N. C. Lenin

Bio: N. C. Lenin is an academic researcher from VIT University. The author has contributed to research in topics: Switched reluctance motor & Reluctance motor. The author has an hindex of 5, co-authored 19 publications receiving 77 citations. Previous affiliations of N. C. Lenin include Anna University.

High Power Density Electrical Machines for Electric Vehicles—Comprehensive Review Based on Material Technology

Abstract: The growth of electric and hybrid electric vehicles has drawn more attention toward the development of high power density electrical machines. The materials used in the fabrication of electrical machines play a crucial role in enhancing their power density. In this paper, the significance of advanced magnetic materials for lamination, nano-material based conducting materials, and high energy product permanent magnets (PMs) is discussed in detail. Finally, a case study has been presented with a 5 kW PM synchronous machine in order to understand the advantages of the discussed materials.

A novel line start synchronous reluctance motor

Abstract: Line Start Synchronous Reluctance Motors (LSSRELMs) is one of the suitable solutions for energy efficient electric motors [1]. Because of reduced rotor mass, less cost, absence of permanent magnets and better efficiency these motors are becoming strong contenders for both induction motors and as well as line start permanent magnet motors [2]. This paper investigates four different rotor structures of 3 phase, 2.2 KW LSSRELM. Initially we designed an induction motor of 2.2 KW used in hermetic compressor. Soon after, using a common stator, LSSRELM has been designed. Even though LSSRELMs provide better efficiency (compare to induction motors), it suffers from poor power factor. Maximizing the saliency ratio leads to better power factor [3]. The saliency ratio depends on direct (d) and quadrature (q) axes inductances. Analytical approach to determine these inductances are found in [4]. In the chosen application two task are considered to develop a novel LSSRELM: (i) power factor and (ii) improvement in startup behavior under different loading conditions. The later criterion is much important in the design stage of LSSRELM because the starting and synchronization of the motor strongly depends on rotor parameters [5]. In this research, four cylindrical pole rotor structures with Aluminium and Copper combinations are investigated. At first, we study the synchronization capability for given load and inertia. Later, dynamic conditions and optimization process are carried out for the power factor improvement through FEA. To validate the designed model, prototype of all the models has been manufactured and tested. Different test results are finally compared with the FEA results. Experimental results show that the new structure provides better power factor, efficiency and pull in capability.

Acoustic noise, vibration, harmonics, thermal of three phase linear switched reluctance machines

Abstract: Acoustic noise in the linear switched reluctance motor (LSRM) is caused primarily by the deformation of the stator lamination stack. Acoustic noise is most severe when the periodic excitation of the LSRM phases excites a natural vibration mode of the stack. Noise and vibration are usually high in LSRM because of doubly salient structures. The natural vibration modes and frequencies of a three-phase LSRM are examined. Structural finite element analysis (FEA) is used to compute the natural modes and frequencies. A harmonic analysis to identify the range of speeds producing high vibration and noise that should be skipped over quickly during acceleration is studied. Apart from vibration, noise and harmonic analysis, a detailed electromagnetic and thermal analysis of the proposed LSRM using FEA are presented.

Torque ripple reduction of switched reluctance motors by phase current optimal profiling

Abstract: Optimal precalculation of the position-phase current projile for current feeding a 4-phase, 4 kW switched reluctance motor, results in a single input, linear. decoupled output torque controller, which provides low torque ripple. A bicubic spline interpolation was used to model the non-linear experimental data. The algorithm is bused 011 minimizing both the average and peak current hence improves the dynamic performance of the novel six switch, current fed, igbt 4 kW, 40 kHz inverter. Test results by instuntaneous speed measurement over the speed runge 100-300 rpm, ruted torque, open-loop optimizing technique are presented,

Sensorless Vector Control of Permanent Magnet Synchronous Linear Motor Based on Self-Adaptive Super-Twisting Sliding Mode Controller

Abstract: Due to its own structural characteristics, permanent magnet synchronous linear motors (PMSLMs) have unstable motor parameters during operation due to the end effect and the inherent magnetic circuit instability. At the same time, linear motors have the characteristics of reciprocating switching motion and high-speed positioning motion in industrial applications, thus placing high demands on the controller. In order to improve the performance of the PMSLM, this paper firstly studies the linear motor structure, the distribution characteristics of its air gap magnetic field are obtained, and the simulation analysis for the back electromotive force (EMF) of PMSLM of its running process is carried out. Then, a state observer based on the sliding mode state observer (SMO) is built to replace the traditional speed sensor and a super-twisting sliding mode controller is designed. The double-closed loop control of the speed and the use of high-order sliding mode control features effectively reduce the chattering of the system and reduce the impact of the observation error brought by the observer on the system. The adaptive sliding mode control strategy is used to effectively suppress the influence of the boundaryless uncertainty interference on the system and reduce the influence of the observation error brought by the observer on the system. This paper also combines the linear motor experimental platform to further verify the control scheme based on the super-twisting sliding mode non-sensing linear motor. The simulation and experimental results show that SMO has accurate speed and position tracking performance, the system's chattering is significantly reduced, the control precision is excellent, and the introduction of adaptive sliding mode controller enhances the robustness of the system.

Design Approaches and Control Strategies for Energy-Efficient Electric Machines for Electric Vehicles—A Review

Abstract: The market penetration of electric vehicles (EVs) is going to significantly increase in the next years and decades. However, EVs still present significant practical limitations in terms of mileage. Hence, the automotive industry is making important research efforts towards the progressive increase of battery energy density, reduction of battery charging time, and enhancement of electric powertrain efficiency. The electric machine is the main power loss contributor of an electric powertrain. This literature survey reviews the design and control methods to improve the energy efficiency of electric machines for EVs. The motor design requirements and specifications are described in terms of power density, efficiency along driving cycles, and cost, according to the targets set by the roadmaps of the main governmental agencies. The review discusses the stator and rotor design parameters, winding configurations, novel materials, construction technologies as well as control methods that are most influential on the power loss characteristics of typical traction machines. Moreover, the paper covers: i) driving cycle based design methods of traction motors, for energy consumption reduction in real operating conditions; and ii) novel machine topologies providing potential efficiency benefits.

Review and Trends in Electric Traction Motors for Battery Electric and Hybrid Vehicles

Abstract: This paper presents an up-to-date review of design trends for electric traction motors of electric vehicles, mainly battery electric vehicles and full hybrid electric vehicles. The focus is on permanent magnet traction motors of the major car brands and includes vehicles from the last decade (from 2010 until today), including Jaguar, Tesla, Toyota, BMW, Nissan, General Motors and Audi. The main topic of this study is the electromagnetic motor design, but also mechanical features of the motor as well as trends in magnetic materials are discussed. Furthermore, key performance numbers are evaluated and compared with respect to power density, motor speed and field weakening performance. Finally, trends in traction motor design and performance are presented as well. The aim is to highlight the latest developments in electric traction motors and to provide an efficient overview of the state-of-the-art motor designs, performances, technical limitations, as well as future concepts and trends.