针对三相LCL并网逆三电平中点钳位(Neutral Point Clamped,NPC)逆变器中有限集模型预测控制(Finite Control Set-Model Predictive Control,FCS-MPC)计算量大和控制速度慢导致NPC逆变器性能变差的问题,设计了一种快速模型预测控制方法...针对三相LCL并网逆三电平中点钳位(Neutral Point Clamped,NPC)逆变器中有限集模型预测控制(Finite Control Set-Model Predictive Control,FCS-MPC)计算量大和控制速度慢导致NPC逆变器性能变差的问题,设计了一种快速模型预测控制方法。通过改变快速模型预测控制中参考电流电角度控制逆变器输出电流的相位,实现入网电流与电网同步;通过在冗余短矢量中选择合适的短矢量,实现直流侧中点电压平衡,减少计算量;通过缩小计算扇区,使快速模型预测控制仅在当前最优输出电压矢量附近进行寻优计算,进一步减少计算量。在MATLAB/SIMULINK中搭建了三相LCL并网NPC逆变器仿真模型,仿真结果验证了上述控制方法的快速性和可行性,运算速度提高了18.31%,入网电流总谐波失真(Total Harmonic Distortion,THD)值减少了2.38%。展开更多
In order to reach a compromise between fast response control and torques matching control in double turboshaft engines,research on nonlinear model predictive control for turboshaft engines based on double engines torq...In order to reach a compromise between fast response control and torques matching control in double turboshaft engines,research on nonlinear model predictive control for turboshaft engines based on double engines torques matching is conducted.Meanwhile,a Nonlinear Model Predictive Control(NMPC)method is proposed,which combines the control index of the power turbine speed with torques matching of double engines creatively.In addition to the control index,the difference of output torques between each engine is also incorporated in the objective function as a penalty term to ensure constant speed control and short torques matching time.Simulation results demonstrate that relative to unilateral torques matching,the settling time of the bidirectional matching method can be reduced by nearly 30.8%.Nevertheless,compared with the bidirectional torques matching method under the cascade PID controller,the NMPC method can decrease the overshoot of the power turbine speed by 65%and reduce the matching time by 15.5%synchronously.Besides fast response control of turboshaft engines,fast torques matching control of double engines is accomplished as well.展开更多
针对有限控制集模型预测控制方法在多电平多相逆变器中预测模型和目标函数在线计算量大的不足,提出一种快速有限控制集模型预测控制方法。该方法根据参考矢量的空间位置,让远离参考矢量的电压矢量不参与预测模型在线计算和目标函数在线...针对有限控制集模型预测控制方法在多电平多相逆变器中预测模型和目标函数在线计算量大的不足,提出一种快速有限控制集模型预测控制方法。该方法根据参考矢量的空间位置,让远离参考矢量的电压矢量不参与预测模型在线计算和目标函数在线评估。对于三电平三相逆变器,快速有限控制集模型预测控制方法使参与计算的电压矢量由27个减少到12个,大大提高计算效率。最后,建立起5 k W二极管钳位型三电平三相逆变器实验平台。对于传统有限控制集模型预测控制和快速有限控制集模型预测控制进行对比稳态和动态实验。实验结果表明:所提出快速有限控制集模型预测控制方法使系统具有良好的静、动态性能。展开更多
文摘针对三相LCL并网逆三电平中点钳位(Neutral Point Clamped,NPC)逆变器中有限集模型预测控制(Finite Control Set-Model Predictive Control,FCS-MPC)计算量大和控制速度慢导致NPC逆变器性能变差的问题,设计了一种快速模型预测控制方法。通过改变快速模型预测控制中参考电流电角度控制逆变器输出电流的相位,实现入网电流与电网同步;通过在冗余短矢量中选择合适的短矢量,实现直流侧中点电压平衡,减少计算量;通过缩小计算扇区,使快速模型预测控制仅在当前最优输出电压矢量附近进行寻优计算,进一步减少计算量。在MATLAB/SIMULINK中搭建了三相LCL并网NPC逆变器仿真模型,仿真结果验证了上述控制方法的快速性和可行性,运算速度提高了18.31%,入网电流总谐波失真(Total Harmonic Distortion,THD)值减少了2.38%。
基金co-supported by the National Natural Science Foundation of China(No.51576096)Qing Lan and 333 Project and Research Funds for Central Universities(No.NF2018003).
文摘In order to reach a compromise between fast response control and torques matching control in double turboshaft engines,research on nonlinear model predictive control for turboshaft engines based on double engines torques matching is conducted.Meanwhile,a Nonlinear Model Predictive Control(NMPC)method is proposed,which combines the control index of the power turbine speed with torques matching of double engines creatively.In addition to the control index,the difference of output torques between each engine is also incorporated in the objective function as a penalty term to ensure constant speed control and short torques matching time.Simulation results demonstrate that relative to unilateral torques matching,the settling time of the bidirectional matching method can be reduced by nearly 30.8%.Nevertheless,compared with the bidirectional torques matching method under the cascade PID controller,the NMPC method can decrease the overshoot of the power turbine speed by 65%and reduce the matching time by 15.5%synchronously.Besides fast response control of turboshaft engines,fast torques matching control of double engines is accomplished as well.
文摘针对有限控制集模型预测控制方法在多电平多相逆变器中预测模型和目标函数在线计算量大的不足,提出一种快速有限控制集模型预测控制方法。该方法根据参考矢量的空间位置,让远离参考矢量的电压矢量不参与预测模型在线计算和目标函数在线评估。对于三电平三相逆变器,快速有限控制集模型预测控制方法使参与计算的电压矢量由27个减少到12个,大大提高计算效率。最后,建立起5 k W二极管钳位型三电平三相逆变器实验平台。对于传统有限控制集模型预测控制和快速有限控制集模型预测控制进行对比稳态和动态实验。实验结果表明:所提出快速有限控制集模型预测控制方法使系统具有良好的静、动态性能。
