The input aggregation strategy can reduce the online computational burden of the model predictive controller. But generally aggregation based MPC controller may lead to poor control quality. Therefore, a new concept, ...The input aggregation strategy can reduce the online computational burden of the model predictive controller. But generally aggregation based MPC controller may lead to poor control quality. Therefore, a new concept, equivalent aggregation, is proposed to guarantee the control quality of aggregation based MPC. From the general framework of input linear aggregation, the design methods of equivalent aggre- gation are developed for unconstrained and terminal zero constrained MPC, which guarantee the actual control inputs exactly to be equal to that of the original MPC. For constrained MPC, quasi-equivalent aggregation strategies are also discussed, aiming to make the difference between the control inputs of aggregation based MPC and original MPC as small as possible. The stability conditions are given for the quasi-equivalent aggregation based MPC as well.展开更多
As system identification theory and model predictive control are belonged to two different research fields separately,so one gap exists between these two subjects.To alleviate this gap between them,one new idea propos...As system identification theory and model predictive control are belonged to two different research fields separately,so one gap exists between these two subjects.To alleviate this gap between them,one new idea proposed in this paper is to introduce system identification theory into model predictive control.As the most important element in model predictive control is the prediction of the output value for a nonlinear system,then the problem of deriving the prediction of the output value can be achieved by system identification theory.More specifically,a Bayesian approach is applied for the nonparametric estimation by modeling the prediction as realizations of zero mean random fields.Through comparing this kind of prediction corresponding to this Bayesian approach and the former direct weight optimization identification for nonlinear system,the authors see that if the unknown weights are chosen appropriately,these two approaches are equivalent to each other.Based on the obtained prediction of the output value,the authors substitute this prediction of the output value into one cost function of model predictive control,and then a quadratic programming problem with inequality constraints is formulated.When to solve this quadratic programming problem,a detailed process about how to derive its dual form is given.As the dual problem has a simple constraint set,it is amenable to the use of the common Gauss-Seidel algorithm,whose convergence can be shown easily.Finally,one simulation example confirms the proposed theoretical results.展开更多
随着风电机组基础结构的不断增大,风电机组的控制方法面临新的机遇和挑战,而遥感测量技术的发展给传统风电机组控制策略提供一个新的研究领域。该文提出了基于激光雷达(light detection and ranging,LIDAR)辅助风电机组模型预测控制方...随着风电机组基础结构的不断增大,风电机组的控制方法面临新的机遇和挑战,而遥感测量技术的发展给传统风电机组控制策略提供一个新的研究领域。该文提出了基于激光雷达(light detection and ranging,LIDAR)辅助风电机组模型预测控制方法来实现控制系统对风速扰动的前馈补偿控制。首先根据叶素动量理论分析风电机组的载荷情况和LIDAR预测风轮迎风面的有效风速,利用扩展卡尔曼滤波重建噪声状态的非线性风电机组模型的未知状态,对预测时域状态值的进行预测实时处理,以求解最小目标函数获取系统当前时刻的最优化控制,使得系统参考轨迹和未来输出值之间差值实现最小化。最后,通过进行风电机组传统控制方法与LIDAR辅助线性模型预测控制、非线性模型预测控制的对比实验,证明LIDAR与模型预测控制相结合的控制方式能在一定程度上提高大型风电机组的风能利用系数,缓解风电机组的疲劳载荷。展开更多
This paper presents an optimized equivalent consumption minimization strategy(ECMS) for four-wheel-drive(4 WD) hybrid electric vehicles(HEVs) incorporating vehicle connectivity. In order to be applicable to the 4 WD a...This paper presents an optimized equivalent consumption minimization strategy(ECMS) for four-wheel-drive(4 WD) hybrid electric vehicles(HEVs) incorporating vehicle connectivity. In order to be applicable to the 4 WD architecture, the ECMS is designed based on a rule-based strategy and used under the condition that a certain propulsion mode is activated. Assuming that a group of 4 WD HEVs are connected and position information can be shared with each other, we formulate a decentralized model predictive control(MPC) framework that compromises fuel efficiency, mobility, and inter-vehicle distance to optimize the velocity profile of each individual vehicle. Based on the optimized velocity profile, an optimization problem considering both fuel economy and battery state of charge(SOC) sustainability is formulated to optimize the equivalent factors(EFs) of the ECMS for HEVs over an appropriate time window. MATLAB User Datagram Protocol(UDP) is used in the codes run on multiple computers to simulate the wireless communication among vehicles, which share position information via UDP-based communication, and dSPACE is used as a software-in-the-loop platform for the simulation of the optimized ECMS. Simulation results validate the control effectiveness of the proposed method.展开更多
This paper proposes a hybrid control strategy of air-conditioning loads(ACLs)for participating in peak load reduction.The hybrid control strategy combines the temperature setpoint adjustment(TSA)control and on/off con...This paper proposes a hybrid control strategy of air-conditioning loads(ACLs)for participating in peak load reduction.The hybrid control strategy combines the temperature setpoint adjustment(TSA)control and on/off control together to make full use of response potentials of ACLs.The primary free transport model of ACLs has been established in literature at or near a fixed temperature setpoint.In this paper,a wide-range transport(WRT)model suitable for larger value of TSA is proposed.The WRT model can be constructed easily through the parameter of devices and indoor and outdoor temperature.To modulate the aggregate response characteristics of ACLs more friendly to the power grid,the safe protocol(SP)is adopted and integrated into the WRT model,which achieves a good unification of oscillation suppression and efficient modeling.Moreover,the hybrid control strategy is implemented based on the WRT model,and the model predictive control(MPC)controller is designed considering the tracking error and control switch cost.At last,the superiority of the hybrid control strategy is verified and the performance of ACLs for peak load reduction under this controller is simulated.The simulation results show that the hybrid control strategy could exploit the load reduction potential of ACLs fully than the TSA mode and track the reference signal more accurately.展开更多
基金Supported by the National Natural Science Foundation of China (Grant No. 60674041)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20070248004)
文摘The input aggregation strategy can reduce the online computational burden of the model predictive controller. But generally aggregation based MPC controller may lead to poor control quality. Therefore, a new concept, equivalent aggregation, is proposed to guarantee the control quality of aggregation based MPC. From the general framework of input linear aggregation, the design methods of equivalent aggre- gation are developed for unconstrained and terminal zero constrained MPC, which guarantee the actual control inputs exactly to be equal to that of the original MPC. For constrained MPC, quasi-equivalent aggregation strategies are also discussed, aiming to make the difference between the control inputs of aggregation based MPC and original MPC as small as possible. The stability conditions are given for the quasi-equivalent aggregation based MPC as well.
