Grid Integration of Single-Stage SPV-STATCOM System Using Symmetric Cascaded Five-Level VSC

Abstract

AbstractThis work proposes a dual-function single-stage solar photovoltaic (SPV) grid-tied system with STATCOM (static compensator) capabilities using a three-phase five-level cascaded VSC (voltage source converter) operating at low switching frequency with low total harmonic distortion (THD) and low switching losses. The proposed SPV-STATCOM system works in three modes: i.e. Mode-1, in which only an active power is transferred to the grid, Mode-2, in which both active and reactive power are supplied to the grid and Mode-3, in which only reactive power is supplied to the grid, thereby utilizing the full capabilities of the SPV system. An incremental conductance algorithm is used to track power from SPV array which is fed to the grid. To synchronize the VSC to the grid, a decoupled current controller with feed-forward term and double decoupled synchronous reference frame phase-locked loop (DDSRF-PLL) is used. The use of a single-stage five-level cascaded VSC offers the advantages of low switching losses and the operation at high power and high voltage which results in an improvement in quality of power of the system. The simulated results demonstrate the system design and control scheme under varying conditions.\n