Abstract: Current-source type actively commutated converter (ACC) using self-turn-off power semiconductors is characterized by decoupled control of active and reactive power, avoidance of commutation failure, no requirement of a large amount of energy storage capacitors and so forth. ACC has good application prospects in high voltage direct current (HVDC) transmission systems. This paper reviewed and analyzed the power semiconductors with voltage sharing technology, converter circuit topology, modulation method, active and reactive power characteristics, control schemes, fault and protection problems of ACC for HVDC applications. The comparisons among ACC, the conventional line commutated converter (LCC) and modular multilevel converter (MMC) were also done for a specific HVDC inverter with the same voltage rating, current rating, and power semiconductor stresses. This paper also analyzed the potential application scenarios, the existing problems, and future trends of ACC technology.