EN
12.8.2022
Official Journal of the European Union
L 212/259
(iv) For each gridpoint defined in accordance with subpoints (e)(i) and (e)(ii) above the actual electric inverter power shall be calculated in accordance with the following equation:
Pel ðT i ; nj Þ ¼ Ploss ðT i ; nj Þ þ T i Ü nj Ü
2π 60
where: Pel
= actual electric inverter power [W]
Ploss
= actual loss power [W]
Ti
= actual torque [Nm]
nj
= actual speed [1/min]
(f) The data of the actual electric power map determined in accordance with subpoint (e) above shall be extended in accordance with subpoints (1), (2), (4) and (5) of point 4.3.4 of this Annex. — Step 7: The drag curve shall be calculated based on the actual power loss map determined in accordance with subpoint (e) above in accordance with the following provisions: (a) From the power loss values for the two gridpoints defined by the normalised torque TTmaxi 1⁄4 0,01, and values of nj 1,00 and 4,00 for normalised speed nrated , the drag torque depending on actual speed and torque shall be calculated in accordance with the following equation: A Æ !
A Æ ! Æ Æ Æ nj Æ nj Æ Ti Æ Ti 60 ;n ;n 1⁄4 0,01 jÆÆ 1⁄4 f1,00; 4,00g 1⁄4 ÄPloss T i ÆÆ 1⁄4 0,01 jÆÆ 1⁄4 f1,00; 4,00g Ü T drag T i ÆÆ T n T n 2π Ü n max
rated
max
rated
j
where: Tdrag
= actual drag torque [Nm]
Ti
= actual torque [Nm]
Tmax
= overall maximum torque of the electric machine system determined from the data generated in accordance with Step 2 above [Nm]
nj
= actual speed [1/min]
nrated
= rated speed of the electric machine system determined from the data generated in accordance with Step 2 above [1/min]
Ploss
= actual loss power [W]
(b) From the two values of drag torque determined in accordance with subpoint (a) above, a third value of drag torque at zero rotational speed shall be calculated by means of linear extrapolation.
(c) From the two values of drag torque determined in accordance with subpoint (a) above, a fourth value of drag torque at the maximum normalised speed value defined in accordance with subpoint (b)(i) of Step 6 above shall be calculated by means of linear extrapolation. — Step 8: The rotational inertia shall be determined by one of the following options: (a) Option 1: Based on the actual rotational inertia defined by the geometric form and the density of the respective materials of the rotor of the electric machine.
Data and methods from a CAD software tool may be used to derive the actual rotational inertia of the rotor of the electric machine.
The detailed method for determining the rotational inertia shall be agreed with the type approval authority.