EASY-RES

Project Description

The stability and security of the traditional electrical power system are largely based on the inherent properties of synchronous generators (SGs). Such properties are the grid-forming capability, the inertia, the damping of transients, and the provision of large currents during faults. The growing penetration of converter-interfaced (thus inertia-less) Distributed Renewable Energy Sources (DRES) will eventually replace dispatchable SGs and increase power volatility, causing large frequency deviations and voltage reg¬ulation problems. The previously proposed solutions to resolve this problem are an increase of SG spinning reserves, the grid reinforcement and the use of central electric energy storage systems, but these solutions have high cost and centralized approach.EASY-RES offer unified bottom-up approach and will develop novel control algorithms for all converter interfaced DRES, to enable them to operate similarly to conventional SGs, providing to the grid inertia, damping of transients, reactive power, fault ride through and fault-clearing capabilities,  and adaptable response to primary and secondary frequency control. These new functionalities will be transparent to all grid voltage levels.

The key objectives of this project are to increase the robustness of the power system towards abrupt frequency changes by introducing virtual inertia and damping in DRES. Contribute to the stability of the grid by providing frequency-dependent active power. Increase the renewable energy penetration levels at both LV and medium voltage (MV) level, while avoiding investments for grid reinforcement. Make the RES more grid-friendly by i) reducing the short-term electric power fluctuations at both DRES and HV/MV substation level and ii) introducing active harmonics filtering to each DRES converter. Preserve the long-term grid security even under very large DRES penetration, by reducing reserve requirements after fault recovery. Develop viable business models for all the stakeholders by (i) proposing new metrics for the quantification of the various AS and (ii) evaluating the economic cost and benefit of all the developed AS. 

TU Delft  contribution in this project is evaluation of the ad-hoc KPIs, performed by simulations of various DRES types and penetration levels. The time-domain or frequency domain distribution-network simulation  evaluation with widely used platforms like PSS/E, DigSILENT, Psim, Neplan.Testing of  functionalities and technologies of all DRES converter in RTDS (Real Time Digital Power System Simulator) with HIL (Hardware In Loop): i. Adaptable inertial response. ii. Adaptable PFR(Primary Frequency Response). iii. Response to various types of faults and ability to follow the FRT (fault-ride-through)curves. iv. High-frequency power smoothing for DRES converters. v. Low-frequency power smoothing for BESS (Battery Energy Storage Systems). vi. Controllable reactive power exchange.vii. Verification of relative converter efficiency degradation due to reactive power exchange. viii. Controllable active harmonic filtering. ix. Recording and quantification methodologies of the various developed AS.

The EASY-RES consortium consists of 5 universities, 1 industrial SME, 3 DSOs, 1 TSO and 1 SME acting as dissemination and exploitation manager. More details about the EASY-RES project you can find on the official project webpage.