Method for powering a heating device for a catalytic converter

A method for powering a heating device (21) for a motor vehicle (1) having a thermal engine (M), said vehicle (1) comprising an electrical network (10), a catalytic converter (20) capable of depolluting the exhaust gases emitted by the engine (M) and comprising an electric heating device (21), a battery (30), a DC/DC converter (80), an electric machine (40), a first switch (60) suitable for switching between a closed-circuit state and an open-circuit state, and a second circuit switch (70) state suitable for switching between a closed-circuit state and an open-circuit state,

• said method comprising the following steps:
• el) checking an open circuit condition of the first switch (60) corresponding to a catalytic converter (20) not electrically heated,
• e2) detecting a need to activate the electric heating device (21) of the catalytic converter (20),
• e3) determining the electrical power required to reach a threshold temperature (Tthreshold) of the catalytic converter (20) and determining the electrical power of the battery (30), if the power of the battery (30) is below a charge level Nthresholdcharge, then proceeding to a fourth step e4);
• if the battery power (30) is above a charge level Nthresholdcharge, then proceeding to a fifth step e5);
• e4) checking that the second switch (70) is in an open-circuit state and then positioning the first switch (60) in the closed-circuit state in order to couple the electric machine (40) to the heating device (21),
• e6) controlling the electric machine (40) in order to generate the electrical power to heat up the catalytic converter (20),
• e7) checking the temperature of the catalytic converter (20),
• e8) switching off the heating device (21) and positioning the second switch (70) in an open-circuit state when the temperature of catalytic converter (20) is at least equal to the threshold temperature (Tthreshold),
• e5) comparing the quantity of electrical power required to heat up the catalytic converter (20) to reach the threshold temperature (Tthreshold) with the electrical power deliverable by the battery