The main problem in improving the tracking performance of linear permanent magnet motors is the presence of force ripple caused by the irregular magnetic field of the permanent magnets and inaccuracy in electronic commutation by the servo amplifier. This paper presents a method to identify and compensate the effect of the force ripple in servo control. A physical model of the linear motor and t...

Abstract: For disadvantages of the large flux and torque ripple and current waveform distortion of Direct Torque Control (BASIC-DTC), the DTC scheme for induction motor based on torque angle closed-loop control was presented and the proposed scheme was realized with three methods of torque angle closed-loop control. The main characteristics of three methods of torque angle closed-loop control f...

Preliminary notes In developing the vane pumps the fundamental basis is experimental research and mathematical modelling of nonstationary hydraulic processes inside the pump, in thrust space and suction and thrust pipeline. By means of experimental research and results of mathematical modelling and software package KRILP, it is possible to determine the parameters of operating processes of vane...

In this study, we used a 30 keV argon cluster ion beam bombardment to investigate the dynamic processes during nano-ripple formation on gold surfaces. Atomic force microscope analysis shows that the gold surface has maximum roughness at an incident angle of 60° from the surface normal; moreover, at this angle, and for an applied fluence of 3 × 1016 clusters/cm², the aspect ratio of the nano-rip...

Switching power converters are widely used due to their excellent efficiency, but they inherently generate ripple. Passive low-pass LC filters have been traditionally employed to meet ripple and EMI specifications [1]. These passive filters can contribute considerably to the volume and weight of a power converter. In particular, capacitors can become relatively large in order to meet strict rip...

We investigate theoretically the nonlinear evolution of sand ripples in a viscous fluid when a granular bed is submitted to a two-dimensional laminar shear flow. On the basis of the hydrodynamic equations and a semi-empirical sand transport law, we derive a non-local and nonlinear equation for the dynamics of the bed profile in the case of infinite flow depth. This equation reveals a coarsening...

In the present paper a simple sensorless spccd estimation scheme is presented , where the speed information is obtained from the motor phase current ripple. The scheme measures the stator current phasor deviation direction to determine the back emf vector position during inverter zero vector switching states. This measurcment of rotor flux position is done indirectly by computing the motor back...

Analysis and minimization of output current ripple of multiphase carrier-based PWM inverters are presented in this paper. Analytical expression of rms value of output current ripple of multiphase PWM inverters as a function of the reference signal is first derived. Based on this expression, it is shown that a pure sinusoidal signal is the optimum reference signal that results in minimum output ...