High Frequency Ac Link Inverter Research Articles

Parallel Connected High Frequency AC Link Inverters Based on Full Digital Control

This paper presents a full digital control strategy for parallel connected modular inverter systems. Each modular inverter is a high frequency (HF) AC link inverter which is composed of a HF inverter and a HF transformer followed by a cycloconverter. To achieve equal sharing of the load current and to suppress the circulating currents among the modules, a three-loop control strategy, consisting of a common output voltage regulation (OVR) loop, individual circulating current suppression (CCS) loops and individual inner current tracking (ICT) loops, is proposed. The ICT loops are implemented with predictive current control from which high precision current tracking can be obtained. The effectiveness of the proposed control strategy is verified by simulation and experimental results from parallel connected two full-bridge HF AC link inverter modules.

A Digitally Controlled Three-Phase Cycloconverter Type High Frequency AC Link Inverter Using Space Vector Modulation

In this paper, a three phase cycloconverter type high frequency AC link inverter is discussed. The configuration consists of a high frequency full-bridge inverter and a high frequency transformer followed by a three phase cycloconverter whose switch is composed of anti-series connected MOSFETs with a common source. A simple digital control strategy based on space vector modulation (SVM) and repetitive control for the cycloconverter is proposed although its input voltage is a high frequency AC pulse. The operation principle of the proposed control strategy is analyzed and the equivalent working modes during one interval are also presented. The effectiveness of the proposed control strategy is verified through Matlab/Simulink simulations and experiments on a 1.45kW prototype.