ICIT - IEEE 2018

From 02/19/2018 to 02/22/2018

Centre de Congrès - Cité Internationale Lyon - 50, quai Charles de Gaulle 69463 Lyon


Tutorial 4 Pr Nihal KULARATNA

Title: Benefits of million-times larger capacitance in EDLCs: Supercapacitor assisted novel circuit topologies

Abstract:
In general, applications of common capacitors include filters, DC blocking and AC to DC converters. They are available up to a few thousand microfarads, with DC voltage ratings of up to several thousand volts. During the last two decades, electronics industry has seen many commercial versions of electrical double layer capacitors (EDLC), which are also known as ultra‐capacitors and supercapacitors (SC), with the aim of complementing or replacing electrochemical batteries. EDLCs come in capacitance values from 0.2 to 7500 farads, with the limitation of very low DC voltage ratings from 0.7 V to 4 V. A general observation is that for the same device volume of an electrolytic capacitor, an EDLC gives an approximately one million times larger capacitance as pictorially shown below.

Compared to conventional capacitors with large DC voltage ratings, EDLCs offer one to two order greater energy density and approximately twice the power density. In a circuit designer’s view point, if a DC blocking capacitor is one million times larger, it will take one million times longer to block the circuit. RC time constants of SC based circuits are in the range of milliseconds to seconds. Based on these facts, supercapacitors can be the basis for unique and novel circuit topologies to achieve: significantly high energy efficiency in DC‐DC converters; surge protection; rapid energy transfer; high density inverters and renewable energy converters with DC‐UPS capability. Seminar will present an indepth discussion on how to develop unique solutions to well‐known issues in power electronics with the examples of developing many patented or patent pending SC assisted (SCA) techniques such as SCA low dropout regulators (SCALDO), SCA surge absorbers (SCASA), SCA temperature modification apparatus (SCATMA) , SCA high density inverter (SCAHDI) and SCA light emitting diodes (SCALED).