Switched Reluctance Motor Drive Research Articles

High efficiency single‐pulse controlled switched reluctance motor drive based on novel multilevel converter

Due to the high back electromotive force and short commutation time at high speed, the phase current of switched reluctance motor (SRM) is difficult to reach a large value, which limits the output performance of the motor in high-speed operation. This paper proposes a novel multilevel converter (MLC) with fast excitation and fast demagnetisation capability, which allows each phase to control independently even in overlapping conduction operation and is suitable for SRM with any number of phases. The excitation current in the rising inductance region is increased by high-voltage fast excitation, thus increasing the phase current level of the motor at high speed; the current tailing in the falling inductance region is suppressed by high-voltage fast demagnetisation, thereby reducing the generation of negative torque. Based on the novel MLC, a maximum torque per ampere (MTPA) control strategy is designed, and closed-loop control of the boost capacitor voltage is developed. By optimising control, the output torque and efficiency of switched reluctance motor drive (SRD) are greatly improved, and the constant power operation range is extended. Simulation study and experimental results verify the effectiveness of the proposed scheme.

Comparative evaluation on switched reluctance motor drive with different phase current sensing methods

Cost-effective phase current sensing is critical for the performance improvement of switched reluctance motor drive (SRD). In this study, a new two -sensor phase current sensing method is proposed and comparatively investigated with conventional m -sensor and one -sensor methods. First, the operation principles of the m -sensor, one -sensor, and proposed two -sensor methods are illustrated in detail on a four-phase SRD. Compared with the one -sensor method, the topology can be maintained without splitting the lower bus into freewheeling bus and excitation bus under the two -sensor method. Next, an advanced decoupling strategy is presented to obtain the complete phase current information and shorten the region of switch signals injection. With the simulation model in Matlab/Simulink environment, the steady and transient performance of SRD in the proposed method are not inferior to m -sensor and one -sensor methods. Meanwhile, the proposed two -sensor method is demonstrated to own superior thermal stress distribution by the finite-element model in ANSYS software. Eventually, the dynamic reliability is proved to be not enhanced as the number of current sensors decreases. Finally, an experimental setup with double-core TMS320F28377D is built to validate the proposed method and evaluation results.

Online sensorless fault diagnosis and remediation strategies selection of transistors for power converter in SRD

The fault diagnosis methods and remediation strategies (RSs) are critical for high-reliability operation of power converters in switched reluctance motor drive (SRD). This study presents an online sensorless fault diagnosis method and effectively selects the RSs from the reliability view. To begin with, the equations of neutral voltage are derived for each phase leg in popular asymmetric half-bridge converter under normal and faulty operation conditions. Next, the diagnosis criterion is proposed with the combination of drive signals and neutral voltage signatures. Besides, the low-cost circuits are designed to save the diagnosis cost, especially for the control strategies without any current or voltage sensor. Moreover, the diagnosis time can be decreased to 7 µs and not affected by the speed, load torque, control strategies and topologies. Moreover, the proposed method can also identify the multiple faults of transistors. In addition, to further enhance the reliability of power converter and then for SRD, the reliability-oriented selection of RSs is carried out by means of the dynamic Markov model. Finally, the experiments of fault diagnosis and thermal stress measurement are conducted to confirm the effectiveness of the proposed diagnosis method and RSs selection.

Reliability Assessment of the Switched Reluctance Motor Drive Under Single Switch Chopping Strategy

In this paper, a detailed set of reliability prediction methodology for switched reluctance motor drive (SRD) considering system specific control strategy and component fault classification is elaborated from component level to system level. At component level, introduction to SRD and its single switch chopping strategy is presented to capture characteristics of SRD reliability under a certain control strategy. The unique fault modes classification and summary methods which are tailored to SRD are applied for identification of system dominant fault modes. Then at system level, binary models (reliability block diagram and part-count model) and multivariate model (Markov model) are adopted to build systematic SRD reliability model, respectively. Especially in the Markov model, state transition diagram and state probability matrix P ( t ) are built in detailed description to constitute the graphical and numerical Markov reliability model. Conclusions can be drawn that compared with RBD, Markov model can capture the effect of specific control strategy on system reliability, and further demonstrates the stronger consistency with SRD practical operation. Fault simulation and experiments are conducted to illustrate the influence on system operation state caused by a control strategy. Also, the results verify the state assessment of system performance after component-level fault occurs.

Switched Reluctance Drive System Design Based on DSP

A switched reluctance motor drive (SRD) is designed in this paper. This system has the characteristics of simple structure and reliable performance. It is designed based on 3 phase, 12/8 pole, 2.2 KW switched reluctance motor (SRM). The TMS320LF2407A is chosen as the core controller. The type of half bridge is adopted in the main power converter circuit, and IGBT is used as the main power switching component and discrete components is used as the main power switch converter device driver circuit. Experimental results show that the designed system can be run steadily under rated load conditions. Moreover, the speed regulation of this system has satisfactory performance.

Research Switched Reluctance Motor Drive (SRD) Based on Fuzzy Sliding Mode Control

For the shortcomings of the torque ripple of switched reluctance motor (SRM), this paper presents a strategy of controlling switched reluctance motor drive (SRD) with fuzzy sliding mode controller. The speed loop uses the conventional PI regulator, and the current loop adopts the fuzzy sliding mode controller which takes the current deviation as switching function and combines with fuzzy reasoning to determine the value of switching gain. The fuzzy sliding mode controller will realize the precise current control and enhance the stability of the system. The simulation results show that the system can suppress the torque ripple effectively and realize high-performance SRD control.