Abstract: When implementing a PMU network, creation of synchrophasors is achieved by centralising the determining of phasors and corresponding time-stamps at a location away from the actual measurement locations. Alternatively, or in addition to time-stamping phasors, time-stamping of any received signals and/or measurements derived from those signals is enabled. These signals are received from appropriate sensors distributed along optical fibres such as may be incorporated in modern power cables. Likewise, control signals can be communicated along optical fibres such as may be incorporated in modern power cables, and a number of approaches to ensuring control signals are received by the intended control modules are provided. Either or both the PMU network and control system can be implemented in a power network by exploiting existing optical fibre infrastructure in this way, and control signals can be transmitted dependent on analysis performed on synchrophasors.

Abstract: The invention enables the measurement of the voltage between phases (phase-to-phase voltages) of a multi-phase power cable, e.g. a three-phase power cable, such as may be used in subsea or subterranean environments for electrical power transfer. The invention does not require a power supply at the measurement location, and relies solely on optical fibres (typically present in such cables) to carry light to and from the sensors. Fibre Bragg grating (FBG) based sensors sample the electric field between conductors and convert to a strain on the fibre, as a result of which certain wavelengths of the reflected light are modulated by the instantaneous magnitude of the phase-to-phase voltages to be measured. A sensor module embodying the invention includes a spacer which holds the conductors in a predetermined geometry and locates the FBG sensors between pairs of conductors on which the phase-to-phase voltage measurements are to be performed.

Abstract: The invention enables the complexity and cost of implementing a PMU network and/or a control system to be substantially reduced by eliminating the requirement for power supplies, GPS equipment, and telecommunication equipment at each measurement and/or control location. In the case of implementing a PMU network, creation of synchrophasors is achieved by centralising the determining of phasors and corresponding time-stamps at a location away from the actual measurement locations. Alternatively, or in addition to time-stamping phasors, the invention enables the time-stamping of any received signals and/or measurements derived from those signals. These signals are received from appropriate sensors distributed along optical fibres such as may be incorporated in modern power cables. Likewise, control signals can be communicated along optical fibres such as may be incorporated in modern power cables, and a number of approaches to ensuring control signals are received by the intended control modules are provided.

Abstract: The invention enables the measurement of the voltage between phases (phase-to-phase voltages) of a multi-phase power cable, e.g. a three-phase power cable, such as may be used in subsea or subterranean environments for electrical power transfer. The invention does not require a power supply at the measurement location, and relies solely on optical fibres (typically present in such cables) to carry light to and from the sensors. Fibre Bragg grating (FBG) based sensors sample the electric field between conductors and convert to a strain on the fibre, as a result of which certain wavelengths of the reflected light are modulated by the instantaneous magnitude of the phase-to-phase voltages to be measured. A sensor module embodying the invention includes a spacer which holds the conductors in a predetermined geometry and locates the FBG sensors between pairs of conductors on which the phase-to-phase voltage measurements are to be performed.