基于功率调节裕度的船舶汽发机组非线性控制切换策略

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

为提高发电机组多工况运行的多目标优化能力,提出一种控制方法随工况变化的切换策略,并以船舶电站汽发机组为对象设计实例。针对船舶电站负荷多变的特点,建立考虑汽压调节特性的汽发机组综合控制模型,选取鲁棒综合控制和暂态最优控制设计加权的混合控制方法。将船舶机组过载情形类比于陆地电网故障,计算机组的过载稳定域边界,建立机组功率调节裕度的量化指标。基于指标值与机组负载率之间的关联性,同时考虑控制切换造成的机组波动,设计了离散、连续两类混合控制权值随指标值变化的方法。模拟船舶孤网的仿真结果表明,相比于单一控制方法,采用切换策略能够整体改善机组对突发变载、故障冲击的响应能力,有助于提高船舶孤网全工况运行的稳定水平。

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.