Results of the INCREASE simulation platform

Within INCREASE a supporting simulation platform has been developed, allowing for the design, analysis, and optimization of the developed solutions. This simulation platform is a valuable tool for DSOs in order to investigate the influence of DRES in their distribution grids, implementing either the INCREASE proposed solutions or any other similar control scheme. The simulation platform is developed using existing open-source software and includes the following major features:

  • Simulation of the distribution system (both LV and MV networks) with the presence of unbalanced loads and generation.
  • Integration of the locally controlled, inverter-interfaced, distributed generation (DG) units, i.e. of the Local Control scheme for overvoltage and voltage unbalance mitigation.
  • Incorporation of a Multi-Agent System (MAS) taking into account the multi-objective Overlay and Scheduling Control algorithms.
  • Implementation of a communication network simulator for the evaluation of the existing infrastructure and the communication requirements for the MAS control system.

The software platform architecture also allows the integration of other external and independent software modules, such as forecasting algorithms, demand side management and demand response simulation modules, as well as constraint optimization tools.

Several deliverables have been written and submitted. The 1st report presents the simulation platform and the results of the incorporation of the INCREASE local control. The analysis starts with the description of the most common practice in the simulation of distribution networks and their classification into distinct categories, according to the adopted solution methods. The technical and numerical difficulties of each approach are analyzed, and the requirements for a new simulation platform are set, to provide multiple, combined simulation capabilities for extended distribution grids and smart grids, including controllable DRESs.

The properties of the INCREASE simulation platform are also introduced, and the overall structure is thoroughly described. The report focuses on the features of GUI and on the software tools needed for the implementation of the core solution algorithm. The proposed scheme is demonstrated in various examples and is further compared with other conventional simulation software packages, revealing its superior performance in terms of accuracy, numerical stability and efficiency.

The INCREASE local control is successfully incorporated in the INCREASE simulation platform. The implemented control is slightly modified with the insertion of an integral term in the power output of the controlled inverters. This term enhances the numerical stability of the calculation procedure, without altering the performance of the system under study and the accuracy of the corresponding power flow results.

Two different implementations of the local control are considered and further demonstrated in various test cases including fictitious representative networks as well as two of the project pilot installations. Both implementations of the local control prove to be quite effective in both overvoltage and voltage unbalance mitigation, while also presenting smaller power curtailment of the injected power of the DG units, compared to the other conventional control schemes. Of the two local control implementations using  the maximum voltage for the droop control and for the calculation of the damping conductance leads to higher power curtailment, since it imposes more strict criteria than the case where the corresponding positive-sequence voltage is used.

The provided results show that the local control implementation in the INCREASE software platform can be applied to both LV and MV distribution grids, for variable time frames including variable load and generation data provided by the DSO. In all examined cases the INCREASE simulation platform performed with remarkably high speed and accuracy, while no numerical stability problems have been detected.

The 2nd and 3rd report describe the overlaying control and the communication network simulator incorporated in the INCREASE simulation platform.

The full version of the overlaying control consists of the OLTC scheme, the congestion control technique, and the FPS algorithm, which are developed to cope with overvoltages and congestion problems, when integrating multiple DRES units in the distribution grid. The performance of the full overlaying control is demonstrated on a selected pilot installation and is compared to the cases of no DRES power curtailment as well as to the local control scheme. Results show the efficiency of the proposed algorithm in mitigating overvoltages by changing the OLTC state and enforcing a fair contribution of the curtailed power among the installed PV inverters, while maintaining low levels of power losses in the distribution network. Moreover, the efficiency of the congestion control technique is also shown, assuming a high DRES penetration level.

The results of WP3 have been presented at the IEEE PowerTech Conference in July 2015 in Eindhoven, the Netherlands. The paper A simulation tool for extended distribution grids with controlled distribution generation  discussing the simulation platform was presented there. The authors of this paper are: Kryonidis, G.C.; Kontis, E.O.; Chrysochos, A.I.; Demoulias, C.S. (Aristotle University of Thessaloniki, Greece); Bozalakov, D.; Meersman, B.; Vandoorn, T.L.; and Vandevelde, L. (Ghent University). 

The 3rd report about this WP (D3.3) is available on the results page of this website.