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

  • a d q rotating frame Dc Bus Voltage controller for bi directional single phase ac Dc converters
    European Conference on Cognitive Ergonomics, 2015
    Co-Authors: Sajjad Makhdoomi Kaviri, Praveen Jain, Majid Pahlevani, Bahador Mohammadpour, Alireza Bakhshai
    Abstract:

    This paper presents a closed-loop control technique in D-Q rotating frame for bi-directional single-phase AC/Dc converters. The proposed control system allows the active and reactive power control in both directions from grid to vehicle and vehicle to grid, while controlling the Dc-Bus Voltage. Due to the lack of freedom degrees required for orthogonal systems, using the D-Q frame is a challenge in single-phase power conditioning systems. In this paper, an all-pass filter has been used to generate the orthogonal signals in the closed-loop control system. This method generates the orthogonal signals without degrading the dynamics of the closed-loop control system and with less noise in comparison to the other common methods such as differentiators. A Dc-Bus Voltage estimator based on adaptive filter has also been used in this paper to remove the double frequency ripple and in turn increase the reliability and speed of the proposed controller. The proposed control scheme is used to implement the smart charging and power management strategies of the residential loads using electric vehicles as a storage system. Simulation and experimental results demonstrate the transient and steady-state performance of the proposed controller in different modes of operation. Also the performance of the proposed Dc-Bus Voltage estimator in removing the double frequency ripple as well as the application of the proposed control scheme in implementation of power management strategies in a typical household, has been shown by using simulation results.

  • A Fast Dc-Bus Voltage Controller for Bidirectional Single-Phase AC/Dc Converters
    IEEE Transactions on Power Electronics, 2015
    Co-Authors: Majid Pahlevani, Praveen Jain
    Abstract:

    This paper presents a new Dc-Bus Voltage control technique for single-phase bidirectional ac/Dc converters. The proposed controller is able to significantly improve the transient response of the Dc-Bus Voltage control loop and provide a roBust and reliable closed-loop control system. In the proposed approach, the Dc value of the Dc-Bus Voltage is precisely estimated through a specific adaptive filter. The structure of the proposed filter provides a very fast and roBust estimation for the Dc value of the Dc-Bus Voltage. In particular, the proposed Dc-extraction technique is able to precisely estimate the Dc value in presence of double-frequency ripple mounted on top of the Dc-Bus Voltage in single-phase ac/Dc converters. Simulation and experimental results demonstrate the superior performance of the proposed closed-loop control system compared to the conventional ones.

  • An Adaptive Droop Dc-Bus Voltage Controller for a Grid-Connected Voltage Source Inverter With LCL Filter
    IEEE Transactions on Power Electronics, 2015
    Co-Authors: Suzan Eren, Alireza Bakhshai, Majid Pahlevani, Praveen Jain
    Abstract:

    This paper presents a very fast Dc-Bus Voltage controller for a single-phase grid-connected Voltage-source inverter (VSI) with an LCL output filter used in renewable energy applications. In single-phase grid-connected inverters, the design of the Dc-Bus Voltage control scheme is very challenging due to the presence of a second harmonic ripple across the Dc-Bus Voltage. The proposed Dc-Bus Voltage control scheme is able to address the difficulties introduced by the second-harmonic ripple. The Dc-Bus Voltage controller is based on an adaptive droop control technique, which is able to provide a very fast transient response for the closed-loop system and ensures the optimal operation of the VSI during steady-state conditions. Also, the simple structure of the controller makes it very practical for grid-connected VSIs used in renewable energy power conditioning systems. Theoretical analysis and experimental results demonstrate the superior performance of the proposed control approach compared to conventional Dc-Bus Voltage control schemes.

Milijana Odavic - One of the best experts on this subject based on the ideXlab platform.

  • theoretical harmonic spectra of pwm waveforms including Dc Bus Voltage ripple application to a low capacitance modular multilevel converter
    IEEE Transactions on Power Electronics, 2020
    Co-Authors: Sumeet Singh Thakur, Milijana Odavic, Ahmed Allu, Z Q Zhu, Kais Atallah
    Abstract:

    This article develops a new closed-form analytical solution to the harmonic spectrum of the pulsewidth modulated (PWM) output Voltage of the single-phase inverter connected to the Dc Bus with considerable Voltage ripple. The solution is based on a double Fourier series expansion in two variables. As the single-phase inverter forms the basic building block of most converters, the developed expressions can be applied to various topologies. This article first identifies the interactions of a single-frequency sinusoidal modulation signal and the carrier signal with the Dc Bus Voltage harmonics. The Dc Bus Voltage harmonics are constrained in this article to multiples of the inverter output Voltage fundamental frequency. The analysis is then extended to include a multifrequency modulation signal. Starting from the general solution, new expressions for the output Voltage harmonics of the modular multilevel converter (MMC) are developed. The low-capacitance MMC is chosen in this analysis due to inherent low-frequency Voltage oscillations in the converter internal capacitors. The MMC analytical harmonic spectrum can incorporate the effects of the circulating current control and third harmonic injection PWM, by including the second- and third-order harmonic components in the modulation signal, respectively. The MMC analytical harmonic spectrum is benchmarked against the experimental results.

