In order to successfully integrate electricity from renewable energy sources such as wind and photovoltaic systems into our power grid, we need power electronics converters (PECs). These are used to convert, control and distribute electrical power so it arrives where and when needed. However, the integration of a large number of PECs can lead to stability and quality problems in power grids. Particularly in weak grids, PECs can cause oscillations that destabilise grid operation.

In the ASPPECT project, a research team from the Institute of Energy Systems and Fluid Engineering (IEFE) at the ZHAW School of Engineering is investigating how PECs cause these stability and quality problems in power grids. The existing categorisation of stability problems is not sufficient to describe these new phenomena. New terms such as ‘transformer-controlled stability’ and ‘resonance stability’ have therefore been introduced. The project aims to develop and test innovative methods to minimise these stability problems in practice. These methods should help to keep power grids stable despite the increasing integration of PEC and improve grid quality.

The solution methods developed in the ASPPECT project are to be tested with a real-time simulation using Power-Hardware-in-the-Loop (P-HIL) under real conditions. In a P-HIL simulation, not only control and signals are simulated, but the actual electrical power is also considered and included in tests. This allows real, powerful generation systems such as wind turbines or PV systems to be tested in a simulated environment: with the simulated system taking into account the high current and voltage requirements of these devices. So-called ‘power amplifiers’ are used in the simulation for this purpose. They ensure that the simulated environment supplies sufficient current and voltage to the environment under test and at the same time provides feedback to the simulation. This creates a closed loop, which makes the test very realistic and accurate.

The ASPPECT project supplements and deepens existing studies by developing new approaches for the stabilisation of power grids with PEC. The aim is to optimise the use of PEC in the energy supply - an important contribution to the successful integration of renewable energies into the electricity grid.

Project name
Assessment of stability and power quality problems in power electronic converters by hardware-in-the-loop tests (ASPPECT)

ZHAW Project team
Petr Korba, Rafael Segundo, Alfredo Velazquez

Project partners
SINTEF, Norway
International Energy Agency (IEA ISGAN)

Funding partner
Swiss Federal Office of Energy (SFOE)

Project duration
October 2024 till September 2028