A Cascaded Photovoltaic System Integrating Segmented Energy Storages With Self-Regulating Power Allocation Control and Wide Range Reactive Power Compensation

Abstract

This paper presents a single-phase photovoltaic (PV) system integrating segmented energy storages (SES) using cascaded multilevel inverter. The system is designed to coordinate power allocation among PV, SES, and utility grid, mitigate the overvoltage at the point of common coupling (PCC), and achieve wide range reactive power compensation. The power allocation principle between PV and SES is described by a vector diagram. Accordingly, a sophisticated power allocation strategy is developed to allocate power between PV and SES based on a novel discrete Fourier transform (DFT) phase-locked loop (PLL) method. An appropriate reactive power allocation coefficient (RPAC) is designed to avoid duty cycle saturation and overmodulation so that wide range reactive power compensation and good power quality can be achieved simultaneously. The self-regulating power allocation control system integrating the preferred RPAC and an advanced active power control algorithm is developed to achieve the aforesaid objective. A 3.5-kW single-phase grid-connected cascaded PV system was built and tested at 1.6 kW in the laboratory. Simulation and experimental results are provided to demonstrate the effectiveness of the proposed cascaded PV system integrating SES.Index Terms-Cascaded photovoltaic (PV) system, power allocation, reactive power compensation, segmented energy storages.

Performance Comparison of Variable-Angle Phase-Shifting Carrier PWM Techniques

“…and can manage different voltage levels [10]- [12]. In all these cases, the conventional PSC-PWM fails since the calculated phaseshifting angles do not allow the cancellation of harmonics up to the 2Nth carrier multiple anymore.…”

“…Therefore, the main advantage of this technique is that it is possible to cancel out all the harmonics of the same carrier group by fulfilling (3). Nevertheless, to set the problem in a closed form, assuming θ 1 = 0, N − 1 degrees of freedom (i.e., θ i ) can only satisfy N -1 equations in (3) [12]. Consequently, there is a relationship between the number of bridges N and the number of harmonic carrier groups m that are cancelled out in the converter output voltage.…”

Realization of UPQC H∞ coordinated control in Microgrid

“…In Microgrid, on one hand, the distributed generation and nonlinear fluctuating load have complex and diverse types, such as wind power and photovoltaic which have characteristics of intermittency, randomness and fluctuation, often leading to the power unbalance between power supply and load [10,11]. On the other hand, a large number of power electronic devices are being used, such as the applications of inverters, solid state switches, the electric vehicle charging equipments and so on [12,13].…”

Análise de um mecanismo de compensação de reativos incorporado aos inversores de um sistema fotovoltaico conectado à rede elétrica

“…• 22 trabalhos têm o objetivo específico de modelar inversores com a funcionalidade de compensação de reativos incorporada e demonstrar sua viabilidade técnica (HASSAINE et al, 2014;CHANG et al, 2014;RESHMA;RAJESH, 2013;MARTI et al, 2013;BELAIDI et al, 2013;NOROOZIAN;GHAREHPETIAN, 2013;LI et al, 2012;HAMZAOUI;BOUCHAFAA;HADJAMMAR, 2011;TURITSYN et al, 2011;LIU et al, 2011;SEO et al, 2009;ALBUQUERQUE et al, 2010;CAGNANO et al, 2011;TSENGENES;ADAMIDIS, 2011;TURITSYN et al, 2010;GHARAKHANY;MOHAMADIAN;VARJANI, 2009;CHUNLING et al, 2009;HAMROUNI;JRAIDI;CHÉRIF, 2008;HASSAINE et al, 2009;LIBO;ZHENGMING;JIANZHENG, 2007;YU;PAN;XIANG, 2005;BARBOSA et al, 1998;KIM;YOO;SONG, 1996);…”

“…• desses 22, 13 têm como base metodológica exclusivamente simulações computadorizadas e apenas 8 apresentam resultados experimentais (CHANG et al, 2014;HASSAINE et al, 2014;LIU et al, 2011;RESHMA;RAJESH, 2013;HASSAINE et al, 2009;LIBO;ZHENGMING;JIANZHENG, 2007;KIM;YOO;SONG, 1996;BARBOSA et al, 1998), ainda que os inversores construídos fossem protótipos laboratoriais de, no máximo, 600 W.…”