@article{cisneros_gao_ortega_husain_2021, title={A PI plus passivity-based control of a wind energy conversion system enabled with a solid-state transformer}, volume={94}, ISSN={["1366-5820"]}, DOI={10.1080/00207179.2019.1710768}, abstractNote={In this paper, we propose a new control scheme for a wind energy conversion system connected to a solid-state transformer-enabled distribution microgrid. The system consists of a wind turbine, a permanent magnet synchronous generator, a rectifier and a load which is connected to the distribution grid dc bus. The scheme combines a classical PI placed, in a nested-loop configuration, with a passivity-based controller. Guaranteeing stability and endowed with disturbance rejection properties, the controller regulates the wind turbine angular velocity to a desired value – in particular, the set-point is selected such that the maximum power from the wind is extracted – maximising the generator efficiency. The fast response of the closed-loop system makes possible to operate under fast-changing wind speed conditions. To assess and validate the controller performance and robustness under parameter variations, realistic simulations comparing our proposal with a classical PI scheme are included.}, number={9}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Cisneros, Rafael and Gao, Rui and Ortega, Romeo and Husain, Iqbal}, year={2021}, month={Sep}, pages={2453–2463} }
 @article{gao_she_husain_huang_2017, title={Solid-State-Transformer-Interfaced Permanent Magnet Wind Turbine Distributed Generation System With Power Management Functions}, volume={53}, ISSN={["1939-9367"]}, DOI={10.1109/tia.2017.2679679}, abstractNote={The higher penetration of wind energy poses increasing demand for grid support and power management functions of a wind energy conversion system (WECS). This paper investigates a medium-voltage solid-state transformer (SST)-interfaced permanent magnet synchronous generator system with integrated active power management and reactive power compensation functions. Specifically, a WECS consisting of wind turbines, SSTs, and dc loads is presented. In addition, a distributed power management algorithm is proposed for a dc network with local wind turbine controls incorporated to achieve a self-contained power-balanced condition without the need for energy storage or communication devices. Scenarios considered include the grid-connected mode, the islanding mode, and the mode transitions. Simulation results are provided to verify the effectiveness of the proposed strategy. Additionally, the concept is experimentally verified using a scaled-down laboratory prototype.}, number={4}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Gao, Rui and She, Xu and Husain, Iqbal and Huang, Alex Q.}, year={2017}, pages={3849–3861} }
 @inproceedings{gao_husain_huang_2016, title={An autonomous power management strategy based on DC bus signaling for solid-state transformer interfaced PMSG wind energy conversion system}, DOI={10.1109/apec.2016.7468353}, abstractNote={The solid-state transformer (SST) enabled DC/AC Microgrid provides an effective solution for distributed renewable energy resources (DRER) integration with conventional utility grid. This paper investigates a DC network system consisting of wind turbines, SST, and DC loads. Without any energy storage devices, an autonomous power management strategy based on improved DC bus signaling (DBS) is proposed to achieve system stable operation and power balance under various scenarios, specifically system grid-connected mode, islanding mode, and the mode transition. The extreme conditions were emphasized and analyzed as a testament to verify the feasibility of proposed control. DC bus voltage level and its gradient information have been employed as the only indication for distinguishing different modes and control implementation. System power management competence has been simulated and verified with MATLAB/Simulink.}, booktitle={Apec 2016 31st annual ieee applied power electronics conference and exposition}, author={Gao, R. and Husain, I. and Huang, A. Q.}, year={2016}, pages={3383–3388} }
 @inproceedings{rahman_morgans_xu_gao_yu_hopkins_husain_2016, title={Design methodology for a planarized high power density EV/HEV traction drive using SiC power modules}, url={https://www.lens.org/036-754-675-774-950}, DOI={10.1109/ecce.2016.7855018}, abstractNote={This paper provides a methodology for overall system level design of a high-power density inverter to be used for EV/HEV traction drive applications. The system design is guided to accommodate off-the-shelf SiC power modules in a planar architecture that ensures proper electrical, thermal, and mechanical performances. Bi-directional interleaved DC-DC boost structure and a three-phase voltage source inverter (VSI) have been utilized with the primary focus on the size, weight and loss reduction of passive components. A stacked layer approach has been used for a unique PCB-based busbar, ultra-low profile gate driver, and controller board. This holistic design approach results in a highly compact traction drive inverter with power density of 12.1 kW/L that has lower volume and weight compared to the commercially available state-of-the-art power converter systems.}, note={\urlhttps://ieeexplore.ieee.org/document/7855018/}, booktitle={2016 ieee energy conversion congress and exposition (ecce)}, author={Rahman, D. and Morgans, A. J. and Xu, Y. and Gao, R. and Yu, W. S. and Hopkins, Douglas C and Husain, I.}, year={2016} }
 @inproceedings{su_gao_husain_2016, title={Model predictive control based field-weakening strategy for traction EV used induction motor}, DOI={10.1109/ecce.2016.7855249}, abstractNote={In typical traction Electric Vehicle applications, the DC-link voltage varies during transient accelerating and decelerating process in field-weakening region. The calculated reference voltages of current PI regulators tend to be larger than the one in steady state, which will result in the undesired flux-producing current oscillations. This further deteriorates the electromagnetic torque performance. To solve this issue, a model predictive control (MPC) based field-weakening algorithm is proposed for traction EV used low-voltage induction motor (IM). n this paper, the DC-link voltage utilization, which is usually set as high as possible to output maximum torque, is decreased temporarily to keep the flux-producing current unchanged during the braking process. The model predictive control is adopted for the voltage loop, in which the steady voltage is calculated with steady flux equation. The influence of overlarge voltage calculated from PI regulator is decreased. The simulation and experimental results provide the evidence of improvements of the proposed field-weakening algorithm.}, booktitle={2016 ieee energy conversion congress and exposition (ecce)}, author={Su, J. Y. and Gao, R. and Husain, I.}, year={2016} }
