Scalable Single-Phase Multi-Functional Inverter for Integration of Rooftop Solar-PV to Low-Voltage Ideal and Weak Utility Grid

Abstract

Integration of rooftop solar-PV (RTSPV) systems and extensive use of nonlinear loads in the low-voltage distribution system (LVDS) leads to poor power quality (PQ). Therefore, it is necessary to address the issues leading to poor PQ at the point of common coupling of the LVDS. In this article, a multi-band hysteresis current control (MB-HCC) for the multi-functional inverter (MFI) is proposed which improves the efficiency of the MFI and also enhances the PQ of the LVDS. The MB-HCC uses simple switching logic and outperforms in its multi-functional tasks such as active power injection and power conditioning. MB-HCC offers better efficiency over variable double-band HCC (VDB-HCC) as it operates at a lower switching frequency. The performance of the proposed system is simulated by using MATLAB/Simulink and validated by OPAL-RT based real-time simulation studies. During the variation of solar irradiation, the proposed MFI has an average efficiency of 98.5% under the ideal grid and 97.34% under the distorted grid. Moreover, the percentage of Total Harmonic Distortion under ideal and distorted grid conditions is brought down to below 5%, and also, reactive power compensation maintains unity power factor operation complying with the IEEE-519-2014 and 1547 standards. These results substantiate the hypothesis of scalability of the single-phase MB-HCC-based MFI for an LVDS contributing to economy and ecology.

Comparison of Different Design Alternatives for Hardware-in-the-Loop of Power Converters

“…Recently, some commercial HIL platforms such as Typhoon HIL [35], Opal-RT [36], and National Instruments (NI) RIO family [37] have appeared to implement HIL models. The latter, programmed through LabVIEW software, is used for several applications, not only HIL.…”

Power management algorithm for a conservative power theory battery storage based multi‐functional three phase grid connectedPVinverter

“…The DC‐link of the inverter is coupled with PV fed DC‐DC boost converter operated by incremental conductance (INC) based maximum power point tracking (MPPT) 40,41 . The PV system is designed to deliver a maximum power of 6 kW.…”

“…In order to validate the proposed PM algorithm, the system depicted in Figure 1 was modeled and validated by the OPAL‐RT based OP 4500 real‐time grid simulator 21,29,38,41,43,48‐50 …”

Evaluation of the Different Numerical Formats for HIL Models of Power Converters after the Adoption of VHDL-2008 by Xilinx

“…Furthermore, the design software considered is of great importance, while software such as MATLAB/Simulink [15] or the use of high-level languages such as HLS [16] decrease the users' design effort, but they are not as efficient as using hard-coding like HDL languages [17,18], which generally ends up on slower and more complex hardware circuit simulations [2,[19][20][21]. Recently, some commercial HIL platforms such as Typhoon HIL [20], Opal-RT [22] or the National Instruments RIO family [23] have appeared to implement HIL models, however, these programs are not generally user-transparent and do not allow the designer to optimize the resulting model. Consequently, in order to optimize the speed and area with the purpose of building a real-time low-cost HIL system, the designer should choose the optimal language, software and NF to ensure a minimal integration step and hardware elements: look up tables (LUTs), digital signal processors (DSPs) and flip-flops (FFs).…”