Increased energy efficiency with reduced costs

Sustainable production using renewable energies starts with an industrial DC grid. Phoenix Contact’s Contactron ELR HDC is a multifunctional DC switching device that includes monitoring and protective functions in a compact design.

At the end of the 19th century, AC technology triumphed over DC in the “war of the currents.” A key factor was Wernher von Siemens’ 1860s discovery of the dynamoelectric principle: steam drives turbines, generating electrical energy with AC generators. This principle is still used in coal and nuclear power plants. Another advantage of AC is its easy transformation to high voltages for low-loss long-distance transmission.

Elimination of loss-inducing AC/DC conversion

Direct current (DC) is becoming more important due to advancements in power electronics, making efficient DC use affordable. Essential components like transistors in computers and controllers require DC. In industry, many loads use frequency converters on a DC link, eliminating loss-inducing AC/DC conversion. Additionally, renewable energy sources like photovoltaics, wind power, and fuel cells always supply DC.

Using electrical energy without rectifying from AC to DC increases efficiency and reduces raw material costs, eliminating the need for transformers. Smaller cable cross-sections reduce copper usage. Dr. Martin Wetter, Executive VP Innovation at Phoenix Contact, says these advantages make DC very economical in industrial plants. Their “Empowering the All Electric Society” strategy promotes DC technology with products and solutions, supporting sustainable power supplies for facilities.

Mastering the standing electric arc

Switching operations in industrial DC grids are challenging due to persistent electric arcs. Unlike AC systems, DC systems need controlled solutions. The Contactron ELR HDC DC miniature circuit breaker from Phoenix Contact uses solid-state technology and DC relays to switch arc-free, ensuring a long service life. In the off state, relays provide electrical isolation. The Contactron ELR HDC is used in DC grids to exchange energy between sources, loads, and the grid at DC branches.

In addition to switching up to 55 A at 810 V, the device performs essential tasks for operating a DC grid:

• Monitors key parameters for process data acquisition.
• Switches off with a time delay if the operating current exceeds the set maximum, including fast short-circuit shutdown.
• Switches off in case of undervoltage or overvoltage in the input.
• Charges capacitors in the output to avoid current peaks during switch-on.

Configuration via the network or with software

The Contactron ELR HDC has a digital I/O and communication interface for network integration. Users can adjust parameters via the network or ClipX Engineer software by connecting the breaker to a notebook via USB-C.

The ELR HDC has proven its performance, confirmed by tests from automobile manufacturers in southern Germany. It is installed in Phoenix Contact’s Building 60 in Blomberg, Germany, serving as a blueprint for DC products. Besides industry and building technology, it is used in power-to-X systems, data centers, and ICT. Expanding the product family, including extended power ranges, is part of the medium-term plans.

The Contactron ELR HDC excels in protecting, monitoring, and switching over 40 kW, with communication capabilities in a compact design. Its intuitive configuration provides a flexible tool for ensuring a sustainable DC supply for production facilities.

Protection and monitoring included

Phoenix Contact’s Contactron ELR HDC is a multifunctional DC switching device that reliably switches DC currents up to 55 A without electric arcs, offering impressive protection and monitoring in a compact design.

Building 60 as an electrifying example of a DC grid

The industrial DC grid in the new G60 building supports DC technology research. Charx High Power modules generate a 650 V DC grid from the AC grid, allowing excess electricity to feed back into the public network. A 100 kW-peak photovoltaic system supplies DC electricity to the low-voltage DC grid. CHARX power modules with MPP tracking simplify DC/DC conversion without AC grid synchronization. An energy management system (EMS) networks generators and loads, integrating PV power with battery storage to minimize public grid feed-in.

A 240 kWh battery storage system in Building 60 compensates for longer power needs, covers peak loads, and ensures stability during public grid interruptions. Bidirectional e-charging stations in the 650 V DC grid use vehicle batteries for short-term storage. With PLCnext Control and an EMS, this setup handles high short-term load peaks and improves grid quality. The 650 V DC grid supplies in-house loads, while 400 V DC branch circuits power lighting and mobile devices.

AC voltage devices currently need power supply units with internal rectification and DC intermediate circuits for PCs, displays, and LED lighting. Supplying these devices directly from a DC grid saves weight and volume in feed-in circuits. Lower voltage in branch circuits ensures personal protection per DIN VDE 0100-410. IT systems are isolation-monitored and shut down in case of an error.

Read more about DC grids in industry.