混合动力挖掘机能量管理系统控制策略研究

针对最优控制理论设计的混合动力挖掘机最佳燃油控制策略具有全局寻优计算量大、需提前预知系统所有工况状态的不足，本文提出一种实时最佳燃油能量管理策略,对发动机的“转速-功率-燃油耗率”进行数值建模,在直流母线电压稳定的约束下,计算使发动机高效运行的储能系统功率补偿量,并作为控制决策输出;随后,采用有限控制集模型预测控制实现储能系统在该控制决策下的快速功率控制.仿真验证了该方法的有效性和正确性;工程试验表明,该策略在挖掘机平地轻载、重载旋转工况下的燃油耗量分别为传统机型的82.2%和77.6%,可供实际设计参考.
The way of using optimal control theory to implement the optimal fuel control strategy of hybrid excavator is limited, because its computational complexity is large and the working conditions must be known in advance for global optimization. A real-time optimal fuel control strategy was proposed in this paper to solve the problem. An engine model of "speed-power-fuel consumption rate" was established. Under the constraint of DC bus voltage stability, the power compensation of the energy storage system was calculated as a control instruction, which can make the engine work efficiently. Finite control set model predictive control algorithm was proposed to follow the instruction speedily and flexibly. Through the simulation, the effectiveness of the proposed approach was demonstrated. Engineering practice results indicate that the fuel consumption is 82.2% and 77.6% of the prediction of the traditional model with flat light load and heavy load, respectively.