TY JOUR TI COMPARISON OF UNINTERRUPTIBLE POWER SUPPLY RELIABILITY IN VARIOUS REDUNDANCY SYSTEMS KW UPS KW electrical engineering complex KW reliability KW failure rate KW availability KW mean time between failures JO Automation and modeling in design and management AU Sirotskiy, M.S. AU Pugachev, A.A. PY 2026 IS 2026 PB Bryansk State Technical University