A Comprehensive Review of Flexible Power-Point-Tracking Algorithms for Grid-Connected Photovoltaic Systems

Abstract

The rapid increase in the penetration of photovoltaic (PV) power plants results in an increased risk of grid failure, primarily due to the intermittent nature of the plant. To overcome this problem, the flexible power point tracking (FPPT) algorithm has been proposed in the literature over the maximum power point tracking (MPPT) algorithm. These algorithms regulate the PV power to a certain value instead of continuously monitoring the maximum power point (MPP). The proposed work carries out a detailed comparative study of various constant power generation (CPG) control strategies. The control strategies are categorized in terms of current-, voltage-, and power-based tracking capabilities. The comparative analysis of various reported CPG/FPPT techniques was carried out. This analysis was based on some key performance indices, such as the type of control strategy, irradiance pattern, variation in G, region of operation, speed of tracking, steady-state power oscillations, drift severity scenario, partial shading scenario, implementation complexity, stability, fast dynamic response, robustness, reactive power, cost, and tracking efficiency. Among existing FPPT algorithms, model-based control has a superior performance in terms of tracking speed and low steady-state power oscillations, with a maximum tracking efficiency of 98.57%.

Analysing active power reserve strategies for photovoltaic systems under varying shading scenarios: a comparative study

“…If the PV system is still operated at the P limit level when P PV exceeds P limit , then a power reserve is generated. The reference voltage V * PV is obtained using the following equation: [42]. Reproduced from [42].…”

“…The reference voltage V * PV is obtained using the following equation: [42]. Reproduced from [42]. CC BY 4.0.…”

“…Moreover, P&O-based CPG has a better steady-state response and stability. An adaptive flexible power point tracking (FPPT) algorithm was proposed in [41][42][43]. The adaptive FPPT algorithm has faster dynamics than conventional FPPT algorithms.…”

“…Voltage step calculations are conducted on the basis of the selected operating mode. To reduce oscillations, a large value of step size [42] is adopted in the transient mode, and a small step size is adopted in the steady-state mode. In the voltage reference calculation algorithm, the PV array can be operated either on the left-hand side or on the right-hand side of the MPP for performing the deloading operation.…”

“…In this algorithm, if the operating point is on the left-hand side of the MPP ( ∆P ∆V > 0), then the reference voltage (V ref ) is increased by a step of V step . As the operating point shifts to the right-hand side, the [42]. Reproduced from [42].…”