User guide
E-scooter motor and controller engineering: BLDC electromagnetics, FOC, KV constant, MOSFET inverter and IEC/UL/ISO/ECE standards
Engineering deep-dive into the e-scooter powertrain — parallel to the introductory overviews «Motors: geared vs direct-drive hub» and «Controller, BMS, display, IoT»: BLDC electromagnetic physics (Lorentz force F=BIL, Faraday EMF ε=-dΦ/dt, Lenz law), KV constant in RPM/V as winding characteristic, torque constant Kt=60/(2π·KV) — why KV 10 on 48 V gives a theoretical 480 RPM/V × 0,95 = 22 N·m/A through mirror symmetry; stator/rotor topology (12-slot 14-pole inrunner vs hub-mount outrunner, NdFeB N42/N48/N52 remanence Br 1.28–1.44 T, ferrite Y30 Br 0.4 T, samarium-cobalt SmCo for high temperatures); three loss types — copper I²R (`P_cu = 3·I²·R_phase`), iron/hysteresis via Steinmetz (`P_h = k_h · f · B^n`, n≈1.6–2.2), eddy currents (`P_e = k_e · f² · B² · t²`); efficiency 85–92 % and why peak efficiency is always near ~50–75 % rated load; thermal management — IEC 60085 insulation class B (130 °C), F (155 °C), H (180 °C), IEC 60529 IP54/65/67 sealing for hub-mounted motors; FOC (Field-Oriented Control) — Clarke transform abc→αβ, Park transform αβ→dq with rotor angle θ, PI controllers for i_d=0 + i_q as torque command, SVPWM (space-vector PWM) modulation; MOSFET inverter — six-MOSFET three-phase bridge, IRFB3077/IPB019N08N3 with RDS(on) 1–5 mΩ, switching losses `0.5·V·I·(t_r+t_f)·f_sw` at 16–32 kHz, dead time 200–500 ns, gate driver 10–15 A peak; DC-link capacitor — ripple current 10–30 A, low-ESR aluminum-electrolytic 1000–2200 μF or polypropylene film; regenerative braking physics — motor as generator, inverter as rectifier, BMS-limited charge acceptance; engineering ↔ symptom diagnostic matrix; full matrix of 9 standards — IEC 60034-1:2022 rotating electrical machines, IEC 60034-30-1 efficiency classes IE1-IE5, UL 1004-1 motors general, UL 1310 Class 2 power units, ISO 21434:2021 road vehicles cybersecurity, IEC 61508 functional safety SIL 1-4, ECE R10 rev 6 EMC + CISPR 14-1, FMVSS 305 high-voltage powertrain, UN ECE R136 L-category propulsion.