FIELD DISTORTION ARRESTERS WITH IMPROVED TIME LIMITS FEATURES AND INCREASED RELIABILITY

Abstract

The article considers the features of the design of four-channel rail arresters with field distortion with improved time characteristics and presents the results of studies of their time characteristics. The need for these studies is associated with the widespread use of such dischargers in capacitive energy storage devices that serve as power sources for electrodynamic mass accelerators. At the present stage of the development of science and technology, the use of such accelerators is the most promising for creating experimental stands for modeling in laboratory conditions the processes of high-speed interaction of structural elements of aircraft with particles of different masses and different origins. According to the operating conditions of the experimental stands, in a wide range of changes in both particle masses and interaction velocities, the amplitude values of currents through the low-inductive load of the mass accelerator can vary from kiloamperes to several megamperes at acceleration times from units to hundreds of microseconds. With this in mind, capacitive energy storage devices are performed in a multi-module design. Each module of a capacitive energy storage device is switched to the load by its own switch. To expand the range of operation of the spark gap of the storage device, to obtain the time characteristics of the spark gap with small delay times, to exclude the probability of spontaneous operation of the spark gap, and to provide the stability of the discharge formation during parallel operation of the switches, the designs of four-channel rail spark gaps with field distortion with improved characteristics were developed, their experimental and theoretical studies were carried out. The results of the conducted studies show that the smallest value of the delay time and, accordingly, the spread of the delay time are obtained for a spark gap with field distortion with two control electrodes. It is shown that the obtained analytical expressions presented in the article and the empirical expression calculated for a spark gap with a field distortion with two control electrodes make it possible to determine the values of threshold voltages and delay times, taking into account the statistical delay time and the time of discharge formation. The value of the threshold voltage is determined, at which the process of direct transformation of the streamer into a spark discharge with high conductivity followed by a breakdown of the interelectrode gap is observed. The dependences of the static voltage on the pressure in the inner chamber of the spark gap with field distortion with improved time characteristics are given. It is shown that at a certain distance between the main electrodes at a pressure of 0,3-0,5 MPa, the arresters operate with a margin of electrical strength when the static breakdown voltage is 1,5-2 times higher than the operating voltage applied to the electrodes of the gas gap of the arrestor. This eliminates the possibility of spontaneous triggering of the dischargers of the capacitive energy storage.