The Rotterdam transport company RET is becoming increasingly green. At the end of 2019, RET introduced 55 fully electric city buses. CoNet programmed and tested the Siemens 8DJH medium-voltage switchgear with SIPROTEC 5 Compact protections for the charging stations and subsequently put them into operation.
By 2030 all RET buses will be emission-free, saving a lot of diesel and thousands of tons of CO2 every year. These new electric buses drive specific routes around Rotterdam, Schiedam and Vlaardingen. The routes are specific as the electric busses must recharge at charging stations at along the route.
Programming and testing of the medium-voltage switchgears and circa 20 SIPROTEC 5 Compact transformer protections was carried out by CoNet for around 80 charging points at six different locations. Programming / settings are done with DIGSI 4. These SIPROTECS were eventually tested and the trip curves checked with Omicron test equipment.
8DJH medium voltage switchgear
CoNet is the first Siemens Solution Partner for Digital Grid technology to be familiar with this technology. “Our client had purchased Siemens 8DJH medium voltage installations of 10 kV and 20 kV to distribute the medium voltage towards the transformers,” According Jeroen Weemhoff of CoNet. “We have programmed, tested and commissioned these switches and the SIPROTEC 5 protections. A great assignment that had a lead time of approximately two months.”
Modbus communication with SCADA
This was the first time that CoNet needed to interface the SIPROTEC 5 Compact to a SCADA system via Modbus. Voltages, currents and trips are passed to the PLC which is linked to the overall SCADA system. With this SCADA system an operator can control and monitor all the remote locations. The charging stations are located at places where the buses must stop for a little longer, including Rotterdam Central Station and the RET depot. At each location there are also a couple fast chargers for the buses which stop for a shorter amount of time.