Voltage Control In Smart Distribution Network With Distributed Energy Resources

Abstract

With the rise of distributed or embedded generation in distribution networks (DN) and local energy producers' involvement, distribution systems have become active and grown more complex. These events caused the distribution network to transition from a passive to an active configuration, increasing its difficulty and causing long-term changes in its characteristics. The state estimate procedure for the active distribution network (ADN) is typically more complex than the transmission network due to factors like the distribution network's high R/X value, high distributed generation (DG) penetration, improper node-to- node communication, and others. In this scenario, significant responsibility for the distribution network operators is implementing advanced management systems with precise monitoring, control, and protection systems to ensure reliable operation. In this regard, distribution state estimation (DSE) plays a predictable role in measuring and monitoring distribution networks. This study intends to investigate the areas of measurement system configuration and state estimation in the ADN utilizing the phasor measurement unit technology (PMU). The front side of a state estimator is a supervisory control and data acquisition (SCADA) system that gathers system information. The SCADA system periodically queries the data collection devices. Nevertheless, the data extracted does not adequately reflect the system's behaviour when it alters during the assessment. In contrast to state estimation using a conventional SCADA system, synchro-phasors allow the status of the power system to be observed. High-speed, consistent data is delivered by the promising synchro-phasor technology. With the introduction of global position system (GPS) receivers, this platform has grown increasingly appealing and cost-effective. Synchro-phasors offer voltage and current measurements with a similar frame of reference; one such standard time source is the GPS. The PMU data is either gathered by the phasor data concentrator or directly sent from the PMU over the communication network. To perform wide-area monitoring protection and control, stability analysis, and grid state estimation, the central station may use the synchronized phasor data gathered by the PMU. As a result, more academics are starting to research the use of PMU technology to keep up with the demands of an active distribution network. This research has been conducted with this motivation. Given the importance of PMUs in current grid networks, first, this work attempts to simplify the selection of the optimum locations for PMUs in various configurations. Hence, ifor full observability of the distribution test feeders, an integer linear programming technique is utilized in the simulation with a minimum number of PMUs with and without zero injection buses (ZIBs). A methodology is suggested to analyze the voltage estimation using the current PMU count while taking zero injections into consideration after the best PMU locations have been determined. As expected, the results reveal that employing zero injection buses (ZIBs) reduced the number of PMUs in the network and had no appreciable impact on the system's voltage profile. Second, although the quantity of PMUs required is reduced by zero injections, the zero-injection bus approach for PMU placement in ADNs has some limitations. Due to the heavy load on distribution networks, loads can change drastically, and DG is gradually being incorporated into it. To accurately estimate the distribution network states and monitor the network's system response, no node or bus can be disregarded. Henceforth, a technique is presented for computing the voltage magnitude of the radial distribution network using PMU technology while disregarding ZIs. To validate the suggested approach, a forward and backward sweep (FBS) load-flow algorithm is employed. In addition to the proposed voltage estimation technique, an algorithm is developed to validate the results of integer linear programming (ILP) performance in radial test feeders for complete system observability with a minimal number of PMUs. Third, the dynamics of the distribution networks, as well as the entire power system, may be impacted by DG expansion. Unbalanced voltage is among the many problems with power quality that are the most serious. When network voltages are unbalanced, voltage management becomes challenging because the unbalanced voltage's negative sequence component results in oscillations with a double fundamental frequency in both reactive and active power injections. To address the issue, this work proposed the multi-agent system (MAS) based control technique to find the best voltage regulator for the operation of unbalanced radial distribution networks. To evaluate the viability of the developed techniques, the standard IEEE Distribution network systems are considered. MATLAB programming is employed to simulate case studies.