TECHNICAL TALK

IEEE Power & Energy Society and Industry Applications Society Delhi Chapter and IEEE Power Electronics Society, and Industrial Electronics Society Delhi Chapter organised a technical talk on “DC - DC Converters Topology and Applications” by Prof. Bhim Singh, Electrical Engineering, IIT Delhi on 16th September 2015 at NSIT, New Delhi. Priya Yadav (16955), student from Computer Science Engineering Dept, Dronacharya College of Engineering, Gurgaon attended the talk.

The IEEE Power & Energy Society is a worldwide association of more than 26,000 individuals engaged in the electric power energy industry. It is the leading provider of scientific and engineering information on electric power and energy for the betterment of society, and the preferred professional development source for the members.

Prof. Bhim Singh firstly explained the importance and application of DC - DC converters introduced with SEPIC, Zeta, Multiple output converter and discussed about various topics such as Grid connected PV system, Chopper and Isolated converter. He gave examples of several Applications of DC - DC converter like in Subway cars, battery operated cars and electric boats. He gave a review of different choppers along with circuit topologies of isolated converters with the brief introduction about Buck - Boost. The buck - boost converter is a type of DC - to - DC converter that has an output voltage magnitude that is either greater than or less than the input voltage magnitude.

Prof. Singh said that Electronic switched-mode DC - to - DC converters convert one DC voltage level to another, by storing the input energy temporarily and then releasing that energy to the output at a different voltage. The storage may be in either magnetic field storage components such as inductors, transformers or electric field storage components like capacitors. He explained that this conversion method is more power efficient than linear voltage regulation, which dissipates unwanted power as heat. The higher efficiency of a switched-mode converter increases the running time of battery operated devices and also reduces the amount of heat sink material needed. Efficiency has improved due to the use of power FETs, which are able to switch more efficiently at higher frequencies than power bipolar transistors, while incurring lower switching losses and requiring a less complicated drive circuit.

Prof. Singh further deliberated on replacing of the flywheel diode with the method of synchronous rectification using a power FET, whose "on resistance" is much lower and that thereby reduces switching losses. Before the wide availability of power semiconductors, low-power DC - to - DC synchronous converters consisted instead of an electro-mechanical vibrator followed by a voltage step-up transformer and a vacuum tube or semiconductor rectifier or synchronous rectifier contacts on the vibrator.

The talk ended with an interactive questions and answers session in which students raised questions and their related doubts about the topic. It was a great experience for the students as they learned a lot on DC-DC Converters Topology and Applications and their queries were also answered.

Some Glimpses: