Electric scooter

The fully-electric scooter Govecs S2.6+, powered by a brushless DC electric motor with the rated power of 3.3 kW and a battery pack consisting of 400 Li-Ni0.33Mn0.33Co0.33O2 (Li-NMC) cells connected in the 20 x 20 matrix, with the total nominal voltage of 72 V, and the total energy capacity of 4.1 kWh. The battery pack is equipped with a Battery Management System (BMS), which provides basic battery quantities’ measurements and estimates accessible through the scooter CAN bus.

For research purposes, the scooter has been equipped with a custom-made measurement and telemetry system illustrated in the figure given below. The system is built around the Artronic SkyTrack telemetry module, which is programmed for acquisition of GPS and CAN measurement data, and storing the data on a server in real-time using GPRS connection. The custom measurement system consists of battery output voltage and current measurements. The battery current is measured by using a precise, low-offset current transducer (LEM CAB 300), while the battery voltage is measured via voltage divider and a 12-bit analogue input of the telemetry module. Current and voltage are sampled every 0.1 s, stored in the module, and occasionally downloaded to a local PC. The CAN bus data, such as battery voltage, current, state-of-charge and temperature, distance travelled, motor on/off flag and similar, as well as the vehicle’s current GPS coordinates and longitudinal velocity, are stored with the sample rate of 1 s. These data are sent via GPRS connection to the server and are accessible through a dedicated web application.

Fig. 1. Scooter measurement and telemetry system.

 


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