  • Theoretical Harmonic Spectra of PWM Waveforms Including Dc Bus Voltage Ripple — Application to Low-Capacitance Modular Multilevel Converter
    IEEE Transactions on Power Electronics, 2020
    Co-Authors: Sumeet Thakur, Milijana Odavic, Ahmed Allu, Kais Atallah
    Abstract:

    This paper develops a new closed-form analytical solution to the harmonic spectrum of the Pulse Width Modulated (PWM) output Voltage of the single-phase inverter connected to the Dc-Bus with considerable Voltage ripple. The solution is based on a double Fourier series expansion in two variables. As the single phase inverter forms the basic building block of most converters, the developed expressions can be applied to various topologies. This study first identifies the interactions of a single-frequency sinusoidal modulation signal and the carrier signal with the Dc-Bus Voltage harmonics. The Dc-Bus Voltage harmonics are constrained in this work to multiples of the inverter output Voltage fundamental frequency. The analysis is then extended to include a multi-frequency modulation signal. Starting from the general solution, new expressions for the output Voltage harmonics of the Modular Multilevel Converter (MMC) are developed. The low-capacitance MMC is chosen in this analysis due to inherent low-frequency Voltage oscillations in the converter internal capacitors. The MMC analytical harmonic spectrum can incorporate the effects of the circulating current control and third harmonic injection PWM, by including the second and third order harmonic components in the modulation signal, respectively. The MMC analytical harmonic spectrum is benchmarked against the experimental results.

  • instantaneous power control for suppressing the second harmonic Dc Bus Voltage under generic unbalanced operating conditions
    IEEE Transactions on Power Electronics, 2017
    Co-Authors: Z Q Zhu, Milijana Odavic
    Abstract:

    This paper proposes a simplified instantaneous output power control to suppress the second harmonic Dc-Bus Voltage due to asymmetry in a three-phase pulsewidth-modulated (PWM) converter system without any sequential component decomposers. Normally, in the instantaneous output power control, the positive and negative sequence output Voltages and currents are required, and they are usually decomposed by notch filters or dual second-order generalized integrals that are difficult to tune and complicated. While in the proposed method, the positive-sequence and negative-sequence currents are regulated by PI plus resonant (PI-R) controllers in the dq frame. Therefore, the sequential current decomposers can be avoided. Meanwhile, the positive-sequence and negative-sequence output Voltages, which are essential for calculating the positive-sequence and negative-sequence current references, are simply obtained from the outputs of the proportional-integral (PI) and resonant controllers, respectively. The proposed method is roBust to any asymmetries and its effectiveness is verified on a prototype asymmetric three-phase permanent-magnet synchronous generator (PMSG) system with inherent and externally added asymmetries.

  • an improved method of Dc Bus Voltage pulsation suppression for asymmetric wind power pmsg systems with a compensation unit in parallel
    IEEE Transactions on Energy Conversion, 2017
    Co-Authors: Z Q Zhu, Milijana Odavic
    Abstract:

    This paper proposes an improved method of simultaneously suppressing the second harmonic (2h) Dc-Bus Voltage pulsation and torque ripple by a compensation unit in parallel with the Dc Bus in the wind power permanent magnet synchronous generator (PMSG) system with asymmetric impedance. Compared to the existing methods, the proposed method uses fewer power devices and requires a much lower compensation current. These results in a lower power rating, lower power switch and copper losses, and a smaller compensation inductor in the compensation unit. In addition, the corresponding compensation current control is much simpler to operate. Overall, it is an effective method of suppressing the 2h Dc Bus Voltage, although a Dc Voltage source is required in the compensation unit. The compensation effectiveness has been experimentally verified on a prototype asymmetric PMSG with inherent asymmetry and deliberately introduced asymmetries.

