Abstract: A method of controlling a plurality of power units in a power distribution network (PDN), comprising: a) receiving one or more requests to increase or decrease the power drawn from, or the power supplied to, the PDN; b) determining, based on aggregated power and/or energy data regarding the plurality of power units, and the one or more requests, one or more parameters defining properties of power units to be controlled in response to the one or more requests; c) receiving status updates from the plurality of power units; d) for each status update, determining whether the properties of the power unit fulfils the determined parameters; and e) if the properties of the power unit fulfils the determined parameters, controlling the power unit to change the amount of power drawn from or supplied to the PDN.

Abstract: A method of controlling a plurality of power units (106a to 106n) in a power distribution network (PDN) is provided. The method comprising: a) receiving a first parameter indicative of the inertia of the PDN; b) determining, based on at least the first parameter, a proportion of the power units to allocate to a reserve and/or charging state; and c) instructing, based on the determination, one or more of the plurality of power units to enter a reserve and/or charging mode in order that the determined proportion of the power units is allocated to the reserve and/or charging state.

Abstract: A method of controlling a plurality of power units in a power distribution network (PDN), comprising: a) receiving one or more requests to increase or decrease the power drawn from, or the power supplied to, the PDN; b) determining, based on aggregated power and/or energy data regarding the plurality of power units, and the one or more requests, one or more parameters defining properties of power units to be controlled in response to the one or more requests; c) receiving status updates from the plurality of power units; d) for each status update, determining whether the properties of the power unit fulfils the determined parameters; and e) if the properties of the power unit fulfils the determined parameters, controlling the power unit to change the amount of power drawn from or supplied to the PDN.

Abstract: A method of producing a transition joint between components produced from two different grades of ferritic steel comprises the steps of successively re-melting in a vacuum arc furnace a first electrode of one of the required grades of ferritic steel and a second electrode of the required grade of ferritic steel and solidifying the melt as it is progressively formed to produce a single composite component.

Abstract: A method of making a composite tubular product which comprises inner and outer tubes of different chemical compositions and in which the stresses produced at the interface between the outer and inner tubes during cooling from a diffusion bonding temperature are such that the interface between the two tubes remains intact during such cooling. The method comprises the step of inserting into the interior of the inner tube a core of a material whose transformation and/or contraction characteristics are sufficient to counteract at least to a substantial amount interfacial stresses which arise during cooling because of differences in the transformation and contraction properties of different materials from which the inner and outer tubes of the composite product are formed.