in order to eliminate the bulky and costly offshore substation, a new offshore wind farm configuration has recently been proposed: series-connected configuration. among the seriesconnected configurations, the pulse width modulation current source converter (csc)-based one is considered a good candidate. in this thesis, a new pwm csc-based wind energy conversion system is proposed for the series-connected wind farms. compared with the previous work, the proposed topology reduces the cost and the manufacturing pressure of the system. a new control scheme is proposed to solve the voltage and current imbalance problem of the proposed configuration. in addition, the optimal modulation scheme is investigated for the series-connected cscs. simulation results are provided to assist in the investigation and verify the performance of the proposed configuration and control schemes.