 @article{cisneros_gao_ortega_husain_2016, title={PI Passivity-Based Control for Maximum Power Extraction of a Wind Energy System with Guaranteed Stability Properties}, volume={17}, ISSN={["1553-779X"]}, DOI={10.1515/ijeeps-2016-0072}, abstractNote={Abstract}, number={5}, journal={INTERNATIONAL JOURNAL OF EMERGING ELECTRIC POWER SYSTEMS}, author={Cisneros, Rafael and Gao, Rui and Ortega, Romeo and Husain, Iqbal}, year={2016}, month={Oct}, pages={567–573} }
 @inproceedings{gao_husain_cisneros_ortega_2016, title={Passivity-based and standard PI controls application to wind energy conversion system}, DOI={10.1109/ecce.2016.7855335}, abstractNote={The controller design for wind energy conversion systems (WECS) is complicated considering the highly nonlinear properties of electric machines and power converters. Targeting at a controller for WECS, this article adopts a passivity-based PI control (PI-PBC) method, to which the stability can be analytically guaranteed. Then, a comparative study between the proposed method and a standard PI is provided. The wind energy system consists of a wind turbine, a Permanent Magnet Synchronous Generator (PMSG), a pulse width modulation (PWM) rectifier, a dc load and an equivalent distributed energy storage device, which is formed with a dc source with internal resistor. The generator rotational velocity is regulated at maximum power point (MPPT) for the investigated wind turbine.}, booktitle={2016 ieee energy conversion congress and exposition (ecce)}, author={Gao, R. and Husain, I. and Cisneros, R. and Ortega, R.}, year={2016} }
 @inproceedings{gao_yang_yu_husain_2016, title={Single chip enabled high frequency link based isolated bias supply for silicon carbide MOSFET six-pack power module gate drives}, DOI={10.1109/ecce.2016.7855435}, abstractNote={Regarded as one of the most successful wide bandgap (WBG) devices, Silicon Carbide (SiC) metal-oxide-semiconductor field-transistors (MOSFETs) are being considered in an increasing number of power electronics applications. One of those applications is the hybrid and electric vehicle (HEV/EV) traction inverters where high-efficiency and high-power density is essential. From the system-level perspective, the gate driver circuit design for such device is challenging considering the device's fast switching speed and compact system structure. This paper presents a low profile (6 mm) isolated bias supply design using commercially available components for the SiC MOSFET modules targeting an HEV/EV traction inverter application. A single chip MAX 13256 (3 mm∗3 mm) is adopted to form the high-frequency link for entire power module gate drive supply. Distributed transformer strategy is highlighted to provide multiple isolated output and compact structure with minimized parasitic capacitance between all the isolation barriers. The featured low profile optimization reduces the parasitic parameters that might deteriorate the system performance for the fast switching WBG devices. Moreover, the open-loop high-frequency link architecture allows easy configuration for customized output voltage level, polarity and higher reliability. A prototype gate driver has been built for 1.2 kV, 50 A SiC six-pack MOSFET power module, and experimental results are presented.}, booktitle={2016 ieee energy conversion congress and exposition (ecce)}, author={Gao, R. and Yang, L. and Yu, Wensong and Husain, I.}, year={2016} }
 @inproceedings{ni_gao_song_huang_yu_2015, title={Development of 6kV SiC hybrid power switch based on 1200V SiC JFET and MOSFET}, DOI={10.1109/ecce.2015.7310240}, abstractNote={Series-connected power switch provides a viable solution to implement high voltage and high frequency converters. By using the commercially available 1200V Silicon Carbide (SiC) Junction Field Effect Transistor (JFET) and Metal Oxide semiconductor Filed-effect Transistor (MOSFET), a 6 kV SiC hybrid power switch concept and its application are demonstrated. To solve the parameter deviation issue in the series device structure, an optimized voltage control method is introduced, which can guarantee the equal voltage sharing under both static and dynamic state. Without Zener diode arrays, this strategy can significantly reduce the turn-off switching loss. Moreover, this hybrid MOSFET-JFETs concept is also presented to suppress the silicon MOSFET parasitic capacitance effect. In addition, the positive gate drive voltage greatly accelerates turn-on speed and decreases the switching loss. Compared with the conventional super-JFETs, the proposed scheme is suitable for series-connected device, and can achieve better performance. The effectiveness of this method is validated by simulations and experiments, and promising results are obtained.}, booktitle={2015 ieee energy conversion congress and exposition (ecce)}, author={Ni, X. J. and Gao, R. and Song, X. Q. and Huang, A. Q. and Yu, Wensong}, year={2015}, pages={4113–4118} }
 @inproceedings{gao_husain_wang_huang_2015, title={Solid-state transformer interfaced PMSG wind energy conversion system}, DOI={10.1109/apec.2015.7104517}, abstractNote={The solid-state transformer (SST) has been regarded as an emerging technology where emphasis is mainly on the design of the device. To explore its system integration opportunities, this paper proposes and demonstrates a SST interfaced permanent magnet synchronous generator (PMSG) wind energy conversion system. The system integration issues along with wind turbine level control methods have been presented and simulated for power management. Moreover, the lab hardware prototype has been set up, which consists of an induction motor based wind turbine emulator (WTE), PMSG, pulse-width modulation (PWM) rectifier, SST, and resistive load bank. Experiments have been carried out to validate the proposed system and control strategy.}, booktitle={2015 thirtieth annual ieee applied power electronics conference and exposition (apec 2015)}, author={Gao, R. and Husain, I. and Wang, F. and Huang, A. Q.}, year={2015}, pages={1310–1317} }