Abstract: A method of controlling an output of a generation plant (2) that is connected to a bulk electrical power network (4) by an electrical route (6). The method comprises determining (31) a phase angle difference between a first phase angle representing a phase angle of a voltage waveform at an output of the generation plant (2) and a second phase angle representing a phase angle of a voltage waveform at a location within the bulk electrical power network (4). The phase angle difference is compared (32) to a threshold phase angle difference that represents a constraint on the electrical route (6). The output of the generation plant (2) is controlled (33, 34) based on the comparison to prevent overloading of the electrical route (6).

Abstract: A method for determining the contribution of a grid subsystem (12) to oscillations in grid frequency experienced by an external electrical grid (14) in an electrical power network (10). A measurement of grid frequency is taken in the grid sub-system (12) and/or the external electrical grid (14). The measurement(s) of grid frequency can be used to extract oscillations in grid frequency in the grid subsystem (12) and/or the external electrical grid (14). A measurement of active power is recorded on a transmission line (16c) between the grid subsystem (12) and the external electrical grid (14). The phase relationship between the oscillations in grid frequency and the oscillations in active power allows the contribution of the grid subsystem (2) to oscillations in grid frequency in the external electrical grid (14) to be determined.

Abstract: There is described a method of monitoring high voltage electrical power system. The method involves measuring small signal power system characteristics under prevailing systems conditions and determining the power transfer limits using said measurements.