Standard
EnergyBus is a standard for connecting electric components of light electric vehicles. It consists of a standardized set of plugs, a communication (bus) protocol that is based on CANopen standard, and an energy management system.
EnergyBus will enable electric LEV components, such as batteries, chargers, motors, controllers etc. to work together as a system no matter which manufacturer produced the single components.
EnergyBus standard is currently under development. Industry representatives and engineers are welcome to join the development committee (see Membership).
Operation Principle
The technical functions and purposes of EnergyBus can be explained in four steps and be compared to the use of a bank credit card when drawing cash from an ATM machine. First is the hardware interface, the EnergyBus plug. Using the bank card example, the hardware interface is the plastic card that uses a magnetic stripe to communicate. Second is the software interface. It is, in both cases, a two-sided communication (negotiation) between the components involved. The ATM checks the bank account, for sufficient money in the account, for correct PIN, etc. EnergyBus checks readiness of the electric components, operating voltage and current, state of battery charge, etc. This negotiation is based on a CAN open protocol. If there is no problem with the components working together, the next step is energy transfer. In the case of vehicles the energy is transferred into forward motion. In the case of bank cards, the ATM releases the money.
If, in the second step, the negotiation detects a problem (if, for example, the customer’s electric bike battery and charger don’t work together), energy transfer does not happen. This prevents the battery from being destroyed. In this case, EnergyBus serves as an important safety device. Without such a communication standard the charger can easily destroy the battery if the two components operate on different voltages of if the charger is not made for certain battery chemistries. Another advantage of EnergyBus becomes obvious in the fourth step, which is related to service. The data interface allows an exchange of information for service and software update, for example in public charging stations, battery rental stations and for battery service.
Protocol
EnergyBus protocol is based on CAN protocol, the dominating bus system in many industries, mainly in the passenger car industry. EnergyBus even further specializes this protocol to fulfill the specific requirements of LEVs. EnergyBus is comprised of the electrical power lines between a variety of electrical devices such as battery, battery charger, and motor. It will also include the CANopen network for controlling these devices and connecting the sensors and the optional board computer.
After several years of research and some experiments with RS-485 and LIN, the Energy-Bus consortium selected CAN communication technology. A study conducted by C&S group headed by Prof. Dr. Wolfhard Lawrenz, which extensively analyzed the requirements of the LEV industry, found that only the internationally standardized CAN (ISO 11898-1/2) is capable to fulfill these requirements.
Development partner for the of EnergyBus protocol, is the Germany-based non-profit organization
CAN in Automation e.V. (CiA)
Plug System
EnergyBus has often been compared to USB in the computer industry. There is, however, a significant difference: LEVs work with much higher current than computers. This is why EnergyBus will require an entire set of plugs whereas USB only uses one universal plug. This plug-set will especially be developed to meet the needs of LEVs.
For further information on the EnergyBus plug system, please contact Melanie Wiederkehr.
Right to Use
Members of the EnergyBus Organization will have access to all information referring EnergyBus standard as well as influence on it’s definition. This is a great business advantage. Members will be permitted to use the EnergyBus logo on certified products. Later on, EnergyBus Organization intends to provide EnergyBus standard to vehicle manufacturers and suppliers without royalties.
