Page 42/95
21January2021/Version 0
LEM International SA
Chemin des Aulx 8
1228 PLAN-LES-OUATES Switzerland
www.lem.com
5.4. Handling energy losses
High power charging implies non-negligible power losses through components of the electrical
circuit. The DCBM offers solutions to avoid billing those losses to the end customer.
Two solutions are available:
• Achieve a compensation to subtract dissipated energy to the consumed energy; using cable loss
compensation
•
Achieve the energy measurement as close to the EV as possible, using four-wire measurement
5.4.1. Cable loss compensation
The DCBM 400/600 product family features a unique solution to compensate energy dissipated
between the energy meter and the EV battery.
5.4.1.1. Principle
Below illustration gives an example of distribution of losses in an installation.
Figure 24: Example of energy losses in an EVSE electrical circuit
If no compensation is performed on the measurement, the total resistance will bend the accuracy
characteristic of the metering system. This bending will be more significant at low system voltage.
87%
4%
7%
2%
0%
Power losses distribution
Cable
Fuse
Contactors
Cabling
Busbar connections
Summary of Contents for DCBM 400 Series
Page 95: ......
