An Improved Model Predictive Current Controller of Switched Reluctance Machines Using Time-Multiplexed Current Sensor

This paper presents a fixed-switching-frequency model predictive current controller using multiplexed current sensor for switched reluctance machine (SRM) drives. The converter was modified to distinguish currents from simultaneously excited phases during the sampling period. The only current sensor installed in the converter was time division multiplexing for phase current sampling. During the commutation stage, the control steps of adjacent phases were shifted so that sampling time was staggered. The maximum and minimum duty ratio of pulse width modulation (PWM) was limited to keep enough sampling time for analog-to-digital (A/D) conversion. Current sensor multiplexing was realized without complex adjustment of either driver circuit nor control algorithms, while it helps to reduce the cost and errors introduced in current sampling due to inconsistency between sensors. The proposed controller is validated by both simulation and experimental results with a 1.5 kW three-phase 12/8 SRM. Satisfied current sampling is received with little difference compared with independent phase current sensors for each phase. The proposed controller tracks the reference current profile as accurately as the model predictive current controller with independent phase current sensors, while having minor tracking errors compared with a hysteresis current controller

Control techniques of switched reluctance motors in electric vehicle applications: A review on torque ripple reduction strategies

As electric vehicles (EVs) continue to acquire prominence in the transportation industry, improving the outcomes and efficiency of their propulsion systems is becoming increasingly critical. Switched Reluctance Motors (SRMs) have become a compelling option for EV applications due to their simplicity, magnet-free design, robustness, and cost-effectiveness, making them an attractive choice for the growing EV market. Despite all these features and compared to other electrical machines, SRMs suffer from some restrictions, such as torque ripple and audible noise generation, stemming from their markedly nonlinear characteristics, which affect their productivity and efficiency. Therefore, to address these problems, especially the torque ripple, it is crucial and challenging to enhance the performance of the SRM drive system. This paper proposed a comprehensive review of torque ripple minimization strategies of SRMs in EV applications. It covered a detailed overview and categorized and compared many strategies, including two general categories of torque ripple mitigation encompassing optimization design topologies and control strategy developments. Then, focused on control strategy improvements and divided them into torque and current control strategies, including the sub-sections. In addition, the research also provided an overview of SRM fundamental operations, converter topologies, and excitation angle approaches. Last, a comparison between each method in torque control and current control strategies was listed, including the adopted method, features, and drawbacks

Estudo da viabilidade energética de amortecedores regenerativos de relutância magnética comutados em veículos elétricos

Esta dissertação centra-se no estudo da viabilidade energética de amortecedores regenerativos de relutância magnética em veículos elétricos. Neste trabalho procura-se contribuir para investigação e desenvolvimento de geradores lineares de relutância variável comutados de topologia tubular com aplicação em sistemas de suspensão regenerativa para conversão de energia de vibração. É descrito o sistema de suspensão, é definido o modelo matemático que rege o seu comportamento e os diferentes tipos de suspensão. Os veículos elétricos têm ganho muito interesse, como alternativa aos veículos movidos por combustíveis fosseis, por serem mais ecológicos. É feita a descrição da evolução dos veículos elétricos desde a primeira geração até à quarta geração. Entretanto, aborda-se o princípio de conversão de energia da máquina linear de relutância variável comutada, estuda-se o modelo dinâmico do gerador, e referem-se os conversores eletrónicos de potência para o seu controlo. Por fim, é feita a análise energética da suspensão regenerativa com o gerador linear de relutância variável comutado, e todo processo de cálculo computacional é implementado em linguagem própria do software Matlab e do software gratuito Finite Element Method Magnetics (FEMM).This Dissertation focuses on the study of the energetic feasibility of magnetic switched reluctance regenerative dampers in electric vehicles. In this work, it is intended to contribute to research and development of linear switched reluctance generators with tubular topology for application in regenerative suspension systems for vibration energy conversion. The suspension system is described, the mathematical model that governs its behavior and the different type of suspensions are defined. Electric vehicles have gained a lot of interest, as an alternative to fossil-powered vehicles, because they are more ecological. Furthermore, the principle of energy conversion in linear switched reluctance machine is discussed, the dynamic model of the generator is studied, and the electronic power converters for its control are presented. Lastly, there is an energy analysis of the regenerative suspension based on linear switched reluctance generator. The computational calculation process is implemented using Matlab and Finite Element Method Magnetics (FEMM) software