Deadbeat current control based on new state-observer for VSR

Previous publications revealed that system stability was degraded due to the delay of computational time and the conversion time of A/D converter. It could induce system oscillation and even system stability could be destroyed. Predictive results of conventional current state observer were not ideal because that it was open loop in essence. To alleviate this problem, a method based on new state observer was proposed. The current state in a control period was described at first. The new output variable was acquired by sampling in the intermediate instant of control period and the observer error was corrected by it. The proposed method eliminates the time delay impact so that not only stability is increased but also deadbeat control is fully realized in current loop. A lab 1 kW VSR prototype with power regeneration ability was set up for the proof of concept. Experimental results verify the validity of the proposed scheme.