Untitled Document
Untitled Document
You may need to enable or update / install Adobe Flash Player Plug-in to display JPE e-Book in your device properly. If you use Google Chrome, please find information here
> Archives > Current Issues
JPE, Vol. 18, No. 2, March 2018
Analyzing and Designing a Current Controller for Circulating Current Reduction in Parallel Three-Phase Voltage-Source Inverters
Kiryong Kim, Dongsul Shin, Hee-Je Kim, and Jong-Pil Lee
Area Analysis, Modeling and Control
Abstract A circulating current is a major problem caused by directly connecting voltage-source inverters (VSIs) in parallel. This circulating current occurs as a zero-sequence current between the inverters by specific switch states. Several studies have presented alternatives using hardware and software methods. When coupled inductors (CIs) are employed for the high-frequency circulating current, a controller is required to prevent the low-frequency circulating current from saturating the CIs. In this study, the zero-sequence circulating current and its alternatives are investigated using hardware and mathematical description. A high-performance circulating current controller is proposed by applying a repetitive controller to the zero-sequence current control loop. The proposed controller can effectively minimize the low-frequency circulating current without any data sharing between the inverters in unfavorable conditions. It can also be applicable to the modular configuration of parallel three-phase VSIs. Experimental results verify the performance of the proposed controller.
Keyword Circulating current,Parallel operation,Voltage source inverter (VSI)
Untitled Document