Abstract: The present invention provides an air cleaner suitable for forced air open-ventilation systems used to cool electrical machines. The air cleaner comprises an air chamber with a first end where air is drawn in from the surroundings, via an inlet, by the open-ventilation system and a second end, opposite the first end, where air is drawn out of the air chamber, via a first outlet, by the open-ventilation system. A rotating means is contained within the air chamber and may be driven to rotate about an axis that extends between the first end and the second end of the chamber. When driven to rotate, the rotating means applies a centrifugal force to any particles contained in the air entering the air chamber and throws them radially outwards from the central axis. These particles are then drawn out of the air chamber, via at least one second outlet formed adjacent to a radially outer edge of the rotating means, by a high-velocity outlet stream of the open-ventilation system.

Abstract: An electronic system with component redundancy includes a first processing unit, connected to a first board, and a second processing unit redundant with respect to the first unit, and connected to a second board redundant with respect to the first board. Each processing unit and each board include a first communication port, the first communication ports of the first unit and of the first board, and, respectively, of the second unit and of the second board, being interconnected by a wired communication link. Each processing unit and each board include a second communication port, the second port of the first board being connected to the second port of the second unit by a wired communication link, and the second port of the second board being connected to the second port of the first unit by a wired communication link, each communication port able to be activated or deactivated by a corresponding software command.

Abstract: An electrical machine has at least two separate groups of at least two circumferentially adjacent magnet poles. One of the circumferentially outer magnet poles in one of the groups of magnet poles is defined as being in its reference position. The reference position of each other magnet pole is defined as the position each other magnet pole would occupy if all the magnet poles were equally circumferentially spaced around the first or second body and the one circumferentially outer pole was in its reference position. At least one of the circumferentially outer magnet poles in each group is sited in its reference position. At least one magnet pole in each group is a displaced magnet pole and is sited in a position that is displaced from its reference position by an amount that is not equal to an integral multiple of the reference angular pitch of the winding slots. The displacement of the magnet poles provides a pronounced reduction in cogging.

Abstract: The present invention provides an electrical machine 1 with reduced cogging. The magnet poles 3 of the electrical machine are comprised of at least two separate groups of at least two circumferentially adjacent magnet poles. One of the circumferentially outer magnet poles 3 in one of the groups of magnet poles is defined as being in its reference position. The reference position of each other magnet pole 3 is defined as the position each other magnet pole would occupy if all the magnet poles were equally circumferentially spaced around the first or second body and the one circumferentially outer pole was in its reference position. At least one of the circumferentially outer magnet poles 3 in each group is sited in its reference position. At least one magnet pole 3 in each group is a displaced magnet pole and is sited in a position that is displaced from its reference position by an amount that is not equal to an integral multiple of the reference angular pitch of the winding slots.

Abstract: The present invention provides a power converter that can be used to interface a generator (4) that provides variable voltage at variable frequency to a supply network operating at nominally fixed voltage and nominally fixed frequency and including features that allow the power converter to remain connected to the supply network and retain control during supply network fault and transient conditions. The power converter includes a generator bridge (10) electrically connected to the stator of the generator (4) and a network bridge (14). A dc link (12) is connected between the generator bridge (10) and the network bridge (14). A filter (16) having network terminals is connected between the network bridge (14) and the supply network. A first controller (18) is provided for controlling the operation of the semiconductor power switching devices of the generator bridge (14).

Abstract: The present invention provides a power converter that can be used to interface a generator (4) that provides variable voltage at variable frequency to a supply network operating at nominally fixed voltage and nominally fixed frequency and including features that allow the power converter to remain connected to the supply network and retain control during supply network fault and transient conditions. The power converter includes a generator bridge (10) electrically connected to the stator of the generator (4) and a network bridge (14). A dc link (12) is connected between the generator bridge (10) and the network bridge (14). A filter (16) having network terminals is connected between the network bridge (14) and the supply network. A first controller (18) is provided for controlling the operation of the semiconductor power switching devices of the generator bridge (14).

Abstract: An improved stator (28) for rotating electrical machines with single-layer stator windings consisting of a plurality of pre-formed coils (22) of equal angular pitch. The stator (28) has a first cylindrical surface in which a plurality of circumferentially spaced winding slots (30) are formed and in which the axially-extending winding runs (24) of the pre-formed coils (22) are positioned. The two winding runs (24) of each coil (22) will each be positioned in a winding slot (30) and the two winding slots (30) that receive the coil (22) define a winding slot pair. The improvement arises from the fact that the winding slots (30) of each winding slot pair extend into the stator (28) in substantially parallel directions. This means that the axially-extending winding runs (24) of each pre-formed coil (22) may also be substantially parallel and need not be angled towards each other.

Abstract: The present invention provides_a power converter that can be used to interface a generator (4) that provides variable voltage at variable frequency to a supply network operating at nominally fixed voltage and nominally fixed frequency and including features that allow the power converter to remain connected to the supply network and retain control during supply network fault and transient conditions. The power converter includes a generator bridge (10) electrically connected to the stator of the generator (4) and a network bridge (14). A dc link (12) is connected between the generator bridge (10) and the network bridge (14). A filter (16) having network terminals is connected between the network bridge (14) and the supply network. A first controller (18) is provided for controlling the operation of the semiconductor power switching devices of the generator bridge (14).

Abstract: The present invention provides a power converter that can be used to interface a generator that provides variable voltage at variable frequency to a supply network operating at nominally fixed voltage and nominally fixed frequency and including features that allow the power converter to remain connected to the supply network and retain control during supply network fault and transient conditions. The power converter includes a generator bridge electrically connected to the stator of the generator and a network bridge. A dc link is connected between the generator bridge and the network bridge. A filter having network terminals is connected between the network bridge and the supply network. A first controller is provided for controlling the operation of the semiconductor power switching devices of the generator bridge. Similarly, a second controller is provided for controlling the operation of the semiconductor power switching devices of the network bridge.

Abstract: A propeller is driven by an electric motor through a mechanical drive train. The output torque of the motor to the drive train is controlled by a controller with respect to a normal torque reference signal and an emergency torque reference signal. When a measured deceleration of the motor exceeds a threshold deceleration value, the normal torque reference signal is modified or replaced by the emergency torque reference signal and the controller signals the motor to reduce or reverse the torque applied to the mechanical drive train by the motor. In this way, the integrity of the propeller and drive train can be protected if the propeller strikes an underwater obstruction.

Abstract: A propulsion unit for propelling a waterborne vessel includes an electric motor arranged to provide propulsion, and a housing arranged to contain the motor. The interior of the housing is maintained at an increased pressure of above roughly 2 bar to increase the cooling effect of a cooling gas maintained therein. An end region of the housing is provided with a heat exchange mechanism arranged to cool a cooling gas passing thereover. The heat exchange mechanism is associated with the housing such that, in use, water surrounding the housing absorbs heat therefrom.