Predictive current control strategy for single phase grid connected inverter

ABSTRACT: In this thesis, the predictive current control method is employed to control the single phase grid connected inverter under the condition of known grid voltage and load current. In real implementation the controller needs a certain time to do the required digital sampling and computations before the control command proceed to the inverter switches. Traditional predictive current control use the previous switching interval values in order to predict the required average inverter output voltage to follow the reference current. Nowadays, the availability of fast and low cost digital signal processer boards (DSP's) makes the implementation of predictive controllers simpler and more sufficient, based on above an improved predictive current control algorithm is developed such that the inverter work with high performance. An improved predictive current control algorithm is developed by setting the sampling point just ahead the controlling point by the period of total sampling and computation delay, this adjustment make the control approach more robust against the system parameter variation. Moreover, the grid voltage prediction using the linear sine wave prediction instead of the traditional linear extrapolation prediction is sufficient to give more enhancements to the injected power in the utility grid. Keywords: predictive current control, single phase grid connected inverters, discrete time control, renewable energy. …………………………………………………………………………………………………………………………