OVERVOLTAGE PROTECTIVE GEAR Russian patent published in 2007 - IPC H02H9/06 

FIELD: electrical engineering; power switching devices; overvoltage protection of electrical equipment.

SUBSTANCE: proposed overvoltage protective device has controllable discharge gap connected in series with working resistor. Controllable discharge gap is made in the form of controllable vacuum discharger. Working resistor is made in the form of parallel-connected nonlinear resistor R with U_pr < KU_m, where 1 < K < 1.8; K is ratio; U_pr is remaining limiting voltage; U_m is peak value of mains rated voltage. Line impedance Z incorporates resistive and reactive components and its value meets following inequality: U_ov/I_ov > Z > U_pr/I_max, where I_max is current through R at U = U_pr = U_pr; I_ov is current through R at which current-voltage characteristic transfers from conductance region to accompanying current region; U_ov is voltage across R at current I = I_ov.

EFFECT: enlarged operating voltage range, enhanced admissible pulse currents and electric strength recovery rate upon disconnection of accompanying current, enhanced reliability and service life.

1 cl, 2 dwg