@article{bipu_cen_husain_2022, title={Estimated Load Current Feedforward Method for DC-DC Converter to Improve DC Bus Voltage Regulation in a Multi-Port Converter Based System}, ISSN={["2329-3721"]}, DOI={10.1109/ECCE50734.2022.9948086}, abstractNote={A multi-port converter (MPC) used in a hybrid AC/DC renewable energy resource based microgrid system typically has a DC/DC converter which is used to regulate the internal DC bus voltage from a battery energy storage system (BESS). Maintaining a steady internal DC bus voltage is essential for reliable operation of the MPC unit, for maintaining desired AC voltage quality, and for avoiding excessive voltage stress on the DC-link bus capacitors. However, because of the DC/AC converter's instantaneous sinusoidal output power, an AC ripple component oscillating at twice the line frequency is always present in the DC bus voltage. A high bandwidth controller for the DC/DC converter is needed for eliminating the AC ripple in the bus voltage which is often difficult to design while maintaining adequate time-scale separation from the other control elements. In this work, an estimated load current feedforward method is used for designing the controller which alleviates the presence of double line frequency AC ripple at the DC bus without the requirement of an extra current sensor. The presented controller is simulated in PLECS and implemented on a laboratory experimental setup for hardware verification showing 22.5% reduction in the peak to peak ripple.}, journal={2022 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)}, author={Bipu, Md Rashed Hassan and Cen, Siye and Husain, Iqbal}, year={2022} }
 @article{rachi_cen_bipu_khan_husain_2021, title={Design and Development of a Multi-Port Converter for Marine Microgrid Applications}, ISSN={["2329-3721"]}, DOI={10.1109/ECCE47101.2021.9595808}, abstractNote={In this work, a multi-port converter (MPC) design is presented that works as the key building block of a marine microgrid. An emulated wave energy converter (WEC) serves as the renewable energy resource of this microgrid system. The proposed MPC is comprised of a WEC interfacing port, energy storage port, and a split-phase AC load/grid port. Stable power exchange among these dissimilar energy resources are facilitated through a 400V internal DC bus. The full MPC design along with its control and thermal model is developed and implemented in PLECS. Commercially available SiC power modules have been used to leverage its high switching frequency capability that to achieve compact system design with reduced passive component sizes. Individual controller for each energy resource interfacing converter is analyzed, developed and implemented initially. A state-machine is developed utilizing these discrete controllers for MPC operation where all three ports are active simultaneously. These discretized controllers along with voltage/current sensor models with limited bandwidth and response delay in the feedback path are implemented in PLECS to emulate practical controller deployment. Simulation results are provided to validate both the power stage and the discrete controller design. Furthermore, iterative thermal analysis is carried out to have a realistic estimation of the device junction temperature during rated condition to evaluate the efficacy of the thermal management system. Finally, a virtual prototype design of the MPC is presented.}, journal={2021 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)}, author={Rachi, Md Rifat Kaisar and Cen, Siye and Bipu, Md Rashed Hassan and Khan, Mehnaz Akhter and Husain, Iqbal}, year={2021}, pages={1184–1190} }
 @article{bipu_awal_cen_zabin_khan_lubkeman_husain_2021, title={Secondary Voltage and Frequency Regulation for Grid Re-Synchronization in Microgrid with Unified Virtual Oscillator Controlled Multi-port Converters}, ISSN={["2329-3721"]}, DOI={10.1109/ECCE47101.2021.9595901}, abstractNote={Unified Virtual Oscillator Controller (uVOC) is a type of oscillator based nonlinear time domain controller that achieves faster primary control response than conventional droop control as no phase-locked loop (PLL) is required. uVOC can be used effectively for either grid following or grid-forming voltage source converters. Grid-forming converter is essential for a microgrid to operate in islanded mode in addition to the more common grid-connected mode. In this paper, a secondary regulation scheme is proposed to augment the capability of uVOC based on a Multi-port Converter (MPC) by adding voltage and frequency regulation for grid re-synchronization. With this method, changing primary controller is not required and seamless transition is achieved. To implement this secondary regulation, communication or data exchange between different components is required. The network connectivity is implemented based on the RIAPS platform, an open-source distributed operating system developed for real-time control of microgrid/smartgrid systems. Finally, the suitability of proposed secondary regulation with uVOC based MPC was verified through simulation and experiment on a microgrid testbed.}, journal={2021 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)}, author={Bipu, Md Rashed Hassan and Awal, M. A. and Cen, Siye and Zabin, Salina and Khan, Mehnaz and Lubkeman, David and Husain, Iqbal}, year={2021}, pages={900–905} }