Power Electronics – One of the Key Technologies for the Decarbonisation of the Energy Sector

Decarbonisation is the process of transforming the economy into an economy that has a minimal output of greenhouse gas emissions into the atmosphere, specifically carbon dioxide. Decarbonisation is mandatory to limit the worldwide temperature rise. Consequences of the temperature rise are for example the increase of local heavy weather events, that induced amongst others in Germany the disastrous flood events during this summer.

Major source of greenhouse gases is the energy production of all types. It contributes approximately 70 % to the global greenhouse gas emissions.

To reduce the greenhouse gas emissions of the energy sector principally three possibilities exist: Decrease of energy consumption by increase of energy efficiency or by decrease of energy usage respectively or transformation of energy production towards renewable energies. The latter is one of the goals of the so-called Energiewende in Germany.

Renewable energies such as wind or solar energy require a power electronic converter for the connection to the electric grid. The electric energy delivered by the generator of the wind power plant or from the photovoltaic modules of the solar power plant has to be transformed suitable for the grid.

 

Grid connection of a wind power plant using a power electronic converter.

Grid connection of a wind power plant using a power electronic converter.

Nowadays power electronic converters for the grid connection of renewable energy systems require a strong electric grid. Grid connection to weak grids is difficult. The strength of an electric grid is described by the so-called short circuit power. The short circuit power is mainly determined by fossil fuel power plants. Renewable energy systems with grid connection using power electronics do not contribute significantly to the short circuit power. Thus, with the ongoing shut down of fossil fuel power plants the short circuit power available is reduced automatically – the grid becomes weaker. It is therefore mandatory that renewable energy systems have to deliver a contribution to the short circuit power of the grid in the future. The power electronic converter control has to be changed and adopted appropriately. Suitable concepts exist. However, there is still a research and development demand, as a large number of power electronic converters connected to the electric grid lead to mutual interferences and to problems with the power quality.

Power electronics is a key technology for the success of the decarbonisation process. Only with the help of power electronics the transformation of the energy sector towards renewable energies is possible. Simultaneously this process demands a change of the operation principles of electric grids, a change where power electronics has to contribute, too.

Power electronics is a future technology and a fascinating field of activity for electrical engineers.


« zurück