Four-way electronic switch for tracking balloon borne transmitter using sequential lobe switching

The tracking of meteorological balloons using dipole matrix array antenna by sequential lobe switching with the help of a motor driven mechanical UHF phasing switch had been in operational use in our national upper air network from last 25 years. A solid state four-way electronic switch at 400 MHz using high conductance-high speed switching diodes has been designed to replace the aged motor driven mechanical phasing switch. Microstripline technique has been used in designing UHF switch to achieve proper impedance, matching, routing and addition of UHF signals received from the four antenna bays. For sequential switching of antenna array and synchronisation of data reception and display system the intelligence is generated by a compact logic in-built in the phasing switch. Unlike, mechanical switch, the present system has no switching noise and has low insertion loss (2 dB), thus improving the data acquisition capability of ground reception system. The design of switch is modular, light weight and highly rugged to suit all types of environmental conditions.

The use of a high-power electronic switch in the deicing on the overhead line network using the pulse-resonance method

The possibility of technical implementation for deicing of double contact wires by pulse-resonance method using a high-power electronic switch is evaluated. For a specific double-track road section of overhead line network, the parameters of the necessary step-down transformer operating in pulse mode and providing heating of the contact wires to positive temperatures are calculated. A possible range of changes in the current density of the contact wires, controlled by the relative pulse duration, is determined.

Digitalized Synchronization of Multi level STATCOM with Switch Fault Elimination

With much advancement in the FACTS technologies STATCOM with multi-level inverter provides reactive compensation with less harmonics injection in the grid system. The voltage stress on each power electronic switch is also reduced as the voltage across each switch is low, in turn reduces the switching losses. In this paper a cascaded multi-level inverter with STATCOM application of 2m+1 levels controlling through Space Vector PWM was considered. Switch fault analysis is carried out by detecting and mitigating the fault with a bypass power electronic switch. Design method and parametric analysis is carried out in MATLAB simulation and results arevalidated.