Recent Trends in Electrical Machines and Drives ISSN: 3139-2067 (Online)

ABSTRACT

The increasing demand for high power density, improved efficiency, and reduced system cost has driven significant research into the integration of power electronics with electric machines. Integrated drive systems, where power converters are physically and functionally combined with electric motors, offer substantial advantages over conventional discrete-drive architectures. This paper presents a comprehensive review of integrated power electronics and electric machines for compact drive applications. Key integration approaches, thermal and electromagnetic challenges, reliability concerns, and performance benefits are discussed. Comparative analysis using reported case studies highlights the potential of integrated drives in industrial automation, electric vehicles, and aerospace systems. The paper concludes with emerging trends and future research directions in integrated drive technology.

 KEYWORDS: - Integrated drives, Power electronics integration, Electric machines, Power density, Compact motor drives, Thermal management

ABSTRACT

The rapid evolution of power semiconductor technology has significantly influenced the performance of modern electric drive systems. Wide bandgap (WBG) semiconductors, particularly silicon carbide (SiC) and gallium nitride (GaN), have emerged as strong alternatives to conventional silicon devices due to their superior electrical and thermal properties. This paper investigates the impact of SiC and GaN devices on the efficiency, power density, thermal performance, and reliability of electric drive systems. Comparative analysis with silicon-based drives is presented using experimental trends reported in literature. Key challenges such as electromagnetic interference, gate drive complexity, and long-term reliability are also discussed. The study concludes that WBG-based drives offer substantial efficiency improvements and enhanced reliability when appropriate design practices are adopted.

 KEYWORDS: - Wide bandgap semiconductors, Silicon carbide, Gallium nitride, Electric drives, Efficiency, Reliability, Power electronics

Abstract

In order to prevent the power switching devices (e.g., the Insulated-Gate-Bipolar-Transistor, IGBT) from shooting through in voltage source converter during a switching period, a dead- time is inserted in between the off going and turning on devices, either in the hardware drivers of the IGBTs or implemented in the software Sinusoidal Pulse-Width Modulation (SPWM) scheme. Both methods will lead to a degradation of the injected current power quality. This paper will present a dead-time elimination scheme for a SPWM controlled inverter. In comparison to using expensive current sensor, this method determines precisely the load of current polarity by detecting the terminal voltage of the anti-parallel diode of power devices. The presented scheme includes the freewheeling current polarity detection circuit and the PWM control generator without dead-time. This method significantly reduces the output voltage loss and harmonic distortion, and improves quality of power. Simulation results are given to demonstrate the effectiveness of the dead-time elimination scheme.

Keywords: Dead time, PWM, Sinusoidal Pulse Width Modulation (SPWM), Harmonics

In this paper practical field performance of poly-crystalline solar photovoltaic (PV) modules was studied and presents the correlation between efficiency, temperature and degradation rate of modules as per STC conditions, which are installed at rooftop of the Department of Electrical Engineering BVRIT. The nominal output power of the PV module considered for the study is 240Wp and the panel is compressed of 60 cells in a 10×6 matrix connected in series. After few operation years under tropical environment the degradation rate of electrical characteristics such as I-V and P-V curves, open-circuit voltage (Voc), short- circuit current (Isc), maximum output current (Imax), maximum output voltage (Vmax), maximum power output (Pmax) and fill factor (FF) are evaluated at standard test conditions (STC). Through this study, it has noticed that the efficiency of solar panel is linearly inversely proportional to temperature and degradation rate in a linear fashion.

