电动汽车蓄电池和电容器储能混合模型

2018-12-03 17:49:35·  来源:洞云书屋
   
(注:本文是译文,Original author:H. Ali Borhan)In all different types of HEVs, the energy storage system (ESS) is one of the degrees of freedom used to assist the engine or to recover the vehicle kinetic energy in the r
(注:本文是译文,Original author: H. Ali Borhan)
In all different types of HEVs, the energy storage system (ESS) is one of the degrees of freedom used to assist the engine or to recover the vehicle kinetic energy in the regenerative braking mode. In general, the ESS unit in hybrid vehicles should have the ability to provide both enough energy and also energy rate (power) over different driving conditions. As can be seen, batteries have better energy density than ultracapacitors but their power density or their ability to release energy in a very short time is typically poor. In addition, besides the fact that cycling life of a battery is much shorter than an ultracapacitor, cycling the battery at high depth of discharge (DOD) can significantly reduce the life of the battery.
在所有不同类型的混合动力汽车中,能量储存系统(ESS)用于辅助发动机或在再生制动模式中恢复车辆动能。通常,混合动力车辆中的ESS单元应该具有在不同行驶条件下提供足够的能量和能量率(功率)的能力。电池比超级电容器具有更好的能量密度,但是它们的功率密度或它们在很短的时间内释放能量的能力通常很差。此外,除了电池的循环寿命比超级电容器短得多的事实外,高放电深度(DOD)循环电池可以显著地降低电池的寿命。
For instance, it is shown that in a Li-Ion battery, by increasing the DOD from 30% to 80%, the battery life is reduced from 2600 cycles to 1000 cycles. On the other hand, although the energy density of ultracapacitors is less than the batteries, their power density is generally much higher than the battery. Also the effective life cycle of ultracapacitors is in the order of a million. based on the discussed advantages and disadvantages of batteries and ultracapacitors, using a combination of them in the ESS unit of HEVs has attracted attention recently.
例如,在锂离子电池中,通过将DOD从30%增加到80%,电池寿命从2600个周期减少到1000个周期。另一方面,尽管超级电容器的能量密度小于电池,但它们的功率密度一般远高于电池。超级电容器的有效生命周期为一百万。基于讨论的电池和超级电容器的优点和缺点,最近在HEV的ESS单元中使用它们的组合引起了注意[。
As it is shown in Figure 1, the model of a power-split HEV consists of a vehicle model, a power transmission model, the model of the engine as the power source and the model of the energy storage system. Each subsystem has different components with their interactions shown schematically in Figure 1.如图1所示,动力分流式混合动力汽车的模型包括车辆模型、动力传递模型、发动机作为动力源的模型和能量存储系统的模型。每个子系统具有不同的组件,它们的交互在图1中示出。
 
Fig. 1. A Power-Split HEV Configuration功率分流混合动力汽车配置
Controller Performance on the Low-order Model
低阶模型的控制器性能
To analyze the effect of using a combination of battery and ultracapacitor as the energy storage system in a power-split HEV, a closed-loop model of the vehicle with MPC as the supervisory controller was developed. Inputs to the plant in the low-order model are commanded directly by the MPC controller.
为了分析在动力分配式混合动力电动汽车中使用蓄电池和超级电容器组合作为能量存储系统的效果,开发了一种以MPC为监控控制器的车辆闭环模型。低阶模型中的设备输入直接由MPC控制器控制。
On the low-order model, for both urban and highway cycles, adding the ultracapacitor without any re-sizing improves both fuel economy and the averaged battery C-rate.
在低阶模型上,对于城市和公路循环,添加超级电容器。或没有任何尺寸调整既提高燃料经济性和平均电池C率。
Controller Performance on the High-order Model
基于高阶模型的控制器性能
In order to analyze the ultracapacitor effect on a more detailed closed-loop model of the HEV, the plant model described in Section II is used. In the high-order plant model of the HEV, the inertial dynamics of the power transmission system and the time response of the motor, generator and engine were modeled. Since the inputs to the high-ordered model are torques plus the splitting factor, a standard PI controller was designed to control the set points evaluated by MPC. In order to compare the results with the low-ordered closed-loop model, the prediction model of the MPC and its tuning parameters were kept the same as before.
在HEV的高阶对象模型中,对动力传动系统的惯性动力学和电机、发电机和发动机的时间响应进行了建模。由于高阶模型的输入是转矩加分裂因子,因此设计了一个标准PI控制器来控制由MPC评估的设定点。为了将结果与低阶闭环模型进行比较,MPC和其调谐参数的预测模型与以前保持不变。
A combination of an ultracapacitor and a battery as the energy storage unit of a power-split HEV was analyzed. First, the plant model of a power-split HEV with an ultracapacitor and battery was developed. Then, based on the control objectives to minimize both the fuel consumption and also cycling the battery at high peak powers, an online supervisory controller based on model predictive control was developed. The closed-loop simulation results show that the controller is able to manage the energy such that all control objectives and constraints are satisfied over a finite prediction horizon. It was observed that by combining an ultracapacitor with a battery, cycling the battery at high C-rates (peak powers) is reduced significantly especially over driving cycles with more stop and start durations. The improved C-rate of the battery are expected to extend battery life and reliability.
分析了超级电容器与蓄电池相结合作为动力分立式混合动力汽车的储能单元。首先,开发了一个超级电容器和电池的动力分流混合动力汽车的工厂模型。然后,基于控制目标,以尽量减少燃料消耗和循环电池在高峰值功率,在线监控控制器基于模型预测控制。闭环仿真结果表明,控制器能够管理能量,使得在有限的预测范围内满足所有控制目标和约束。观察到,通过将超级电容器与电池相结合,在高C速率(峰值功率)下循环电池显著减少,尤其是在具有更多停止和启动持续时间的驱动循环中。电池的改进的C速率有望延长电池寿命和可靠性。