OVERLOAD PROTECTION OF VOLTAGE-REDUCING DEVICE Russian patent published in 2012 - IPC H02H7/04 H02H9/06 G05F1/567 G05F1/569 G05F1/573 

FIELD: electricity.

SUBSTANCE: system for reduction of voltage in an electric source of AC power supply for a load with the purpose to increase energy efficiency comprises a transformer and a power converter connected into a circuit between the electric source of AC supply and the load, and a shunting switch S, which provides for transformer disconnection from the circuit and which connects the electric source of supply with the load in case of continuous overload of the transformer. The system comprises a facility (14) to measure transformer temperature, a facility (17) to measure current in the circuit and a control facility (15), receiving signals from sensors (14, 17) and for control of the shunting switch S, to shunt the transformer and make it possible for it to be cooled down. A safety fuse F₂ and a device (16) of thermal opening are connected into the circuit of the secondary winding of the transformer, as a safety device for interrupting of power supply into the transformer, if there is a failure in operation of the shunting switch.

EFFECT: provision of a system, by means of which the transformer may be shunted to eliminate heating, prevent damage of a transformer and reduce a potential risk of fire.