Power Quality

The quality of voltage and current

Devices connected to the electricity grid not only consume energy, but can also have an effect on the voltage quality or Power Quality. This also applies to electric vehicles and DC chargers. Poor Power Quality can lead to malfunctions or even damage to equipment and can reduce the usability of sustainable energy. That is why ElaadNL tests and researches these devices and their effects so that all electric vehicles can charge smoothly and sustainably.

At ElaadNL we test electric vehicles and DC chargers and look at any disruptions they cause. It is also being examined whether the chargers are immune to disturbances from the grid originating from other vehicles. Chargers are often connected in different environments, such as the charger at home, at work, or along the highway. These are all different nets and they are simulated to determine if the charger works well everywhere.

In addition, ElaadNL is investigating the influence of charging electric vehicles on Power Quality. This involves research into the influence on the electricity grid and on other appliances. This is to work towards limits for certain types of disturbances, which can then be enforced in standards.

TEPQEV Symposium November 11, 2022

On November 11, Elaad hosted the TEPQEV Symposium 2022. Various speakers from Eindhoven University of Technology, KEMA Labs and Heliox, among others, spoke about the research into Power Quality.

Download and view the presentaties

What is Power Quality?

Power Quality describes the quality of voltage and current, and the interaction between them. The impact of a new technology is often viewed from the capacity issue; is there enough power and energy available? It is often forgotten to look at the quality issue; can these new devices work with each other and with the net? Power Quality is a broad concept and can be divided into various aspects.

For almost every aspect there is a standard that specifies guidelines and limits, but not yet for all! For example, supraharmonics are disturbances for which there are no standards yet. These are disturbances between 2 and 150 kHz, which are switching frequencies that are often used by inverters, such as in electric vehicles.

At ElaadNL, we also test and investigate precisely those aspects that have not yet been standardised, in order to get an idea of the expected impact, to advise manufacturers at an early stage and to work towards new or adjusted standards.

Power Quality testing in the ElaadNL Testlab

In the test lab we look at the different aspects of power quality, at all the different charging levels that the vehicle or DC charger supports. To do this, we connect the device to a clean or disrupted network. In terms of disturbances, we look at the following types:

Harmonics: Does the device meet the emission limits for frequencies up to 2 kHz, and is the vehicle itself immune?
Supraharmonics: is the device a source of disturbances between 2 and 150 kHz?
Voltage imbalance: can the device handle real voltage imbalance?
Voltage dips/swells: is the device immune to short, large, variations in the voltage level?
Undervoltage and overvoltage: does the device stop charging when the voltage of the grid reaches its lowest or highest limit?
Reactive power: Is the device inverter efficient even at lower load levels?