This paper aims to optimize real-time control for the degraded mode of a fault-tolerant power architecture, but not the fault detection and isolation procedure itself. Such power architecture is dedicated to electric vehicles in which it performs the three following essential functions: traction, battery charging and electric grid assistance. For safety reason, in degraded mode, the power control is limited to the traction mode. Thus, for a given torque the proposed innovative strategy uses a novel current/voltage transform which leads to an efficient real-time control of the torque. The key idea is to drive the current without a priori restrictions on its waveform, while minimizing the Joule losses, i.e. the effective value of the current. It has been validated on a laboratory test bench. The studied system is based on a 3- phase open-end-winding synchronous machine powered by a 3 full H-bridges inverter. The last section of the paper analyses the comparison between the classic sinusoidal current waveforms and the proposed ones while operating on the two remaining motor phases. It results in a 14% increase of the torque produced by the permanent magnet machine under test, and a 14% decrease of the global system losses in traction mode. As a result, the new control strategy enhances traction performance in degraded mode and increases electric vehicle autonomy in postfailure condition.