Test circuit for high-voltage switchgear breaking capacity - includes nonlinear voltage regulator for application of test current with standard four-parameter transient recovery voltage

摘要

A heavy-current circuit (1) which contains an AC source (3) with an auxiliary switch (5) and the switch under test (8) is connected at live and earthed terminals (6, 7) to a high-voltage circuit (2) including a regulator (17) and a spark gap (22) triggered from a current transformer (9) and control unit (10). Relative to a predetermined zero crossing of test current, the circuit ensures the correct current in the test switch (8) immediately before breaking and the correct voltage after it. The nonlinear component (20) of the regulator (17) may be mfd. of varistor material. USE/ADVANTAGE - For synthetic overcurrent and overvoltage testing of HV power switches. Necessary frequency variations can be achieved with inexpensive and proven circuit elements. Space is saved with elimination of bulky and costly inductors and capacitors.