Creeping discharge element drive device and creeping discharge element drive method

A creeping discharge element drive device comprising:

• a switching element configured to connect to a creeping discharge element;
• a current detector configured to detect an alternating current flowing through the switching element;
• a zero-cross detection circuit configured to detect a zero-cross point of the alternating current detected by the current detector;
• a storage configured to store a first threshold value of a resonant period for determining an abnormality of the creeping discharge element during test operation;
• and
• a controller programmed to:
• drive the switching element to apply a test voltage to the creeping discharge element during the test operation, the test voltage being lower than a voltage applied to the creeping discharge element at a start of regular operation;
• determine a resonant period of the alternating current from a zero-cross point of the alternating current detected by the zero-cross detection circuit during the test operation;
• and
• restrict or stop the driving of the switching element in response to the resonant period exceeding the first threshold value.