Electrical Supply

Can you save energy in your factory with direct current?

Power converters (e.g. inverters) use powerful semiconductors to achieve an efficiency of over 95 % in converting DC voltages - a modern alternative to the transformer. Highly automated productions rely on inverters to allow specific motion sequences. An increasing proportion of industrial drives for pumps, conveyor belts, saws and fans are operated with frequency inverters.

Power converters convert your energy in two conversion stages: first, the AC voltage from the grid is converted to DC voltage in order to generate an AC voltage signal with a variable frequency and amplitude.

Together with partners from industry, we are developing an industrial energy supply system that uses DC voltage to transmit power. It saves on conversion sites and enables energy stored in the processes to be recovered and reused.

“Tests on CNC machines show a potential energy saving of more than 6% per work cycle”.

Already today, we are integrating DC grids with pioneers dedicated to an efficient and climate-neutral energy supply. We show you what a direct current grid looks like, the advantages it offers your company and how we assist our partners in their projects.

Interesting facts about direct current grids:

The transmission of electrical energy can use a DC or AC voltage to generate a current. In 1880, the Pearl Street Station in New York was the first commercial electrical grid with direct voltage. The fact that AC voltage dominates today is due to the invention of the transformer by Galard and Gibbs in 1885 and the invention of the AC motor by the Westinghouse company. Transformers enable voltage to be efficiently converted and electricity to be transmitted over long distances. The AC motor paved the way for industrial applications. Today, power converters are the reason why we are reliant on transformers and directly operated AC drives.

Are microgrids a strategic option for you?

A microgrid is a local network of electrical generators, storage systems and consumers, which can be operated independently of the external grid using its own control system.

Microgrids open up a range of optimization possibilities for your electrical supply. For example, you can guarantee supply reliability, consume your own power that you have generated using renewable sources, cap peak loads or operate consumers in an energy-flexible manner.

We have made it our business to help you convert to a reliable and sustainable electrical supply. With this in mind, we offer a range of planning services that go beyond the state of the art:

Development of a strategic transformation process towards sustainable supply

• We show you when it makes sense to invest in new technologies. Let us develop a long-term roadmap for your sustainable transformation.Optimieren des Gesamtsystems mit Modellen
  

Optimization of the overall system with models

• We create a digital map of your supply infrastructure for you and perform parameter studies to maximize the energy generated from renewable sources on your production site, to protect your supply against external supply failures or to identify excess capacity and save costs.
• Our aim is not only to dimension systems with a suitable size and output, but also to transfer your design to real control algorithms.n

• Would you like to test new supply technologies on a prototype facility and develop an industry standard for your worldwide production? We help you calculate energy requirements for individual machines and certify suppliers with you. In addition, we solve technological problems and enable your suppliers to deliver equipment tailored to your needs.

Interesting facts about industrial microgrids:

Electricity is a medium that transmits energy. It is generated in one place and simultaneously consumed in another. Only small quantities of electricity can be stored temporarily.

The interconnected grid links up the majority of electrical consumers and power plants in a common supply system. Thanks to its size, the fluctuating demand for electrical power is stochastically balanced out as the number of consumers in the total load increases. As expected, the installed power plant capacity increases as the size of the interconnected grid grows, but the reserve capacity of maximum loads and thus the supply costs decrease in proportion.

These days, with the energy turnaround, this model is being called into question:

1. The output from regenerative power plants is dependent on meteorological conditions. To ensure a stable energy supply, consumers and energy storage systems must adapt to the energy being generated at any given time.
2. Regenerative power plants are connected locally in the company grid but must be integrated into the grid’s control system.
3. Regenerative power plants generate much less energy than conventional power plants. Thus, a more complex control system is needed if regenerative power plants are to be integrated.

You can turn this threat to your production into a competitive advantage.

How will you manage your energy flows in the future?

Energy efficiency according to DIN ISO 50001 has so far been accomplished with individual measures: the use of frequency inverters for electric drives or LED lighting in production halls. The success of these measures can be easily quantified, but the potential to tap further isolated efficiency potential declines with increasing maturity.

Only by thinking “energy in the system” can further potential towards a sustainable energy supply be realized. For example, by installing regenerative power plants or energy storage systems that enable you to optimize your energy consumption in the production hall.

So that you can cope with the increasing complexity, we have developed an energy control system that automatically directs energy flows. What is more, we are researching how this can adapt autonomously to changing environmental conditions in the future.

Decide when production is running which energy source minimizes costs and use it immediately

• Investing in an energy storage system is an expensive business. Using it to cap peak loads can drastically reduce your grid fees. But do you know how your peak loads occur and when an energy storage system makes sense?

Minimize your local carbon emissions and maximize your energy consumption from your own regenerative power plants

• The amount of energy generated by regenerative power plants fluctuates depending on the weather. To ensure their optimal use, the operating strategy of your grid should be checked every quarter hour.

Operate loads flexibly to obtain electricity from the grid at low cost

• Large energy consumers such as ventilators, pumps or heat pumps do not have to be switched on permanently to fulfil their task. You can automatically reduce the amount of energy purchased from the grid to respond to fluctuations in energy prices.

Can Artificial Intelligence make your product easier?

Production machines display high load fluctuations at the point where they are connected to the grid. Thus, the amount of energy consumed during acceleration phases is often 5 to 10 times higher than during normal operation. Energy storage devices, such as double-layer capacitors or flywheel mass storage devices, make it possible to reduce these power peaks.

But do you want to adjust each of these systems individually and to the specific conditions of a machine? We are working on this problem. The field of computational intelligence includes, among others, artificial neural networks. We combine these methods to adapt industrial control systems to the specific application.

Just imagine - a new machine and no commissioning required. Taking the flywheel mass storage system as an example, let us show you how machines will be commissioned in the future.

At our location in Stuttgart, we operate a research laboratory where we work together with our industrial partners to transfer new ideas into practice.

We have selected some current examples to demonstrate how our results from the laboratory can benefit you. If you require more information, please visit us in person in Stuttgart or give us a call.

Setting up a direct current grid in reality

• Setting up a DC grid is comparable to planning and designing an AC supply infrastructure. Is it really that simple?

DC-ready: converting a production machine to direct current

• While inverters can be operated with direct current without any problem, sometimes structural conditions get in the way when it comes to operating a production machine. Using the example of retrofitting an injection molding machine, in our laboratory we show you how we identify these problem areas.

Parallel operated power converters

• In a DC grid, power converters are connected in parallel. Their control systems can interfere with one other and endanger the stability of the supply voltage. We have developed a device for measuring output impedance which helps to avoid this problem when putting the converters into operation.

Self-adjusting flywheel mass energy storage system

• Our simulations show that artificial intelligence is capable of taking over the setting of devices during commissioning. We investigate how complex algorithms with real-time requirements can be transferred into practice