The invention relates to an energy storage comprising a plurality of series connectable energy modules connected to a string via a plurality of switches. Wherein a string controller controls which of the energy modules that are part of a current path through the string by control of the status of the switches. An energy storage monitoring system is monitoring an energy storage element operating parameter of an energy module, the energy storage monitoring system comprises: a current sensor and a plurality of energy module print. The plurality of energy module prints establishes an energy module operating parameter of the associated energy module. The current sensor establishes the current in the current path. The string controller is configured for by-passing an energy module based on information of status of the switches, the measured current in the current path and the battery operating parameter measured at the energy modules.

There is provided a switching valve for a voltage source converter, the switching valve comprising a plurality of modules, each module including at least one switching element and at least one energy storage device, each switching element and each energy storage device in each module arranged to be combinable to selectively provide a voltage source, the switching valve including a regulator programmed to selectively control the switching of the switching elements to select one or more of the modules to contribute a respective voltage to a switching valve voltage, wherein the regulator is programmed to selectively regulate an energy stored in each energy storage device by controlling the switching of the switching elements to regulate a voltage of each energy storage device towards a target voltage, and the regulator is programmed to vary the target voltage of each energy storage device as a function of a number of healthy modules.

In a power conversion device in which cell converters are connected in series, each cell converter includes: main circuit conductors connecting switching elements and a capacitor to each other; a bypass portion disposed between two external terminals connected to other cell converters; external output conductors connecting the external terminals and the main circuit conductors to each other; and bypass connection conductors connecting the external output conductors and the bypass portion to each other. The bypass connection conductors or the external output conductors are disposed so as to oppose each other at a high-potential side and a low-potential side thereof. The conductors are bent so as to have portions at which currents in parts of the conductors have the same direction. Thus, mutual inductances and self-inductances are increased, whereby short-circuit current flowing to the bypass portion at the time of double failures is suppressed.

A power converter system is described. The power converter system includes a power converter comprising at least one converter unit, each converter unit comprising a plurality of semiconductor devices, each semiconductor device including at least a controllable semiconductor switch. A local controller is associated with at least one converter unit and adapted to receive CD and MD from a main controller. In response to a detected fault condition of the power converter system, the local controller is adapted to use at least one of the one or more locally-stored values to determine an operating state of the power converter system, and to use the determined operating state to select a fault operating procedure to control each associated converter unit according to the selected fault operating procedure without using any CD from the main controller.

A submodule for a modular multilevel converter has nine semiconductor switches that can be switched off, four capacitors, six network nodes, and two terminals. The components are mounted such that different voltages are generated between the terminals of the submodule by controlling the semiconductor switches. This arrangement of components substantially improves the behavior of the converter and of the submodule in the event of a fault.

A power conversion device is provided between a power supply and a load, and converts power from the power supply and supplies the converted power to the load. The power conversion device includes a plurality of switching elements composed of semiconductor elements, and a control device which generates drive signals for controlling the plurality of switching elements. Voltages are respectively applied to the plurality of semiconductor elements, on the basis of the drive signals generated by the control device. The plurality of semiconductor elements have equivalent failure probabilities due to neutron beams. Thus, a failure of the power conversion device due to neutron beams is prevented, and size increase thereof is suppressed.

A converter apparatus includes a string of electrically interconnected modules that includes a first group of modules comprising a first module and a second group of modules comprising a second module. A first screen is connected to a first defined electric potential and is located adjacent the first group of modules and a second screen is connected to a second defined electric potential and is located adjacent the second group of modules. During operation of the converter apparatus a resonance loop is created from the first module via the first and second screens and the second module back to the first module. A damping unit is located in the resonance loop and is set to dampen electromagnetic noise.

Methods for modifying converter cells for switched-mode power converters, and corresponding power converter cells. The modified converter cells exhibit reduced inductance requirements, enable use of lower voltage and smaller switches, provide improved power density and efficiency, and provide for improved input/output voltage dynamic range. Embodiments of the methods generate converter cell topologies having 3 or more node voltage levels by successively applying a “split switches and connect through a capacitor” operation. The inventive processes, or variants of those processes, may be applied to converter cell topologies that are 2-level converter cells including at least one inductance and two switches, and particularly 2-level converter cells including either (1) an order of at least 3 (i.e., 3 or more energy storage elements in some combination of inductances and capacitances, but with at least one inductance) and at least 2 switches, or (2) at least 1 designed-in inductance and at least 4 switches.

A circuit comprises a power source, an Open Loop Reactance Matching Circuit Control Signal Generator (OLRMCCSG), an Open Loop Reactance Matching (OLRM) circuit, and a load. The power source supplies an input voltage and an input current used to drive the load. The load is an inductive type load or a capacitive type load. If the power source operates as a voltage source, then the OLRMCCSG uses input voltage information to control the OLRM circuit to generate a reactance matching voltage that is phase delayed with respect to the input voltage. If the power source operates as a current source, then the OLRMCCSG uses input current information to control the OLRM circuit to generate a reactance matching current that is phase delayed with respect to the input current. The reactance matching voltage or the reactance matching current causes the input voltage and the input current to be in phase.

A transformer arrangement is provided. The transformer arrangement includes a transformer with a primary and a secondary winding and a chain link of switching blocks connected in series between one of the windings and a load, where the switching blocks comprise a first set of voltage contribution blocks and a second set of circuit breaker blocks, where the first set of voltage contribution blocks is configured to adjust a voltage output by the transformer with an offset voltage and the second set of circuit breaker blocks is configured to interrupt a current running through the chain link.