A photovoltaic (PV) generator is internally a power-limited nonlinear current source having both constant-current- and constant-voltage-like properties depending on the operating point. This paper investigates dynamic of PV demonstrates that it has profound effect operation interfacing converter. The most important an input should have in order to emulate real are defined. These important, since power electronic substitute often used validation process instead generator. also qualifies two...

The large-scale harvesting of solar energy is an important action to decelerate the observed climate changes. Reliably operating solar-energy systems composing arrays and their interfacing converters are prime importance maximize harvesting. paper investigates solar-generator in terms current-fed (CF) maximum-power-point (MPP) tracking converter. investigations show that CF converter under input-voltage control can usually operate from short-circuit open-circuit conditions generator without...

A grid connected solar photovoltaic (PV) research facility equipped with comprehensive climatic and electric measuring systems has been designed built in the Department of Electrical Engineering Tampere University Technology (TUT). The system is composed an accurate weather station, radiation measurements, a mesh irradiance PV module temperature measurements located throughout facility. Furthermore, electrical can be taken from single modules strings synchronized data. All measured...

Long strings of photovoltaic (PV) modules are found to be vulnerable shading effects, causing significant reduction in the system power output. To overcome this, distributed maximum point-tracking (DMPPT) schemes have been proposed, which individual dc-dc converters connected each PV module enable module-wise extraction. There two main concepts implement DMMPT systems: series and parallel configuration, describing connection output terminals converters. Both systems studied intensively, with...

Interfacing a single photovoltaic (PV) module into either single-phase or three-phase inverter requires an interfacing converter with wide conversion ratio and sufficient dynamic headroom. In terms of avoiding issues common-mode currents between the PV inverter, galvanic isolation is preferred. This especially important emerging thin-film modules that have larger cell-to-frame parasitic capacitances compared to traditional modules. paper presents properties analysis current-fed quadratic...

The large-scale harvesting of solar energy is an important action to decelerate the observed climate changes and ensuring availability also in future. Reliably operating solar-energy systems composing arrays their interfacing converters are prime importance maximize harvesting. main obstacle for improvements reliability turned out be lack full understanding solar-generator interfacing. paper investigates terms voltage-fed maximum-power-point (MPP) tracking converters. investigations confirm...

The concern on observed climate change has increased the utilization of renewable energy sources. harvesting solar is recognized as one key issues in reducing green house gas emission. Reliable solar-energy systems composing arrays and their interfacing converters are prime importance uninterrupted production. maximum-power-point implemented usually by modifying conventional voltage-fed converters. Actually, modifications converter into a current-fed with corresponding steady-state dynamic...

This paper presents the general dynamic descriptions of current-fed converters applied in solar or photovoltaic applications including an impedance-based method to assess stability corresponding interconnected system. Several earlier unknown parameters are indentified governing either low-frequency behavior closed-loop converter affecting source load interactions. Experimental evidence is provided support theoretical findings based on superbuck and boost both time frequency domains.

Switched-mode converters are often the key to operating various electronic systems in everyday life. This means that reliable operation of is prime importance and functioning must be verified during both design phase production. Recent studies have shown can fully characterized by a set frequency responses efficiently used validate analyze related systems. Several methods been proposed for quickly accurately measuring responses, but surprisingly, use multiple-input multiple-output (MIMO)...

Reliably operating solar-energy systems composing of solar arrays and their interfacing converters are prime importance to maximize the harvesting. The paper investigates solar-generator-interfacing problems in terms voltage-fed maximum-power-point tracking shows that there two main reasons for observed stability which one is violation Kirchhoff's current law governing operation generator other phenomenon known as negative resistance oscillation. In practice, this means converter can...

Long strings of photovoltaic (PV) modules have been observed to be prone shading effects causing significant reduction in the system power output. To overcome this, distributed maximum point-tracking (DMPPT) schemes proposed, which individual dc-dc converters are connected each PV module enable extraction out modules. The output terminals these either series or parallel, followed by a grid-connected inverter. concept has under intensive study with novel topologies and control schemes, yet...

Cascaded control systems are usually adopted in interfacing renewable energy sources to the power grid for maximum point tracking purposes. This paper reveals that negative output impedance behaviour is an inherent property of such grid-parallel inverters. It alarming observation since reduces damping and will definitely cause stability concerns future. (6 pages)

Large-scale harvesting of solar energy is an important action to decelerate the observed climate changes and ensuring availability also in future. It has been that maximum-power-point (MPP) tracking converters have high contribution on reliability problems photovoltaic systems because misunderstanding their real nature. The paper shows most applied are current-fed but usually assumed be conventional voltage-fed converters. general dynamic properties a converter method assess stability...

Fourth-order converter known as superbuck is used in the applications requiring continuous input current such interfacing solar generators or improving power factor of a converter. Peak-current-mode control to reduce resonant behaviour for facilitating design. The input-current ripple can be reduced substantially by applying coupled-inductor technique. paper investigates dynamic effects application technique causes features higher-order converters are usually not well due complexity...

Recent investigations on the nature of power electronic converters in renewable energy applications have revealed that most are not what they claimed to be. The voltage-type sources dominated as especially past. Therefore, developed and designed for such even if some them known current-sourced converters. rapidly growing number renewable-energy-based distributed systems has forced pay closer attention structure those within systems. This paper summarizes recent findings states real...

The paper presents a method to analyze robust stability and transient performance of distributed power system consisting commercial converter modules interconnected through common input filter. is based on the use four transfer functions, which are measurable from output terminals. It shown that these parameters provide important information module sensitivity interactions caused by external impedances. Practical characterization for described structure performed introducing special...

A photovoltaic (PV) generator is internally a power limited non-linear current source having both constant and voltage like properties depending on the operating point. This paper investigates dynamic of PV demonstrates that it has profound effect operation interfacing converter. The most important an input should have in order to emulate real are defined. These important, since electronic substitute often used validation process instead generator. also qualifies one commercial solar array...

Interfacing a single photovoltaic (PV) module into either single-phase or three-phase inverter requires an interfacing converter with wide conversion range and sufficient dynamic headroom. In terms of avoiding issues common-mode currents between the PV inverter, galvanic isolation is preferred. This especially important emerging thin-film modules that have larger cell-to-frame parasitic capacitances compared to traditional modules. paper discusses characteristics current-fed quadratic...