Simulation study and mathematical-physical analysis on a model of boiler-turbine-generator unit

The correctness of mathematical model that is as basis to research work will have a direct impact on the practical application of boiler-turbine coordinated control system. So selecting a correct mathematical model as the reference of control strategy and its controlled object of simulation test is an important process to acquire success in practice. Various modeling methods all should be guided by some basic principles. ldquoFactuality-physical concept of a model need to be clearlyrdquo is particularly important to practical engineering problems. This paper based on the energy conservation law, and synthesizes application of classical theory and concepts such as the system stability analysis, boiler dynamic analysis and system identification, the Bell- Astrom model has been analyzed by mathematical deduction and the potential problem of physical concept of the model has also been pointed out. Both mathematical calculation and simulation tests show that in the case of the Bell- Astrom model, whether boiler heat load or active power of generator, the same value of any one of them will corresponding to opening positions of the fuel control valve u₁, the steam control valve u₂ and the water control valve u₃ at different scales. The result is contrary to the law of energy conservation on the physical concept. The paper mentions this query to attract the common concern of the experts and scholars whose study interesting at this field.