Fundamental Operation of Direct Linked Type Frequency Changer with Bilateral Switching Circuits

Abstract

This paper describes a direct linked type frequency changer (hereafter called DLT-FC) proposed by the authors. The DLT-FC is a converter circuit with a new configuration for direct frequency change. The DLT-FC does not require a dc link circuit, nor bilateral switches. In addition, dc snubber circuits can be applied without the need for a regenerative circuit of snubber energy. Therefore, the DLT-FC can be designed to be compact and light weight, and has a long life.
The authors manufactured a prototype of the DLT-FC and experimentally checked its CVCF and VVVF operation. The results indicate that the performance of the DLT-FC makes it suitable for industrial use.