Keywords: Open-Circuit Voltage; Short-Circuit Current; Maximum Output Voltage; Maximum Power Output; Fill Factor; Efficiency; Degradation Rate

ABSTRACT

The demand for high-performance electric vehicles (EVs) has led to a focus on traction machines with high torque density and compatibility with fast-charging systems. Achieving elevated torque density while maintaining efficiency under fast charging conditions presents significant challenges in electromagnetic design, thermal management, and control strategy. This paper reviews state-of-the-art electric traction machines for EVs, covering permanent magnet synchronous machines (PMSMs), induction motors, and switched reluctance machines (SRMs). Key considerations include high current operation, thermal management for fast-changing conditions, and the impact on torque and efficiency. Tables and 2D figures illustrate design trade-offs, thermal distribution, and control schemes. The paper also discusses emerging trends, including wide-bandgap inverters and additive manufacturing for rotor/stator optimization.

 KEYWORDS: - Electric vehicles, Traction machines, Fast charging, High torque density, PMSM, Thermal management

ABSTRACT

The integration of electrical drives with wind turbine generators (WTGs) and micro-grids is a crucial enabler for renewable energy systems. Variable-speed wind turbines require high-performance electrical drives capable of maximizing energy capture, providing grid support, and ensuring reliability in distributed power networks. This paper reviews the state-of-the-art integration of electrical drives with WTGs and micro-grids, including design considerations, control strategies, and system-level performance. Tables and 2D figures illustrate drive topologies, wind-turbine integration schemes, and micro-grid control hierarchies. Key challenges such as grid stability, fault tolerance, and power quality are discussed along with emerging trends in wide-bandgap inverter technology and energy storage integration.

 KEYWORDS: - Electrical drives, Wind turbine generators, Micro-grids, Variable-speed drives, Renewable energy integration, Grid support

ABSTRACT

High-speed electrical machines (HSEMs) are vital for aerospace propulsion, industrial compressors, and turbo-machinery applications where compactness, high power density, and dynamic performance are critical. Unlike conventional low-speed machines, HSEMs face challenges including rotor dynamics, bearing stresses, magnetic saturation, thermal management, and insulation degradation at high rotational speeds. This paper reviews the design principles, performance characteristics, and challenges of high-speed electrical machines, with a focus on permanent magnet synchronous machines (PMSMs) and induction-based HSEMs. Tables and 2D figures are included to illustrate comparative performance metrics, design trade-offs, and thermal distribution. Emerging trends such as wide-bandgap semiconductors, additive manufacturing, and active magnetic bearings are also discussed.

KEYWORDS: - High-speed electrical machines, Permanent magnet synchronous machines, Aerospace motors, Industrial high-speed drives, Rotor dynamics, Thermal management

ABSTRACT

Electric drives are pivotal in modern robotic systems and precision motion control applications. These drives convert electrical energy into controlled mechanical motion with high accuracy. This paper reviews the types of electric drives, key performance criteria, and their integration into robotics and precision motion platforms. We also analyze performance metrics and present comparisons among popular drive technologies.

 KEYWORDS:- Electric drives; Robotics; Precision motion control; Drive technologies; Performance metrics; Motion control systems; Actuators

ABSTRACT

Energy-efficient motor systems (EEMS) are central to reducing industrial energy consumption, enhancing productivity, and meeting global sustainability targets. Industrial electrification increasingly mandates adherence to international and regional standards, such as IEC 60034-30, NEMA Premium, and IS 12615, for optimized motor efficiency and reduced lifecycle costs. This paper reviews the design, operation, and regulatory standards of energy-efficient motor systems for industrial applications. Performance metrics, comparative efficiency tables, and 2D figures illustrating energy losses, thermal distribution, and standardized efficiency classes are provided. Emerging trends in variable speed drives, intelligent monitoring, and integration with renewable energy sources are discussed, along with practical considerations for industrial adoption.

