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Tubular-switched reluctance linear launcher (TSRLL) with novel structure is proposed in this paper. The structure of switched reluctance motor is simplified, and the unbalanced force of common types of switched reluctance linear launcher is alleviated in TSRLL. The structure of the single-phase TSRLL with transverse flux is introduced thoroughly. The 3-D finite-element (FE) model of the proposed TSRLL is constructed, and electromagnetic analysis is performed by the FE method (FEM). To improve the electromagnetic force of the proposed launcher, the sensitivity analysis is conducted by means of 3-D FEM. The stator yoke thickness, mover cylinder’s thickness, stator pole arc, and pole width ratio of TSRLL are optimized, and the results of the sensitivity analyses are presented. TSRLL with two different polarity distribution patterns is compared via static FE analysis. The dynamic simulation of TSRLL with optimal specification and polarity distribution is carried out and demonstrated, of which the results agree well with the static analysis by FEM. [ABSTRACT FROM AUTHOR]

This paper analyzed the flux characteristics of a single-phase tubular switched reluctance linear motor (TSRLM) based on magnetic equivalent circuit (MEC) method. The single-phase TSRLM is divided into five different parts, which are the teeth of the stator, the yoke of the stator, air gap, the teeth of the mover, and the yoke of the mover. The reluctance of every part is expressed in analytical formulas at five special mover positions. The flux linkages at five special mover positions are calculated by magnet tube method and Gauss–Seidel iteration method which takes the saturation into consideration. A high-order Fourier series method is used to map the nonlinear relationship between flux linkage, current, and mover position with the flux linkage data calculated by the MEC method. The calculated flux linkage is consistent with 3-D finite-element method and experimental results. The dynamic and static performance of the simulation utilized with MEC method is consistent with those in experiments, which verifies the accuracy of the MEC method proposed in this paper. [ABSTRACT FROM AUTHOR]

The iron loss of doubled-sided linear switch reluctance motor (DLSRM) is analyzed and calculated in this paper. Because of the double salient structure of the switched reluctance motor and the nonlinearity of the magnetization curve of the ferromagnetic material, the flux density waveform is nonsinusoidal. So, it is difficult to calculate the iron loss of DLSRM. This paper mainly introduces the calculation method of dynamic magnetic density of the DLSRM, and basing on this, the simulation model of iron loss of DLSRM is built and compared the iron loss in different parts of the total as a percentage of the motor. Finally, an experimental platform based on DLSRM is built to measure the actual iron loss in the motor and verify the correctness of the calculation of iron loss. [ABSTRACT FROM AUTHOR]

Single-stage reluctance launcher simulations and experiment reaching velocity of 54.3 m/s are presented. A comparison between the experimental and two type of simulations, a numeric simulation and a quasi-analytic simulation was done. An average accuracy of ~4% was obtained for the numeric simulation and ~6% for the quasi-analytic simulation. The two complementary approaches of simulations can be used for effective optimization of many parameters of the launcher making it possible to improve the system. [ABSTRACT FROM AUTHOR]

Reluctance coilgun (RCG) is a special coilgun which uses solid ferromagnetic material instead of induction coil as projectile. RCG has shown great advantages and potential in the application of antiterrorism weaponry due to its simplicity, reliability, and excellent controllability. As a compact lightweight pulsed-power supply (PPS), the compensated pulsed alternator (Compulsator) will play a key role in promoting this kind of electromagnetic weapon into practical applications. Focused on a specific RCG which has conductive rails and brushes, this paper deduced the electromagnetic force analytical formula by using the virtual displacement principle and researched the feasibility of the electromagnetic launch design scheme which uses compulsator as the PPS of the RCG system by co-simulation method. Finally, this paper finished tests of the system by taking advantages of a small demonstrative RCG and a scale-model prototype of the compulsator. The results indicate that the design scheme is completely feasible. [ABSTRACT FROM PUBLISHER]

A reciprocating single-phase tubular switched reluctance linear launcher (TSRLL) with a short stroke is presented in this paper. The parametric design of this launcher is achieved based on finite-element method (FEM). By using the finite-element (FE) software FLUX, the 2-D and 3-D electromagnetic analyses of this launcher are carried out, respectively. The characteristic curves of position-current-flux linkage are analyzed by the 2-D and 3-D FEM. The prototype tests are conducted to verify the FE analyses. The static tests results show that the 3-D FE calculated results are more precise than the 2-D FE calculated results, and they coincide well with prototype static test results. The effectiveness of the FE model for the TSRLL is further testified by the results of prototype dynamic tests. Finally, some analyses on sensitivity parameters are conducted to further improve the performance of the TSRLL. [ABSTRACT FROM PUBLISHER]

