Design, development, and implementation of grid-connected solar photovoltaic power conversion system

In this paper, a detailed documentation revealing the design, development, and implementation aspects of grid-connected solar photovoltaic (SPV) power conversion system is presented. Since the inverter is considered as a key constituent of an SPV system, a laboratory developed three-phase four-legged (3P4L) inverter is employed to diminish the overall cost of the SPV system considerably. The multifunctional inverter controlled SPV system proposed in this work not only injects active power into the electric grid, but it also serves as an active power filter (APF) to provide various power quality (PQ) solutions. This typically includes source current harmonic attenuation, load reactive current mitigation, neutral current elimination, source current balancing, in addition to ensure unity power factor operation. A various hardware circuits including signal sensing circuit, signal conditioning circuit, pulse amplification and isolation circuit, and blanking circuit are fabricated and assembled to develop a complete laboratory prototype model. In addition, the voltage and current controllers, the synchronize reference frame theory (SRFT)-based approach, and the phase-locked loop (PLL) control algorithms are embedded in dSPACE 1104 control platform. Furthermore, an STM32F407VGT microcontroller is employed to implement the incremental conductance based maximum power point (MPP) tracking algorithm. The effectiveness of the developed SPV system is first simulated in MATLAB/Simulink software. In the second step, the efficacy of the proposed configuration is investigated under balanced and unbalanced nonlinear loads on a laboratory developed prototype.