Abstract
Recently, a variety of differential power-processing (DPP) architectures have been shown to improve the efficiency of photovoltaic (PV) systems. This paper proposes a simple control strategy for the isolated-port DPP architecture, and provides a comprehensive stability analysis for this system. The proposed controller drives the duty-cycle of the differential submodule integrated converters (subMICs) in proportion to a voltage difference between the submodule and the isolated-port. This method requires no additional sensing, complex processing, or communication between subMICs, and is therefore well suited for low-cost integrated hardware solutions. Stability of the resulting high-order nonlinear system is analyzed both in the time and frequency domains. A decoupled model is developed that reduces the high-order system dynamics to a 1-D control loop, which allows stable, well-behaved responses using a proportional or a lag compensator. Experimental results for a 72-cell PV module with three subMICs verify static and dynamic operation, and show that overall PV module efficiency exceeds 99% with no shading, and is higher than 96% under significant (50%) shading.
Original language | English |
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Article number | 6822511 |
Pages (from-to) | 821-832 |
Number of pages | 12 |
Journal | IEEE Journal of Emerging and Selected Topics in Power Electronics |
Volume | 2 |
Issue number | 4 |
DOIs | |
State | Published - 1 Dec 2014 |
Externally published | Yes |
Keywords
- DC optimizer
- differential power processing
- maximum power point tracking (MPPT)
- module integrated converter (MIC)
- partial power processing
- partial shading
- photovoltaic
- solar
All Science Journal Classification (ASJC) codes
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering