More renewable energy, thanks to innovative system management

How automation can contribute to greater grid utilization.

Everyone wants an energy transition, but no one wants new power lines in their backyard. But in order to transmit more and more locally generated power from renewable sources, the grids will have to be expanded over a period of years. In the InnoSys 2030 research project, German grid operators are looking for innovative approaches to operating power grids. The goal is to increase the utilization of the existing grid while maintaining the same level of security – with the aid of automated assistance systems.

Suddenly an alarm flashes on the huge screens in the grid control center: A violent storm has uprooted a tree and damaged an overhead power line. The system immediately disconnects the section, and other lines have to take over the load. But this only works if the other lines aren’t already operating at their capacity limits.

 

“The fact that we have so few power failures in Germany – currently averaging only about 14 minutes per consumer per year – is because grid operators have a backup for every line, every transformer, and every device in the system. Experts call this preventive (n-1) security,” explains Chris Heyde, a grid planning expert at Siemens. “This means that redundant equipment always has to be held in reserve for the few times that a failure occurs,” adds his colleague Pascal Wiest.

 

Heyde and Wiest belong to the team that’s currently developing and testing new solutions. Their focus in the state-funded InnoSys 2030 research project is on automated, curative, and highly precise measures. In the future, these measures will help grid operators work even better with planned and existing lines by intervening curatively only when an overload actually occurs. In these cases, wind turbines could be immediately throttled back, or batteries could be activated to store surplus electricity.

Faster reactions rather than redundancies

“We’re assuming that without assistance systems, even experienced control room operators need at least 15 minutes to decide on which of the many possible measures should be taken. That’s far too long,” says Heyde, and Wiest agrees: “Grids and their operation are becoming increasingly complex due to the energy transition. This is exactly where automated assistance systems come into play, because they can quickly recommend the right curative measures to the operator or, in a later development stage, they could execute these measures fully automatically. This is how the grid can remain secure – and with fewer costly operational interventions and redundancies.”

Grids and their operation are becoming increasingly complex due to the energy transition. This is where automated assistance systems come into play.
Pascal Wiest, grid planning expert at Siemens

But the project team hasn’t reached that stage yet. Even though there are initial findings from the earlier DynaGridCenter project, the theory now has to be put into practice. In the meantime, Heyde and Wiest have defined data for the assistance systems that tells them which activation or deactivation measures are possible for given technologies and scenarios. It’s now up to the university partners and research institutes: They’re currently running simulations to see how often curative measures might actually be necessary and whether the switching strategies in the computer model work.

Increasingly complex grids

“The project really opened my eyes,” says Heyde. “The problem doesn’t lie in the technology, because it’s there and it works. The crux of the matter is to have appropriate processes for coordinating the measures used by grid operators. The more complex a power grid, the more complex the required measures. That’s what makes designing assistance systems for power grids so difficult,” he adds. He makes the following comparison: Whereas a driver assistance system in a car only has to coordinate the control of a single vehicle, an assistance system in a central control center must be able to safely control all the cars on the highway.

While simulations are being performed at the university, a Siemens team in Ilmenau is preparing the control room, where the next step will be to test the assistance systems under real conditions. “This is where it really gets exciting,” says Wiest. “In what’s known as a demonstrator, we’ll see whether the assistance system does what it’s supposed to do when interacting with Siemens technologies, and whether it really succeeds in optimally utilizing the grids as expected.”

The problem doesn’t lie in the technology. The crux of the matter is to have appropriate processes for coordinating the measures used by grid operators.
Chris Heyde, grid planning expert at Siemens

The demonstrator only simulates the behavior of the power grid; everything else is “real.” The demonstrator in Ilmenau uses protection and telecontrol devices as well as control systems from Siemens.

The solutions used in the project aren’t just applicable to the German transmission grid. Wherever more and more renewable energy is being generated locally, additional assistance systems integrated in the grid’s operation can help prevent grid overload. In grids where there are more frequent equipment failures and extreme conditions, they can also provide valuable decision support to ensure secure grid operation. The solutions can also be applied to distribution grids and even municipal grids.

Basically, the largest demonstrator in the project is the Spectrum Power 7 control system from Siemens. In addition, the Siguard DSA (dynamic security assessment) software tool analyzes dynamic system stability and evaluates the curative measures, while Siguard PDP (phasor data processor) monitors the grid using synchrophasors. The process data is generated in real time using PSS Sincal grid simulation software and transmitted to the control system via a protocol gateway. The control signals are also transmitted to the simulation software via a telecontrol protocol.

InnoSys 2030

InnoSys 2030 is a collaborative research project with 17 partners. All four major transmission system operators and a number of distribution system operators are working with universities, research institutes, and with Siemens to investigate options for increasing the utilization of power grids. The project is being funded by the German Federal Ministry for Economic Affairs and was launched in October 2018.

November 30, 2020

Picture Credits: Siemens AG

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