Procedure for economical operation of an island network with renewable sources of energy and a circuit for execution of the procedure

Claim 2

Circuit arrangement for the economical operation of an isolated network which comprises energy converters fed by different and also renewable energy sources and has fluctuating energy consumption, a coordinating frequency controller specifying a total power set-point value for the energy converters which is initially applied to the most economical primary energy converter with renewable energy source; only after the full capacity of said energy converter has been utilized is the difference with respect to the total power set-point value applied to the next most economical unit as power set-point value, characterized in that there is incorporated in the isolated network an energy storage system (42) which is loaded by a set power load (9), in that, if the instantaneous deliverable summated power of the units (2, 4) which are fed by renewable energy sources (3, 5) is greater than the instantaneous total power consumption of the loads (60, 61, 62), the total power set-point value from the coordinating frequency controller P soll is increased at an addition point (15) by the maximum power requirement P max,sp. of the energy storage system (42), in that this increased total power set-point value P soll,erh. is used for the priority-controlled, successive full-load connection of the units (2, 4), in that after said units (2, 4) have been connected, the remaining residual set-point value serves to control the energy consumption of the energy storage system (42) by deriving from the maximum power requirement P max,sp. of the energy storage system (42) and the residual set-point value a difference value P red.,2 - P max,sp. at a comparison point (46) in the system, which difference serves as power set-point value for controlling the energy consumption, in that after the energy store (63) has been loaded, the value P max, sp. is reduced or set to zero, and in that only then is the power set-point value of one of the units (2, 4) fed by renewable power sources (3, 5) reduced.

Claim 3

Circuit arrangement according to Claim 2, characterized in that, if there is present a plurality of different energy storage systems (42) which comprise a set power load (9) for feeding the store, the energy store (63) itself and an energy converter for converting the energy of the store into that of the network, the set power loads (9) for the energy storage are connected in the sequence of the economic efficiency which results from the total economic efficiency of the energy storage systems.

Claim 4

Circuit arrangement according to Claim 3, characterized in that the maximum power requirement P max,sp. added to the power set-point value P soll is formed from the sum of the power requirement of all the set power loads (9) of the energy storage systems (42).

Claim 5

Circuit arrangement according to one of Claims 2 to 4, characterized in that a minimum power P min,D is always fed as power set-point value to an only concomitantly running diesel unit (11) as primary energy converter, by which minimum power the increased total power set-point value P soll,erh. formed at the addition point (15) is reduced before being fed to the unit controllers at a comparison point (19).

Claim 6

Circuit arrangement according to one of Claims 2 to 5, characterized in that rechargeable batteries, hydrogen stores - fed from electrolysis - and steam pressure containers are used as energy stores (63) for isolated networks, pump storage reservoirs, air pressure reservoirs in sealed caves or mines.