A Delay-compensated Deadbeat Current Controller for AC Electronic Load

Previous publications revealed that system stability was degraded due to the delay of computational time and the conversion time of A/D converter. To alleviate this problem, a new VSR model with time delay effect was constructed and a new method based on state feedback was proposed in this paper. According to the new VSR model new state equations based on error variable were established. A new digital controller was proposed to realize linear state feedback and poles placement. With the new controller the delay impact is eliminated so that not only stability is guaranteed but also deadbeat control is fully realized in current loop. A 1kW AC electric load prototype with power regeneration ability was set up for the proof of control strategy. The prototype system was operated at 20 kHz switching frequency and a TI TMS320F2812 DSP is used to realize controller. From the analysis presented, it is shown that new method compensates time delay, while remaining an accurate current controller. Simulation and experimental results verify the validity of the proposed scheme.