The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform
Yushi Miura - One of the best experts on this subject based on the ideXlab platform.
-
Fixed-Parameter Damping Methods of Virtual Synchronous Generator Control Using State Feedback
IEEE Access, 2019Co-Authors: Yushi MiuraAbstract:Virtual synchronous generator (VSG) control is a promising control method for grid-tied inverters, as it can provide inertia support for the grid. However, VSG-controlled grid-tied inverters are subjected to intrinsic low-frequency oscillation, because the emulation of swing equation of a conventional synchronous generator (SG) also introduces an oscillatory mode. In this paper, a damping term produced from state feedback control is added to VSG control to solve this issue. This method is then further developed by applying a low pass filter to the measured active power, to improve its Ripple Attenuation ability, at the cost of increased design complexity. Both the proposed state feedback damping method without and with low pass filter have one more design degree of freedom than previous methods, which is used to improve dynamic response to active power reference change. The small-signal analyses and experimental results show that both methods can well damp the intrinsic low-frequency oscillation with better dynamic responses than previous fixed-parameter damping methods, whereas the method with a low pass filter has the best overall performance thanks to its improved Ripple Attenuation ability.
-
A Comparative Study on Damping Methods of Virtual Synchronous Generator Control
2019 21st European Conference on Power Electronics and Applications (EPE '19 ECCE Europe), 2019Co-Authors: Yushi MiuraAbstract:Grid-tied inverters adopting virtual synchronous generator (VSG) control can provide frequency support for the power grid in a similar way to conventional synchronous generators. However, virtual inertia emulation also introduces an oscillatory mode. Various damping methods capable to assign closed-loop poles are proposed in the literature. In this paper, theoretical analyses and experimental results are presented to compare these methods, in respect of dynamic response and Ripple Attenuation ability.
Iqbal Husain - One of the best experts on this subject based on the ideXlab platform.
-
SiC Based Interleaved Voltage Source Converter for Active Power Filter Applications
2020 IEEE Applied Power Electronics Conference and Exposition (APEC), 2020Co-Authors: M A Awal, Dhrubo Rahman, Li Yang, Wensong Yu, Iqbal HusainAbstract:An interleaved voltage source converter (VSC) based on commercially available SiC power devices is proposed and implemented for active power filter (APF) application to reach an effective switching frequency of 300 kHz. We developed a hybrid current controller combining multiple resonant (MR) and plug-in-repetitive (PIRC) compensators that enable enhanced transient and steady-state performance with a low computational burden. Leveraging a high performance FPGA based digital controller, a control update rate of 100 kHz is achieved. We analytically show that the high control update rate combined with enhanced Ripple Attenuation capability of the SiC-based interleaved topology facilitates natural damping of harmonic resonances: no passive or active damping measures are necessary to retain stable operation irrespective of variation in grid impedance over a very wide range. The need for load harmonics detection is eliminated by indirect harmonic compensation using only the grid current measurement. Active current balancing among the interleaved sub-phases is achieved by low-cost and low-bandwidth current sensors. Experimental results are presented to validate the performance of the proposed APF.
Darwin G. Caldwell - One of the best experts on this subject based on the ideXlab platform.
-
ROBIO - Impedance control with inner PI torque loop: Disturbance Attenuation and impedance emulation
2013 IEEE International Conference on Robotics and Biomimetics (ROBIO), 2013Co-Authors: Mohamad Mosadeghzad, Gustavo A. Medrano-cerda, Nikos Tsagarakis, Darwin G. CaldwellAbstract:This paper investigates the performance of impedance control utilizing an inner loop PI torque controller. Stiffness and damping shaping vary within a specified range of values. The impedance control problem is formulated taking into account a specified range of stiffness and damping parameters. The analysis and design is carried out in discrete time. Stability, passivity, impedance emulation as well as disturbance (friction/torque Ripple) Attenuation properties are discussed. The controller is evaluated on a series elastic actuator and some experimental results are presented.
-
Impedance control with inner PI torque loop: Disturbance Attenuation and impedance emulation
2013 IEEE International Conference on Robotics and Biomimetics (ROBIO), 2013Co-Authors: Mohamad Mosadeghzad, Gustavo A. Medrano-cerda, Nikos Tsagarakis, Darwin G. CaldwellAbstract:This paper investigates the performance of impedance control utilizing an inner loop PI torque controller. Stiffness and damping shaping vary within a specified range of values. The impedance control problem is formulated taking into account a specified range of stiffness and damping parameters. The analysis and design is carried out in discrete time. Stability, passivity, impedance emulation as well as disturbance (friction/torque Ripple) Attenuation properties are discussed. The controller is evaluated on a series elastic actuator and some experimental results are presented.
Hak-kyung Sung - One of the best experts on this subject based on the ideXlab platform.
-
High-Precision Tracking by Digital Repetitive Control Scheme with Periodic-Type Hold Function
1992 American Control Conference, 1992Co-Authors: Shinji Hara, Hiroyuki Kawamura, Hak-kyung SungAbstract:The Ripple Attenuation problem is investigated by an appropriate selection of the periodic-type hold in the digital repetitive control system. To attenuate the Ripple, we propose a design method of the periodic-type hold, where each sampling period in a reference signal period has a different type of the hold. Furthermore, we shaw that the level of the Ripple can be reduced by the hold designed by assigning the values of output and/or its velocities at several instants in the steady-state.
Sakda Somkun - One of the best experts on this subject based on the ideXlab platform.
-
A Galvanic-Isolated Grid-Connected fuel cell single phase AC power generation system with LCL filter
International Journal of Renewable Energy Research, 2018Co-Authors: Prabhuraj Shanmugham, Sakda SomkunAbstract:Fuel cell system is a promising alternate way of power generation from clean, green fuel such as Hydrogen with almost zero emissions. It can be a primary power or an aiding power to the grid during instability. Grid connected fuel cell systems experience double line frequency Ripples from the inverters which affect the life of fuel cells. The current Ripples are to be limited within 15% for safe operation of the fuel cells. This paper presents design of a dual active bridge DC-DC converter to step up the low voltage DC output from fuel cell to a high voltage DC with galvanic isolation and a PLL based grid synchronized single phase PWM inverter with dq reference frame grid current control suitable for fuel cell systems. Extended Symmetrical Optimum method is used for optimal tuning of the PI controllers. An LCL filter is designed for effective Ripple Attenuation in the grid current with active damping of the resonance in the region of stability. MATLAB/Simulink ® is used for the design and is verified with a 1kW Horizon PEM fuel cell system. The power is exported to the grid with measured THD i of 1.7% in the grid current with reactive power injection by simple phase shift modulation control. The maximum overall system efficiency is measured to be 85%.
-
Single-phase grid-connected voltage source converter for LCL filter with grid-current feedback
2017 International Electrical Engineering Congress (iEECON), 2017Co-Authors: Prabhuraj Shanmugham, Sakda SomkunAbstract:LCL filters are extensively integrated with single-phase grid-tied voltage source converters due to their higher Ripple Attenuation capability. LCL filters lead to system instability due to the resonance of the filter. Limited range of resonance frequency and bandwidth ensures the stability of the system by proper design of the current controller and filter. This paper presents the modeling, design and control of a single-phase grid-connected VSC, including an LCL filter, with reactive power injecting capability. A simple PI controller in the unbalanced synchronous reference frame is designed with the Extended Symmetrical Optimum method for the grid current feedback control loop. The q-axis current control is used to inject the reactive power. The system is modeled and simulated in MATLAB/Simulink® and results are verified with an experimental setup of 1.5 kVA VSC.
