Аналитическое исследование переходных процессов в электрическом амортизаторе

Abstract

The kinetic energy of vibration that occurs when an electric car moves on a rough road is usually transformed into thermal energy in mechanical shock absorbers and other means of damping and dissipates; that is, this energy is wasted. By using an electric shock absorber it becomes possible to convert the energy of vibration into electrical energy with subsequently storing it in a battery. The electric shock absorber consists of a cylindrical permanent- magnet linear generator, a spring and an electric energy storage battery. The generator, which operates as a damper and a converter together with the battery, are the shock absorber main parts. The aim of the article is to analyze the transient triggered by a step load. The generator operates constantly in a transient mode, which is described by a system of third-order differential equations (DЕs), which describes the transient in the electrical circuit and the oscillations of the shock absorber mechanical part. Depending on the DЕ coefficients, the transient may be aperiodic or oscillatory in nature. The analytical solution of the DЕ system using the operator method is presented. A solution using which the transients triggered by a disturbing force described by different variation laws can be studied is obtained. The calculation results for the secondary part displacement and velocity, and for the generator current for the case when the system is subjected to a stepped force are given. It is shown that for ensuring correct operation of the shock absorber under the conditions when the generator EMF is less than the storage battery voltage, the generator winding should be short-circuited, and the battery itself should be disconnected from the network. In that case, the characteristic polynomial will have real and negative roots, and the displacement and velocity fluctuations will be aperiodic in nature.