In electrolytic capacitorless permanent magnet synchronous motor(PMSM) drives, the DC-link voltage will fluctuate in a wide range due to the use of slim film capacitor. When the flux-weakening current is lower than-ψ...In electrolytic capacitorless permanent magnet synchronous motor(PMSM) drives, the DC-link voltage will fluctuate in a wide range due to the use of slim film capacitor. When the flux-weakening current is lower than-ψf/Ld during the high speed operation, the flux-weakening control loop will transform to a positive feedback mode, which means the reduction of flux-weakening current will lead to the acceleration of the voltage saturation, thus the whole system will be unstable. In order to solve this issue, this paper proposes a novel flux-weakening method for electrolytic capacitorless motor drives to maintain a negative feedback characteristic of the control loop during high speed operation. Based on the analysis of the instability mechanism in flux-weakening region, a quadrature voltage constrain mechanism is constructed to stabilize the system.Meanwhile, the parameters of the controller are theoretically designed for easier industrial application. The proposed algorithm is implemented on a 1.5 kW electrolytic capacitorless PMSM drive to verify the effectiveness of the flux-weakening performance.展开更多
The purpose of this paper is to investigate charging strategies for integrated electrolytic capacitorless onboard chargers(OBC)in electric vehicles(EVs).An integrated OBC shares power converters and inductance with th...The purpose of this paper is to investigate charging strategies for integrated electrolytic capacitorless onboard chargers(OBC)in electric vehicles(EVs).An integrated OBC shares power converters and inductance with the traction system.An electrolytic capacitor is avoided in DC link of this integrated OBC.Thus,volume is reduced and reliability is improved for the power conversion system.In this paper,a charging strategy is proposed for this integrated system with uncontrolled rectification,where active switches are kept off in the power inverter on machine side.Consequently,a virtual DC-link voltage is with a half-wave shape.An extended phase-shift(EPS)operation is proposed for high-frequency DC/DC converters with this charging strategy,respectively.By designing a dedicated modulation and control strategy,sinusoidal charging power and the satisfied grid current are achieved for the system.Both theoretical analysis of operation modes and experimental verification with laboratory prototypes have been presented for the proposed charging strategy.展开更多
基金supported in part by the Research Fund for the National Natural Science Foundation of China under Grant 52125701, 52007039, 51877054in part by the Key areas R&D Program of Guangdong Province China under Grant 2021B0101310001。
文摘In electrolytic capacitorless permanent magnet synchronous motor(PMSM) drives, the DC-link voltage will fluctuate in a wide range due to the use of slim film capacitor. When the flux-weakening current is lower than-ψf/Ld during the high speed operation, the flux-weakening control loop will transform to a positive feedback mode, which means the reduction of flux-weakening current will lead to the acceleration of the voltage saturation, thus the whole system will be unstable. In order to solve this issue, this paper proposes a novel flux-weakening method for electrolytic capacitorless motor drives to maintain a negative feedback characteristic of the control loop during high speed operation. Based on the analysis of the instability mechanism in flux-weakening region, a quadrature voltage constrain mechanism is constructed to stabilize the system.Meanwhile, the parameters of the controller are theoretically designed for easier industrial application. The proposed algorithm is implemented on a 1.5 kW electrolytic capacitorless PMSM drive to verify the effectiveness of the flux-weakening performance.
文摘The purpose of this paper is to investigate charging strategies for integrated electrolytic capacitorless onboard chargers(OBC)in electric vehicles(EVs).An integrated OBC shares power converters and inductance with the traction system.An electrolytic capacitor is avoided in DC link of this integrated OBC.Thus,volume is reduced and reliability is improved for the power conversion system.In this paper,a charging strategy is proposed for this integrated system with uncontrolled rectification,where active switches are kept off in the power inverter on machine side.Consequently,a virtual DC-link voltage is with a half-wave shape.An extended phase-shift(EPS)operation is proposed for high-frequency DC/DC converters with this charging strategy,respectively.By designing a dedicated modulation and control strategy,sinusoidal charging power and the satisfied grid current are achieved for the system.Both theoretical analysis of operation modes and experimental verification with laboratory prototypes have been presented for the proposed charging strategy.
