Sylvia Méndez Prince

The switched reluctance machine (SRM) has certain advantages such as robustness and the absence of permanent magnets which have encouraged its use in recent years. One of its applications is as a self-excited generator. This behavior is produced when a capacitor is series or parallel connected to each single phase forming a nonlinear pseudoresonant circuit. This application can be used in isolated sites with a wind turbine for energy generation. This paper describes a novel method used for the… Mostrar más

The switched reluctance machine (SRM) has certain advantages such as robustness and the absence of permanent magnets which have encouraged its use in recent years. One of its applications is as a self-excited generator. This behavior is produced when a capacitor is series or parallel connected to each single phase forming a nonlinear pseudoresonant circuit. This application can be used in isolated sites with a wind turbine for energy generation. This paper describes a novel method used for the specific design of a 1-kW self-excited SRM for wind power applications based on torque considerations. The machine volume, dimensions, finite-element analysis, model verification, simulations, and experimental results are all presented. Mostrar menos

This paper analyzes the influence of excitation in the experimental determination of flux linkage vs. current vs. position relationship of a switched reluctance motor. Results of the experimental characterization of the SRM in the cases of rectangular bipolar excitation, rectangular unipolar excitation and sinusoidal excitation are compared. An equivalent model of a motor phase including magnetic flux leakage and core losses is presented and the simulation results are discussed. The component… Mostrar más

This paper analyzes the influence of excitation in the experimental determination of flux linkage vs. current vs. position relationship of a switched reluctance motor. Results of the experimental characterization of the SRM in the cases of rectangular bipolar excitation, rectangular unipolar excitation and sinusoidal excitation are compared. An equivalent model of a motor phase including magnetic flux leakage and core losses is presented and the simulation results are discussed. The component values obtained experimentally with sinusoidal excitation are maintained for both cases of rectangular excitation. The good fit between the phase current obtained experimentally and that obtained from the simulation in all three cases demonstrates the validity of the model. This enables the study of the dependence of the effects of the magnetic core on the behavior of a phase of the SRM using the same model. Mostrar menos

This paper proposes an alternative method to obtain the experimental determination of the flux linkage-current-position characteristics of a switched reluctance motor. Simulations are performed using different models of a phase of the motor. The results are compared with experimental measurements showing the influence of non-ideal effects associated with the magnetic core on determining the flux-current-position characteristics.

A Switched Reluctance Machine can be used as a self-excited generator if a capacitor is connected in parallel to each phase forming an L-C resonant circuit. In this case, the energy generated is related to the scanned area in the flux-current trajectory. This paper proposes a simple control of the energy that can be extracted from the system with a triac. This is the control element of current setting, that implies control of the flux-current area and, consequently, in the generated energy. The… Mostrar más

A Switched Reluctance Machine can be used as a self-excited generator if a capacitor is connected in parallel to each phase forming an L-C resonant circuit. In this case, the energy generated is related to the scanned area in the flux-current trajectory. This paper proposes a simple control of the energy that can be extracted from the system with a triac. This is the control element of current setting, that implies control of the flux-current area and, consequently, in the generated energy. The control technique described in this paper is patent pending. Mostrar menos

A knowledge of the electromagnetic characteristics of switched reluctance motors (SRM) is crucial for the simulation, analysis, control and development of drive systems based on these machines. Various experimental methods for determining flux-linkage-current-position characteristics can be found in the literature. References relating to the experimental determination of torque-current-position characteristics are few and focus on motors with a low number of poles. Moreover, in all of them the… Mostrar más

A knowledge of the electromagnetic characteristics of switched reluctance motors (SRM) is crucial for the simulation, analysis, control and development of drive systems based on these machines. Various experimental methods for determining flux-linkage-current-position characteristics can be found in the literature. References relating to the experimental determination of torque-current-position characteristics are few and focus on motors with a low number of poles. Moreover, in all of them the procedure uses the same number of tests as current and position samples necessary for the motor characterization (NI*NP tests, NI being the number of current samples and NP the number of position samples). This paper analyzes the problems related to the application of classical methods for torque experimental determination in a SRM with a high number of poles. We present a new method that avoids these problems and reduces the number of tests (independently of the number of current samples) to one for each position sample. The results are compared with those of classical methods, showing the improvements provided by the proposed experimental determination of the torque-current-position characteristics of a SRM. Mostrar menos

Analytical characterization of a switched reluctance motor (SRM) by means of magnetic circuit theory can be a tedious task. Specific software based on the finite elements method (FEM) for solving non linear magneto-static problems has proved very useful for this characterization. However, to solve the Maxwell equations it is necessary first to know the magnetization curve of the material used for building the motor, which may not be available in the program materials library. A simple and low… Mostrar más

Analytical characterization of a switched reluctance motor (SRM) by means of magnetic circuit theory can be a tedious task. Specific software based on the finite elements method (FEM) for solving non linear magneto-static problems has proved very useful for this characterization. However, to solve the Maxwell equations it is necessary first to know the magnetization curve of the material used for building the motor, which may not be available in the program materials library. A simple and low cost method for a direct determination of the first magnetization curve of a magnetic material is presented in this communication. Through one single test of short duration, (which allows to reach high values of the magnetic field strength while keeping the material temperature practically constant), we obtain a B-H curve that fits correctly to the samples obtained by a traditional method requiring the identification of multiple hysteresis loops. This B-H curve has been included in a FEM program to determine the flux linkage-current-position characteristic of a SRM prototype. The results again fit those obtained experimentally, confirming the validity of the proposed method. Mostrar menos

The Switched Reluctance Machine has certain advantages such as robustness and the absence of permanent magnets, which have encouraged its use in recent years. One of its applications is as a self - excited generator. This behavior is produced when a capacitor is connected in parallel to each single phase forming a resonant circuit. This application can be used in isolated sites with a wind turbine for energy generation. This paper presents the specific design of a 1 kW self - excited switched… Mostrar más

The Switched Reluctance Machine has certain advantages such as robustness and the absence of permanent magnets, which have encouraged its use in recent years. One of its applications is as a self - excited generator. This behavior is produced when a capacitor is connected in parallel to each single phase forming a resonant circuit. This application can be used in isolated sites with a wind turbine for energy generation. This paper presents the specific design of a 1 kW self - excited switched reluctance machine for wind power applications. In addition, presentation is made of the specifications, finite elements analysis, thermal profile and experimental results. Mostrar menos

The Switched Reluctance Machine can be used as an AC generator. In this operation mode, a capacitor is connected in parallel with each phase forming an L-C tank. Due to L characteristics, the behavior of the machine is highly nonlinear and generally, analytical solutions for the system differential equations are not possible. The steady state behavior of the system is a limit cycle. To predict and to analyze this behavior, nonlinear analysis tools must be used. The describing function is a… Mostrar más

The Switched Reluctance Machine can be used as an AC generator. In this operation mode, a capacitor is connected in parallel with each phase forming an L-C tank. Due to L characteristics, the behavior of the machine is highly nonlinear and generally, analytical solutions for the system differential equations are not possible. The steady state behavior of the system is a limit cycle. To predict and to analyze this behavior, nonlinear analysis tools must be used. The describing function is a method used for predicting limit cycles in nonlinear systems. In this paper, a study of stability in the switched reluctance generator based on the second order differential equation that describes the system is presented, then the analysis and characterization of the limit cycle behavior are carried out using the describing function. Mostrar menos