  • Dc Bus Voltage pulsation suppression of the permanent magnet synchronous generator with asymmetries accounting for torque ripple
    IEEE Transactions on Energy Conversion, 2016
    Co-Authors: Milijana Odavic, Z Q Zhu
    Abstract:

    This paper proposes an effective method for suppressing the second harmonic Dc Bus Voltage pulsation accounting for the second harmonic torque ripple in the permanent magnet synchronous generator (PMSG) system with asymmetric impedance. Neither the balanced current control nor the instantaneous power control can cope with the second harmonic Dc Bus Voltage pulsation and the second harmonic torque ripple simultaneously in an asymmetric PMSG system. In this paper, the average power control is employed and only the positive sequence currents appear in the system, thus the second harmonic torque ripple will be avoided with balanced back electromagnetic forces. The second harmonic power and Dc link Voltage pulsations are then reduced by a compensation unit in parallel with Dc Bus diverting the second harmonic power. The effectiveness of the proposed method is verified through a small-scale wind turbine PMSG prototype with inherent asymmetry and deliberately introduced asymmetries.

Li Xi-guo - One of the best experts on this subject based on the ideXlab platform.

  • RoBust and autonomous Dc Bus Voltage control and stability analysis for a Dc microgrid
    2016 IEEE 8th International Power Electronics and Motion Control Conference (IPEMC-ECCE Asia), 2016
    Co-Authors: Xialin Li, Li Xi-guo, Chengshan Wang, Shaohui Zhang, Yu Rong, Yibin Feng, Yun Wei Li
    Abstract:

    In this paper, a novel approach for roBust and autonomous Dc Bus Voltage control in a Dc microgrid has been proposed. A nonlinear disturbance observer (NDO) only with local information is designed firstly to track power disturbances caused by load changing or the volatility of the renewable sources in the Dc microgrid. With the observer, Voltage droop method has been adopted in achieving power sharing and autonomous operation of a Dc microgrid. Furthermore, an improved current feedforward is developed to suppress wide fluctuations of the Dc Bus Voltage during transients. In addition, a notch filter has been used to effectively eliminate the second harmonic ripple components in the inductor currents of the droop control units to improve the power quality. The effectiveness of the proposed control scheme is verified on a laboratory prototype including two bidirectional Dc-Dc converters supplied by two programmable Dc power supply systems, a Dc load with a resistor connected to the Dc Bus via a buck type Dc-Dc converter and a three-phase unbalanced ac load.

  • A nonlinear-disturbance-observer-based Dc-Bus Voltage control for a hybrid AC/Dc microgrid
    IEEE Transactions on Power Electronics, 2014
    Co-Authors: Chengshan Wang, Xialin Li, Li Xi-guo, Yun Wei Li
    Abstract:

    Dc-Bus Voltage control is an important task in the operation of a Dc or a hybrid ac/Dc microgrid system. To improve the Dc-Bus Voltage control dynamics, traditional approaches attempt to measure and feedforward the load or source power in the Dc-Bus control scheme. However, in a microgrid system with distributed Dc sources and loads, the traditional feedforward-based methods need remote measurement with communications. In this paper, a nonlinear disturbance observer (NDO) based Dc-Bus Voltage control is proposed, which does not need the remote measurement and enables the important �plug-and-play� feature. Based on this observer, a novel Dc-Bus Voltage control scheme is developed to suppress the transient fluctuations of Dc-Bus Voltage and improve the power quality in such a microgrid system. Details on the design of the observer, the Dc-Bus controller and the pulsewidth-modulation (PWM) dead-time compensation are provided in this paper. The effects of possible Dc-Bus capacitance variation are also considered. The performance of the proposed control strategy has been successfully verified in a 30 kVA hybrid microgrid including ac/Dc Buses, battery energy storage system, and photovoltaic (PV) power generation system.

  • A nonlinear disturbance observer based Dc Bus Voltage control for a hybrid AC/Dc microgrid
    2013 IEEE Energy Conversion Congress and Exposition, 2013
    Co-Authors: Chengshan Wang, Li Xi-guo
    Abstract:

    Dc Bus Voltage control is an important task in the control of a Dc microgrid or hybrid ac/Dc microgrid system. To improve the Dc Bus Voltage control dynamics, traditional approaches are mainly based on feeding forward the load or source power. However, in the microgrid system with distributed Dc sources and loads, the traditional feedforward based methods need remote measurement or communications. In this paper, a nonlinear disturbance observer (NDO) based Dc Bus Voltage control is proposed, which does not need the remote measurement or communication with a true “plug-and-play” feature. Based on this observer, a novel Dc Bus Voltage control scheme with pulse-width-modulation (PWM) dead-time compensation is developed. The proposed method can suppress the transient fluctuations of Dc Bus Voltage, and improve the power quality in such a hybrid microgrid system. The performance of the presented control strategy has been successfully verified in a 30 kVA Dc subgrid including battery energy storage system, photovoltaic power generation system and a Dc load.

