- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Power rating analysis and protection for photovoltaic-isolated port based differential power processing systems
摘要： In a photovoltaic generation system (PGS), photovoltaic (PV) modules are often connected in series for increased string voltage. However, a significant reduction in the actual output power is observed due to the manufacturing tolerance, module aging and partial shaded. Compared with conventional methods such as bypass diodes and PV module reconfiguration, modular distributed architecture especially the differential power processing (DPP) is able to yield high output power even under partial shading conditions. Moreover, the system efficiency is improved since only the differential power is processed by the DPP converters. This paper mainly focuses on the power rating analysis and protection of PV-isolated Port (PV-IP) based DPP systems considering the significant power stress difference among DPP converters under different partial shading conditions. The voltage equalization (VE) control used in this work is able to provide up to 77% efficiency improvement through the simulation evaluation. The protection algorithm is proposed for the PV-IP DPP architecture to improve the system reliability even when some DPP converters are found failed. With the proposed protection strategy, not only the high output power yield can be maintained, but also the modular design of DPP converters with smaller power capacity can be achieved. Simulation and indoor experimental tests under various partial shading conditions were carried out to validate the effectiveness of the proposed power rating analysis and protection scheme.
关键词： Partial shading,Differential power processing (DPP),Power rating,PV submodule integrated converter (subMIC),Optimization,PV-Isolated Port (PV-IP) DPP
更新于2025-09-16 10:30:52
-
Power recovery and equalization in partially shaded photovoltaic strings by an efficient switched capacitor converter
摘要： Partial shading is the major complication encountered by the Photovoltaic strings while delivering maximum power to the load. This scenario consequently diminishes the functionality of the modules causing mismatch, hotspot, power loss and multiple peaks formation in the characteristics curves of the strings. Also, formation of multiple peaks affects the performance of the maximum power point trackers due to false tracking resulting in severe power loss. In this paper, a switched-capacitor converter for power recovery and equalization in the strings during shading is proposed. The parallel-ladder architecture of the converter maintains voltage ratios by transferring power between the shaded and unshaded modules of the strings. The converter enables the string to generate maximum power by ensuring single peak in the characteristics curves during shading. The performance of the string with the proposed converter is compared to conventional strings using characteristics curves, and various performance parameters. The systems are tested in MATLAB/Simulink and experimental setup under various static and dynamic partial shading conditions. Also, the conduction losses encountered by the converter during power balancing in the strings are analysed and expressed mathematically. The results clearly indicate that the proposed converter can be easily implemented in the strings to recover the power losses and avoid multiple peaks formation in the characteristics curves during partial shading with efficiency greater than 99%.
关键词： Maximum power point,Photovoltaic (PV) strings,Partial shading,Differential power processing (DPP),Switched-capacitor (SC) converter
更新于2025-09-16 10:30:52
-
Increasing Energy Capture from Partially Shaded PV String Using Differential Power Processing
摘要： In PV strings based on series-connected PV modules, mismatches among the modules due to partial shading, will cause in power loss either due to series connection constraint or due to bypass diodes. This paper proposes a new distributed MPPT (DMPPT) scheme using multi-winding forward-based converter, acts as a current balancing differential power processing (DPP) converter. The converter is configured in the way that each converter port is connected in parallel with individual PV module to enable module-level maximum power extraction. The proposed architecture operates in two modes: local MPPT mode and current balancing mode. The new MPPs at module-level are tracked in local MPPT mode and then dispatched to start current balancing mode of operation. In the current balancing mode, this paper proposes a simple control approach to maximize output power from partially shaded PV string by maintaining an effective MPPT at module-levels and directly transferring the compensation currents toward the shaded modules from modules under normal conditions without any intermediary. The proposed DMPPT scheme is validated by simulation and experimental results. The results show that using the proposed scheme, the system efficiency is significantly improved compared to other existing topologies.
关键词： distributed maximum power point tracking (DMPPT),partial shading (PS),photovoltaic (PV),differential power processing (DPP)
更新于2025-09-09 09:28:46