A power conversion system includes N power converters. Each power converter includes an input terminal, a first output terminal and a second output terminal. Each of the N power converters receives a DC power through the input terminal. The first output terminal of a first power converter and the second output terminal of an N-th power converter are connected in parallel to form an N-th total output terminal. The first output terminal of an i-th power converter and the second output terminal of an (i−1)-th power converter are connected in parallel to form an (i−1)-th total output terminal. The two input terminals of the load are connected with two total output terminals of N total output terminals. A (2k−1)-th power converter is connected with a first power source. A 2k-th power converter is connected with a second power source. The redundancy of the power conversion system can be achieved.