METHOD OF AUTOMATIC SWITCHING ON OF STAND-BY POWER SUPPLY OF USERS Russian patent published in 1995 - IPC

FIELD: electrical engineering. SUBSTANCE: in compliance with method of automatic switching on of stand-by power supply of users with synchronous motors drop of voltage of main power supply source and direction of active power across lead-in to main power supply source of buses (or its lack) are registered, user is switched over to stand-by power supply source, direction of current of forward sequence across lead-in of main power supply source is measured with respect to reference voltage formed from sum of voltage of forward sequence of section of buses of main power supply source and of voltage of make-up from stand-by power supply source matching it in phase and switching over of user to stand-by power supply source is performed if vector of current of forward sequence across lead-in of main power supply source has active-reactive character with reactive component directed predominantly from user's buses to main power supply source (or diminishes to value less than specified one) and value of current of main power supply source decreases simultaneously to those values that are less than specified ones. EFFECT: enhanced reliability of switching over. 4 dwg