This paper presents the design optimization of a self-circulated ventilation system for an enclosed permanent magnet(PM)traction motor utilized in the propulsion systems for subway trains.In order to analyze accuratel...This paper presents the design optimization of a self-circulated ventilation system for an enclosed permanent magnet(PM)traction motor utilized in the propulsion systems for subway trains.In order to analyze accurately the machine's inherent cooling capacity when the train is running,the ambient airflow and the related heat transfer coefficient(HTC)are numerically investigated considering synchronously the bogie installation structure.The machine is preliminary cooled with air ducts set on the motor shell,and the fluidic-thermal field distributions with only the shell air duct cooling are numerically calculated.During simulations,the HTC obtained in the former steps is applied to the external surface of the machine to model the inherent cooling characteristic caused by the train movement.To reduce the temperature rise and thus guarantee the motor's working reliability,an internal self-circulated air cooling system is proposed according to the machine temperature distribution.The air enclosed in the end-caps is driven by the blades mounted on both sides of the rotor core and forms two air circuits to bring the excessive power losses generated in the heating components to cool regions.The fluid flow and temperature rise distributions of the cooling system's structural parameters are further improved by the Taguchi method in order to confirm the efficacy of the internal air cooling system.展开更多
In power converter control,predictive control has several merits,such as simple concept and fast response.However,the necessity to use the weighting factor inside the cost function makes the control design complex in ...In power converter control,predictive control has several merits,such as simple concept and fast response.However,the necessity to use the weighting factor inside the cost function makes the control design complex in the case of regulating multivariables where the value of the weighting factor is obtained by a nontrivial process.Also,it primarily depends on the system parameters and operating points of the control system.This paper aims to enhance the model predictive algorithm of the singlestage topology of a quasi-Z Source Inverter(qZSI).The concept of a multi-objective optimization approach is used in addition to the sub-cost function definition to remove the weighting factors.By using the sub-cost function definition,the inductor current is pushed away from the main loop of the predictive algorithm.Thus,no weighting factor is needed to manage the priority of the inductor current.The other two control targets,which are the capacitor voltage and load currents,will be controlled by the multi-objective optimization approach without using any weighting factors.A detailed theoretical analysis of the proposed technique will be given and validated based on simulation results.展开更多
基金supported by the National Natural Science Foundation of China under Grant 52107007the China Scholarship Council under Grant 202008120084the“Chunhui Plan”Collaborative Research Project of Chinese Ministry of Education under Grant HZKY20220604。
文摘This paper presents the design optimization of a self-circulated ventilation system for an enclosed permanent magnet(PM)traction motor utilized in the propulsion systems for subway trains.In order to analyze accurately the machine's inherent cooling capacity when the train is running,the ambient airflow and the related heat transfer coefficient(HTC)are numerically investigated considering synchronously the bogie installation structure.The machine is preliminary cooled with air ducts set on the motor shell,and the fluidic-thermal field distributions with only the shell air duct cooling are numerically calculated.During simulations,the HTC obtained in the former steps is applied to the external surface of the machine to model the inherent cooling characteristic caused by the train movement.To reduce the temperature rise and thus guarantee the motor's working reliability,an internal self-circulated air cooling system is proposed according to the machine temperature distribution.The air enclosed in the end-caps is driven by the blades mounted on both sides of the rotor core and forms two air circuits to bring the excessive power losses generated in the heating components to cool regions.The fluid flow and temperature rise distributions of the cooling system's structural parameters are further improved by the Taguchi method in order to confirm the efficacy of the internal air cooling system.
基金supported in part by the Estonian Research Council grant PUT1443in part by the Estonian Centre of Excellence in Zero Energy and Resource Efficient Smart Buildings and Districts,ZEBE,grant 2014-2020.4.01.15-0016 funded by the European Regional Development Fund.
文摘In power converter control,predictive control has several merits,such as simple concept and fast response.However,the necessity to use the weighting factor inside the cost function makes the control design complex in the case of regulating multivariables where the value of the weighting factor is obtained by a nontrivial process.Also,it primarily depends on the system parameters and operating points of the control system.This paper aims to enhance the model predictive algorithm of the singlestage topology of a quasi-Z Source Inverter(qZSI).The concept of a multi-objective optimization approach is used in addition to the sub-cost function definition to remove the weighting factors.By using the sub-cost function definition,the inductor current is pushed away from the main loop of the predictive algorithm.Thus,no weighting factor is needed to manage the priority of the inductor current.The other two control targets,which are the capacitor voltage and load currents,will be controlled by the multi-objective optimization approach without using any weighting factors.A detailed theoretical analysis of the proposed technique will be given and validated based on simulation results.
