Permanent magnet synchronous motors(PMSMs)are widely used in high-power-density and flexible control methods.Generally,the inductance changes significantly in real-time machine operations because of magnetic saturatio...Permanent magnet synchronous motors(PMSMs)are widely used in high-power-density and flexible control methods.Generally,the inductance changes significantly in real-time machine operations because of magnetic saturation and coupling effects.Therefore,the identification of inductance is crucial for PMSM control.Existing inductance identification methods are primarily based on the voltage source inverter(VSI),making inverter nonlinearity one of the main error sources in inductance identification.To improve the accuracy of inductance identification,it is necessary to compensate for the inverter nonlinearity effect.In this study,an overview of the PMSM inductance identification and the related inverter nonlinearity self-learning methods are presented.展开更多
The grid-connected converter(GCC) is widely used as the interface between various distributed generations and the utility grid. To achieve precise power control for GCC, this paper presents a model predictive direct p...The grid-connected converter(GCC) is widely used as the interface between various distributed generations and the utility grid. To achieve precise power control for GCC, this paper presents a model predictive direct power control(MPDPC)with consideration of the unbalanced filter inductance and grid conditions. First, the characteristics of GCC with unbalanced filter inductance are analyzed and a modified voltage control function is derived. On this basis, to compensate for the power oscillation caused by unbalanced filter inductance, a novel power compensation method is proposed for MPDPC to eliminate the DC-side current ripple while maintaining sinusoidal grid current. Besides, to improve the control robustness against mismatched filter inductance, a filter inductance identification scheme is proposed. Through this scheme, the estimated value of filter inductance is updated in each control period and applied in the proposed MPDPC. Finally, simulation results in PSCAD/EMTDC confirm the validity of the proposed MPDPC and the filter inductance identification scheme.展开更多
The harmonic components of stator winding current in induction motor will change under the condition of stator inter-turn short circuit.According to these characteristics,in this paper,a novel technique based on morph...The harmonic components of stator winding current in induction motor will change under the condition of stator inter-turn short circuit.According to these characteristics,in this paper,a novel technique based on morphological maxlifting scheme is proposed for identification of induction motor stator inter-turn short circuit.A max-lifting scheme is applied to process stator winding currents to extract these characteristics.An indicator,r,is computed to identify the short circuit.The transient model of induction motor is employed to simulate oneturn to six-turn stator inter-turn short circuits in an induction motor.Extensive simulation work has been conducted under normal conditions,abnormal conditions(voltage imbalance and varying load),stator inter-turn short circuit conditions,and conditions of any combinations of the above.The results have shown that the scheme proposed in this paper has a high identification rate for induction motor stator inter-turn short circuit.展开更多
基金National Natural Science Foundation of China(52307048)the Postdoctoral General Foundation of Heilongjiang(LBH-Z23022).
文摘Permanent magnet synchronous motors(PMSMs)are widely used in high-power-density and flexible control methods.Generally,the inductance changes significantly in real-time machine operations because of magnetic saturation and coupling effects.Therefore,the identification of inductance is crucial for PMSM control.Existing inductance identification methods are primarily based on the voltage source inverter(VSI),making inverter nonlinearity one of the main error sources in inductance identification.To improve the accuracy of inductance identification,it is necessary to compensate for the inverter nonlinearity effect.In this study,an overview of the PMSM inductance identification and the related inverter nonlinearity self-learning methods are presented.
基金supported by the Science and Technology Projects of State Grid Corporation of China “Key Technologies and Demonstration Application of Distributed Power Clusters Regulation”(No. 52153220000U)。
文摘The grid-connected converter(GCC) is widely used as the interface between various distributed generations and the utility grid. To achieve precise power control for GCC, this paper presents a model predictive direct power control(MPDPC)with consideration of the unbalanced filter inductance and grid conditions. First, the characteristics of GCC with unbalanced filter inductance are analyzed and a modified voltage control function is derived. On this basis, to compensate for the power oscillation caused by unbalanced filter inductance, a novel power compensation method is proposed for MPDPC to eliminate the DC-side current ripple while maintaining sinusoidal grid current. Besides, to improve the control robustness against mismatched filter inductance, a filter inductance identification scheme is proposed. Through this scheme, the estimated value of filter inductance is updated in each control period and applied in the proposed MPDPC. Finally, simulation results in PSCAD/EMTDC confirm the validity of the proposed MPDPC and the filter inductance identification scheme.
基金This work was supported by the Fundamental Research Funds for the Central Universities(2015ZZ019)Guangdong Innovative Research Team Program(No.201001N0104744201).
文摘The harmonic components of stator winding current in induction motor will change under the condition of stator inter-turn short circuit.According to these characteristics,in this paper,a novel technique based on morphological maxlifting scheme is proposed for identification of induction motor stator inter-turn short circuit.A max-lifting scheme is applied to process stator winding currents to extract these characteristics.An indicator,r,is computed to identify the short circuit.The transient model of induction motor is employed to simulate oneturn to six-turn stator inter-turn short circuits in an induction motor.Extensive simulation work has been conducted under normal conditions,abnormal conditions(voltage imbalance and varying load),stator inter-turn short circuit conditions,and conditions of any combinations of the above.The results have shown that the scheme proposed in this paper has a high identification rate for induction motor stator inter-turn short circuit.
