VARIABLE VOLTAGE STABILIZER WITH PROTECTION FROM OVERLOADING Russian patent published in 2005 - IPC

FIELD: electric engineering.

SUBSTANCE: in case of continuous grid voltage excess higher than acceptable level contacts of stabilizer overload protection relay disengage, disabling adjusting transformer. Power for microprocessor device for controlling stabilizer and for all relays is taken from additionally provided power source with independent low-power transformer, constantly connected to stabilizer input and not switching off during overloads. After stop of effect from grid voltage excess contacts of overload protection relay engage, and normal operation of stabilizer is continued. Power for stabilizer control microprocessor and for all relays automatically switches to operation from power source, connected to windings of adjusting transformer of stabilizer. In case of effect from short-time pulse overloads in the grid, fast protection circuit, on dischargers and varistors, switches to operation, which does not disrupt stabilizer operation mode. Power for all relays and control microprocessor is taken from rectifier connected to windings of adjusting transformer of stabilizer, without switching to continuous protection mode. At the beginning of stabilizer operation microprocessor sets necessary states of relay for providing given voltage at output, after that voltage from adjusting transformer is sent to stabilizer output.

EFFECT: lesser dimensions, simplified construction, higher reliability.

1 dwg