Low-head hydroelectric installation
AssigneeNeyrpic
InventorLucien Megnint
Life of this patent
Estimating the term…
Abstract
Low-head hydroelectric installation, in particular for a tidal power station, intended to operate under variable heads of water that can fall to values in the region of zero. When the head of water is lower than a defined value (Hd), lower than at least half the nominal head (Hn), the turbo-machine (1) is made to rotate at a speed (n1, n2, n2, . . . ) lower than the synchronous speed (ns) and bringing its efficiency near to the heart of the efficiency contours. For this purpose, a frequency converter (7) is inserted between the rotary electrical machine (3) and the network (4), the converter (7) being constructed for a power in all cases lower than at least half the nominal power (Pn).
Claims5
In a low-head hydroelectric installation, of the type including at least one hydraulic turbo-machine (1) constructed to give optimum efficiency under a defined head of water or pressure head (Hn), called the nominal head, corresponding to a nominal power (Pn) of the installation and for a speed of rotation corresponding to the speed of synchronism (ns) with the frequency of an electric network (4), and at least one rotary electrical machine (3) drive-coupled to said turbo-machine and electrically connected to said network, the improvement comprising
- automatic control means (5) enabling rotation of said turbo-machine at its speed of synchronism with the frequency of said network, comprising means (5, 9 to 11) making it possible, when said head of water or pressure head is less than a value (Hd) equal to a defined fraction less than one-half of said nominal head (Hn), to cause said turbo-machine to rotate at a speed lower than said synchronous speed, and consequently to insert between said network and said electrical machine a frequency matching device (7) of maximum power at least less than one-half of said nominal power.
Process for obtaining a frequency at the output of a turbo machine of a nominal power corresponding to a synchronous speed with respect to that of an electric network, comprising the
- (a) inserting a frequency matching device between said turbo machine and said network of maximum power at least less than half of said nominal power;
- and
- (b) connecting said frequency device to said turbo machine when the head of water or pressure head is less than a value equal to a defined fraction of nominal head, i.e., when said turbo machine rotates at a speed lower than said synchronous speed.
Dependencies are inferred from the claim text.