摘要:
A converter, and in particular a current source converter, including a bridge having an AC terminal for each of one or more AC lines, and first and second DC terminals. A converter arm is connected between each respective AC terminal and the first DC terminal, and between each respective AC terminal and the second DC terminal. Each converter arm includes a first power semiconductor switching device capable of being turned ‘on’ and ‘off’ by gate control and having a recovery time. The converter is adapted to be operated in one or more inverting modes.
摘要:
A power transmission and distribution system suitable for subsea electrical loads includes a primary dc transmission cable connected to an onshore AC/DC converter module that connects the onshore end of the cable to an ac supply network. The subsea end of the cable is connected to a primary subsea power distribution unit and includes a DC/DC converter module having a modular topology with a series of interconnected DC/DC converter units. The DC/DC converter module is connected between the cable and a primary dc distribution network. Secondary dc transmission cables and associated circuit breakers connect the primary subsea power distribution unit to secondary subsea power distribution units that are located near the subsea loads. Each secondary subsea power distribution unit includes a DC/DC converter module having a modular topology with a series of interconnected DC/DC converter units. Respective secondary dc distribution networks supply power to one or more subsea loads.
摘要:
A method of manufacturing a coil support member in which a thermosetting or thermoplastic material is introduced into a mould cavity and hardened, wherein one or more components are positioned within the mould cavity during the manufacturing process before the thermosetting or thermoplastic material is introduced, the components are then embedded in the thermosetting or thermoplastic material and form an integral part of the coil support member, and one or more functional filler materials are added to the thermosetting or thermoplastic material to improve the thermal matching between the integral components and the thermosetting or thermoplastic material.
摘要:
A dc electrical machine with a large number of phases. The machine includes a rotor and a stator assembly. The rotor has Np rotating field poles. The stator has Ns winding slots, where Ns/Np is a non-integer ratio. A stator winding includes a plurality of coils received in the winding slots and defines a plurality of stator phases. A power electronic switching assembly includes first and second dc load terminals that can be connected to external equipment and a plurality of switching modules. Each switching module includes power electronic devices and is connected to a respective stator coil. A first proportion of the switching modules are connected together in series between the first and second dc load terminals and a second proportion of the switching modules are connected together in series between the first and second dc load terminals to define two parallel dc circuits.
摘要:
Insulation for a cryogenic component is described. The insulation includes an inner portion formed of a multi-layer insulating material comprising alternating layers of metalized polymer film and polymer netting. An outer supporting mesh surrounds the inner portion and is formed of stainless steel. The insulation is particularly suitable for insulating cryogenic components that move during operation since the supporting mesh acts to support the inner portion against damage caused by forces resulting from motion of the cryogenic component.
摘要:
The present invention provides an improved single-layer coil for a rotating or linear electrical machine. The coil has a first endwinding that is substantially straight to a longitudinal axis of the coil and a second endwinding that is bent relative to the longitudinal axis of the coil. The coil therefore has differently shaped endwindings with one end 12 being ‘straight’ and the other end being ‘bent.’
摘要:
An assembly includes an electrical machine connected to a power converter by a three-phase circuit having three conductors, e.g. cables. Each conductor is associated with a switching device such as a contactor or the like that connects the conductor to a common conductor or terminal. In the event of a fault current being developed in the circuit or the power converter, the switching devices are operated to close the fault current and connect together the conductors or the three-phase circuit to provide a full three-phase short circuit.
摘要:
This method determines the value of a characteristic quantity (U1dc, U2dc) of a system for powering a load which comprises M DC-DC converters, connected in series to the terminals of the load and at the output of a DC current power supply, and at least one storage capacitor.This determination method comprises the measurement of a plurality of values of a first characteristic quantity (Ic) with a first high resolution, the measurement with a low resolution of a value of a second characteristic quantity (U1dc, U2dc), and a determination with a second high resolution of a value of the second characteristic quantity (U1dc, U2dc) from the plurality of values measured with the first high resolution of the first characteristic quantity (Ic) and from the value with the low resolution of the second characteristic quantity (U1dc, U2dc). The first and second high resolutions are at least 10 times greater than the low resolution.
摘要:
An electrical system forming part of a solar power plant is described. The electrical system includes a plurality of photovoltaic (PV) panels, a power converter, and a controller. In response to a detected electric arc on the DC side of the power converter, the controller is configured to enable a short circuit state of the power converter by controlling semiconductor switches of the power converter (e.g., turning on some or all of the semiconductor switches) to create a short circuit between DC input terminals of the power converter. The short circuit path though the power converter will extinguish the detected electric arc in the connected DC circuit.
摘要:
A method of short-circuiting a faulty submodule for a voltage-source power converter is disclosed. The submodule is based on a full-bridge, asymmetric full-bridge or half-bridge circuit design having power semiconductor switches with anti-parallel freewheeling diodes and optionally non-controllable semiconductor valves. The method 36 includes identifying a faulty semiconductor device and determining a failure mode selected from a short-circuit failure mode and an open circuit failure mode. The method further includes selecting a minimum number of power semiconductor switches suitable to provide a bypass path through the submodule depending on the identified faulty semiconductor device and the determined failure mode and driving the selected power semiconductor switches by a modified driving voltage compared to normal operation to cause them to break down in order to provide a durable, stable, low impedance short-circuit path between the AC voltage terminals of the submodule. A power converter comprising a series connection of such submodules and supporting the method of short-circuiting a faulty submodule is also disclosed.