An error bounded current controller with constant sampling frequency

In this paper, a constantly sampled current controller is proposed such that the controlled current can track the command within a specified error bound to guarantee the desired power quality. The authors further propose a simple two-value inner bound for current error comparison to determine the right time to add the zero-mode control to reduce both the switching frequency and the resulting current error. Moreover, an upper bound of the constant sampling period for the controller to guarantee the desired performance is derived and some design criteria are given for proper coordination among the design parameters. Finally, some simulation and experimental results are given to demonstrate the feasibility of the proposed current controller.