POWER ELECTRONICS ABSTRACT 2016-2017 EFFECTIVE VOLTAGE BALANCE CONTROL FOR BIPOLAR-DC-BUS FED EV CHARGING STATION WITH THREE-LEVEL DC-DC FAST CHARGER The development of high-power charging stations with fast chargers is a promising solution to shorten the charging time for electric vehicles (EVs). The neutral-point-clamped (NPC) converter based bipolar-dc-bus fed charging station brings manymer its, but it has inherent voltage balance limits. To solve this issue, a voltage balance control (VBC) method based on a new modulation together with three-level (TL) dc-dc converter based fast charger is proposed. Additionally, an effective VBC coordination between the TL dc-dc converter and NPC converter is formulated. Through the proposed VBC coordination, the controllable balancing region is extended so that additional balancing circuits are eliminated. Meanwhile, the grid-side currents quality is improved as the NPC converter has more free Dom to control currents. The low-frequency voltage fluctuations in dcbuses are removed because the TL dc-dc converter performs most of the balancing tasks. Faster VBC perturbation performance is achieved due to higher available balancing current at TL dc-dc converter side. In addition, the voltage balance limits of both the TL dc-dc converter and the NPC converter are explored. The voltage balancing performances are compared when VBC is located at different sides. Simulation and experimental results are provided to verify the proposed VBC and the VBC coordination.