L5 EGs

• Inverter

• Electric Machine

• Gearbox

• Cooling System

• High demand for E-Drives

• Electric mobility

Pulse Width Modulation

• transforms DC to AC current

• switches are turned on and off to create sin-wave pulse

• Permanent magnet synchronous machines

  • Rotor with buried permanent magnets

  • rare earths necessary

  • rotor turns synchronous to AC current

• Induction machines

  • rotor turns asynchronous to AC current

  • lower power density

  • higher losses

• point where torque decreases and is no longer constant

• DC voltage no longer sufficient

• caused by counter electromagnetic force (EMF) of rotor

• 1/n for PMSM

• 1/n^2 for IM

• Torque is relative to diameter squared

• Torque is relative to length

• Single-speed:

  • single-speed offset, helical

  • single-speed coaxial, helical

  • single-speed coaxial, planetary

  • single-speed offset, combination

• Dual-speed offset, helical

• Twin single-speed offset, helical

• twin. single-speed coaxial, planetary

8-14

• inverter: 98,5%

• electric machine: 95%

• gearbox: 98%

  
  

• required torque over speed curve

• load spectrum for service life

• available installation space

• driving cycle for rating energy efficiency

• permissible DC voltage ripple

• system design

• domain-specific design

• system integration

degrees of freedom when designing the e-drive

• e-drive typically has 50

• high energy efficiency

• compact design

• good performance

• low cost

• f: function defining objective space

• x: optimization parameters defining search space

• h: equality constraints

• g: inequality constraints

point where one objective value can’t be improved without worsening another

• mathematical system design optimization approach

• transforms system requirements into optimal system designs

• combination of analysis models and optimization algorithm to automate loops through v-model