Research On Integrated Control For Steam Turbine Generators Based On Reactive Current Compensation

The excitation control and steam valve control of generators are the main adjustment approach to improve the transient stability and voltage regulation of power system operation. This paper presents a integrated control for steam turbine generators based on reactive current compensation. Firstly, a mathematical model considering the excitation and valve control is proposed, and the nonlinear model is achieved in Matlab/ Simulink succesfully; Secondly, the PID+PSS method and the coordinated passivity method are discussed through two aspects of the the linear control and nonlinear control. According to the simulation, coordinated passivity design has the superiority that it can effectively compensate the nonlinear characteristics of the power system, but this approch still has some shortcomings. Finally, as most excitation and steam valve controllers are designed without consideration of the steady-state error of active power and reactive power supporting capability of the generator, this paper presents a new passivity design for the excitation and steam valve control. Based on the nonlinear model which two integrators are added in the differential equations, steam-valving control is designed by backstepping method at first,and excitatation control is achieved using the coordinated passivation approach incorporating the reactive current compensation. The simulation shows the approach has strong positive impact on the performance of active and reactive power of the generator.