OVERVOLTAGE PROTECTIVE GEAR FOR MULTIPHASE CIRCUITS Russian patent published in 2003 - IPC

FIELD: power engineering. SUBSTANCE: high-linear series-connected resistors are inserted between phases of circuit under protection and ground for extreme phases and for intermediate phase. Two more high-linear resistors are inserted between points of connection of series-connected resistors of each extreme phase and same point of intermediate phase. Sum of voltages at rated discharge current through upper resistor of any of extreme phases and through additional resistor inserted between extreme and intermediate phases equals voltage at rated discharge current of intermediate-phase upper resistor; voltage ratio at rated discharge current of intermediate-phase upper and lower resistors is . EFFECT: improved protective characteristics and operating stability of device. 1 cl, 1 dwg