Speed regulation system of a turbine and relevant control method

A regulation system (20) of an expansion turbine (3) speed in an isolated grid, comprising:

• an organic Rankine cycle system (10) comprising at least one expansion turbine (3), said expansion turbine being provided with at least one inlet valve (AV) and at least one by-pass valve (BV) and mechanically connected to a generator (4) of electricity;
• a control unit (21) configured to control processes of the regulation system (20);
• an electric accumulation system (22);
• a dissipative electric brake (24);
• a control for interruptible electrical loads (25);
• a system for modulating heat generation or recovery of the organic Rankine cycle system;
• wherein the control unit (21) is configured to regulate the speed of the expansion turbine (3) and the frequency of the electrical energy produced by the generator (4) operating according to a predetermined management logic on the at least one inlet valve (AV), the at least one by-pass valve (BV), the electrical accumulation system (22), the dissipative electric brake (24), the control of interruptible electrical loads (25) and the system for modulating the heat generation or recovery of the organic Rankine cycle system;
• and
• wherein the predetermined management logic includes a primary regulation that takes place within 10 s for guaranteeing the stability of regulation of the grid frequencies and a secondary regulation that takes place in a time between 30 s and 30 min for optimizing the energy management in the isolated grid.