Module Integrated Converter Research Articles

A Review of the Single Phase Photovoltaic Module Integrated Converter Topologies With Three Different DC Link Configurations

The annual world photovoltaic (PV) cell/module production is growing at almost an exponential rate and has reached 1727 MW in 2005. Building integrated PV (BIPV) projects are emerging as the strongest part of the PV market and grid interactive inverters are a key component in determining the total system cost. Module integrated converter (MIC) technology has become a global trend in grid interactive PV applications and may assist in driving down the balance of system costs to secure an improved total system cost. This paper concentrates on the topology study of the PV MICs in the power range below 500 W and covers most topologies recently proposed for MIC applications. The MIC topologies are classified into three different arrangements based on the dc link configurations. A systematic discussion is also provided at the end of the paper that focuses on the major advantages and disadvantages of each MIC arrangement. These are considered in detail and will provide a useful framework and point of reference for the next generation MIC designs and applications.

A Novel Microcontroller for Grid-Connected Photovoltaic Systems

The purpose of this paper is to develop a novel microcontroller for grid-connected photovoltaic (PV) systems. As a prototype model, a 100-W-class module-integrated converter composed of the proposed controller and a flyback inverter has been built and tested. The prototype model is designed to satisfy the Japanese grid-connection guideline. Basic functions as those of a grid-connected PV inverter, such as the maximum-power-point tracking and the anti-islanding protection, have been confirmed in the experiments using a distribution network simulator located in a laboratory. This paper presents the description of the controller and the experimental results. A microcontroller has been developed with a 50-MHz-class microcomputer and simple interfaces. By revising the program, the proposed controller can be applied to various types of PV systems or grid-connected equipment

The resonant half bridge dual converter with a resonant gate drive

The resonant half bridge dual converter, which is suitable for the photovoltaic Module Integrated Converter (MIC), has been previously developed. The 100-Watt converter has achieved a reasonable efficiency under a 1 MHz switching frequency. However at these frequencies the power required to drive the mosfets becomes a major part of the total power loss of the resonant converter. The power dissipates as heat in the drive circuit and significantly reduces the efficiency of the converter. This paper studies a resonant transition mosfet gate drive circuit for the half bridge dual converter, which ideally has zero power loss. The operation of the resonant gate drive circuit is explained. Both of the simulation and experimental results are provided to verify the theoretical analysis.

Further improvement of a transformerless, voltage-boosting inverter for AC modules

For reducing the manufacturing cost and for increasing the efficiency of module-integrated converter the transformerless concept is suitable. The new type inverter, which is proposed in this paper, basically works as buck boost DC–DC converter. Therefore, it is possible to reduce the number of the active switches in comparison with conventional inverter for AC modules because of simple circuit topology. In this paper authors present the control method and operation test results including both stand alone and grid connected for the new type transformerless inverter. These measurement results show that the performances can compete with the conventional small inverter (rated capacity around 50 W).

Impact of power electronics packaging on the reliability of grid connected photovoltaic converters for outdoor applications

This paper deals with thermal and reliability aspects of converters for grid connected photovoltaic applications (rate power approximately 100 W) which can be integrated into solar modules. The use of these Module Integrated Converters (MIC) promises a reduction of costs due to mass production. It improves behaviour of the whole photovoltaic system, as there is no voltage mismatch caused by shading effects. The electronic components of the MIC are exposed to extreme environmental conditions. Lifetime limiting factors are described. Methods to increase the lifetime of the most crucial components in the MIC, electrolytic capacitors, are described. The presented 1st generation Low Profile MIC with “optimised design” is capable of running in very high ambient temperatures. This design maximises availability of the photovoltaic system, which consequently leads to a cost reduction of the electrical energy delivered to the grid. Different realisations of how to integrate the designed Low Profile MIC into the solar module are discussed. A detailed thermal simulation is used to optimise the MIC design according to temperature and reliability issues. The models used for thermal simulation are described.