 KEYWORDS: - Energy-efficient motors, Industrial electrification, Standards, Variable speed drives, Motor efficiency, IEC 60034-30, NEMA Premium

Abstract

Electric drives are the backbone of modern industrial automation, renewable energy systems, electric vehicles, aerospace actuators, and robotics. Traditional control strategies such as PID and linear state feedback have dominated the field for decades. However, with growing demands for high dynamic performance, robustness under uncertainty, and adaptation to parameter variations, artificial intelligence (AI)-based adaptive control strategies have emerged as a promising alternative. This paper explores the integration of neural networks (NN) and fuzzy logic systems (FLS) into adaptive controllers for electric drives, offering insights into architecture, learning algorithms, stability analysis, and real-world performance metrics. Detailed comparisons, case studies, and simulation results are provided to illustrate the advantages and limitations of these approaches.

Keywords: Electric drives, adaptive control, neural networks, fuzzy logic, robustness, parameter uncertainty, AI control, induction motor, permanent magnet synchronous motor (PMSM).

ABSTRACT

Multiphase and dual-inverter drive systems have gained increasing attention in high-performance and high-reliability applications such as electric vehicles, aerospace actuators, and industrial processes. These systems offer advantages including reduced current stress, improved fault tolerance, and enhanced power density. However, their performance is strongly influenced by the modulation strategy used for inverter switching. This paper presents a detailed study of advanced modulation techniques developed for multiphase and dual-inverter systems. Space vector modulation, carrier-based methods, zero-sequence injection, and fault-tolerant modulation strategies are discussed and compared. Performance evaluation in terms of harmonic reduction, DC-link utilization, and fault resilience is presented using reported results. The paper highlights the role of advanced modulation in fully exploiting the benefits of multiphase and dual-inverter architectures.

KEYWORDS: - Multiphase inverters, Dual-inverter systems, Space vector modulation, Harmonic reduction, Fault-tolerant drives, Advanced modulation

Abstract

This work presents a three phase shunt active power filter based inverter with Multi Levels. In this study, the novel approach i.e NPC based Multi-Level inverter proposed. The proposed approach reveals unwanted active current component with fundamental frequency contained in the compensation current which causes oscillation and fall of the DC voltage level of shunt active power filter. The proportional-integral controller that has been widely used by researchers is used to maintain the reference DC voltage level. The proposed system is modeled with MATLAB/Simulink and simulation studies are carried out on RL and RC type load with both PI controller and Fuzzy controller. The obtained results from the simulation studies show that the proposed approach give the good results when the level of the inverter increases.

Keywords: NPC; Multilevel; PI; Fuzzy;

ABSTRACT

Thermal management remains a critical constraint in the design and operation of high-performance electrical machines. With increasing power density requirements, conventional air and liquid cooling methods often become inadequate. Cryogenic cooling techniques, combined with advanced thermal enhancement strategies, offer significant improvements in machine efficiency, power density, and reliability. This paper reviews recent developments in cryogenic cooling, thermal conductivity enhancement, and hybrid cooling solutions for electrical machines. The effects on stator and rotor design, insulation, and overall machine performance are discussed. Tables and 2D figures illustrate key concepts, comparative performance metrics, and thermal distributions. Emerging trends and practical challenges are also addressed.

 KEYWORDS: - Cryogenic cooling, Thermal enhancement, Electrical machines, High-power density, Liquid nitrogen, Advanced cooling techniques

ABSTRACT

Thermal management is a critical factor influencing the performance, reliability, and lifetime of electric drive systems. Excessive temperature rise in electrical machines, power electronic converters, and insulation materials leads to accelerated aging, efficiency degradation, and potential system failure. Traditional thermal modeling techniques rely on physics-based lumped parameter or finite-element models, which often require precise parameter knowledge and are computationally intensive. Recent advances in data-driven methods and digital twin technology have enabled real-time thermal estimation, predictive analysis, and intelligent thermal control of electric drive systems. This paper presents a comprehensive study on data-driven thermal management techniques and the role of digital twins in modern drive systems. Machine learning models, sensor fusion, and real-time simulation frameworks are discussed along with their integration into digital twin architectures.

 KEYWORDS: - Thermal management, digital twin, electric drives, data-driven modeling, temperature prediction, machine learning, reliability