Xiaomin Lu

A Twofold Daubechies-Wavelet-Based Module for Fault Detection and Voltage Regulation in SEIGs for Distributed Wind Power Generation

As Canada and the world move rapidly toward increased reliance on wind power generation, self-excited induction generators (SEIGs) will play an important role in distributed wind power generation (DWPG). Understanding the significance and prospects of SEIGs in DWPG, first, this paper elucidates the significance of fault detection (FD) and voltage regulation (VR) in the aforementioned application. A comprehensive analysis of VR and faults on niche industrial 7.5-hp copper-rotor SEIG and conventional 7.5-hp aluminum-rotor SEIG is performed through numerical simulations, and the calculated results are validated through experimental investigations. Second, a twofold Daubechies-wavelet-transform-based module is designed for the following: 1) FD and 2) VR, respectively. A discrete-wavelet-transform-based algorithm is proposed and implemented on a low-cost embedded system to provide an economical solution for the aforementioned issues. Thereafter, the aforementioned schemes are tested, and results are investigated.

Investigation of Permanent-Magnet Motor Drives Incorporating Damper Bars for Electrified Vehicles

Understanding the need for steady-state and transient performance improvement in an interior permanent-magnet synchronous machine (IPMSM) drive, this paper exclusively investigates the IPMSM incorporating damper bars in the rotor of electric motor for electrified vehicles (EVs). First, motivation for the employment of damper bars in IPMSM is provided and justified with a case study. Thereafter, a mathematical model of an IPMSM drive with damper bars in the rotor has been developed based on dq-axis theory and validated through experiments performed on a laboratory IPMSM containing damper bars. The validated mathematical model has been then employed to arrive at satisfactory rotor bar parameters for an existing IPMSM on board a commercially available EV. Moreover, a replica of the existing onboard EV motor with and without incorporating dampers have been designed, and finite-element analysis has been performed to investigate various performance characteristics. Comparative performance analyzes of both the machines with and without damper bars under steady-state and transient conditions have been performed wherever necessary, and the results elicited have been discussed.

Design of a Novel Wavelet Based Transient Detection Unit for In-Vehicle Fault Determination and Hybrid Energy Storage Utilization

This paper addresses the performance and reliability issues as encountered by the present EV technology. The research work presented in this paper is based on an ongoing project which has a twofold research motivation: 1) use of wavelet analysis to determine transients in electric vehicles; and 2) application the information obtained during transient detection to address the performance and reliability concerns. The novel wavelet based transient detection unit designed and developed as part of this project is discussed in this paper. The prototype is developed on a low-cost embedded system in order to provide an economical solution. Significance of the developed transient detection unit is also illustrated in this paper by developing applications that ensure a robust and reliable drivetrain with enhanced performance. Firstly, the information gathered from the transient detection unit is used to determine in-vehicle electrical faults. Secondly, this transient detector is used to facilitate the optimization of hybrid energy storage system (battery/ultra-capacitor combination) and to ensure smooth battery operation.

Rule-Based Control Strategy With Novel Parameters Optimization Using NSGA-II for Power-Split PHEV Operation Cost Minimization

One of the major considerations in the automotive industry is the reduction of hybrid electric vehicle fuel consumption and operation cost. This paper is the first to use the nondominated sorting genetic algorithm-II (NSGA-II) for power-split plug-in hybrid electric vehicle (PHEV) applications. The NSGA-II, one of the most efficient multiobjective genetic algorithms (MOGAs), simultaneously optimized operation cost, including gasoline and electricity consumption. The Pareto optimal solutions are discussed for the parameter calibrations of the rule-based control strategy as a useful guide in PHEV development, particularly in the earlier phases. The optimized operation cost at the different power-split device (PSD) gear ratios is used to determine the ideal PSD gear ratio to further minimize the operation cost. To validate the proposed strategy, dynamic PSD and powertrain models of PHEV are developed in the numerical analysis. The two typically different driving cycles, namely, the Urban Dynamometer Driving Schedule (UDDS) and the Highway Fuel Economic Drive Schedule (HWFET), with different numbers of driving cycles, are used for control strategy optimization.

Development of a Novel Magnetic Circuit Model for Design of Premium Efficiency Three-Phase Line Start Permanent Magnet Machines With Improved Starting Performance

This paper presents challenges in an ongoing project related to the design of a premium efficiency three-phase line start permanent magnet synchronous motor (LSPMSM) and proposes an exclusive solution through development of a novel magnetic circuit model. Since the LSPMSM is rapidly replacing the conventional induction motors in industrial applications such as pumps, fans and conveyors which require the machine to operate under both frequent start-stop and steady-state conditions for a wide range of time, a trade-off has to be reached between their starting performance and efficiency post-synchronization. Until now this has only been possible with time consuming FEA based design methodology. Hence, understanding the need and scanty availability of literature on simplistic and yet precise magnetic circuit based design of three-phase LSPMSM, this manuscript proposes exclusively a novel magnetic circuit model to design LSPMSM with improved starting performance. Firstly, the aforementioned design issues have been illustrated using different machine configurations developed. Further, a detailed procedure to deal with the design issues with the help of the developed magnetic circuit model is discussed and validated by developing a machine where the trade-off has been reached.

