Home › Research › Research Groups
Grid Tie Inverter using Advanced Modulation Technique
The increasing demand of global energy for human being, decreasing availability of natural energy sources and concern about global climate change necessitate the development of green energy technologies, and has put the renewable energy in the forefront of global issues. The renewable energy sources such as solar, wind and hydropower generates clean electricity that is alternative of fossil fuels. Solar energy is an important type of renewable energy source that produce direct current (DC) power. Power electronics play an important role for integrating present day's renewable energy into our daily life as an inverter is essential to convert DC power to alternating current (AC) power due to supply the solar power to the grid.
Due to rapid development and increasing use of renewable energy, highly efficient and cost effective equipment such as pure sine wave inverter, charge controller, etc. are highly demanded in the local as well as global market. This research proposal addresses such an issue to design and develop a grid-tie inverter using an advanced modulation technique, called harmonic injection modulation (HIM) to generate power using solar panel and feeding it to the existing power grid. In a power-hungry country like Bangladesh, where load-shedding is one of the major issues, developing such an efficient grid-tie inverter in utilizing the solar energy can be highly beneficial and could bring solution to many problems.
Two-stage Power Charger using T-LCL Immittance Converter
With the increase in oil price and the trend of eco-conscious, people have started to worry about the green house effect due to increasing emission of carbon dioxide. Therefore, the demand of clean and environment-friendly energies grows rapidly. The development of electric vehicles and power-charging modules has become a trend that will make the earth healthier. In order to prevent current leakage from rechargeable batteries during charging, a transformer is required to be added to the power-charging module. The power-charging modules can be categorized into high-frequency isolated power-charging modules and low-frequency isolated power-charging modules. Since the high-frequency transformer is compact in size and weight, it gains larger popularity. The single-staged power-charging modules are commonly used due to its advantageous features of simple configuration and low cost, but it results in large output ripple current and is thus not suitable for use as a power-charging module for electric vehicles. The dual-staged converter is more complicated, but it results in lower output ripple current and achieves output current stability. Therefore, in this paper, the dual-staged configuration is adapted with high-frequency switching control using a T-LCL immittance circuit so as to reduce the size of the transformer and thus the cost of the power-charging module.
The objective of this research is to develop a dual-stage AC-DC converter applicable to a power-charging module. The AC-DC converter comprises two parts: a first stage being a low-frequency AC to high-frequency AC converter comprising an input full-bridge rectifier, a full-bridge inverter and an immittance conversion circuit and a second stage being an AC-DC converter comprising a single-phase transformer and a full-bridge rectifier, where the inverter in the first stage is switched at high frequencies so as to reduce the size of the transformer in the second stage. Additionally, the immittance conversion circuit is further characterized in voltage to current conversion so as to simplify the control mechanism of the power-charging module, reduce the number of current measuring elements and the cost thereof.
Electric Vehicle With the increase in oil price and the trend of eco-conscious, people have started to worry about the green house effect due to increasing emission of carbon dioxide. Therefore, the demand of clean and environment-friendly electric vehicles, that will make the earth healthier, grows rapidly. The objective of this research is to develop an efficient and cost-effective electric vehicle using induction motor with built-in inverter developed by space vector modulation technique.
Dr. Khosru M Salim
Dr. Abdur Razzak