Maturo Dynamometer for E-Bikes

Maturo GmbH designed the new state-of-the-art dynamometer for EMC testing of E- Bikes according to new Standard EN 15194:2009-06 appendix C for EPACs (Electrically Power Assisted Cycles).

The market for E-Bikes has changed drastically with the implementation of the new standard in year 2009.

Pedelecs (all motorised bicycles) have to fulfil from now on the same EMC test requirements as ca, motorcycles and mopeds according to new safety standard EN 15194 EPAC appendix C.

The dynamometer for E-Bike allows the testing and inspection of bicycles with electromotive drive support (EPAC) in respect to the electromagnetic compatibility.

An EPAC (electrically power assisted cycles – EPAC Bicycles) remains a “bicycle“ without the necessity of a road traffic-legal approval, if:

• the motor-driven support speed does not exceed 25 km/h
• the motor-driven support is only activated, if there is also the pedal force / pedal movement activated
• the motor output is maximum 250 W
• the possible mode of a “starting support” does not exceed a maximum of 6 km/h, also at the mode without pedal movement

The vehicle is liable to the European permission requirements for the road traffic (directives 2002/24/EG and 97/24/EG), if one of the above criteria is exceeding.

Technical Requirements

The technical requirements are described in the standard EN 15194:2009 and also include
the EMI requirements to EPAC’s at attachment C as follows:

• Measurement of the electromagnetic radiation with load according to CISPR 12
• Testing of the electromagnetic immunity to HF-filed (according to ISO 11451-1/-2) in the operation mode “standstill”, without pedal movement at standstill with 0 km/h
• Testing of the electromagnetic immunity in mode “during operation” with movement of the motor at movement or pedal force
• Testing of the electromagnetic immunity in mode “starting support” for vehicles which this option.

The dynamometer itself must be interference-resistant up to field strength of 30 V/m for all operation modes above. No high frequency interference must be created by the dynamometer, which could affect the test result. The dynamometer is portable for use in anechoic chambers. The system itself does not create any major influence of the test results, except due to the construction.

The new E-Bike dynamometer allows the input of a target speed for the tyres as well as the readout of the speed for each tyre. This function can be selected for each individual drive – front wheel drive, pedal drive and rear wheel drive.

An additional feature of the system is the input of torque for the simulation of uphill and downhill drives. A third drive unit, with adaptation to the foot pedal of the EPAC, can be used for simulations of the pedal movement if required. This pedal movement is evaluated as an indication of the rotating movement at many E-Bikes.

The compliance of a constant speed, also by the influence of high frequent emission, is the main criteria for the test of the electromagnetic immunity. At the operation mode “standstill”, the E-Bike must not be activated; the speed therefore must remain a “0” km/h.

The Controller NCD of the dynamometer has an output function of a scalable value for the voltage. This function enables the automation of the test sequence in the EMI laboratory, where the possible reactions or speed fluctuations are recorded as a function of the test frequency.

Voltage output for documentation:

The analogue voltage can be output in relation to the operating mode and speed. The value can be measured with either a voltmeter or a test receiver.

Features of the system:

• Adjustment of the wheelbase
• Adjustments to the tyre width / wheel rim
• Calibration to the tyre diameter
• Adaptation to the foot pedal at removed pedal arm
• Velocity control
• Torque Control
• Fastening device for the E-Bike to the dynamometer
• Movable by integrated casters