Systeme de commande pour regulation multivariable de centrale thermique a flamme

Abstract

Control system for multivariable regulation of a fossil fuel power station comprising: —a boiler ( 103 ) and auxiliaries assembly ( 102 ), with a fuel supply (GC), which is the heat source of a circuit for fluid in steam phase over part of said circuit, said steam supplying —a turbine ( 114 ) at a pressure (P) and a temperature (T), which is connected to an alternator producing electrical power (W), the supply of steam being determined by the opening (SR) of regulating valves upstream of said turbine ( 114 ), the system comprising: —a loop for regulating the steam pressure (P), —a loop for regulating the electrical power (W), with at least one loop based on a power station internal model command, one considering a pure delay τ in a parameter of the internal model, one variable in each loop acting as a disturbing influence in the other.

1 . A control system for multivariable regulation of a fossil fuel power station for the generation of electricity from fuel, said power station comprising:
 an assembly ( 102 ) comprising a boiler ( 103 ) and its auxiliaires forming the subject matter of a fuel supply (GC) for acting as heat source to a working fluid circuit such that the latter is in steam phase over part of said circuit,   a turbine ( 114 ) supplied by said steam at a steam pressure (P) and temperature (T), said turbine ( 114 ) being mechanically connected to an electrical alternator ( 116 ) producing electric power (W), the steam feed of said turbine ( 114 ) being determined by the opening (SR) of regulating valves located upstream of said turbine ( 114 ), said control system comprising:   a regulating loop ( 200 ,  300 ) of steam pressure (P) having a control variable and an instruction (P REF ),   a regulating loop ( 400 ) of electric power (W) having a control variable and an instruction (W REF ),   characterised in that at least one of the regulating loops ( 200 ,  300 ,  400 ) is based on an internal model command type, defined in that it comprises a representation of a physical process to be controlled, taking into account a pure delay τ of one of the parameters of the internal model of the power station, and   for each of the regulating loops ( 200 ,  300 ,  400 ) a variable of a loop is taken into account as a disturbing influence in the other loop.   
     
     
         2 . The control system according to  claim 1 , in which the regulating loop ( 200 ,  300 ) of steam pressure (P) comprises a rejection chain of disturbing influence ( 202 ,  302 ) for taking into account a variable of the loop for regulating electric power (W) as a disturbing influence. 
     
     
         3 . The control system according to any one of the preceding claims, in which the variable of the regulating loop ( 400 ) of electric power (W) taken into account as a disturbing influence in said regulating loop of steam pressure (P) is the opening of regulating valves (SR) upstream of the turbine ( 114 ). 
     
     
         4 . The control system according to any one of the preceding claims, in which the regulating loop ( 200 ,  300 ) of steam pressure (P) comprises a modelling chain ( 206 ,  306 ) of a transfer function (H GC-P1 ) between the fuel supply (GC) and the contribution (P1) at the steam pressure (P) of the fuel supply (GC), said modelling chain ( 206 ,  306 ) not taking into account the variable of the regulating loop ( 400 ) of electric power (W) taken into account in said regulating loop ( 200 ,  300 ) of steam pressure (P) as a disturbing influence. 
     
     
         5 . The control system according to  claim 4 , in which the pure delay τ is taken into account in the regulating loop ( 200 ,  300 ) of steam pressure (P) in the modelling chain ( 206 ,  306 ) of the transfer function (H GC-P1 ) between the fuel supply (GC) and the contribution (P1) at the steam pressure (P) of the fuel supply (GC). 
     
     
         6 . The control system according to any one of  claims 4  or  5 , in which the modelling chain ( 206 ) of a transfer function (H GC-P1 ) between the fuel supply (GC) and the contribution (P1) at the steam pressure (P) of the fuel supply (GC) is of form G 1 (s)·e −τs , with G 1 (s) a stable function of the first order. 
     
     
         7 . The control system according to any one of the preceding claims, in which the regulating loop ( 200 ) of steam pressure (P) comprises ane determination chain ( 204 ) of a control variable without disturbing influence for determining a control variable without disturbing influence from a steam pressure (P REF ) instruction. 
     
