Pourya Shamsi

Design and Development of Very High Frequency Resonant DC–DC Boost Converters

This paper presents a very high frequency dc-dc boost converter. This design features low voltage stress on the switch, high efficiency, and simple control. The low energy storage requirements provide a more effective integration. A proposed resonant gate driver provides variable duty cycle and possibility of the control of the converter at very high frequencies. A 60-MHz prototype of the proposed converter is designed and implemented. Experimental results demonstrate the effectiveness of the proposed control strategy.

Dynamic Behavior of Multiport Power Electronic Interface Under Source/Load Disturbances

This paper presents the dynamic behavior of multiport power electronic interface (MPEI) under load/source disturbances. A cascaded topology for MPEI is considered. This system is capable of power management for local generations, loads, and storage systems. Large-signal and small-signal models for MPEI are developed. These models are combined with corresponding control algorithms. Simulated and experimental transient responses to disturbances on each port are presented. The behavior of MPEI in response to each disturbance is analyzed. Simulation and experimental results are compared in order to verify the model.

Economic Dispatch of a Hybrid Microgrid With Distributed Energy Storage

This paper introduces a distributed economic dispatch strategy for microgrids with multiple energy storage systems. This strategy overcomes the challenges of dynamic couplings among all decision variables and stochastic variables in a centralized dispatching formulation. The proposed strategy can be implemented in the microgrid central controller as multiple problems with simplified and decomposed formulations. It can also be implemented in the local controllers and managed by the central controller. Numerical studies and experimental results illustrate the effectiveness of the proposed dispatching systems.

Stability Assessment of a DC Distribution Network in a Hybrid Micro-Grid Application

This paper studies the stability analysis of a dc distribution network in a hybrid micro-grid. A micro-grid with ac and dc distribution networks based on multi-port power electronic interfaces (MPEIs) is conceptualized. Afterwards, an extended averaging method for modeling systems with multiple switching converters is introduced. Using this method, the dc distribution network is modeled. Furthermore, the stability assessment of this network is performed using pole-zero analysis of the small-signal model. Simulation results and experimental measurements are provided to validate the stability assessment of the hybrid micro-grid.

Economic Dispatch for an Agent-Based Community Microgrid

In this paper, an economic dispatch (ED) problem for a community microgrid is studied. In this microgrid, each agent pursues an ED for its personal resources. In addition, each agent is capable of trading electricity with other agents through a local energy market. In this paper, an energy market operating in the presence of the grid is introduced. The proposed market is mainly developed for an experimental community microgrid at the Missouri University of Science and Technology, Rolla, MO, USA, and can be applied to other distribution level microgrids. To develop the algorithm, first, the microgrid is modeled and a dynamic ED algorithm for each agent is developed. Afterwards, an algorithm for handling the market is introduced. Lastly, simulation results are provided to demonstrate the proposed community market, and show the effectiveness of the market in reducing the operation costs of passive and active agents.

Model Predictive Current Control of Switched Reluctance Motors With Inductance Auto-Calibration

This paper investigates application of an unconstrained model predictive controller (MPC) known as a finite horizon linear quadratic regulator (LQR) for current control of a switched reluctance motor (SRM). The proposed LQR can cope with the measurement noise as well as uncertainties within the machine inductance profile. This paper utilizes MPC to generate the optimal duty cycles for drive of SRMs using pulse-width modulation (PWM) in oppose to delta-modulation. In this paper, first a practical MPC scheme for embedded implementation of the system is introduced. Afterward, Kalman filtering is used for state estimation while an adaptive controller is used to dynamically tune and update both MPC and Kalman models. Hence, the overall control structure is considered as a stochastic MPC with adaptive model calibration. Finally, simulation and experimental results are provided to demonstrate the effectiveness of the proposed method.

Single-Bus Star-Connected Switched Reluctance Drive

Switched reluctance machines provide a feasible solution for automotive applications. However, a small and low cost power electronics driver is of interest for this purpose. This paper presents a control algorithm for a single-bus star-connected switched reluctance drive system. This algorithm enables the conventional Miller topology to control the phase currents in the multiphase excitation mode of operation. This control algorithm is introduced for motoring and generating modes of operation. The introduced algorithm is simulated under motoring and generating modes. Afterward, experimental measurements are illustrated to prove the practicality of the proposed concept.

Analysis and design of bipolar Dickson DC-DC converter

This paper presents a novel converter based on the Dickson voltage multiplier for high voltage applications. This converter will have two Dickson chains connected differently to improve the original Dickson voltage multiplier. The main advantage of this converter is that the stresses on the capacitor will be reduced by half, and the output voltage ripples are reduced. The required energy storage of the capacitor is 30% of the original Dickson voltage switched capacitor converter. The analysis and design of this converter are presented and verified by simulation. A 20W prototype was implemented to validate the analysis and simulation. The results show that the proposed converter is an improved version of the original Dickson and modified Dickson converters and it has higher efficiency up to 94%.

A novel non-isolated high-gain dc-dc boost converter

In this paper, a novel interleaved boost converter topology is introduced. The proposed converter is based on a combination of two types of voltage multiplier cells (VMC): Dickson and Cockroft-Walton (CW) voltage multiplier. Connecting VMCs to an interleaved boost stage yields many benefits, including smaller ripples on the input current, reduced voltage stress across switches and capacitors, and high overall voltage gain. These advantages allow designers to design high gain dc-dc converters with low-rated and highly efficient semiconductor components. Moreover, the use of VMC can reduce the requirements of the required energy storage and also allow to design with smaller capacitors than the conventional boost converter. This paper presents the analysis of steady state voltage gain, the design of the converter, selection of the components, and simulation of the voltage and current stresses across switches and storage elements. Also, A 200 W prototype was implemented to convert 20 to 400 Vdc. The implementation details and major waveforms are included and illustrated.

Effective on-line parameters for transformer monitoring and protection

Whatever a system is more complex, its protection and monitoring will be more difficult. This paper attempts to discuss about the transformer condition monitoring methods and its relationships perfectly. Useful experimental results, which have performed in Mobarakeh Steel Plant, are expressed too. The introduced methods for transformer condition monitoring are divided in two general groups, which are off-line and on-line methods. The results of these experiments are resulted from Mobarakeh Steel Plant. For example ultrasonic tests and partial discharge test and other methods are explained. Transformer condition monitoring results are outcome in faults presence, and by comparing them to global statistics, effective on-line parameters for transformer condition monitoring and protection always are predictable.