Abstract: A method of operating a flying capacitor multilevel converter having a direct current link and a plurality of phase legs each having a plurality of flying capacitors includes employing redundant states to balance flying capacitor voltages by charging or discharging flying capacitors. The redundant states are employed by obtaining a load current of the flying capacitor multilevel converter. If a load current value is lower than a threshold value then a capacitor current of a phase terminal capacitor is utilized to determine redundant states else a load current direction is utilized to determine the redundant states.

Abstract: A grid-side transformerless power conversion system configured to perform power conversion between a power grid and a load, the transformerless power conversion system includes a first converter, a first filter, and a second converter. The first converter is configured to convert first AC power provided from the power grid into DC power. The first converter includes a first converter module and a second converter module coupled to the first converter module to form a nested neutral point piloted topology. The first filter is coupled between the power grid and the first converter. The second converter is coupled to the first converter. The second converter is configured to convert the DC power into second AC power and provide the second AC power to the load.

Abstract: A converter includes a first converter module and a second converter module coupled to the first converter module in a nested manner. Each of the first converter module and the second converter module includes a plurality of switch units. When the converter is operated to perform power conversion, at least two of the plurality of switch units is configured to be switched both in a complementary pattern and a non-complementary pattern.

Abstract: A power converter is presented. The power converter includes at least one leg operatively coupled between a first bus and a second bus and includes a first string including a plurality of non-controllable semiconductor switches, a first node, a second node, and a third node, where the first node is coupled to a third bus, one or more second strings, where each of the one or more second strings includes at least one fully controllable semiconductor switch, and where one of the second strings is coupled between the first node and the third bus and another second string is coupled between the second node and the third node, and one or more third strings, where each of the one or more third strings includes at least one energy storage device and is coupled to the first string, the one or more second strings, or a combination thereof.

Abstract: A power converter module including a voltage source current controlled power converter for providing unidirectional current having at least four output voltage levels is provided. The voltage source current controlled power converter includes an input terminal and an output terminal, and a first conductive path and a second conductive path is coupled in parallel to each other between the input terminal and the output terminal. Each of the conductive paths comprises at least one diode and at least one switch coupled in series to the respective conductive path. The at least one diode in the first conductive path are coupled closer to the input terminal and the at least one diode in the second conductive path are coupled closer to the output terminal. The voltage source current controlled power converter further includes at least two energy storage elements coupled between the first conductive path and the second conductive path.

Abstract: An electromagnetic shielding structure includes a first shielding material disposed at a first location with respect to at least one radiation source and a second shielding material attached with the first shielding material by fastening means. The second shielding material is disposed at a second location with respect to the at least one electromagnetic radiation source so as to define a predetermined gap between the first shielding material and the second shielding material. The first shielding material shields at least part of first frequency electromagnetic radiations generated from the at least one electromagnetic radiation source and penetrating through the second shielding material and the predetermined gap. The second shielding material shields at least part of second frequency electromagnetic radiations generated from the at least one electromagnetic radiation source.

Abstract: A method of assembling a testing apparatus for a full-power converter assembly includes coupling an electric power supply apparatus to an electric power grid. The method also includes coupling a direct current (DC) generation apparatus to the electric power supply apparatus. The method further includes coupling an electric power grid simulation device to the DC generation apparatus. The method also includes coupling a full-power converter assembly test connection to the electric power grid simulation device.

Abstract: A load bypass switch enables continuous power to remote loads in the event of 1) failure of one or more remote loads, or 2) faults within the remote loads, within a dc power system. The bypass switch utilizes the passive components of the dc loads or inverters and therefore reduces overall component count. A black start method for the remote dc system uses the same passives present inside the loads/inverters and simultaneously uses some of the features of the bypass switch. A bypass-module-yard uses multiple bypass switches enabling continuous power to the remote loads in the event of failure of one or more power distribution cables (in-feed to the remote loads) located remotely in the dc system.

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.

Abstract: A multilevel converter includes a plurality of phase legs each having at least two inner switching devices, at least two outer switching devices, at least two clamping diodes, a split DC link and a switching device failure detection circuit. The switching device failure detection circuit includes a logic module for each of the switching devices, a voltage calculation module and a failure detection algorithm. The logic module generates a blocking state logic signal by comparing a switching device voltage and a threshold reference voltage and the voltage calculation module determines an expected voltage blocking state for each of the switching devices based on the gate drive signals of the switching devices and an output current direction. The failure detection algorithm detects a failure condition in any of the switching devices based on the blocking state logic signals and the expected voltage blocking states of the switching devices.

Abstract: A multi-phase converter includes a plurality of phase paths. Each phase path includes at least one dc-link that is independent from every other phase path dc-link such that each output phase voltage is generated from a corresponding dc-link voltage source that can be different from every other phase voltage dc-link voltage source. A total dc-link voltage level is determined for each output phase voltage. A common-mode injection voltage is calculated based on all dc-link voltage levels and all phase reference voltages. Each phase path reference voltage is then adjusted based on the calculated common-mode injection voltage, such that each generated output phase voltage level is adjusted in response to its corresponding adjusted reference voltage.

