A solution for SRM starting hesitation: from FE analysis to bench validation

Author(s):  
Zaatar Makni ◽  
Kamel Bouallaga

Purpose – The starting hesitation of a switched reluctance motor (SRM) is an issue which must be considered in the early motor design. It is mostly handled as a control concern. The starting procedure of a SRM using a single Hall-effect position sensor is analysed in this paper. This low cost position measurement solution requires a specific control strategy. That has been developed for a three-phase 6/4 SRM. The paper aims to discuss these issues. Design/methodology/approach – The starting procedure begins with a rotor alignment step intending to bring the rotor to a known position. Afterward, only one phase is supplied on a periodic basis, to drive the rotor in the desired direction and accelerate up to a predefined speed threshold. Thus, the proposed procedure drastically simplifies the control strategy and permits a low cost sensor based control. 2D finite elements simulations are performed to analyse the starting performances in terms of response time and power efficiency. Both electrical and mechanical transients are considered in the simulation model thanks to simplifying assumption which consists in applying a time averaged voltages instead of instantaneous switching. Finally, the entire starting procedure with a one phase supply procedure is tested experimentally. Findings – A starting procedure of a three-phase SRM is implemented. The control effectiveness is validated by complementary FE calculations and measurements. Originality/value – The starting hesitation issue of a three-phase SRM is solved with an easy control strategy. During the acceleration phase, only one phase is self-controlled.

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1554 ◽  
Author(s):  
Man Zhang ◽  
Imen Bahri ◽  
Xavier Mininger ◽  
Cristina Vlad ◽  
Hongqin Xie ◽  
...  

Due to their inherent advantages such as low cost, robustness and wide speed range, switched reluctance machines (SRMs) have attracted great attention in electrical vehicles. However, the vibration and noise problems of SRMs limit their application in the automotive industry because of the negative impact on driver and passengers’ comfort. In this paper, a new control method is proposed to improve the vibratory and acoustic behavior of SRMs. Two additional control blocks —direct force control (DFC) and reference current adapter (RCA)—are introduced to the conventional control method (average torque control (ATC)) of SRM. DFC is adopted to control the radial force in the teeth of the stator, since the dynamic of the radial force has a large impact on the vibratory performance. RCA is proposed to handle the trade-off between the DFC and ATC. It produces an auto-tuning current reference to update the reference current automatically depending on the control requirement. The effectiveness of the proposed control strategy is verified by experimental results under both steady and transient condition. The results show that the proposed method improves the acoustic performance of the SRM and maintains the dynamic response of it, which proves the potential of the proposed control strategy.


2018 ◽  
Vol 30 (3) ◽  
pp. 412-427 ◽  
Author(s):  
Yuhui Wei ◽  
Zhaowei Su ◽  
Huashan Lu ◽  
Xue Mei Ding

Purpose The purpose of this paper is to develop an efficient termination control strategy of air-vented dryer in term of energy saving, improving smoothness and reducing microscopic damage of fiber. Design/methodology/approach A simple, low cost termination control strategy is developed by testing the instantaneous humidity of exhaust air and then deducing the drying degree of fabric in process. The practicability evaluation of this novel strategy was investigated by using both experimental and mathematical approaches. The effect of termination control strategy on drying efficiency and fabric apparent properties were also discussed. Findings Termination control strategy significantly affects drying time, energy consumption, smoothness and microscopic of fiber. Specially, a novel termination control strategy that the combination of equilibrium moisture content of fabric in ambient environment and relative humidity of exhaust air in exhaust duct is workable and can save 25.2 percent of energy consumption, 26.7 percent of the drying time and improve 0.7 grade of the appearance smoothness, as well as significantly reduce the microscopic damage of fiber compare to the original control strategy of dryer. This indicates possible ways to minimize drying energy consumption and dryer damage by reducing unnecessary migrate out of the water from the clothes. Practical implications The paper is helpful in not only the development of new drying product but also the optimization of appearance smoothness of fabric after drying and reduce the microscopic damage of fiber. Originality/value A novel termination control strategy of dryer is applied to improve drying efficiency of dryer and reduce fabric damage.


Author(s):  
Feng Dong ◽  
Hao Chen ◽  
Shuai Xu ◽  
Sihang Cui

Purpose This paper aims to present a novel position sensorless control scheme with fault-tolerance ability for switched reluctance motor at low speed. Design/methodology/approach First, the detection pulses are injected in the freewheeling and idle intervals of each phase. Second, the aligned position of each phase can be detected by comparing the consecutive rise time of detection current. Third, the whole-region rotor position and real-time rotational speed can be updated four times for the improvement of detection accuracy. Finally, the fault-tolerant control strategy is performed to enhance the robustness and reliability of proposed sensorless scheme under faulty conditions. Findings Based on proposed sensorless control strategy, the estimated rotor position is in good agreement with the actual rotor position and the maximum rotor position error is 1.5°. Meanwhile, the proposed sensorless scheme is still effective when the motor with multiphase loss and the maximum rotor position error is 1.9°. Moreover, the accuracy of the rotor position estimation can be ensured even if the motor is in an accelerated state or decelerated state. Originality/value The proposed sensorless method does not require extensive memory, complicated computation and prior knowledge of the electromagnetic properties of the motor, which is easy to implement. Furthermore, it is suitable for different control strategies at low speed without negative torque generation.


Author(s):  
J.F. Pan ◽  
Norbert Cheung

PurposeThe paper aims to discuss a new direction of design outline of four‐axis machine with multi‐dimensional motors. It proposes an integrated, direct‐drive machine based on switched reluctance (SR) principles. This includes how the machine is constructed and the structure of each axis of motion. The simulation and control results are also provided for performance prediction. The study aims to provide a solution and find applications for high‐performance, low‐cost manufacturing facilities.Design/methodology/approachThe study is based on simulation and experimental results for performance prediction of the multi‐dimensional motors. With the approach of grounded theory on SR machines, design and construction of each axis of motion is verified with finite element analysis. Then, corresponding control strategy is provided for the control of each axis of motion. Some corresponding experimental results are carried out to verify motor performance.FindingsThe paper provides a general design procedure for direct‐drive, integrated, multi‐dimensional SR motors. It suggests a mechanically robust, low‐cost and simple machine structure for potential applications of industrial multi‐axis machines.Research limitations/implicationsConsidering the performance from the prototype, it is expected to find applications in low‐level force and torque output such as automated small‐scale printed circuit board drillings.Practical implicationsOwing to the limitations of the present study, the machine needs further control tests for robust or adaptive applications. Therefore, researchers are encouraged to implement further advanced control strategies on the machine.Originality/valueThe authors attempt to provide a comprehensive solution of multi‐axis machine design based on direct‐drive, low‐cost multi‐dimensional SR motors.


2012 ◽  
Vol 3 (1) ◽  
pp. 53-62
Author(s):  
Z. Elbarbary

Abstract In this paper, a single-phase to three-phase converter is proposed to provide variable output voltage and frequency. The proposed topology employs only six IGBT switches, which form the front-end rectifier and the output inverter for the one step conversion from single-phase supply to output three-phase supply. The front-end rectifier permits bidirectional power flow and provides excellent regulation against fluctuations in source voltage. Moreover, it incorporates active input current shaping feature. An easy method to implement control strategy is proposed. This control strategy ensures nearly unity input power factor with sinusoidal input current over the operating range. Based on sensorless vector control technique, the proposed converter is used for the speed control of the three-phase induction motor. A low cost motor drive can be achieved using the proposed converter and control technique. Simulation and experimental results are carried out to analyse and explore the characteristics of the low cost drive system.


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