Advanced static VAR compensator using a new topology of multilevel inverters energized from non-equal DC sources

Recent improvement in the speed-power characteristics of power semiconductor switches has increased the interest to incorporate multilevel inverters in the medium and high power-level ranges, particularly in power system control and compensation. Since multilevel inverters supplied from equal and constant dc sources are almost donpsilat exist in the practical applications. This paper presents an advanced static VAR compensator system based on a new configuration of multilevel inverters having least number of switching devices and operating with non-equal dc voltage sources. The static VAR compensation is achieved through controlling the switching angles of the inverter while eliminating the dominant line harmonics. The switching angles of the inverter are obtained by solving the relevant equations using the theory of resultant, which is based on solving polynomial equations which produces all possible solutions. System simulations are carried out and experimentally validated.