Synchrophasor based Steady State Model Synthesis of Active Distribution Networks

Sammanfattning: With the increased penetration of distributed energy resources (DERs) at lower voltage levels, distribution networks (DNs) are being transformed into active grids. This has led to a paradigm shift in the operation, planning and control of DNs. Traditional monitoring infrastructure is unlikely to satisfy the requirements that active distribution networks (ADNs) pose in terms of higher speed networking, time synchronization and signal resolution, precision and accuracy, scope, etc. As a result, high performance monitoring infrastructures are needed to fully utilize the potential of sensing devices at DNs, capable of monitoring ADNs in real-time. In this context, phasor measurement units (PMUs) have emerged as one of the most promising alternatives for ADNs monitoring in real-time.The focus of this thesis is to exploit PMU measurements to perform real-time steady state model synthesis (SSMS) of ADNs. To this end, methods for pre-processing PMU data are developed in this thesis. As the focus of this thesis is the development of a steady state PMU application, the methods presented herein extract the quasi-steady state component in PMU measurements and feeds them to the SSMS application. In addition, the methods are capable of filtering noise, compensating for missing data, and removing the outliers in PMU signals in real-time.The synthesis method can be applied to multiple sections of unbalanced ADNs requiring measurements from multiple PMUs. The proposed approach is generic and can be applied to any portion of a DN with any feeder configuration. The performance and the effectiveness of the proposed methodology have been illustrated in details by using real-time hardware-in-the-loop (HIL) experiments.A detailed sensitivity analysis of the SSMS application is performed in order to show how sensitive the output of the SSMS method is to changes in its inputs. An extended version of the total vector error (TVE) was developed as an evaluation metric. The location of PMUs, system operating point and the occurrence of different disturbances are considered when evaluating the SSMS method. The sensitivity analysis is performed through several case studies as discussed above.Finally, the thesis provides extensive experimental validation experiments on the SSMS application. Syncrophasor measurements acquired from real PMUs installed at an actual active distribution feeder in a university campus were used for this purpose. A detailed performance assessment of the SSMS method is conducted for different conditions. Additionally, a comprehensive analysis is performed to help power system operators to determine how to configure the SSMS application.