     
         8 . The control system according to  claims 2  and  7  in combination, in which the control variable of the regulating loop ( 200 ) of steam pressure (P) is the fuel supply (GC) achieved by the output of the determination chain ( 204 ) of the control variable without disturbing influence from which is subtracted the output of the rejection chain of disturbing influence ( 202 ). 
     
     
         9 . The control system according to any one of the preceding claims, in which the system comprises a determination chain ( 204 ) of the control variable without disturbing influence, a rejection chain of disturbing influence ( 202 ) and a modelling chain ( 206 ) of a transfer function (H GC-P1 ) between the fuel supply (GC) and contribution (P1) at the steam pressure (P) of the fuel supply (GC) of the form G 1 (s)·e −τs , with G 1 (s) a stable function of the first order and in which:
 the determination chain ( 204 ) of the control variable without disturbing influence is constituted by a transfer function inputting a steam pressure instruction (P REF ), function of type G 1   −1 (s)·F 1 (s), with F 1 (s) a filter of greater order or equal to the order of G1(s), and 
 the rejection chain of disturbing influence ( 202 ) is constituted by a transfer function G 1   −1 (s)·F2(s), with F 2 (s) a filter of greater order or equal to the order of G1(s). 
 
     
     
         10 . The control system according to  claim 5 , in which the regulating loop ( 300 ) of steam pressure (P) comprises a return loop without delay ( 316 ) for taking into account, in the determination of the fuel supply (GC), the part of said modelling chain ( 306 ) of a transfer function between the fuel supply (GC) and contribution (P1) at the steam pressure (P) of the fuel supply (GC) which is independent of the pure delay τ. 
     
     
         11 . The control system according to any one of the preceding claims, in which the variable of the regulating loop ( 200 ,  300 ) of pressure (P) taken into account in said regulating loop ( 400 ) of electric power (W) as a disturbing influence is the steam pressure (P). 
     
     
         12 . The control system according to any one of the preceding claims, in which the regulating loop ( 400 ) of electric power (W) comprises an integral proportional regulator ( 402 ) and a rejection chain of disturbing influence and anticipation of follow-up of instruction ( 404 ) for taking into account a variable of the regulating loop ( 200 ) of steam pressure (P) as a disturbing influence. 
     
     
         13 . The control system according to  claim 12 , in which the opening of regulating valves (SR) upstream of the turbine ( 114 ) is achieved by the output of the integral proportional regulator ( 402 ) from which is subtracted the output of the rejection chain of disturbing influence and anticipation of follow-up of instruction ( 404 ) of the regulating loop ( 400 ) of the electric power (W). 
     
     
         14 . The control system according to any one of the preceding claims, in which parameters of the regulating loop ( 200 ,  300 ) based on an internal model command type are estimated online by an adaptive regulation method, said adaptive regulation inputting variables (GC, SR, P) of the control system. 
     
     
         15 . A fossil fuel power station comprising:
 an assembly ( 102 ) comprising a boiler ( 103 ) and its auxiliaires forming the subject matter of a fuel supply (GC) to serve as heat source to a working fluid circuit such that the latter is in steam phase over part of said circuit,   a turbine ( 114 ) supplied by said steam at a steam pressure (P) and temperature (T), said turbine ( 114 ) being mechanically connected to an electrical alternator ( 116 ) producing electric power (W), the steam feed of said turbine ( 114 ) being determined by the opening (SR) of regulating valves located upstream of said turbine ( 114 ),   characterised in that it comprises a control system according to any one of the preceding claims.   
     
     
         16 . A control process of a fossil fuel power station according to  claim 15 , characterised in that:
 the steam pressure (P) is regulated by a regulating loop ( 200 ,  300 ) of steam pressure (P), and   the electric power is regulated by a regulating loop ( 400 ) of electric power (W),   at least one of the regulating loops ( 200 ,  300 ,  400 ) being based on an internal model command type taking into account a pure delay τ of one of the parameters of the internal model of the power station, and for each of the regulating loops ( 200 ,  300 ,  400 ) a variable of a loop being taken into account as a disturbing influence in the other loop.