GE ENERGY POWER CONVERSION TECHNOLOGY LIMITED

A submodule for a power converter is described. The submodule includes a first and a second power storage devices and a first stack of electronic device packages. The first stack includes a first, a second, a third, and a fourth electronic device package. A first power device and the first and second electronic device packages form a first half bridge converter, and a second power device and the third and fourth electronic device packages form a second half bridge converter.

Provided is a stator assembly of an axial flux electrical machine that includes stator coils and core segments arranged circumferentially to define a segmented stator core. Each core segment has a tooth part extending axially and adapted to mount a respective stator coil. The stator core can also be non-segmented with tooth parts arranged circumferentially. Adjacent mounted stator coils are spaced apart by a substantially trapezoidal void. The stator assembly also includes stator coil retainers. Each retainer is received in a respective void between a pair of adjacent mounted stator coils and its position in the radial direction is independently adjustable and each also includes at least one channel for receiving a cooling fluid and a pair of contact surfaces that are spaced apart in the circumferential direction and each retainer applies a contact pressure to the respective pair of adjacent mounted stator coils through the contact surfaces.

Provided is a method of monitoring the condition of energy storage device assemblies of a modular multi-level converter (MMC) that includes series-connected submodules having a full-bridge or half-bridge topology Whereby each submodule include an energy storage device assembly with one or more individual energy storage devices electrically connected in parallel. The MMC so includes at least one AC terminal electrically connectable to an AC power source by means of a pre-charge circuit and during two or more pre-charge processes where the individual energy storage device assemblies are initially charged to a rated voltage by an AC pre-charge current supplied to the AC terminal, one or more measurements of DC voltage across each energy storage device assembly are obtained at one or more times between a start and an end of each pre-charge process and compared to determine the health of each energy storage device assembly.

A cooling system for cooling an item of industrial equipment is described. The cooling system includes a primary circuit around which a cooling fluid is circulated, and which includes a two-phase heat exchanger. A secondary circuit is fluidly connected to the primary circuit in parallel with the heat exchanger. The secondary circuit includes a condenser, a pump, a separator and reservoir tank and a restrictor. The boiling point of the cooling fluid at the inlet of the heat exchanger is reduced by the action of the secondary circuit, thereby improving the cooling performance of the cooling system.

The rotor for rotary electric machine has a magnetic mass clamped between two compaction elements, and tie rods passing through the magnetic mass and connecting the two compaction elements, at least a first compaction element has as many through holes as tie rods, each through hole of the first compaction element has a counterbore on one side opposite to the side in contact with the magnetic mass, each tie rod passing through a different through hole of the first compaction element and being fixed in the said through hole by a fixing element of the first compaction element logged in the counterbore, characterized in that each fixing element and the associated counterbore cooperate so that each fixing element is in contact with the counterbore in a radial direction of the rotor.

Provided is a rotating stabiliser which is electrically connectable to a power grid, and includes a synchronous condenser, a starter/exciter, and a power converter. The synchronous condenser includes a stator assembly with a stator winding that is electrically connectable to the power grid, and a rotor assembly with a rotor winding. The starter/exciter includes a stator assembly with a stator winding and a rotor assembly with a rotor winding And the rotor assemblies are mechanically connected by a rotor shaft. A power converter of the starter/exciter is electrically connected to the rotor windings of the synchronous condenser and starter/exciter and is mounted for rotation on the rotor shaft. The power converter has first terminals electrically connectable to the power grid and second terminals electrically connected to the stator winding of the starter/exciter.

A power converter system is provided and includes a power converter having a first converter that includes at least a controllable semiconductor switch having a threshold voltage and a gate voltage for normal on-state conduction, DC terminals connected to a DC link, and AC terminals, a controller of the system supplies current to the first converter for short circuiting by controlling the switches to create a short circuit path through the converter that carries the current. At least one switch in a short circuit path is operated with modified on-state conduction to increase conduction losses by applying a modified gate voltage less than the gate voltage for normal on-state conduction, the modified gate voltage equals the threshold voltage plus x volts, where x ranges from 100 mV to 4 V, and when the converter is short-circuited, the DC link voltage is less than that during a normal switching operation.

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.

Provided is an electric stabilizer that includes a track for guiding a mobile stabilizing mass along a track direction, a linear motor having a planar stator that extends along the track, and a planar rotor that moves forward and backwards along the track with the mobile stabilizing mass, the stator includes a polyphase stator winding and the rotor having permanent motor magnets facing the polyphase stator winding that define rotor poles of alternating polarity along the track direction. The electric stabilizer has at least one line of electromagnets for selectively attracting the mobile stabilizing mass in a direction away from the track, and a stop for limiting the movement of the mobile stabilizing mass towards the electromagnets.

Provided is a switching module and a process of commutating the switching module. The switching module includes an H-bridge circuit with bidirectional switches and an active clamp with switches that are also arranged as an H-bridge. The process of commutating the switching module includes a sequence of alternating first and second commutation events where timing signals used to control the switches during each commutation event are varied according to closed loop control of the voltage across the energy storage device of the active clamp.