LQ current controller with integral and oscillatory terms

LQ current controller for a three-phase PWM rectifier under distorted grid voltage conditions.

The developed scheme is based on a voltage-oriented control method. Instead of proportional-integral current controllers a state-feedback current controller in rotating reference frame is used. In order to achieve a zero steady-state current control error in response to step commands, integral terms are incorporated into the current control scheme. Similarly, to ensure the rejection of the sinusoidal component of current control error caused by unbalance and distortion in the grid voltage, the oscillatory terms are added to the current control system. To calculate the current controller gains, an augmented plant model is developed and linear-quadratic optimization method is applied.
More details on LQ current controller with oscillatory terms is presented in:
https://doi.org/10.1109/CPE.2015.7231071
https://doi.org/10.15199/48.2015.01.11
https://doi.org/10.1109/EPEPEMC.2014.6980686