Magnetic Characteristics Of Switched Reluctance Motor Research Articles

Quad Sampling Incremental Inductance Measurement Through Current Loop for Switched Reluctance Motor

Magnetic characteristics of a switched reluctance motor (SRM) determine the modeling accuracy, the performance of a position sensorless control, and the torque ripple reduction control. Due to double saliency structure and core saturation, the magnetic characteristics of SRM is dependent on both the rotor position and the winding current amplitude, which makes it difficult to measure the actual incremental inductance or flux linkage. This article presents the magnetic characteristics identification method. A quad current sampling technique is proposed to capture the derivative of the winding current at a specific rotor position and current amplitude. The flux linkage, co-energy, and torque are calculated from the obtained incremental inductance profile. The proposed method can be easily implemented on digital signal processor-based SRM drive without any extra circuit. The LCR meter and torque sensor measurements are provided to validate the proposed incremental inductance measurement method.

Torque modeling of Switched Reluctance Motor using LSSVM-DE

An accurate and precised model of Switched Reluctance Motor (SRM) captures the performance of the machine. The model is highly nonlinear and complicated due to its doubly salient structure. In this paper, a nonparametric regression model for torque parameter of SRM was developed using Least Square Support Vector Machine (LSSVM) applying the concept of kernel based learning. Hyperparameters of LSSVM improves the model accuracy and generalization ability. The optimal values of hyperparameters were obtained by using Differential Evolution (DE) and high accuracy was observed. The regression model was developed using the magnetic characteristics of SRM by 2-D Finite Element Methods (FEM). The results obtained have been compared with the other optimization algorithms such as Genetic Algorithm (GA) and Particle Swarm Optimization (PSO).

Sensorless Control of Switched Reluctance Motor Based on Phase Inductance Vectors

A new sensorless control method based on phase inductance vectors of switched reluctance motor (SRM) is presented in this paper. To implement this method, the following was done. First, based on the pulse injection technique, a new method called phase current slope difference is proposed for identifying the full-cycle phase inductance of each phase. Second, the phase inductances are considered as vectors with fixed phase difference and the composed vector is rotated with the varied rotor position. Combining the composed vector orthogonal decomposition method and a new inductance subregional method, the rotor position can be estimated. This method can realize sensorless control of SRM from starting up at standstill to high-speed operation and is quite easy to implement. No additional hardware or complex computation is required and no a priori knowledge on magnetic characteristics of SRM is necessary. To verify the performance of the proposed sensorless scheme, the following experiments have been performed: 1) the initial rotor position at standstill and rotating shaft conditions are estimated for sensorless startup control; and 2) the rotor position and rotational speed are estimated at different reference speeds for sensorless speed closed-loop control and the dynamic performance is fully validated.

Flux linkage measurement method for switched reluctance motors and inductor/transformers using a real-time DSP system

The switched reluctance motor (SRM) has received considerable attention from researchers for its many inherent advantages, and thus has become a popular research topic in the field of variable-speed drives as well as servo drives. The research on SRMs mainly includes its design, modelling and performance analysis, control, as well as applications. However, for verification of design, performance prediction and development of a high-performance sensorless control algorithm, accurate measurement of the magnetic characteristics of the SRM is most critical. Hence, one of the most important problems in the field of SRMs is a practical and accurate instrumentation system for the measurement of the SRM magnetic characteristics. This paper first describes an accurate, fully automated digital method for the measurement of the magnetic characteristics of SRMs, including on-line offset error removal and winding resistance estimation. In this method, a digital signal processor-based virtual instrumentation for measurement of flux linkage is developed. Then the results of measurement conducted on a four-phase SRM are presented. The accuracy of the measurement system is verified by comparing it with that found via a magnetics analyzer. Finally, the various sources of errors are discussed and their contributions to the errors are quantified. The scheme can also be used in general for transformers or inductors