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 whilst 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 utilising operational voltage margins from a desired voltage as control signals to the electrical current controller.

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: A generator control arrangement for an electrical power generator, the arrangement comprising a controller arranged to regulate output voltage from a generator to a target value, the controller including a voltage comparator for comparing a presented voltage with a desired output voltage, the presented voltage derived in a transfer comparator by combination of a reference voltage value and an error value between a reference electrical current value and a measured electrical current value subject to a processor gain whereby the processor gain can be specifically set at zero to enable control by voltage or the processor gain can be specifically set at greater than zero to enable control by electrical current.

Abstract: In DC electrical power systems used for example in aircraft typically an earthing arrangement is provided between electrical power supply rails in the form of a pair of capacitors with a mid electrical voltage earthing point. In such circumstances in previous arrangements an earth fault will have low impedance to the ground and therefore have excess electrical current flow. By aspects of the present invention electrical resistance is provided in the earthing path to limit electrical current flow and therefore allow continued operation despite the earth fault.

Abstract: Electrical power generation through a number of generators has efficiency benefits particularly with regard to aerospace applications. However, should parallel operation of these generators be interrupted through malfunction of one of the generators or otherwise, care must be taken in order to maintain the rate of electrical voltage for system demands. Previously it has been known to control parallel operating electrical power generators respectively through voltage control and electrical current control regimes so at least some of the generators must be able to operate under both regimes. This necessitated separate control loops which at least is inconvenient. By providing a common voltage comparator which receives a reference electrical current Vtgt from a transfer comparator 23 it is possible to achieve voltage as well as electrical current control.