Upgrading Voltage Control Method Based on Photovoltaic Penetration Rate

Abstract

In this paper, we propose a comprehensive scheme to determine a suitable method and timing for upgrading the voltage control method. Voltage control methods are expected to be upgraded in accordance with the photovoltaic (PV) penetration in distribution systems. The suitable method and timing detailed in this paper are based on the limit of the PV penetration rate, which is constrained by the regulated voltage deviation. The upgrade process involves moving the on-load tap changer (OLTC) control method from the conventional scalar line drop compensator (LDC) method to the vector LDC method or centralized control method. Then, a static var compensator (SVC) or step voltage regulator (SVR) is installed. The locations of the SVR and SVC are determined to maximize the PV penetration rate. The suitable method and timing are demonstrated using a general distribution system. In addition to the numerical simulations, experiments are performed using an active network system with energy resources. The experimental results are consistent with the numerical simulation results, thus validating the proposed scheme. The maximum PV penetration rate obtained using the OLTC control method is 55%. Whereas, the installation of the SVR and SVC increased the rate to 95% and 100%, respectively. Index Terms-Line drop compensator (LDC), on-load tap changer (OLTC), photovoltaic (PV) system, static var compensator (SVC), step voltage regulator (SVR).I. INTRODUCTION T HE USE of photovoltaic (PV) systems is continually increasing worldwide. In 2014, the cumulative solar electricity capacities installed by the United States, Germany, and Japan were 20 GW, 38.2 GW, and 23.2 GW, respectively [1]. The PV capacity increased by approximately 40 GW in 2014. Close to half of the new PV capacities were installed in Asia,

A Review of Strategies to Increase PV Penetration Level in Smart Grids

“…Akagi et al [51] has proposed a comprehensive approach to determine the appropriate voltage control method for upgrades based on the limit of penetration rate. The process involves upgrading scalar line drop compensation (LDC) to Vector LDC/centralized Control method and then to on-line tap changer (OLTC).…”

“…When BESS is fully charged, the method switches to reactive power compensation. Traditional control methods [51] have been adopted for the high penetration of PV power into the grids but the SVCs and OLTCs are often exposed to high stress causing degradation and reduction in lifetime [55]. Incorporating the BESS in low-voltage networks is found to be a promising solution against the over voltages and address these issues.…”

Microgrid Controller Testing Using Power Hardware-in-the-Loop

“…Laboratory testing has the capability to test hardware with high fidelity conditions. There are power system research testbeds that can provide flexible testing environments composed of inverter-based emulators and some distributed energy resources (DERs) [10][11][12]. Since the control system parts of these labs are built by the flexible modeling tools, it is supposed that they have advantages in the stage of developing microgrid control algorithms.…”

Real‐time multiperiod voltage control algorithm with OLTC and switched capacitors for smart distribution networks in the presence of energy storage system

“…Other related works are presented as follows: Satoru et al 11 proposed a timing scheme in upgrading the conventional scalar line drop compensator OLTC to vector line drop compensator. The author installed a static var compensator and step voltage regulator on a location that maximizes the photovoltaic penetration rate.…”