Z Q Zhu - One of the best experts on this subject based on the ideXlab platform.

  • theoretical harmonic spectra of pwm waveforms including Dc Bus Voltage ripple application to a low capacitance modular multilevel converter
    IEEE Transactions on Power Electronics, 2020
    Co-Authors: Sumeet Singh Thakur, Milijana Odavic, Ahmed Allu, Z Q Zhu, Kais Atallah
    Abstract:

    This article develops a new closed-form analytical solution to the harmonic spectrum of the pulsewidth modulated (PWM) output Voltage of the single-phase inverter connected to the Dc Bus with considerable Voltage ripple. The solution is based on a double Fourier series expansion in two variables. As the single-phase inverter forms the basic building block of most converters, the developed expressions can be applied to various topologies. This article first identifies the interactions of a single-frequency sinusoidal modulation signal and the carrier signal with the Dc Bus Voltage harmonics. The Dc Bus Voltage harmonics are constrained in this article to multiples of the inverter output Voltage fundamental frequency. The analysis is then extended to include a multifrequency modulation signal. Starting from the general solution, new expressions for the output Voltage harmonics of the modular multilevel converter (MMC) are developed. The low-capacitance MMC is chosen in this analysis due to inherent low-frequency Voltage oscillations in the converter internal capacitors. The MMC analytical harmonic spectrum can incorporate the effects of the circulating current control and third harmonic injection PWM, by including the second- and third-order harmonic components in the modulation signal, respectively. The MMC analytical harmonic spectrum is benchmarked against the experimental results.

  • instantaneous power control for suppressing the second harmonic Dc Bus Voltage under generic unbalanced operating conditions
    IEEE Transactions on Power Electronics, 2017
    Co-Authors: Z Q Zhu, Milijana Odavic
    Abstract:

    This paper proposes a simplified instantaneous output power control to suppress the second harmonic Dc-Bus Voltage due to asymmetry in a three-phase pulsewidth-modulated (PWM) converter system without any sequential component decomposers. Normally, in the instantaneous output power control, the positive and negative sequence output Voltages and currents are required, and they are usually decomposed by notch filters or dual second-order generalized integrals that are difficult to tune and complicated. While in the proposed method, the positive-sequence and negative-sequence currents are regulated by PI plus resonant (PI-R) controllers in the dq frame. Therefore, the sequential current decomposers can be avoided. Meanwhile, the positive-sequence and negative-sequence output Voltages, which are essential for calculating the positive-sequence and negative-sequence current references, are simply obtained from the outputs of the proportional-integral (PI) and resonant controllers, respectively. The proposed method is roBust to any asymmetries and its effectiveness is verified on a prototype asymmetric three-phase permanent-magnet synchronous generator (PMSG) system with inherent and externally added asymmetries.

  • an improved method of Dc Bus Voltage pulsation suppression for asymmetric wind power pmsg systems with a compensation unit in parallel
    IEEE Transactions on Energy Conversion, 2017
    Co-Authors: Z Q Zhu, Milijana Odavic
    Abstract:

    This paper proposes an improved method of simultaneously suppressing the second harmonic (2h) Dc-Bus Voltage pulsation and torque ripple by a compensation unit in parallel with the Dc Bus in the wind power permanent magnet synchronous generator (PMSG) system with asymmetric impedance. Compared to the existing methods, the proposed method uses fewer power devices and requires a much lower compensation current. These results in a lower power rating, lower power switch and copper losses, and a smaller compensation inductor in the compensation unit. In addition, the corresponding compensation current control is much simpler to operate. Overall, it is an effective method of suppressing the 2h Dc Bus Voltage, although a Dc Voltage source is required in the compensation unit. The compensation effectiveness has been experimentally verified on a prototype asymmetric PMSG with inherent asymmetry and deliberately introduced asymmetries.

