On-load tap changing apparatus and on-load tap changing system

An on-load tap changing system comprising:

• an on-load tap changing apparatus that comprises:
• a first switching unit connected to a first tap of a transformer provided in a power system, and a power supplied from the first tap;
• a first impedance changing unit connected in series with the first switching unit, and increasing an impedance when the first switching unit executes a switching operation;
• a second switching unit connected to a second tap of the transformer, and switching a power supplied from the second tap;
• and
• a second variable impedance unit connected in series with the second switching unit, and increasing an impedance when the second switching unit executes a switching operation;
• a first main switch contact connected in parallel with the first switching unit of the on-load tap changing apparatus;
• and
• a second main switch contact connected in parallel with the second switching unit of the on-load tap changing apparatus, wherein:
• the first impedance unit of the on-load tap changing apparatus becomes higher impedance than an impedance of the first main switch contact when the first switching unit executes a switching operation, and becomes lower impedance than the impedance of the first main switch contact when becoming low impedance;
• and
• the second impedance changing unit of the on-load tap changing apparatus becomes higher impedance than an impedance of the second main switch contact when the second switching unit executes a switching operation, and becomes lower impedance than the impedance of the second main switch contact when becoming low impedance.