Electric hub motor improves EV range: Part 2—Manufacturability and practical application
Part 1of this feature described this hub electric motor's basic technology
To drive the vehicle at speeds faster than 45 km/h (28 mph), a different connecting scheme than shown in Part 1, page 3 of this article is required.
The motor stacks are connected in two groups of six stacks. The CEMF (counter-electromotive force) on each group is 63V at 45km/h.
In each group, 16 switches are in series, introducing a series resistance of 3.2 Ω. The current flowing in each stack is (130 – 63) / 3.2 = 21A, generating a motor torque of 260 Nm.
The modulation of this torque can be done by:
- Powering only two wheels
- Powering only one of the two wire networks in each motor (red or green wires in motor cross section, Part 1)
- Powering only one of the two groups of six stacks
- PWM (pulse-width modulation).
This set up can be used up to 90 km/h (56 mph) . For faster speeds, three groups of four stacks have to be used (up to 135 km/h (84 mph)), then four groups of three stacks (up to 180 km/h (112 mph)).
This concept controls the motor torque at any speed, just by introducing switches between the battery and the coils. Losses are limited to joule effect in the switches (and the coils).
Optimizing energetic yield
Careful selection of the switches is key. In this exemple, they are dominant in the generation of the losses, and in the limitation of the torque.
The figure below shows the electric command circuit for all applications (motor and brake). This circuit has to be duplicated to power the two networks in each motor, (shown in Part 1); only one circuit has been drawn here to clarify the picture).
Electrical schematic for motor and generator usages (to be duplicated for each of the two wire networks in each motor.
This figure shows an internal combustion engine and an electrical generator used to charge the battery (hybrid electric vehicle in series; the electric motor is the only driving mechanical energy source).
To read the entire article, which describes the calculations required to dimension the motor, please click here. Courtesy of EE Times USA.
- No news
- Will DIY spray-on solar cells be a reality soon?
- Porsche reveals prototype battery-driven sports car
- Transparent coating cools solar cells while boosting efficiency
- More-than-Moore will lead, argues GloFo's Wijburg
- Elon Musk targets high-volume solar panel dominance
- Dialog to acquire Atmel for USD4.6bn in IoT push
- Super-battery charges mobile devices in 15 seconds or less
- Hybrid solar panel roof helps slash energy bills
- Are mushrooms the answer to lithium-ion battery degradation?
- World efficiency record claimed for both sides-contacted solar cells
- DC-DC Conversion Handbook on GaN
- GaN soon on 8-inch silicon wafers, hopes MACOM
- Heat helps rechargeable batteries extend lifetimes
- Next-Generation batteries - Can all-silicon anodes be commercially viable?
- Report: Cypress preps bid to snatch Atmel from Dialog
- Determine Balancing Current for the LTC3305 Lead-Acid Battery Balancer
- Testing PSRR with High-Frequency Ripple
- Why Making the Move from a Variable Transformer to a VariPLUS is the Right Decision
- A SEPIC Fed Buck Converter
- Minimizing the Impact of Source Resistance on High-Voltage DC to DC Converters
- Dual Phase Buck Controller Drives High Density 1.2V/60A Supply with Submilliohm DCR Sensing
- Battery Management System Tutorial