A static var compensation apparatus comprising: a thyristor switched capacitor -TSC- and a thyristor controlled reactor -TCR-; wherein the TSC comprises: a plurality of capacitor banks (310, 824, 825, 826) in a structure of Y connection configured to supply three-phase alternating current -AC- power in order to perform reactive power compensation; a plurality of bidirectional thyristors (320, 821, 822, 823) configured to open and close the plurality of capacitor banks; a plurality of harmonic filters (710, 827, 828, 829) connected to the plurality of capacitor banks respectively and configured to absorb harmonics; a plurality of switches inserted between the plurality of harmonic filters and the plurality of capacitor banks; and a controller configured to: calculate the amount of reactive power necessary to be compensated and to control the plurality of bidirectional thyristors to open and close the plurality of capacitor banks in correspondence to the calculated amount of reactive power, and calculate an amount of harmonics occurring during operation of the static var compensation apparatus and control transmission of power to the plurality of harmonic filters by opening and closing the plurality of switches based on the calculated amount. a thyristor switched capacitor -TSC- and a thyristor controlled reactor -TCR-; wherein the TSC comprises: a plurality of capacitor banks (310, 824, 825, 826) in a structure of Y connection configured to supply three-phase alternating current -AC- power in order to perform reactive power compensation; a plurality of bidirectional thyristors (320, 821, 822, 823) configured to open and close the plurality of capacitor banks; a plurality of harmonic filters (710, 827, 828, 829) connected to the plurality of capacitor banks respectively and configured to absorb harmonics; a plurality of switches inserted between the plurality of harmonic filters and the plurality of capacitor banks; and a controller configured to: calculate the amount of reactive power necessary to be compensated and to control the plurality of bidirectional thyristors to open and close the plurality of capacitor banks in correspondence to the calculated amount of reactive power, and calculate an amount of harmonics occurring during operation of the static var compensation apparatus and control transmission of power to the plurality of harmonic filters by opening and closing the plurality of switches based on the calculated amount. a plurality of capacitor banks (310, 824, 825, 826) in a structure of Y connection configured to supply three-phase alternating current -AC- power in order to perform reactive power compensation; a plurality of bidirectional thyristors (320, 821, 822, 823) configured to open and close the plurality of capacitor banks; a plurality of harmonic filters (710, 827, 828, 829) connected to the plurality of capacitor banks respectively and configured to absorb harmonics; a plurality of switches inserted between the plurality of harmonic filters and the plurality of capacitor banks; and a controller configured to: calculate the amount of reactive power necessary to be compensated and to control the plurality of bidirectional thyristors to open and close the plurality of capacitor banks in correspondence to the calculated amount of reactive power, and calculate an amount of harmonics occurring during operation of the static var compensation apparatus and control transmission of power to the plurality of harmonic filters by opening and closing the plurality of switches based on the calculated amount. calculate the amount of reactive power necessary to be compensated and to control the plurality of bidirectional thyristors to open and close the plurality of capacitor banks in correspondence to the calculated amount of reactive power, and calculate an amount of harmonics occurring during operation of the static var compensation apparatus and control transmission of power to the plurality of harmonic filters by opening and closing the plurality of switches based on the calculated amount.