Patent ID: 8810179

Claim:
A method of controlling a polyphase electrical machine by at least two polyphase inverters in parallel, each inverter comprising a number of branches equal to a number of phases of the electrical machine, and each branch comprising two power switches connected in series between two opposite terminals of a DC electrical power supply and connected to opposite sides of a point that is connected to an electrical phase of the electrical machine, the method comprising: controlling the inverters by pulse-width modulation so as to control switching of the power switches, and detecting an inverter branch fault; wherein in response to detecting an inverter branch of a first inverter that is faulty, the faulty branch is isolated, the phase of the electrical machine corresponding to the faulty branch is powered by a corresponding inverter branch of a second inverter, and the pulse-width modulation control is modified, or to make the power switches of the corresponding inverter branch of the second inverter conductive in succession and without switching while the absolute value of a phase current concerned is greater than or equal to a threshold lying in a range of 80% to 120% of n - 1 n ⁢ I ma ⁢ ⁢ x , wherein n is the number of inverters and I max is the absolute value of the maximum phase current, and while continuing to generate substantially sinusoidal voltage on each phase of the machine.