Senior Motor Design Engineer

ABOUT THE ROLE

OM Motors designs high-performance BLDC motors for heavy-lift industrial multirotor platforms. We are looking for an engineer with deep expertise in electromagnetic design who can independently lead the full development cycle — from propulsion system sizing through series production. Working language is English.

KEY RESPONSIBILITIES

• System-level motor sizing: derive target KV from propeller bench data (RPM–thrust–torque), calculate operating point at given DC-bus voltage, select topology and slot/pole combination
• Demagnetisation analysis: verify magnet operating point under peak current and maximum temperature, confirm Hcj margin accounting for degradation
• Develop and validate FEA models (Maxwell, JMAG, FEMM, MotorCAD): flux, losses, efficiency, torque
• Winding design: wire gauge selection, parallel strand count, fill factor calculation, R_phase and L_d/L_q; Litz wire application at high electrical frequencies
• PWM harmonic loss analysis: additional iron and copper losses (skin effect, proximity effect) from inverter switching; impact on thermal balance and efficiency
• Cogging torque optimisation: magnet arc shaping, stator/rotor skew, slot opening optimisation — aligned with Grade A vibration requirement per ISO 10816
• Thermal analysis: LPTN models, cooling strategy selection, insulation class verification
• Dynamometer testing: back-EMF characterisation, efficiency map, thermal run
• Production support: winding quality control, electrical testing, supplier management

CANDIDATE REQUIREMENTS

Essential experience

• 5+ years of BLDC / PMSM design
• FEA tools: Maxwell, JMAG or FEMM
• KV sizing from propeller data and bus voltage
• Winding factor calculation (Kw = Kp × Kd)
• Bertotti iron loss model
• Demagnetisation check under peak current and temperature
• Outrunner SPM/IPM EM design
• Field weakening, characteristic current, CPSR
• PWM harmonic loss analysis
• Python or MATLAB for calculation automation
• IEC 60034, IEC 60085, IP55; English (working language)

Nice to have

• Experience with UAV / drone motors
• MotorCAD multi-physics optimisation
• CFD thermal analysis
• Multi-objective optimisation (NSGA-II)
• Axial flux machine experience (AFPM)
• Experience with Chinese manufacturers
• Technical documentation reading in Chinese

TECHNICAL COMPETENCIES

• Propulsion system: propeller–motor–ESC matching, operating point calculation, throttle efficiency
• EM theory: cogging torque and reduction techniques, slot/pole LCM, BH magnetisation curve
• Winding: strand count and gauge for fill factor, Litz wire, AC losses at f > 200 Hz
• Materials: electrical steel grades (NO20, M19), NdFeB magnets — Br, Hcj, BHmax, temperature coefficient
• Rotor mechanics: magnet retention (CF bandage, adhesive, steel ring), balancing
• Reliability: L10h bearing life, FFT vibration analysis, QC methods
• Manufacturing: needle winding, VPI potting, Hi-Pot/surge testing

CONDITIONS

• Remote work; team working language is English
• Work on real products for heavy-lift cargo aviation — not a research project
• Direct involvement in design decisions from day one
• Competitive compensation, discussed individually