Design and Implementation of Fully Digital-Controlled Parallel System with Current Sharing

• Main Authors: Ming-Chieh Chang, 張銘杰
• Other Authors: Yen-Shin Lai
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/dasb6b

碩士 === 國立臺北科技大學 === 自動化科技研究所 === 103 === The objective of this thesis is to design and implement a parallel voltage source inverter system with current sharing. The system consists of two single phase inverters with digital control, and the output voltage is controlled by voltage loop. The functions of this system include soft start, over current protection and over voltage protection. A coupled inductor is need to limit the circulating current between two inverters in the parallel inverter system. Therefore, current sharing can be achieved. The effect of coupled inductance and coefficient on circulating current is investigated by simulation results. The experimental specifications of the system are as follows: input DC voltage = 380 V, output AC Voltage = 220 V/60 Hz, total power rating = 2 kW, switching frequency = 9.6 kHz. Experimental results verify under variant load conditions, efficiency is higher than 95%, and the total voltage harmonic distortion is less than 1.2%, and the loop current is less than 0.1 A in the parallel system.