Distribution-level synchrophasor assisted monitoring and control of active distribution networks

Abstract

The ever increasing power demand and negative environmental impact of fossil fuel-based generation has enhanced the participation of renewable-based Distributed Generation (DG) and, thereby, has given rise to the concept of Active Distribution Networks (ADNs). Despite of their environmental and economic benefits, integration of DG brings a lot of technical challenges such as bidirectional power flows, unintentional islanding, voltage-rise, power quality degradation, etc. An advanced monitoring, protection and control framework for the present-day modern distribution networks can immensely help in analyzing and combating these challenges. Conventionally, Supervisory Control And Data Acquisition System (SCADA) is used to monitor and control the passive distribution networks. However, after the integration of DGs into distribution systems, the SCADA becomes inadequate in providing fast, accurate and desirable measurements. To this end, this thesis carries out a detailed research work in order to build a synchrophasor technological solution for the monitoring and control of ADNs. Although the Synchrophasor Technology (ST) is well established for the transmission system, it is in its incipient stage at the distribution system. Because of some fundamental differences between both the systems, the ST of transmission system cannot be directly borrowed to the distribution system. Thus, this thesis provides a step-wise solution for implementing the synchrophasor technology at the active distribution networks. To begin with, the thesis develops the core instrument of the ST i.e., Distribution-Level Phasor Measurement Unit (DPMU), to measure distribution level synchrophasors. Next, the optimal number and locations of DPMUs are suggested to be deploy in the ADNs. Next, the DPMU data is collected at centralized control centre and utilized to develop a robust state estimation framework. Thereafter, the DPMU data is scrutinized to detect island formation in a local as well as in a global manner. At the last, a control algorithm is developed to generate the active-reactive power dispatch points for the DGs to mitigate voltage rise issues of the network. The control algorithm is implemented using a private and permissioned blockchain framework having a new mining approach such as Proof of Network (PoN). The off-line testing of various developed methodologies are performed usingMATLAB, PSCAD, RSCAD and Python. For the real-time testing, various hardware platforms such as Real-Time Digital Simulator (RTDS), DS1104 Research & Development controller-board, WAMASTER PMU are utilized. Keywords- Synchrophasor Technology, Active Distribution Networks,Wavelet Transform, Integer Linear Programming, Weighted Least Square, Teager-Kaiser Energy Operator, Blockchain Technology.