SVPWM-based current controller with grid harmonic compensation for three-phase grid-connected VSI

Voltage space vector pulse-width modulation (SVPWM) is widely used in the current control of three-phase voltage-source inverters (VSI). However, as a voltage-type modulator, SVPWM brings some drawbacks to controllers, such as the compromised output current due to the back EMF disturbance and nonlinearity of the system, the lack of inherent overcurrent protection, etc. In this paper, SVPWM-based current control strategy with grid harmonics compensation and dual-timer sampling scheme is proposed and implemented in a 30 kW three-phase grid-connected VSI. Both simulation and experimental results verify that the proposed current controller offers a high performance of current control even under the influence of the grid harmonics. At the same time, the proposed dual-timer sampling scheme not only minimizes the system control delay but also offers an improved response for overcurrent protection to the system.