Due to high fuel prices and growing environmental awareness.The electric bicycle H (e-bike) is rapidly emerging as a new form of simple and cost-effective transportation for smog-infested urban areas.
The e-bike is a hybrid light electric vehicle (HLEV) that can be powered both by pedals and/or an electric motor. Adapted from the standard bicycle, the additional components of an e-bike include a bat- tery, a motor and an electronic controller. The primary role of the controller is to provide smooth power flow to the motor. There are currently a number of companies specializing in e-bikes such as Currie Technologies, EV Global Motors, and ZapWorld. It has been estimated that in China alone, approximately sold over 1 million electric bikes in 2002 .
The efficiency of the e-bike is unquestionably superior to the automo- bile; a simple calculation shows that a typical e-bike requires 50 times less energy per kilometer than a standard car. In addition, as solar panel technology becomes more affordable, the net amount of energy required to power an e-bike can be reduced. For example, roof mounted solar panels could be used to charge spare batteries during the workday.
In the past, the majority of e-bikes were built by hobbyists, resulting in low-efficiency designs. However, with advances in power electronics and microelectronics, vast improvements have recently appeared on the market. These include the use of high efficiency motors, such as Brushless DC motor , regenerative braking and fault monitoring. A BLDC motor is conceptually similar to a traditional permanent magnet DC motor except that operates without brushes and a mechanical commutator. The stator's magnetic field must be rotated electronically, which increases the motor drive complexity. However, when compared to DC motors, BLDC motors have higher efficiency, superior heat dissipation, increased power density and lower maintenance. Regenerative braking refers to the use of the motor as a generator to capture kinetic energy from the bicycle during braking. The energy is redirected to the battery, increasing battery life and system efficiency.
This paper describes the design and implementation of a high perfor- mance BLDC motor drive controller and a test-bench for an e-bike. Our design demonstrates the first e-bike controller that incorporates all of the following features:
M&C have designed brushless controller series with Cypress CY8C24423 based on 27 year professional experience in industry and most advanced technology. This controller represents the highest industry level with most appropriate quality vs price and has been put into market with strict competition run for more than 2 years.
Functions and specifications
Item:DCNV-350
* Rated voltage: DC 24V/36V/48V
* Rated Power: 150~350W
* Low Voltage Protection: DC 21V±0.5V / DC31.5V±0.5V / DC42V±0.5V
* Current Limit: 8~16A(±0.5A)
* Standby Power Consumption: < 3W
* Speed Limit: Highest Speed range 35km/h ～ 45km/h (specified by motor).
Speed limit under 20km/h
* Cruise Mode: Automatic Cruise or Manual Cruise. Stabilizing throttle for consecutive 8 seconds enters automatic cruise mode which makes e-bikes run at a const speed once releasing control from throttle
* Indicators: Work with multiple serial or parallel indicators, positive or negative shared indication LEDs( low voltage, current limit or cruise )
* Speed Indicators: Hall sensor speed indicators, positive or negative phase line speed indicators
* 1:1 pedal assistance: controller provides power assistance based on pedal feedback(speed) during pedaling. Various central hall sensors are provided like central shaft speed sensors or Torque sensors.
* Braking: work with open circuits low voltage brake, high voltage brake( +5V, +12V…)
* EABS braking: soft EABS braking system without braking noise and damage on motor. It makes motor sharply stop with a soft effect similar to that of EABS on vehicles. This regenerative braking brings energy back to battery from motor motion.
* Running regeneration: after throttle being released, the running motor transfer energy from motion into electrical power being stored into battery. This is power saving but will shorten distance of running. This function is selectable.
* Super low noise: super low noise at motor start and run beyond the performance of traditional brushless controller, making a low vibration and enlarge length of use
* Low heat generation: use the most advanced complementary PWM technique to lower the system heat generation. It optimizes power usage and extend length of use
* Multiple current limits: Use average current limit and peak current limit. Peak current limit checks current peak at every PWM cycle and protect MOSFET from resistless peak current and avoid damage. Average current limit makes controller a const current limit performance on all motors at low load, medium load, high load or stall. This simplifies testing process and checking process for e-bike manufacturers.
* Runaway protection: solve the problem of motor runaway from the problem of throttle or circuits and improves reliability.
* Stall protection: controller protects motor stall from stopping motor at 3 seconds in stall
* Short Circuits protection: controller protected once two or all of three phase lines are connected.
All of above functionalities are software based and will not increase the cost. PSoc system makes parts number as low as possible with its in-chip function blocks. This lowers the cost of hardware and improves reliability.
The newest product functionalities includes: 8 second cruise, running regeneration, alarm lock motor, 3-speed mode, 74hc164 serial indicators, three-wheeler reverse run button, sensorless brushless, non-standstill start and ratio pedal assistance for exportation.
Electricmotor