The Experts below are selected from a list of 10602 Experts worldwide ranked by ideXlab platform

Amit Kumar Jain - One of the best experts on this subject based on the ideXlab platform.

  • Harmonics reduction in standalone DFIG-Dc System by shunt active filter controlled in stator flux reference frame
    Sādhanā, 2018
    Co-Authors: Himanshu Misra, Amit Kumar Jain
    Abstract:

    The presence of diode rectifier in standalone Doubly Fed Induction Generator-Direct Current (DFIG-Dc) System leads to considerable current, voltage and torque harmonics and requires reactive power from the machine. A unique shunt active filter arrangement is proposed for addressing these requirements. The Dc Link of DFIG-Dc itself acts as input to shunt active filter and there is no requirement of creating and regulating a separate one. Since the stator flux reference frame is known in FOC of DFIG-Dc System; the same can be used as PLL for the generation of current references for harmonics and reactive compensation in active filter control scheme. Hence, the AC voltage sensing is not needed in the proposed active filter control. In this paper, it is shown that current, voltage and torque harmonics are reduced with the help of shunt active filter, which have lower rating compared to the rotor side converter. The proposed scheme is verified by detailed experiments on a 5.5 kW slip-ring induction machine.

  • Mathematical Modeling and Control of Standalone DFIG-Dc System in Rotor Flux Reference Frame
    IEEE Transactions on Industrial Electronics, 2018
    Co-Authors: Himanshu Misra, Amit Kumar Jain
    Abstract:

    The mathematical modeling of doubly fed induction machine (DFIG)-Dc System, including dominant harmonic (fifth and seventh), along with its control in rotor flux reference frame is presented in this paper. Modeling of the System provides the feedforward terms that consist of the fundamental and oscillatory components of the current. The use of nonderivative feedforward terms with proportional integral can reduce the steady-state current ripple, but for controlling the transient current ripple use of resonant controller is suggested such that the use of derivative feedforward terms can be avoided. The resonant controller is capable of controlling the current ripple by itself, but its use with suitable feedforward terms can enhance the performance of the System. Dc voltage regulation of standalone DFIG-Dc System is obtained by four combinations of above mentioned controllers and feedforward terms. A comparison is made on performance of these control structures. Feedforward terms used in the control structure require decoupled currents. Therefore, decoupling of various currents in different d-q axes are obtained with mathematical understanding. The proposed control schemes are verified on 5.5-KW slip ring induction machine for standalone application.

  • Dc voltage regulation with field oriented control of WRIG-Dc System feeding an isolated Dc load
    2016 IEEE 6th International Conference on Power Systems (ICPS), 2016
    Co-Authors: Akhila Gundavarapu, Himanshu Misra, Amit Kumar Jain
    Abstract:

    This paper presents a standalone configuration of WRIM-Dc System and proposes a control scheme for regulation of Dc voltage and supplying an isolated Dc load. WRIG-Dc System refers to a System where the stator and rotor are connected to a Dc load by an uncontrolled diode bridge rectifier and a VSI respectively. The stator frequency and Dc voltage regulation are achieved by field oriented control, where the d-axis and q-axis current control are used for regulating voltage against load changes and supply the load respectively. Stator frequency is regulated by controlling the position of the stator flux vector. The control scheme is presented and design criteria for the voltage controller are reported. The performance of the proposed control scheme is verified by detailed simulations and reported.

Heng Nian - One of the best experts on this subject based on the ideXlab platform.

  • Sinusoidal Current Operation of a DFIG-Dc System Without Stator Voltage Sensors
    IEEE Transactions on Industrial Electronics, 2018
    Co-Authors: Chao Wu, Heng Nian
    Abstract:

    This paper presents a sinusoidal current control scheme for the doubly fed induction generator (DFIG)-Dc System to reduce the harmonic current losses of the stator and rotor windings. The DFIG-Dc System can be controlled as an open-winding System if the DFIG is equivalent in the Γ circuit. The stator is connected to the Dc link through the diode bridge and the rotor is connected to the same Dc link through the rotor-side converter. A phase-locked loop based on stator flux is applied for estimating not only the stator frequency but also the angle of stator flux linkage. The sinusoidal stator current can be achieved by injecting appropriate harmonic voltages to the rotor side. The rotor harmonic voltages are produced by applying the stator voltage directly without employing a series of resonant controllers. Since the voltage of the diode bridge depends on the direction of the flowing current, the stator voltage of DFIG can be expressed by the stator current avoiding the stator voltage sensors. In this way, the harmonic current losses of the stator and rotor windings can be greatly reduced, which is beneficial for System efficiency. Furthermore, the torque ripple and power ripple can also be reduced, which is a good operation condition of the DFIG-Dc System. The proposed control method is validated through experiments.

Himanshu Misra - One of the best experts on this subject based on the ideXlab platform.

  • Harmonics reduction in standalone DFIG-Dc System by shunt active filter controlled in stator flux reference frame
    Sādhanā, 2018
    Co-Authors: Himanshu Misra, Amit Kumar Jain
    Abstract:

    The presence of diode rectifier in standalone Doubly Fed Induction Generator-Direct Current (DFIG-Dc) System leads to considerable current, voltage and torque harmonics and requires reactive power from the machine. A unique shunt active filter arrangement is proposed for addressing these requirements. The Dc Link of DFIG-Dc itself acts as input to shunt active filter and there is no requirement of creating and regulating a separate one. Since the stator flux reference frame is known in FOC of DFIG-Dc System; the same can be used as PLL for the generation of current references for harmonics and reactive compensation in active filter control scheme. Hence, the AC voltage sensing is not needed in the proposed active filter control. In this paper, it is shown that current, voltage and torque harmonics are reduced with the help of shunt active filter, which have lower rating compared to the rotor side converter. The proposed scheme is verified by detailed experiments on a 5.5 kW slip-ring induction machine.

