary and secondary bridges. The controller is configured to obtain a plurality of measured system parameter values, select from the switching mode map one of the plurality of switching modes that correlates to the set of system parameter values containing the plurality of measured system parameter values, and adjust gate trigger voltage timings of at least one of the primary and secondary bridges, according to the selected switching mode.

Abstract: A method for protecting a circuit is provided, wherein the circuit comprises a plurality of switch devices connected in series. The method comprises detecting a failure risk indicator of each switch device; determining whether each switch device has a failure risk based on the corresponding failure risk indicator; and making each of the switch device(s) having the failure risk in a constant on-state to eliminate the failure risk and prevent a failure of the switch device optionally if a number of the switch device(s) which have or had the failure risk is less than or equal to a preset value.

Abstract: This disclosure relates to systems and methods for controlling a wind converter for a weak electrical grid. In one embodiment of the disclosure, a system for controlling the wind converter includes a wind converter connected to an electrical grid at a point of connection (POC) and operable to transfer a power to the electrical grid. The system includes a first control loop operable to calculate, based on electrical grid parameters and wind converter characteristics, a voltage reference to be generated by the wind converter. The system includes a second control loop to convert, based on the electrical grid parameters, the voltage reference into a current reference. The second loop converts the angle information of the voltage reference into a voltage at the POC. The system includes a third control to regulate, based at least on the current reference, the power transferred by the wind converter to the electrical grid.

Abstract: This disclosure relates to systems and methods for controlling a wind converter for a weak electrical grid. In one embodiment of the disclosure, a system for controlling the wind converter includes a wind converter connected to an electrical grid at a point of connection (POC) and operable to transfer a power to the electrical grid. The system includes a first control loop operable to calculate, based on electrical grid parameters and wind converter characteristics, a voltage reference to be generated by the wind converter. The system includes a second control loop to convert, based on the electrical grid parameters, the voltage reference into a current reference. The second loop converts the angle information of the voltage reference into a voltage at the POC. The system includes a third control to regulate, based at least on the current reference, the power transferred by the wind converter to the electrical grid.

Abstract: A system, a switch assembly and an associated method. The system includes a number of switch assemblies, each including a switch module, isolation circuits, a detection unit, and a drive unit. The switch module includes power switch devices connected in parallel. The switch modules are connected in series. The isolation circuits each are connected in series to a gate terminal of at least one corresponding power switch device of the power switch devices. Each isolation circuit includes a capacitor or a controllable switch. The detection unit detects faults in at least one of the power switch devices. The drive unit is coupled to the switch module via the isolation circuits for driving the power switch devices of the corresponding switch module, and when the fault is detected, the drive unit is for turning on the power switch devices parallel connected to the at least one of faulty power switch devices.

Abstract: A modular substation (10) for subsea applications includes a plurality of modular DC/AC converters (32) configured for converting DC electrical power transmitted along a DC transmission link (24) into AC electrical power for supplying to a plurality of subsea loads (56). The plurality of modular DC/AC converters (32) is configured to couple in series to the DC transmission link (24) and couple in parallel to an AC distribution network (52). At least a first modular DC/AC converter (32) is configured to be selectively electrically and mechanically disconnected from the DC transmission link (24) and the AC distribution network (52) to facilitate maintenance of the first modular DC/AC converters (32) while the AC distribution network (52) continues to supply AC electrical power to at least one of the plurality of subsea loads (56). The modular substation (10) also comprises protection and bypass circuits (26) intended to isolate faulty DC/AC converters (32) and to facilitate safe maintenance and repair.

Abstract: A common mode choke includes at least two groups of multi-phase coils wound on a magnetic core for balancing differential mode inductance between the phases. The multi-phase coils in each group are series connected and concentrically wound on a respective portion of the magnetic core. Each group of multi-phase coils is non-overlapping with each other group of multi-phase coils.

