This paper presents an online algorithm of multi-phase converter fault-tolerant operation in case of typical semiconductor switch failures. The goal of this research is to design a control system for avoiding converter shutdown and providing an effective solution for converter operation with optimal performance in case of active semiconductor switch fault. The proposed control algorithm uses fault detection method with PWM carrier redistribution, that is verified experimentally on 5-phase converter prototype. The experimental results for converter operation with active fault and enabled fault-tolerant algorithm show nearly same converter efficiency, as in normal operation. Hence, the proposed algorithm ensures optimal converter performance even with active fault.