In this paper we describe a developed switched reluctance linear launcher system with diagrams and photographs, which consists of a three-phase 6/4 structure simple side-switched reluctance linear motor, a three-phase asymmetric bridge power converter, and a TMS320F28335 DSP digital controller. The acceleration closed-loop control of the mover is proposed and verified for the first time. The acceleration closed-loop control of the mover is implemented by a fuzzy control algorithm. The turn-on angle and the turn-off angle of the main switches in the power converter are fixed, and the triggering signals of the main switches are modulated by the pulse width modulation (PWM) signal. The deviation of the acceleration between the given acceleration and the feedback practical acceleration, and the variation from the deviation of the acceleration are the two input control parameters. The increment of the duty ratio of the PWM signal is the output control parameter. The duty ratio of the PWM signal is regulated based on the fuzzy control algorithm. Flow diagrams of the software, such as the main program, the encoder unit time interrupt subroutine, analog-to-digital converter interrupt subroutine, and the fuzzy control algorithm subroutine are given. The developed prototype is tested experimentally. It is shown that the velocity response of the mover is satisfactory. [ABSTRACT FROM PUBLISHER]

A nonlinear simulation model of switched reluctance linear launcher drive based on MATLAB platform is presented in this paper. It consists of a three-phase 6/4 structure simple side switched reluctance linear motor, a three-phase asymmetric bridge power converter, and a closed-loop velocity controller, which is integrated with the magnetization curves of the switched reluctance linear motor obtained by the two-dimension finite-element electromagnetic field calculation, the nonlinear electrical network model of the power converter, and the excitation/commutation/velocity control algorithms. Those include mover relative position calculation module, controller module, power converter module, phase winding modules, and velocity calculation module. The simulated phase current waveforms and velocity curves agree well with the tested phase current waveforms and velocity curves experimentally. It is shown that the proposed nonlinear simulation model of the three-phase 6/4 structure switched reluctance linear launcher system is valid. [ABSTRACT FROM PUBLISHER]

In this paper, a magnetic analysis of large linear motors with long primary and short interior permanent magnet (PM) secondary is presented. The calculations are carried out using a finite-element method, taking into account the secondary motion and saturation in iron parts. Reluctance force could be increased using interior PM secondary. The thrust force oscillations are evaluated to obtain minimum force ripple. Furthermore, a magnet demagnetization analysis is presented to evaluate the magnet demagnetization risk under loading. Reduction in the magnet volume is considered for cheaper and simpler secondary structure. [ABSTRACT FROM AUTHOR]

The permanent-magnet (PM) synchronous motor (PMSM) takes advantages of small capacity, high efficiency, and high power density and have become commonplace in electric-vehicle driving systems. However, the excitation of PMSM cannot be adjusted, which restrains the PMSM from widening the speed range above its base speed. A PMSM with a variable magnetic reluctance field adjustment is presented in this paper. A new structure of the rotor is introduced, and flux-weakening (FW) principle is formulated. Analysis is discussed, including the force on the main PM, the movement process of the PM in the PM slot, the characteristics of the movement of the PM, and the FW performance of the new PMSM used for electric vehicles. The emulation analysis coincides with the test result, which verifies the availability and feasibility of the FW method for this kind of PMSM used for electric vehicles. [ABSTRACT FROM PUBLISHER]

As the exploitation of astrospace deepens, many new types of space-based electromagnetic launchers (EMLs) have aroused wide attention and discussions. Compared with traditional slotted electromagnetic linear launchers, a slotless-plate permanent-magnet linear synchronous motor can easily meet demands such as flexible structure, light weight, and high control precision for space use. This paper analyzes the magnetic field of the slotless inverted- U structure based on the equivalent-magnetizing-current method. The validity of this technique for integral-slot configuration is confirmed with finite-element analysis. Then, the influence of the main design parameters is investigated, and design optimization guides are established for the selection of the key design parameters. To reach the suitable air-gap flux density here, some new constructional optimization details are discussed. Design optimization is also performed to fulfill enough thrust for the EML system. [ABSTRACT FROM AUTHOR]