Abstract: Within generator systems maintenance of stability in terms of voltage is desirable. Generally, several generators will be arranged in parallel within the generator system with one generator voltage controlled to provide dynamic responsiveness to load switching. With regard to some loads which are generally of an active nature, the capacity of a first generator, which is voltage controlled, may be insufficient to adequately avoid transient voltage instability. By providing an actuator signal from a load to act as a pre-emptive or forward feed to an electrical current controlled generator, that second electrical current generator can be arranged to provide additional or reduced electrical current to avoid system voltage instability.

Abstract: Utilisation of a number of electrical machines such as generators all driven by a common prime mover, such as a gas turbine engine, are known. However, faults in one phase of one particular electrical machine may cause torque vibration and therefore stressing to mechanical linkages between the electrical machine and the prime mover. By determining torque vibration and then utilising a second electrical machine to introduce an anti-phase torque vibration a substantially balanced and steady torque loading to the mechanical linkages can be achieved.

Abstract: An earthing arrangement for a DC electrical system (10), the electrical system (10) comprises a plurality of earthing points (24A, 24B, 24C) and each earthing point (24A, 24B, 24C) is directly and permanently connected to earth (26) by a high impedance connection (28A, 28B, 28C). Each earthing point (24A, 24B, 24C) is selectively connectable to earth (26) in electrical parallel with the high impedance connection (28A, 28B, 28C) by a solid connection (30A, 30B, 30C) and a switch (32A, 32B, 32C). In first mode of operation the switch (32A) between the earthing point (24A) and the earth (26) of only one of the plurality of earthing points (24A, 24B, 24C) is closed.

Abstract: Electrical power generation systems typically comprise an electrical power distribution arrangement in which a number of electrical power generators are coupled in parallel. In such circumstances in order to avoid conflict generally a first electrical power generator is controlled with a voltage controller while second electrical power generators have electrical current controllers. As loads are switched into and out of the electrical distribution system in normal operation the first electrical power generator and its voltage controller can accommodate voltage dynamics and therefore maintain a desired voltage. However, in order to accommodate heavier loads switching, the dynamic operation of the electrical current controller is achieved through utilizing operational voltage margins from a desired voltage as control signals to the electrical current controller.