基金supported by Jiangxi Provincial National Science Foundation under Grant No.jxxjb18020。
文摘As system identification theory and model predictive control are belonged to two different research fields separately,so one gap exists between these two subjects.To alleviate this gap between them,one new idea proposed in this paper is to introduce system identification theory into model predictive control.As the most important element in model predictive control is the prediction of the output value for a nonlinear system,then the problem of deriving the prediction of the output value can be achieved by system identification theory.More specifically,a Bayesian approach is applied for the nonparametric estimation by modeling the prediction as realizations of zero mean random fields.Through comparing this kind of prediction corresponding to this Bayesian approach and the former direct weight optimization identification for nonlinear system,the authors see that if the unknown weights are chosen appropriately,these two approaches are equivalent to each other.Based on the obtained prediction of the output value,the authors substitute this prediction of the output value into one cost function of model predictive control,and then a quadratic programming problem with inequality constraints is formulated.When to solve this quadratic programming problem,a detailed process about how to derive its dual form is given.As the dual problem has a simple constraint set,it is amenable to the use of the common Gauss-Seidel algorithm,whose convergence can be shown easily.Finally,one simulation example confirms the proposed theoretical results.
文摘随着风电机组基础结构的不断增大,风电机组的控制方法面临新的机遇和挑战,而遥感测量技术的发展给传统风电机组控制策略提供一个新的研究领域。该文提出了基于激光雷达(light detection and ranging,LIDAR)辅助风电机组模型预测控制方法来实现控制系统对风速扰动的前馈补偿控制。首先根据叶素动量理论分析风电机组的载荷情况和LIDAR预测风轮迎风面的有效风速,利用扩展卡尔曼滤波重建噪声状态的非线性风电机组模型的未知状态,对预测时域状态值的进行预测实时处理,以求解最小目标函数获取系统当前时刻的最优化控制,使得系统参考轨迹和未来输出值之间差值实现最小化。最后,通过进行风电机组传统控制方法与LIDAR辅助线性模型预测控制、非线性模型预测控制的对比实验,证明LIDAR与模型预测控制相结合的控制方式能在一定程度上提高大型风电机组的风能利用系数,缓解风电机组的疲劳载荷。
基金supported by the National Hi-Tech Research and Development Program of China(Grant No.2015BAG17B04)China Scholarship Council(Grant No.201506690009)U.S.GATE Program
文摘This paper presents an optimized equivalent consumption minimization strategy(ECMS) for four-wheel-drive(4 WD) hybrid electric vehicles(HEVs) incorporating vehicle connectivity. In order to be applicable to the 4 WD architecture, the ECMS is designed based on a rule-based strategy and used under the condition that a certain propulsion mode is activated. Assuming that a group of 4 WD HEVs are connected and position information can be shared with each other, we formulate a decentralized model predictive control(MPC) framework that compromises fuel efficiency, mobility, and inter-vehicle distance to optimize the velocity profile of each individual vehicle. Based on the optimized velocity profile, an optimization problem considering both fuel economy and battery state of charge(SOC) sustainability is formulated to optimize the equivalent factors(EFs) of the ECMS for HEVs over an appropriate time window. MATLAB User Datagram Protocol(UDP) is used in the codes run on multiple computers to simulate the wireless communication among vehicles, which share position information via UDP-based communication, and dSPACE is used as a software-in-the-loop platform for the simulation of the optimized ECMS. Simulation results validate the control effectiveness of the proposed method.
基金supported by National Key R&D Program of China(No.2018YFE0122200)the Fundamental Research Funds for the Central Universities(No.2020MS095).
文摘This paper proposes a hybrid control strategy of air-conditioning loads(ACLs)for participating in peak load reduction.The hybrid control strategy combines the temperature setpoint adjustment(TSA)control and on/off control together to make full use of response potentials of ACLs.The primary free transport model of ACLs has been established in literature at or near a fixed temperature setpoint.In this paper,a wide-range transport(WRT)model suitable for larger value of TSA is proposed.The WRT model can be constructed easily through the parameter of devices and indoor and outdoor temperature.To modulate the aggregate response characteristics of ACLs more friendly to the power grid,the safe protocol(SP)is adopted and integrated into the WRT model,which achieves a good unification of oscillation suppression and efficient modeling.Moreover,the hybrid control strategy is implemented based on the WRT model,and the model predictive control(MPC)controller is designed considering the tracking error and control switch cost.At last,the superiority of the hybrid control strategy is verified and the performance of ACLs for peak load reduction under this controller is simulated.The simulation results show that the hybrid control strategy could exploit the load reduction potential of ACLs fully than the TSA mode and track the reference signal more accurately.