  • Dc Bus Voltage pulsation suppression of the permanent magnet synchronous generator with asymmetries accounting for torque ripple
    IEEE Transactions on Energy Conversion, 2016
    Co-Authors: Milijana Odavic, Z Q Zhu
    Abstract:

    This paper proposes an effective method for suppressing the second harmonic Dc Bus Voltage pulsation accounting for the second harmonic torque ripple in the permanent magnet synchronous generator (PMSG) system with asymmetric impedance. Neither the balanced current control nor the instantaneous power control can cope with the second harmonic Dc Bus Voltage pulsation and the second harmonic torque ripple simultaneously in an asymmetric PMSG system. In this paper, the average power control is employed and only the positive sequence currents appear in the system, thus the second harmonic torque ripple will be avoided with balanced back electromagnetic forces. The second harmonic power and Dc link Voltage pulsations are then reduced by a compensation unit in parallel with Dc Bus diverting the second harmonic power. The effectiveness of the proposed method is verified through a small-scale wind turbine PMSG prototype with inherent asymmetry and deliberately introduced asymmetries.

Chengshan Wang - One of the best experts on this subject based on the ideXlab platform.

  • RoBust and autonomous Dc Bus Voltage control and stability analysis for a Dc microgrid
    2016 IEEE 8th International Power Electronics and Motion Control Conference (IPEMC-ECCE Asia), 2016
    Co-Authors: Xialin Li, Li Xi-guo, Chengshan Wang, Shaohui Zhang, Yu Rong, Yibin Feng, Yun Wei Li
    Abstract:

    In this paper, a novel approach for roBust and autonomous Dc Bus Voltage control in a Dc microgrid has been proposed. A nonlinear disturbance observer (NDO) only with local information is designed firstly to track power disturbances caused by load changing or the volatility of the renewable sources in the Dc microgrid. With the observer, Voltage droop method has been adopted in achieving power sharing and autonomous operation of a Dc microgrid. Furthermore, an improved current feedforward is developed to suppress wide fluctuations of the Dc Bus Voltage during transients. In addition, a notch filter has been used to effectively eliminate the second harmonic ripple components in the inductor currents of the droop control units to improve the power quality. The effectiveness of the proposed control scheme is verified on a laboratory prototype including two bidirectional Dc-Dc converters supplied by two programmable Dc power supply systems, a Dc load with a resistor connected to the Dc Bus via a buck type Dc-Dc converter and a three-phase unbalanced ac load.

  • A nonlinear-disturbance-observer-based Dc-Bus Voltage control for a hybrid AC/Dc microgrid
    IEEE Transactions on Power Electronics, 2014
    Co-Authors: Chengshan Wang, Xialin Li, Li Xi-guo, Yun Wei Li
    Abstract:

    Dc-Bus Voltage control is an important task in the operation of a Dc or a hybrid ac/Dc microgrid system. To improve the Dc-Bus Voltage control dynamics, traditional approaches attempt to measure and feedforward the load or source power in the Dc-Bus control scheme. However, in a microgrid system with distributed Dc sources and loads, the traditional feedforward-based methods need remote measurement with communications. In this paper, a nonlinear disturbance observer (NDO) based Dc-Bus Voltage control is proposed, which does not need the remote measurement and enables the important �plug-and-play� feature. Based on this observer, a novel Dc-Bus Voltage control scheme is developed to suppress the transient fluctuations of Dc-Bus Voltage and improve the power quality in such a microgrid system. Details on the design of the observer, the Dc-Bus controller and the pulsewidth-modulation (PWM) dead-time compensation are provided in this paper. The effects of possible Dc-Bus capacitance variation are also considered. The performance of the proposed control strategy has been successfully verified in a 30 kVA hybrid microgrid including ac/Dc Buses, battery energy storage system, and photovoltaic (PV) power generation system.

  • A nonlinear disturbance observer based Dc Bus Voltage control for a hybrid AC/Dc microgrid
    2013 IEEE Energy Conversion Congress and Exposition, 2013
    Co-Authors: Chengshan Wang, Li Xi-guo
    Abstract:

    Dc Bus Voltage control is an important task in the control of a Dc microgrid or hybrid ac/Dc microgrid system. To improve the Dc Bus Voltage control dynamics, traditional approaches are mainly based on feeding forward the load or source power. However, in the microgrid system with distributed Dc sources and loads, the traditional feedforward based methods need remote measurement or communications. In this paper, a nonlinear disturbance observer (NDO) based Dc Bus Voltage control is proposed, which does not need the remote measurement or communication with a true “plug-and-play” feature. Based on this observer, a novel Dc Bus Voltage control scheme with pulse-width-modulation (PWM) dead-time compensation is developed. The proposed method can suppress the transient fluctuations of Dc Bus Voltage, and improve the power quality in such a hybrid microgrid system. The performance of the presented control strategy has been successfully verified in a 30 kVA Dc subgrid including battery energy storage system, photovoltaic power generation system and a Dc load.