The input current I1 to the DAB converter when a resistive load is connected.

<p>The input current I1 to the DAB converter when a resistive load is connected.</p

Control Strategies for the DAB Based PV Interface System

<div><p>This paper presents an interface system based on the Dual Active Bridge (DAB) converter for Photovoltaic (PV) arrays. Two control strategies are proposed for the DAB converter to harvest the maximum power from the PV array. The first strategy is based on a simple PI controller to regulate the terminal PV voltage through the phase shift angle of the DAB converter. The Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) technique is utilized to set the reference of the PV terminal voltage. The second strategy presented in this paper employs the Artificial Neural Network (ANN) to directly set the phase shift angle of the DAB converter that results in harvesting maximum power. This feed-forward strategy overcomes the stability issues of the feedback strategy. The proposed PV interface systems are modeled and simulated using MATLAB/SIMULINK and the EMTDC/PSCAD software packages. The simulation results reveal accurate and fast response of the proposed systems. The dynamic performance of the proposed feed-forward strategy outdoes that of the feedback strategy in terms of accuracy and response time. Moreover, an experimental prototype is built to test and validate the proposed PV interface system.</p></div

Dynamic performance of the proposed feedback strategy: (a) the harvested power from the PV, (b) the actual and reference voltage of PV, and (c) the phase shift angle φ.

<p>Dynamic performance of the proposed feedback strategy: (a) the harvested power from the PV, (b) the actual and reference voltage of PV, and (c) the phase shift angle φ.</p

The voltages at the terminals of the coil connecting the two bridges of the DAB, V1 and V2.

<p>The voltages at the terminals of the coil connecting the two bridges of the DAB, V1 and V2.</p

The load current when a resistive load is connected.

<p>The load current when a resistive load is connected.</p

Dynamic Performance of the proposed feed-forward strategy: (a) the PV irradiance, (b) the PV power, (c) the PV terminal voltage, and (d) the phase shift angle φ.

<p>Dynamic Performance of the proposed feed-forward strategy: (a) the PV irradiance, (b) the PV power, (c) the PV terminal voltage, and (d) the phase shift angle φ.</p

Performance of the DAB converter: (a) The input AC voltage, (b) the output AC voltage, (c) the input current to the high-frequency transformer, (d) the output current to the DAB (e) The input current from the DAB.

<p>Performance of the DAB converter: (a) The input AC voltage, (b) the output AC voltage, (c) the input current to the high-frequency transformer, (d) the output current to the DAB (e) The input current from the DAB.</p

Steady state performance of the feed-forward strategy.

<p>Steady state performance of the feed-forward strategy.</p

ANN structure.

<p>ANN structure.</p

Block diagram of the proposed feed-forward strategy for DAB based PV interface system.

<p>Block diagram of the proposed feed-forward strategy for DAB based PV interface system.</p