Reliability Varying Characteristics of PV-ESS-Based Standalone Microgrid

Abstract

Reliability is of critical importance for the microgrid (MG) and deserved more attention. Aiming at photovoltaics (PV) and energy storage system (ESS) based MG, the microturbine (MT), PV, ESS and comprehensive load (CL) which is composed of hourly time-varying component, stochastic component, and controllable component, are chronologically modeled and combined with model of load shedding minimization and sequential Monte Carlo (SMC) simulation algorithm. Then, the reliability assessment framework is developed and employed in the comprehensive case studies. Firstly, varying characteristics of reliability indices, including loss of load probability (LOLP), average service availability index (ASAI), system average interruption duration index (SAIDI), system average interruption frequency index (SAIFI) and customer average interruption duration index (CAIDI), over PV penetration are investigated, and the surge effect of SAIFI (SE-SAIFI) is especially put forward and studied, followed by the principle of PV capacity decision considering SE-SAIFI. Secondly, the clear pictures of reliability profiles over ESS sizes are depicted and analyzed, following with a novel method to reasonably decide ESS sizes based on the definition of expected hourly redundant power (EHRP). At last, reliability indices of multiple scenarios with different percentages of controllable load are calculated and the benefits of load management are analyzed in the viewpoint of reliability of standalone MG. Results of the case studies also confirm the necessities of reliability assessment during the MG planning and size optimization, and the validity of the methodologies developed in this work.INDEX TERMS Standalone microgrid, energy storage system, sequential Monte Carlo simulation, reliability varying characteristics.

Energy Management System for Small Scale Hybrid Wind Solar Battery Based Microgrid

“…The power in the microgrid must be balanced under different generation of power from renewable energy sources and load demand conditions. The power balance equation is given as follows P w + P pv = P L + P bat (5) The various modes of operation of the energy management system are presented in the flowchart in Fig. 9.…”

“…The most commonly used hybrid renewable energy sources are solar and wind energy [3], [4]. Both these sources of energy are intermittent in nature; therefore, the use of an energy storage system (ESS) is standard in stand-alone applications [5], [6]. In hybrid renewable energy systems; there are multiple control techniques to provide an efficient power transfer.…”

Practical Power Management of PV/ESS Integrated System

“…Because the amount of PV generation must be charged to the ESS, both the rated capacity of the INV for PV and the PCS for ESS are implemented to be equal as 100 kW. Also, the rated capacity of ESS is designed such that it is 2.5 to 3 times bigger than that of maximum PV generation [22], [23]. Therefore, the ESS of 274 kWh is connected to the PEIS.…”

Reliability of a Power System With High Penetration of Renewables: A Scenario-Based Study

“…Reliability studies that involve the LOLP were also concerned in microgrids [15][16][17][18] and standalone (off-grid) power systems [19][20][21][22]. MCS was conducted to study storage-reserve sizing [15].…”

“…A time-varying probabilityordered tree was presented to evaluate the LOLP in [16]. A model of load shedding minimization combined with sequential MCS was used to study energy storage sizing in [17]. An energy storage size was determined for a specific LOLP in a microgrid with a large penetration of renewables, considering generation and load forecast error in [18].…”