In recent years, the power system has drastically changed. Traditionally there were large, centralized production units on one side and centralized consumption areas on the other side. Due to large incentives, arising primarily from the environmental reasons, the penetration of the distributed (renewable) energy sources (DRES) has drastically increased and therefore the classical understanding of the power system has changed. All these changes and issues are the driver for constant development and improvement of the solutions in the field of generation, energy consumption, as well as advanced operation and control algorithms for the power system.

From the technical point of view, the most important issue is the nature of power feed-in of the DRES. They are very intermittent and thus it is hard to predict when the power will be produced. On the other hand, the network wasn’t designed for mass integration of DRES, which results in poor network performance in case of high DRES production. Primary role of the distribution network was to support power flow from the transmission network to the end customers. Nowadays, due to DRES, the direction of the power-flow can change.

These changes can have a high stress on the voltage quality and reliability of supply in the network. Over-voltages, congestions and impact on protection devices are only few of the issues and challenges of the Distribution System Operators (DSOs). However, since DRES are highly desired, especially due to environmental aspects, all issues regarding operation and control of the distribution power system have to be tackled accordingly.

The INCREASE project focuses on the development of the solutions which address the question “How to increase the integration of renewable power in the distribution network”. The objective is followed from different perspectives, such as analysis of the power system problems, mapping possible solutions, development of the advanced voltage control algorithms, implementation of the algorithms into the prototypes, evaluation of the solutions by means of field trials and preparation of the regulatory framework. Using this approach, maximal exploitation of the project outcomes and integration of the solutions into real-life European distribution networks can be achieved.

The INCREASE solutions consist of advanced control of DRES generation and implementation of demand response using controllable loads. INCREASE control schemes are used to cope with voltage issues and congestions in the distribution network. A cornerstone of the INCREASE solutions is an advanced PV inverter with integrated droop control. Using droop, the inverter can curtail the PV output in case of high voltage at the connection point of the inverter. That way over-voltages are avoided, in addition the green energy feed-in is maintained at certain level and not completely shut-down as in case of classic PV inverters.

Advanced INCREASE control scheme consists of three layers, from local to the control centre level in order to achieve maximal benefits:

  • Local control using advanced PV inverter provides fast response in case of local voltage issues
  • Overlaying remote control takes into account voltage and other measurements from multiple points of the network and provides remote set-points for advanced PV inverters and adjustable distribution transformers - OLTCs. That way proper voltage conditions are achieved in the whole network
  • Scheduling control aims to further exploit the developed control strategies by including market signals, optimization, etc.

To develop and enhance a complete set of the INCREASE solutions, different partners from industry are required. The development process can be divided into various fields of required technical expertise:

  • Hardware Industry – development of sensors, monitoring devices, instrumentation, controllers, switches, etc.
  • PV Industry – development of PV inverters,
  • Information - Communication Industry as a part of hardware and services; from implementation of the modems, data concentrators, databases, communication technology for sending/receiving the signals, to the service part of data acquisition from concentrators to the central data repositories,
  • Industrial software development, required to develop the control algorithms, embedding the algorithms to the control units or implementation of the control infrastructure at the control centre of the DSOs,
  • Business Software development, which arises from other aspects of control, such as planning of ancillary services and network investments (decision support system), monitoring of control actions for billing purposes, sharing the control capabilities and actions with different system or stakeholders, etc.

For maximal exploitation of the INCREASE solutions potential, as many as possible generation and load units have to be included into the process. The participation of the units has to be driven by the energy market incentives and regulatory framework. Different market players can compete for the best business model, which includes analysis of the potential units, their owners and unit aggregation to provide the service of flexibility of energy generation/demand and use to the power market stakeholders.

From the energy market’s point of view, the potential in the industry arises from:

  • Energy producers and customers, as providers of flexible generation and load units, which can be implemented into controllable energy portfolio
  • ESCOs (Energy Service Companies), which provide control capacities of the aggregated generation and load as flexibility products to other stakeholders,
  • Energy Retail and Energy Trading companies, which use energy from ESCOs for energy balancing of their portfolio,
  • DSO-s (Distribution System Operators), as users of services for improving the networks’ operation and consequently the quality and reliability of the supply
  • TSO-s (Transmission System Operators), as users of the ancillary services of power reserve from flexible distributed generation and load units

Within the duration of the INCREASE project, the consortium partners have delivered many results and answers to the question how the developed solutions have to be properly addressed and implemented into real-life environment:

  • Deliverables in Work Package 1 provide a general overview of the problem and a current state-of-the art of possible solutions. In addition, there is also an overview of the relevant regulatory and policy framework in different EU countries.
  • Work Package 2 results in algorithms and methodologies to obtain sufficient level of DRES control in order to achieve reliable operation of the distribution network in case of high DRES penetration. These algorithms can be embedded into controllers (inverters, switches, adjustable distribution transformers – OLTCs, etc.), or deployed centrally in the SCADA or similar control system of the DSO.
  • Work Package 3 provides the outline for development and use of the simulation platform to test developed solutions before their actual deployment on the field.
  • Work Package 4 is meant to validate the developed control schemes by means of simulations, lab and finally the field trials in real distribution networks across the Europe.
  • Deliverables in Work Package 5 introduce the market potential of using and selling the flexibility/control services obtained from the implementation of the INCREASE solutions.

Using the outcomes of the INCREASE project, together with strong cooperation with different industrial stakeholders, can result in further improvement of the INCREASE solutions and mass implementation into the distribution networks of European DSOs. That way an important step towards reliable energy supply and increased penetration of DRES can be made.