Power Quality

The quality of voltage and current

Devices connected in the power grid not only consume energy but can also have an effect on voltage quality or Power Quality. This includes electric vehicles and DC chargers. Poor Power Quality can lead to equipment malfunction or even damage and can reduce renewable energy deployment. That’s why ElaadNL tests and researches these devices and their effects so that all electric vehicles can recharge smoothly and sustainably.

At ElaadNL, we test electric vehicles and DC chargers, looking at any disruptions they cause. We also look at whether the chargers are immune to disturbances from the grid coming from other vehicles. Chargers are often connected in different environments, think about the charger at your home, at work, or along the highway. These are all different grids and these are simulated to determine if the charger works properly everywhere.

In addition, ElaadNL is investigating the impact of electric vehicle charging on Power Quality. This involves examining the influence on the power grid and on other devices. This in order to work towards limits for certain types of disruptions, which can then be enforced in standards.

Sign up directly for a Power Quality test in the Elaad Test Lab

What is Power Quality?

Power Quality describes the quality of voltage and current, and the interaction between them. Often the impact of a new technology is looked at 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 interact with each other and with the grid? Power quality is a broad concept and can be divided into several aspects.

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

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

Power Quality testing in the ElaadNL Test Lab

In the test lab we look at the different aspects of power quality, at all the different charging levels the vehicle or DC charger supports. To do this, we connect the device to a clean, or conversely, a disturbed grid. 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 to this?
Supraharmonics: is the device 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 if the grid voltage reaches its lowest or highest limit?
Reactive power: is the device’s inverter efficient even at lower charging levels?

TEPQEV Symposium November 11, 2022

On Nov. 11, Elaad hosted the TEPQEV Symposium 2022. Several speakers from TU Eindhoven, KEMA Labs and Heliox, among others, spoke about Power Quality research.

Looking back at the TEPQEV Symposium on November 11 2022