Electrical engineering & Electromechanics (Aug 2020)
EXCITATION WITH A SERIES OF PULSES OF A LINEAR PULSE ELECTRODYNAMIC TYPE CONVERTER OPERATING IN POWER AND HIGH-SPEED MODES
Abstract
Purpose. The aim of the article is to increase the efficiency of linear pulse electrodynamic type converter (LPEC) when operating in high-speed and force modes by reducing the amplitude of the recoil force by exciting its windings with a series of pulses from the capacitive energy storage (CES). Methodology. Using the LPEC mathematical model, in which the equations describing the interconnected electrical, magnetic, mechanical and thermal processes are presented in a recursive form, the electrodynamic and electromechanical characteristics of LPEC are simulated by excitation by a single and a series of pulses from CES sections. Results. It was found that when a single pulse is excited by an LPEC operating in a high-speed mode, in which the armature accelerates the actuator, compared with the force mode in which the armature is inhibited, the current amplitude in the windings decreases by 7.5 %, and the amplitudes of electrodynamic force (EDF) – by 21.8 %, impulse values of EDF – by 27.1 %. In this case, the armature winding with the actuating element accelerates to a speed of 7.1 m/s. When excited by a series of pulses from the same sections of the CES during LPEC operation in the force mode, the amplitudes of the current pulses and the EDF are practically unchanged, and when operating in high-speed mode, the amplitudes of the currents and the EDF gradually decrease. Both in power and in high-speed operating modes, an increase in the number of excitation pulses while conserving the energy of the CES leads to a decrease in the main indicators of LPEC. But by reducing the amplitude of the EDF, which manifests itself as a recoil force, the efficiency of LPEC increases. Originality. It is shown that the excitation of LPEC by a series of pulses increases the efficiency of LPEC when operating in high-speed and power modes, providing a minimum amplitude of the EDF, which determines the recoil force acting on the inductor winding. Practical value. For LPEC operating in high-speed mode, it is proposed to reduce the maximum current amplitudes and EDF due to the sequential increase in capacitances of sections of the CES, forming a series of excitation pulses. For LPEC, operating in force mode, it is advisable to use the same capacities of all sections of the CES.
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