Voltage control services are needed when there are sudden changes in demand. This is because the amount of reactive power changes, which affects the voltage and quality of supply. The increasing penetration of non-synchronous, renewable energy in modern power systems replaces synchronous generation and affects voltage stability.
This drives the need for additional voltage control sources. A market for voltage control services allows distributed energy resources connected to the distribution grid to provide reactive power support through an ICT platform. The advantage of distributed energy resources (DER) is that reactive power can be produced where voltage problems occur, thereby providing a more suitable solution to the problem.
Components & enablers
- ICT platform that supports a technical and commercial solution. Must be able to provide network support at transmission level, while respecting constraints at the distribution level.
- The participants do not need to change their technology, but they need to integrate the control system, DERMS (distributed energy resources management system).
State of the art in application and research
Voltage control services are not typically part of existing markets. The new market solution uses distributed energy resources (DER) connected to the distribution grid to provide reactive power support. DER will be instructed via a centralised ICT platform called DERMS (Distributed Energy Resources Management System). In theory everyone can participate in the market (PV power plants, wind farms, batteries and storage sites, synchronous generators and aggregators.
Until now Power Potential has not been able to include aggregators, but the goal is that every producer of power can participate. It is still in the testing phase and the results will not be available until 2020.
The required response time for participation in the voltage market is under 5 seconds. This means that it is fast enough to handle quick reductions in voltage, for example from when a big load disconnects from the power grid. The market has been tested in 400 000 houses, but it is still in the testing phase.
Technology Readiness Level
TRL 5 - development:
This new market platform is being tested in a simulation environment, it is still in a research/development phase and not fully operational. It is getting ready to conduct trials in the live system in 2019.
Current focus of R&D and research gaps
The main challenge for the project is to implement and integrate the ICT platform into existing systems. The research focus also covers enabling aggregator participation.
NODES is looking to integrate voltage control services into its market platform in the future, but this is currently at an early research stage.
In addition to National grid ESO reactive power/voltage control markets many TSOs/DSOs mandate or remunerate the delivery of voltage control from any grid user already.
EU-SysFlex has also done research regarding the liberalization of “voltage markets”: Commercial Control of Reactive Power in an Electricity Distribution Company.
 Power Potential. [Link]
 EU-SysFlex. [Link]