A Single-Stage Grid Connected Inverter Topology for Solar PV Systems With Maximum Power Point Tracking

Abstract

Abstract-This paper proposes a high performance, single-stage inverter topology for grid connected PV systems. The proposed configuration can not only boost the usually low photovoltaic (PV) array voltage, but can also convert the solar dc power into high quality ac power for feeding into the grid, while tracking the maximum power from the PV array. Total harmonic distortion of the current, fed into the grid, is restricted as per the IEEE-519 standard. The proposed topology has several desirable features such as better utilization of the PV array, higher efficiency, low cost and compact size. Further, due to the very nature of the proposed topology, the PV array appears as a floating source to the grid, thereby enhancing the overall safety of the system. A survey of the existing topologies, suitable for single-stage, grid connected PV applications, is carried out and a detailed comparison with the proposed topology is presented. A complete steady-state analysis, including the design procedure and expressions for peak device stresses, is included. Necessary condition on the modulation index " " for sinusoidal pulsewidth modulated control of the proposed inverter topology has also been derived for discontinuous conduction mode operation. All the analytical, simulation and experimental results are presented.

A Review on Recent Advances and Future Trends of Transformerless Inverter Structures for Single-Phase Grid-Connected Photovoltaic Systems

“…In order to satisfy the requirements/demands, the generic control structure comprises of two cascaded loops [100,101]. The inner control loop is accountable for shaping the current while outer voltage/power control loop produces the current command.…”

“…In this way, the quality of power is sustained along with various other functionalities as depicted in Figure 23 The two-main classifications of the control are: maximize the power from PV panels, the PV-side control is incorporated; (b) for the purpose of fulfilling the demands to the power grid, the grid-side control is performed. In order to satisfy the requirements/demands, the generic control structure comprises of two cascaded loops [100,101]. The inner control loop is accountable for shaping the current while outer voltage/power control loop produces the current command.…”

A methodology for characterizing and modeling inverters for grid integration studies using Power Hardware-in-the-Loop

“…The output is filtered and synchronized with the grid in the final stage before being connected. There have been systems developed that accomplish all of these functions in a single stage [23].…”

“…They have a wide range of applications including, variable speed drives, power factor correction and grid-tied distributed resources. They also come in various configurations, such as single-level or multi-level, voltage source or current source, each yielding different features [24], [23]. One common application of inverters is with PV systems.…”

“…Number of stages, grid interconnection, and transformer type are considerations that allow for a multitude of inverter topologies. Many single phase inverter topologies can be found in [23], [27] and [26]. Converters are summarized in [27] and the most effective are identified for different situations.…”