Influence of limiting the duration of the armature winding current on the operating indicators of a linear pulse electromechanical induction type converter

Introduction. Linear pulse electromechanical converters of induction type (LPECIT) are used in many branches of science and technology as shock-power devices and electromechanical accelerators. In them, due to the phase shift between the excitation current in the inductor winding and the induced current in the armature winding, in addition to the initial electrodynamic forces (EDF) of repulsion, subsequent EDF of attraction also arise. As a result, the operating indicators of LPECIT are reduced. The purpose of the article is to increase the performance of linear pulse electromechanical induction-type converters when operating as a shock-power device and an electromechanical accelerator by limiting the duration of the induced current in the armature winding until its polarity changes. Methodology. To analyze the electromechanical characteristics and indicators of LPECIT, a mathematical model was used, in which the solutions of equations describing interrelated electrical, magnetic, mechanical and thermal processes are presented in a recurrent form. Results. To eliminate the EDF of attraction between the LPIECIT windings, it is proposed to limit the duration of the induced current in the armature winding before changing its polarity by connecting a rectifier diode to it. It was found that when the converter operates as a shock-power device without limiting the armature winding current, the value of the EDF pulse after reaching the maximum value decreases by the end of the operating cycle. In the presence of a diode in the armature winding, the efficiency criterion, taking into account the EDF pulse, recoil force, current and heating temperature of the inductor winding, increases. When the converter operates as an electromechanical accelerator without limiting the armature winding current, the speed and efficiency decrease, taking into account the kinetic energy and voltage of the capacitive energy storage at the end of the operating cycle. In the presence of a diode in the armature winding, the efficiency criterion increases, the temperature rise of the armature winding decreases, the value of the maximum efficiency increases, reaching 16.16 %. Originality. It has been established that due to the limitation of the duration of the armature winding current, the power indicators of the LPECIT increase when operating as a shock-power device and the speed indicators when the LPECIT operates as an electromechanical accelerator. Practical value. It was found that with the help of a rectifier diode connected to the multi-turn winding of the armature, unipolarity of the current is ensured, which leads to the elimination of the EDF of attraction and an increase in the performance of the LPECIT.

An air insulated linear pulse transformer for electrodischarge technology

A linear pulse transformer with air insulation at atmospheric pressure was created and tested under both constant resistance and non linear loads. The maximum power of the transformer output pulse reached ∼500 MW at a matched load with a charge voltage 50 kV. The transformer transferred ∼60% of the stored energy to the load over a characteristic time of about 1 μs. The scalability the generator was studied by connecting two identical transformers in series which gave a power output of ∼850 MW with doubled output voltage and reduced current. The frequency mode of operation was studied using one and two transformers with a charge voltage of 50 kV and a load that was, close to matched. In both cases, the power maximum and jitter showed no significant changes at any of the frequencies tested (up to 5 Hz). These results mean that the use of this generator can be recommended for a wide field of applications due to its scalability and low internal impedance.

Research on time synchronization of linear pulse-coupled oscillators model with delay in nearest neighbor wireless multi-hop networks

Time synchronicity works as a popular requirement in wireless sensor networks. Pulse-coupled oscillators similar to firefly flashing and synchronization via discrete pulse coupling are widely used in wireless sensor networks. In this article, we have studied the time synchronization with communication delay in the nearest neighbor network of distributed sensors, based on the pulse-coupled oscillators model of synchronicity achieved by biological systems. First, we present a linear pulse-coupled oscillators model with coupling delay and the model is used to analyze the wireless sensor networks synchronization with communication delay. Second, we mathematically analyze the firing behaviors in the linear pulse-coupled oscillators network using the delayed excitatory coupling and track the synchronization process of the two and multi-oscillators and obtain the synchronization conditions from the regression mapping. Finally, through the proposed model implementation in the wireless sensor networks simulation framework, we demonstrate that the multi-oscillators system can be synchronized from a random starting stage distribution under linear phase responding functions and the nearest neighbor communication. The results show that our approach can achieve clock synchronization in wireless sensor networks with delayed nearest neighbor communication.

INFLUENCE OF AN EXCITATION SOURCE ON THE POWER INDICATORS OF A LINEAR PULSE ELECTROMECHANICAL CONVERTER OF INDUCTION TYPE

The purpose of the article is to evaluate the efficiency of an induction-type linear pulse electromechanical converter (LPEC) when operating in shock-power mode and excitation from an alternating voltage source (AVS) in comparison with excitation from a capacitive energy storage (CES). A mathematical model of an induction-type LPEC has been developed both when excited by a unipolar pulse from a CES and from an AVS using lumped parameters of the windings, which takes into account the interrelated electromagnetic, mechanical and thermal processes. It has been found that when the LPEC is excited from the AVS with a voltage frequency of 50 Hz, the electrodynamic force takes on a periodic decaying character with a significant prevalence of positive components of forces over negative ones. The maximum value of the force is much less, and the value of its impulse is much greater than in the LPEC, excited from the CES. With an increase in the frequency of the AVS voltage from 50 to 150 Hz, the highest value of the current density of the inductor winding decreases, and in the armature winding it increases. The greatest values of force and impulse of force are realized at a voltage frequency of 150 Hz. With an increase in the AVS frequency, the relative indicator of the efficiency of the LPEC increases. References 15, figures 4.