Compact and efficient transformerless power conversion system

Abstract

The DC Transformation Inc. (DCT) transformerless Power Conversion System (PCS) is a new technology that efficiently steps-up and steps-down DC at high power and high voltage levels. The transformation is accomplished through the use of low cost solid state switching devices, capacitors, air-core inductors and an intelligent control system. The technology is based on the property of resonant circuits. This permits the use of soft switching and self commutating, low dI/dt solid state devices. Due to the sinusoidal nature and low dI/dt of the current flowing through the switches, less expensive, more available and slower thyristors may be used. This allows the scale up of this technology to high power and high voltage operation for large power systems and utility power transmission and distribution. Data is presented of a 1 kV to 6 kV, 100 kW DC to DC step-up and a 12 kV to 2 kV, 100 kV DC to DC step-down demonstration.