Switching Strategy of Shipboard Turbo-generator Nonlinear Control Method Based on Its Power Regulation Margin

In order to improve the multi-objective optimization ability of power-unit under multi-operating conditions, a switching strategy of control method changing with working conditions was proposed, and the shipboard turbo-generator was taken as an example for description. According to the characteristics of load-changing of shipboard power-unit, the integrated control model of turbo-generator considering steam-pressure regulation was established, then multi-index nonlinear robust control (MINRC) and nonlinear optimal system control (NOSC) were chosen for weighted hybrid control design. By making an analogy between shipboard power-unit's overload and land-based power-unit's failure, the boundary of stability region under overload condition was given, and the quantitative index of power regulation margin was built. Based on the correlation between index value and unit load-rate, and by taking the fluctuation of power-unit caused by control switching into account, the method of hybrid control weight changing with index value including discrete and continuous modes were designed and compared. The result of simulation test indicates that, comparing with single control method, the switching strategy can improve the response ability of power-unit to sudden load-change and fault impact, and maintain the stable operation of shipboard isolated network under all working conditions. © 2020 Chin. Soc. for Elec. Eng.