Abstract: A power converter includes an active front end (AFE) that is coupled by a dc link stage to a plurality of H-bridge inverters. One or more multi-phase electro-magnetic energy conversion devices, such as transformers or electric machines, with open windings that are connected to only the AFE or only the H-bridge inverters or to both the AFE and H-bridge inverters, provide a regenerative or partial regenerative power converter.

Abstract: A control system for a multilevel converter includes a differential mode current regulator, a neutral point (NP) controller and a PWM controller for generating switching pulses for the multilevel converter. The differential mode current regulator generates reference voltage command signals based on a difference between reference current command signals and actual current command signals, and the NP controller determines a modified neutral point current signal in response to a DC link voltage unbalance. The NP controller utilizes the modified neutral point current signal to generate a common mode reference voltage signal. The switching pulses are generated by the PWM controller based on the reference voltage command signals and the common mode reference voltage signal.

Abstract: A three level neutral point clamped (NPC) converter includes a plurality of phase legs each having at least two inner switching devices, at least two outer switching devices, at least two clamping diodes, and a protection circuit. An inner component failure sensing circuit is employed in the protection circuit to detect a failure condition in any of the inner switching devices or clamping diodes. The protection circuit further includes a gating signal generation circuit configured to generate a turn ON signal for a respective outer switching device that is adjacent to the failed inner switching device or the clamping diode.

Abstract: A power inverter system includes a DC to AC inverter configured to convert DC voltage from a DC power source to AC voltage. A DC link couples the DC power source and the inverter. An inverter pre-charger operates to pre-charge the inverter to achieve a desired DC link voltage prior to connecting the power inverter system to an AC power grid. A phased lock loop synchronizes the pre-charged inverter to the AC power grid prior to connecting the power inverter system to the AC power grid. The pre-charged inverter regulates the DC link voltage to about the minimum voltage level that allows control of AC grid currents via the inverter subsequent to connecting the power inverter system to the AC grid. The inverter operates in a maximum power point tracking control mode only subsequent to a first voltage transient caused by connecting the DC power source to energize the power inverter system.

Abstract: A power distribution system includes a plurality of load side power converters configured in a modular stacked DC (MSDC) converter architecture. Each load side converter includes a respective energy storage device such that together the plurality of energy storage devices provides a distributed subsea energy storage system configured to maintain a common subsea busbar voltage substantially constant during intermittent load voltage excursions.

Abstract: Authorized or unauthorized opening of access to equipment of a telecommunications network in a control center is detected on the basis of alarm messages. The telecommunication network is a mobile radio network or a hard-wired network. The control center monitors the access equipment and transmits alarm messages as a result of the access equipment being opened. A message is first transmitted by a signaling device to a signaling server before the access equipment is opened. Then the server, after receiving the message from the signaling device, generates an alarm-suppression information item. This alarm-suppression information item is evaluated in the control center, and, whenever an alarm message is received, this message is compared with the alarm-suppression information items and the alarm message is filtered in the event of a positive association.

Abstract: A substrate layer for use in an inductor is provided. The substrate layer comprises traces disposed on a first side of the substrate layer, wherein the traces are configured to facilitate conduction of current in a winding of the inductor, a sealing layer disposed on a second side of the substrate layer, wherein the sealing layer is configured to provide a sealing border for an electrically isolated cooling channel and an interconnect foil disposed on the second side of the substrate layer, wherein the interconnect foil is configured to facilitate operationally coupling the substrate layer to a second substrate layer. Further, the first substrate layer and the second substrate layer may be operationally coupled to form a winding for use in an inductor with an electrically isolated cooling channel in between.

Abstract: A method of operating a neutral point clamped (NPC) three level converter is provided. The NPC converter includes at least two legs, each leg comprising first and second top switches connected in series at a first mid point. The converter further includes first and second bottom switches connected in series at a second mid point, and first and second middle switches connected in series at a third mid point therebetween. The first top and second bottom switches are connected in series at a DC link and the first and the second middle switches are connected between the first and the second mid points. Each of the top, bottom and middle switches has an antiparallel diode thereacross. The method includes alternately switching the first and second top switches to ON state when the first middle switch is in ON state and the second middle switch is in OFF state.

Abstract: A method and system for a control power supply system is provided. The control power supply system includes a first conductor configured to carry a direct current (DC) electrical current from a source to a load, a second conductor configured to carry the DC electrical current from the load to the source, a electrical device electrically coupled in series with at least one of the first and second conductor. The electrical device is configured to fail in a shorted condition such that failure of the electrical device maintains a direct current (DC) ring bus including the first and second conductor. The control power supply system also includes a control power circuit electrically coupled in parallel with at least a portion of the electrical device such that a DC voltage across at least a portion of the electrical device provides a DC voltage supply to the control power circuit.