Abstract: An electrical circuit for a power converter includes a first switching device proximate an AC source. The circuit also includes a voltage measurement device proximate a DC link and extends between the AC source and the DC link. The circuit further includes a DC voltage source and a first capacitive device. The first capacitive device is positioned between the first switching device and the voltage measurement device. The circuit further includes a second switching device positioned between the first capacitive device and the voltage measurement device. The circuit also includes a controller operatively coupled to the DC voltage source, the voltage measurement device, and the switching devices. The controller is configured to open the second switching device when a measured voltage signal generated by the voltage measurement device is substantially representative of a reference voltage value.

Abstract: A method of operating a multilevel power converter includes using, through a processing device, a model of an electrical circuit that includes a plurality of switching devices, a plurality of flying capacitors, and an AC terminal. The method also includes regulating a voltage level of the AC terminal through selecting, at least partially based on the model, a possible charging state of the electrical circuit. Each possible switching state has a voltage level that at least partially corresponds to a commanded voltage level for the AC terminal. The method further includes selecting, at least partially based on the model of the electrical circuit and at least partially based on the selected possible switching state, a charging state from a plurality of possible charging states. The method also includes setting the switching state of the electrical circuit at least partially based on the selected charging state of the electrical circuit.

Abstract: An electrical circuit for a power converter includes a first switching device proximate an AC source. The circuit also includes a voltage measurement device proximate a DC link and extends between the AC source and the DC link. The circuit further includes a DC voltage source and a first capacitive device. The first capacitive device is positioned between the first switching device and the voltage measurement device. The circuit further includes a second switching device positioned between the first capacitive device and the voltage measurement device. The circuit also includes a controller operatively coupled to the DC voltage source, the voltage measurement device, and the switching devices. The controller is configured to open the second switching device when a measured voltage signal generated by the voltage measurement device is substantially representative of a reference voltage value.

Abstract: A power converter includes primary and secondary bridges, a transformer, and a controller configured to generate a switching mode map that correlates each of a plurality of switching modes to a respective set of value ranges of system parameters of the power converter. The sets of system parameter value ranges are contiguous and non-overlapping across the switching mode map, each of the plurality of switching modes includes gate trigger voltage timings for commuting at least one of the primary and secondary bridges. The controller is configured to obtain a plurality of measured system parameter values, select from the switching mode map one of the plurality of switching modes that correlates to the set of system parameter values containing the plurality of measured system parameter values, and adjust gate trigger voltage timings of at least one of the primary and secondary bridges, according to the selected switching mode.

Abstract: A common mode choke includes at least two groups of multi-phase coils wound on a magnetic core for balancing differential mode inductance between the phases. The multi-phase coils in each group are series connected and concentrically wound on a respective portion of the magnetic core. Each group of multi-phase coils is non-overlapping with each other group of multi-phase coils.

Abstract: A power converter apparatus includes a primary bridge having a plurality of diagonally opposed primary power elements, and a secondary bridge having a plurality of diagonally opposed secondary power elements. The primary and secondary bridges are electrically coupled by a transformer. At least one control unit is configured to phase-shift switch the primary and secondary power elements, such that one or more of the primary and secondary power elements are switched off under near-zero current conditions to reduce voltage and current stresses and commutation losses within the power converter.

Abstract: Provided is an apparatus, including a capacitor module having a plurality of connecting terminals and a plurality of switch elements. Each switch element has at least one switch terminal coupled to a corresponding connecting terminal, wherein the switch elements are configured for mutually exclusive operation via a control device.

Abstract: A power converter apparatus includes a primary bridge having a plurality of diagonally opposed primary power elements, and a secondary bridge having a plurality of diagonally opposed secondary power elements. The primary and secondary bridges are electrically coupled by a transformer. At least one control unit is configured to phase-shift switch the primary and secondary power elements, such that one or more of the primary and secondary power elements are switched off under near-zero current conditions to reduce voltage and current stresses and commutation losses within the power converter.

Abstract: A high voltage direct current system is presented. The system includes at least three high voltage direct current terminals. Furthermore, the system include at least two transmission lines configured to operatively couple the at least three high voltage direct current terminals. Moreover, the system includes a power flow control device operatively coupled to at least one end of one or more of the at least two transmission lines and at least one of a local grid and another power flow control device. Methods to perform the method for power flow control are also presented.