Low computational burden grid voltage estimation for grid connected voltage source converter-based power applications

This study presents a simple and efficient approach for grid voltage estimation based on the converter equations in the stationary reference frame. The proposed technique is adopted for the sensorless operation of the voltage source converter-based power conditioners. In this study, the effectiveness of the proposed estimation method when it is combined with a proportional-resonant (PR)-based current controller is investigated. When the PR controller is combined with the proposed voltage estimation technique, it offers an additional benefit, such that the grid voltage synchronisation is done without using any phase-locked loop or band-pass filter. The proposed sensorless control method shows an excellent steady-state and transient performance. It is proven through extensive simulations and experiments that the grid voltage estimation with a very low computational burden is achieved even when the grid voltage is distorted.