A Wavelet/PSO Based Voltage Regulation Scheme and Suitability Analysis of Copper- and Aluminum-Rotor Induction Machines for Distributed Wind Power Generation

Centralized generation is being supplemented or replaced fast by distributed generation, a new way of thinking about electricity generation, transmission and distribution. Understanding the significance and prospects of self-excited induction generators (SEIGs) in distributed wind power generation (DWPG), this paper firstly presents a comprehensive suitability analysis of commercially available niche copper-rotor induction motor (CRIM) and conventional aluminum-rotor induction motor (ARIM) to be used as induction generators in the above application, through experimental investigations performed on two industrial 7.5 hp CRIM and ARIM. The results of the performance analyses on the two machines provide data for development of a novel control scheme comprising of wavelet transforms and particle swarm optimization technique, proposed next, to alleviate the problem of voltage regulation (VR) associated with the SEIGs. The developed controller for VR is implemented on a low cost embedded system, hence making it economical and flexible for patenting. The developed embedded system is validated initially through an actuator performing mechanical switching of requisite capacitances and finally by integrating it with another actuator, namely, the static synchronous compensator (STATCOM), for efficient voltage regulation. Finally, the tested results are presented.

A Novel Two-Axis Theory-Based Approach Towards Parameter Determination of Line-Start Permanent Magnet Synchronous Machines

Understanding the importance and the scanty availability of research literature on parameter estimation of line-start permanent magnet synchronous machine (LSPMSM), this paper proposes a novel and yet fundamental approach towards parameter estimation. Experiments have been performed on a laboratory LSPMSM based on the proposed dq axis methodology and measurements have been validated by analyzing the performance of the machine under different conditions using a developed computer program and an experimental setup. Dynamic and steady state performance analyses have been subsequently performed using the determined parameters and the results have been presented under direct online (DOL) starting and a sudden increase in load torque.

A Dual Purpose Triangular Neural Network Based Module for Monitoring and Protection in Bi-Directional Off-Board Level-3 Charging of EV/PHEV

Understanding the need for improvement in monitoring and protection in high performance charging technology for a growing demand of EVs/PHEVs, this research manuscript presents a part of an ongoing project and proposes a novel low cost dual purpose triangular neural network based module for power quality monitoring and protection (M&P) and elicits its performance in times of abnormalities or malfunction in a high performance off-board level 3 bi-directional charger for electric vehicles. Firstly, design and implementation of the low cost dual purpose triangular neural network based device for monitoring the power quality and hence, protecting the grid has been explained and its performance has been presented through numerical investigations. Going a step further, the device has also been experimentally tested using an in-house electric vehicle containing a commercially available battery charger and the measured results are analyzed. Secondly, a high-performance vector-controlled bi-directional off-board level-3 charger for faster and efficient charging has been developed and investigations have been performed on the healthy charger to analyze its performance. The primary aim of developing this charger was to elicit the usage and performance of the previously developed M&P device to protect the grid in case of some typical charger malfunction problem in such a charger, which is not detectable by conventional low cost sensors employed with such chargers. Once the module detects any abnormalities in the chargers operation, information gathered can be used to tune the controller in the charger to obtain a constant improved performance of the charger or the power transfer can be terminated.

Investigation of Integrated Charging and Discharging Incorporating Interior Permanent Magnet Machine With Damper Bars for Electric Vehicles

Integrated charging technology in electric vehicles is expected to reduce the overall cost as well as the weight of the vehicle, while leading to fast charging capability in the vehicle. Understanding the above, this paper puts an effort to exclusively investigate interior permanent magnet synchronous machine (IPMSM) drive incorporating damper bars in rotor for integrated charging application in electric vehicles. First, motivation for the employment of IPMSM with damper bars for integrated charging is provided and justified. Thereafter, a novel parameter determination method based on dq-axis theory to determine the parameters of a laboratory IPMSM with dampers is proposed and experimentally validated. The determined parameters are then employed to design, control, and compare the performance of an integrated charging system incorporating an IPMSM drive with and without damper bars. The developed system is then experimentally tested under both vehicle-to-grid and grid-to-vehicle modes, and results elicited from the investigations are discussed.

Study of permanent magnet machine based flywheel energy storage system for peaking power series hybrid vehicle control strategy

Transit agencies are increasingly focused on making bus fleets cleaner, more efficient and cost effective by incorporating new clean propulsion technologies. Increased maintenance cost and lower lifetime of battery packs in existing hybrid electric buses have been major bottlenecks in motivating transit bus operators to rapidly switch to this energy efficient technology. Understanding the demerits of the current battery based energy storage technology and merits of the prospective flywheel based energy storage technology for transit bus application, this paper puts an effort to study the permanent magnet synchronous machine based flywheel energy storage system for the aforementioned application. A series transit hybrid bus with peaking vehicle control strategy has been taken into consideration with a macro objective to compare the performance of the battery based and flywheel based hybrid transit bus in terms of fuel consumption and cost of the installed system. However, the focus of this paper remains on the development and study of a 100 kW flywheel energy storage system based on vector control technique which forms the first step towards this macro objective.