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.
- Cracking the diode compromise
- Electric vehicle infrastructure-based chargers made easy
- SiC power devices gain traction among electric vehicles manufacturers
- AC voltage motor drives look to digital isolators
- Advanced LED drivers display digital signage credentials
- Progressive regenerative braking using real-time speed sensing
- How hybrid electric vehicles can pay off
- Mechatronic approach facilitates automotive electric motor control
- Real-time power management system for sensorless motor control and short circuit localization
- Novel architectures for EV power management: About distributed architectures
- Advanced BLDC motor controller with power saving features
- Delivering optimized motor control for 1.5-kW applications with a uMini-DIP package
- Tactile feedback solutions using piezoelectric actuators (Part 2 of 2)
- Tactile feedback solutions using piezoelectric actuators (Part 1 of 2)
- Hybrid and electric vehicles pose electric/magnetic isolation challenges
- First round-the-world solar plane flight prepares for take-off
- Are next generation EV batteries a step closer?
- Are power management researchers really 21st century alchemists?
- Overcoming patient leakage current issues
- Long life aluminium-air battery resolves rechargeable challenges
- Solar-powered radio chip monitors windows to save energy
- How to measure capacity versus bias voltage on MLCCs
- Conquering the 'kink' in sub-threshold power MOSFET behavior: A simple compact modeling approach
- Bamboo bike uses peddle power to recharge smartphones
- Apple Watch spurs wireless charging growth in 2015
- Hybrid fuel cell advance boosts power by 20 percent
- LED buck regulator with current-mode control simplifies compensation
- Product How-to: Ultra-low noise linear regulators for powering PLL/VCO and clocking ICs
- Improved dendrite formation control helps lithium batteries last longer
- Multi-crystalline silicon PV module claims power output world record
- Investigating Die attach Failure in IGBTs using Power Cycling Tests
- Power Systems Design eBook
- Wireless Power User Guide
- A Novel Approach to Industrial Rectifier Systems
- Smartphone SoC Power Efficiency - DVFS Capacitor Switching
- Power Modules: The New Super Power
- Digital Power Management Reduces Energy Costs While Improving System Performance