  • Mathematical Modeling and Control of Standalone DFIG-Dc System in Rotor Flux Reference Frame
    IEEE Transactions on Industrial Electronics, 2018
    Co-Authors: Himanshu Misra, Amit Kumar Jain
    Abstract:

    The mathematical modeling of doubly fed induction machine (DFIG)-Dc System, including dominant harmonic (fifth and seventh), along with its control in rotor flux reference frame is presented in this paper. Modeling of the System provides the feedforward terms that consist of the fundamental and oscillatory components of the current. The use of nonderivative feedforward terms with proportional integral can reduce the steady-state current ripple, but for controlling the transient current ripple use of resonant controller is suggested such that the use of derivative feedforward terms can be avoided. The resonant controller is capable of controlling the current ripple by itself, but its use with suitable feedforward terms can enhance the performance of the System. Dc voltage regulation of standalone DFIG-Dc System is obtained by four combinations of above mentioned controllers and feedforward terms. A comparison is made on performance of these control structures. Feedforward terms used in the control structure require decoupled currents. Therefore, decoupling of various currents in different d-q axes are obtained with mathematical understanding. The proposed control schemes are verified on 5.5-KW slip ring induction machine for standalone application.

  • Dc voltage regulation with field oriented control of WRIG-Dc System feeding an isolated Dc load
    2016 IEEE 6th International Conference on Power Systems (ICPS), 2016
    Co-Authors: Akhila Gundavarapu, Himanshu Misra, Amit Kumar Jain
    Abstract:

    This paper presents a standalone configuration of WRIM-Dc System and proposes a control scheme for regulation of Dc voltage and supplying an isolated Dc load. WRIG-Dc System refers to a System where the stator and rotor are connected to a Dc load by an uncontrolled diode bridge rectifier and a VSI respectively. The stator frequency and Dc voltage regulation are achieved by field oriented control, where the d-axis and q-axis current control are used for regulating voltage against load changes and supply the load respectively. Stator frequency is regulated by controlling the position of the stator flux vector. The control scheme is presented and design criteria for the voltage controller are reported. The performance of the proposed control scheme is verified by detailed simulations and reported.

Chao Wu - One of the best experts on this subject based on the ideXlab platform.

  • Sinusoidal Current Operation of a DFIG-Dc System Without Stator Voltage Sensors
    IEEE Transactions on Industrial Electronics, 2018
    Co-Authors: Chao Wu, Heng Nian
    Abstract:

    This paper presents a sinusoidal current control scheme for the doubly fed induction generator (DFIG)-Dc System to reduce the harmonic current losses of the stator and rotor windings. The DFIG-Dc System can be controlled as an open-winding System if the DFIG is equivalent in the Γ circuit. The stator is connected to the Dc link through the diode bridge and the rotor is connected to the same Dc link through the rotor-side converter. A phase-locked loop based on stator flux is applied for estimating not only the stator frequency but also the angle of stator flux linkage. The sinusoidal stator current can be achieved by injecting appropriate harmonic voltages to the rotor side. The rotor harmonic voltages are produced by applying the stator voltage directly without employing a series of resonant controllers. Since the voltage of the diode bridge depends on the direction of the flowing current, the stator voltage of DFIG can be expressed by the stator current avoiding the stator voltage sensors. In this way, the harmonic current losses of the stator and rotor windings can be greatly reduced, which is beneficial for System efficiency. Furthermore, the torque ripple and power ripple can also be reduced, which is a good operation condition of the DFIG-Dc System. The proposed control method is validated through experiments.

Yinfeng Zhang - One of the best experts on this subject based on the ideXlab platform.

  • A novel solid-state protection scheme for Dc System
    2016 IEEE 8th International Power Electronics and Motion Control Conference (IPEMC-ECCE Asia), 2016
    Co-Authors: Changle Li, Huayu Li, Yinfeng Zhang
    Abstract:

    The short-circuit fault will affect the continuity and reliability of the Dc System seriously, so it must be detected and isolated quickly. Dc circuit breaker can be used to break the System fault circuit more effectively. However, different from the AC System, the Dc current has no natural zero crossing. If the mechanical circuit breaker is used for short circuit fault protection, it will bring an arc, which will require total time few milliseconds or even larger for complete interruption. As a result, the Dc System voltage will drop during this period. In this paper, a new scheme will make use of impendence source to design a new type of Dc circuit breaker: T-source Dc solid-state breaker, which can break the short circuit fault more quickly so as to improve the continuity and power quality of the System. The main topological structure is presented and mathematical model is derived through comprehensive analysis. The simulation and laboratory results are shown to verify the theoretical analysis.

  • A novel solid-state protection scheme for Dc System
    2016 IEEE 8th International Power Electronics and Motion Control Conference IPEMC-ECCE Asia 2016, 2016
    Co-Authors: Changle Li, Ziling Nie, Huayu Li, Yinfeng Zhang
    Abstract:

    —The short-circuit fault will affect the continuity and reliability of the Dc System seriously, so it must be detected and isolated quickly. Dc circuit breaker can be used to break the System fault circuit more effectively. However, different from the AC System, the Dc current has no natural zero crossing. If the mechanical circuit breaker is used for short circuit fault protection, it will bring an arc, which will require total time few milliseconds or even larger for complete interruption. As a result, the Dc System voltage will drop during this period. In this paper, a new scheme will make use of impendence source to design a new type of Dc circuit breaker: T-source Dc solid-state breaker, which can break the short circuit fault more quickly so as to improve the continuity and power quality of the System. The main topological structure is presented and mathematical model is derived through comprehensive analysis. The simulation and laboratory results are shown to verify the theoretical analysis. Keywords—Dc