Amsterdam is built around waterways, and ferries play a vital role in its transport network. The diesel ferries operating along Amsterdam’s North Sea Canal had been in service since the 1930s and were in urgent need of replacement. The city’s public transport company Gemeentelijk vervoerbedrijf (GVB) decided to replace them with five new electric ferries. The new ferries are an important step towards realization of GVB’s strategy to become an emission-free transportation company.
100% electric operation
The contract for constructing the DC charging stations for the new ferries was awarded to BAM Infra Rail bv, part of BAM Group, a major construction, property and civil engineering company.
“The new ferries will operate 24 hours per day, and in most weather conditions they’ll run 100% electrically,” says Jeroen Borst, lead engineer, traction and energy solutions at BAM Infra Rail. “We have built DC charging stations on each of the three routes to charge them after every 20-minute round trip.”
Each ferry has 2 x 340 kWh of battery capacity. The onboard charging system needs a supply of 750 V DC and is designed for charging at 2 MW for 145 seconds. The DC voltage has to be extremely stable and unaffected by any fluctuations in the power grid. BAM approached ABB for a suitable solution to convert the AC grid voltage to a stable DC supply.
Active rectifiers for a stable output
“Stability of the DC voltage was a critical requirement for BAM and GVB,” says Marcel Zevenbergen, Sales Manager System Drives at ABB. “To meet this requirement we have delivered three ACS880 supply module packages including Rittal VX25 assembly kits to streamline the panel building by BAM Modulair bv. We worked closely with BAM, providing support throughout the entire design and implementation process.”
The supply modules are active rectifier units based on IGBT (integrated-gate bipolar transistor) technology. They can react to network events and compensate for voltage drops, resulting in a very stable DC output and minimal distortion of the grid.
The rectifiers include LCL filters to avoid harmonic distortion of the power grid. The resulting THDI (total harmonic current distortion) is less than 3%. The benefit of low harmonic distortion is that the DC charging stations will not cause disturbances in the network. Lower current harmonics also mean less heating in equipment like transformers, enabling use of a smaller transformer. The transformer can typically be 6% smaller when an IGBT-based unit is used rather than a diode-based rectifier with filters.
Image of GVB with courtesy of BAM 
Image of GVB with courtesy of BAM
Standardized modules save engineering time
The inverter supply module packages supplied to BAM are standardized and completely predesigned for assembly into Rittal VX25 enclosures by third-party panel builders. In this project BAM Modulair designed and built the complete enclosures, which also include a high power DC switching panel. Standardized module packages mean easy maintenance, programming and integration for panel builders. Other benefits of ABB’s standard module packages are availability of spares, excellent serviceability and the capability to plan maintenance predictively.
Rigorous testing for the highest reliability
The DC charging stations on the North Sea Canal are a key part of Amsterdam’s urban transport infrastructure, and uptime is a crucial factor. The charging stations have to work around the clock to keep the ferries running on time and enable people to get to their destinations.
To ensure ultimate reliability for mission-critical applications like these, the rectifier units – like all ABB drive products - are subjected to extensive in-house and external testing. Moreover, ABB offers an extensive range of services to ensure reliable operation over a long lifetime.
Successful operation
The first electric ferry in the Amsterdam area has been operating since August, 2021.
“Charging is fully automated, takes less than three minutes and can easily be integrated into the ferry’s timetable. Electric operation means there are no nitrogen or carbon dioxide emissions. When all five electric ferries are in service and the old diesel vessels are retired, we will save 800,000 liters of diesel per year, reducing 2440,4 tons of carbon emission” says Alain Asin, project manager at GVB.
The new ferries are 41 meters long and 13.9 meters wide and can carry up to 400 passengers, 20 cars or 4 trucks. Passengers have commented that their journey on the electric ferry is now much more comfortable, quieter and cleaner than before. The introduction of electric ferries takes Amsterdam’s public transport system closer to sustainable, emission-free operation.
