Residual voltage test circuit of controllable metal oxide arrester and method thereof

The invention discloses a residual voltage test circuit of a controllable metal oxide arrester and a method thereof. The test circuit comprises an impulse current generation device, an impulse modulation capacitor, a voltage divider, a Rogowski coil and a wave form recorder; wherein the impulse current generation device generates operation impulse current and/or lightning impulse current, and is provided with a high voltage output end and a low voltage output end; the impulse modulation capacitor is connected in parallel with a controllable arrester sample between the high voltage output end and the low voltage output end; one end of the voltage divider is connected with the high voltage output end of the impulse current generation device, while the other end is earthed; the Rogowski coil is directly sleeved on a conductor on a branch circuit of the controllable arrester sample; the wave form recorder is connected with the voltage divider and the output end of the Rogowski coil respectively, and is used for recording voltage and current wave form of the controllable arrester sample. The residual voltage test circuit for the controllable arrester and the method thereof prolong wave head time of the residual voltage on the controllable arrester sample by using the impulse modulation capacitor without changing parameters of the test circuit or the wave form of the lightning impulse current, so that tests have better system equivalence.